JP7377040B2 - rover - Google Patents

Description

The present invention relates to a vehicle (hereinafter referred to as a "rover") suitable for running on sandy terrain, such as when exploring the surface of the moon or Mars.

Many rovers are already exploring the surfaces of the moon and planets. Wheel mechanisms, crawler mechanisms, leg mechanisms, and leg-wheel mechanisms are being considered as transportation mechanisms for traveling on the lunar and planetary surfaces, which are covered with rocks and loose sand and have slopes near craters. Until now, rover missions have mainly used wheel mechanisms. However, there is a problem in that the wheels tend to slip on soft ground. When the amount of wheel subsidence increases due to an increase in slip, the traction force decreases. As a result, the rover would be unable to move forward and its wheels would become stuck (wheels spinning). In fact, the Opportunity and Spirit wheels got stuck during the mission. In June 2006, Opportunity sped up its wheels and escaped from the stack, but in January 2010, Spirit gave up on mobile exploration and decided to conduct observations around the rover ( (See Non-Patent Document 1).

On the lunar surface, craters and cliffs are of great scientific interest because they expose the crust, and it is hoped that future rover missions will explore such rugged terrain. Additionally, a thick layer of sand called regolith accumulates on the moon's surface, which could affect the movement of wheeled robots. Therefore, next-generation wheeled robots are required to have high running performance when traveling on the lunar surface. Therefore, in order to realize a wheel with a ground contact area parallel to the running surface, it has been proposed to utilize the elastic properties of metal materials. Wheels that utilize this elastic property can continuously contact the ground parallel to the running surface by elastically deforming the surface material, and as a result, can maintain low normal stress (see Non-Patent Document 2) .

Circular wheels with a large number of lugs protruding from the contact surface, approximately pentagonal wheels with five curved concave contact surfaces, and wheels that combine these two features are designed to reduce the interaction between the wheel and the sand when running on a slope. Studies on action models are also known (see Non-Patent Documents 3 and 4).

In addition, in the field of hand-throwing robots for security and military use, left and right hemispherical shells that also serve as wheels are attached to the left and right axles that protrude from the vehicle body. While the body is closed and the entire body is spherical, when driving on the ground or on the floor, these hemispherical shells are separated and photographed by the camera on the vehicle body, and furthermore, when driving on the ground or the floor, the camera on the vehicle body takes pictures. BACKGROUND ART A technique in which an extending bar-shaped stabilizer is used to prevent the vehicle body from rotating along with the rotation is conventionally known (see Patent Document 1).

In addition, in the field of similar hand-thrown robots for security and military use, each of the left and right hemispherical drive wheels is further divided into two to provide a pair of left and right auxiliary drive wheels, and the rotation axis of the main drive wheel and the auxiliary A technique for improving stability during running by making the rotating shaft of the drive wheel eccentric is conventionally known (see Patent Document 2).

Furthermore, in the field of toys, technology has been developed to make the center of a wheel consisting of a pair of hemispherical shells eccentric to the center of its rotation axis, thereby realizing comical vertical rocking when traveling on a flat surface. , is conventionally known (see Patent Document 3).

Japanese Patent Application Publication No. 2008-229813 Japanese Patent Application Publication No. 2010-264555 Japanese Unexamined Patent Publication No. 62-079078

Noriaki Mizukami and two others, "Proposal of a wheel model based on terra mechanics that takes into account dynamic settlement", [online], April 2012, Japan Society of Mechanical Engineers, [Retrieved July 22, 2019] ], Internet <URL: https://www.jstage.jst.go.jp/article/kikaic/78/788/78_788_1109/_pdf/-char/ja> Kojiro Iizuka and two others, "Study of wheel shape of lunar surface exploration wheeled robot for running on soft sand ground considering elastic properties", [online], December 2008, Japan Society of Mechanical Engineers, [Reiwa 1 Searched on July 22, 2017], Internet <URL: https://www.jstage.jst.go.jp/article/kikaic1979/74/748/74_748_2962/_pdf/-char/ja> Kojiro Iizuka and 3 others, "Study of driving performance considering wheel shape of lunar and planetary exploration rover", [online], December 2008, Japan Society of Mechanical Engineers, [searched on July 22, 2019], Internet <URL: https://ci.nii.ac.jp/naid/110006153475> Kojiro Iizuka and 1 other person, "Verification of the running system for the lunar surface exploration rover for running on soft sandy ground", Science and Technology Research, Vol. 1, No. 1, 2012

Although the rovers described in the above-mentioned non-patent documents 1 to 4 have improved running performance by focusing on the shape and material of the wheels, there is a limit to their propulsion power, and in particular, there is a limit to the propulsion of the rovers. It does not exhibit sufficient running performance when running uphill.

This invention was made against the above-mentioned technical background, and its purpose is to provide a rover that can exhibit sufficient running performance even when running uphill on a regolith-accumulated slope. be.

Still other objects and effects of the present invention will be easily understood by those skilled in the art by referring to the following description of the specification.

It is believed that the above-mentioned technical problem can be solved by a rover having the following disclosure.
That is, the rover according to the present disclosure is
The car body and
left and right wheels,
left and right axles supported by the vehicle body and coupled to each of the left and right wheels;
a rotation drive unit for rotating each of the left and right axles;
a stabilizer for preventing the vehicle body from rotating along with the rotation of the wheels;
Each of the left and right wheels and each of the left and right axles are designed such that the distance between the ground contact surface of the wheel and the axle varies greatly depending on the rotation angle of the wheel.

As a method of realizing such a mechanism, for example, as shown in FIG. 31(a), the axle P is placed at the center of a flat polygonal wheel including an ellipse or an ellipse, and the method shown in FIG. 31(b) ), one example is one in which the axle P is arranged with the center of the polygonal wheel including a circle shifted (eccentrically).
As shown in FIG. 31(a), when the axle P is placed at the center of a flat polygon (an ellipse in the illustrated example), for example, when the wheel is rotated clockwise as shown by the arrow, In the two angular regions A1 and A2 located at A small contact pressure and a small scraping force act on the regolith in front of the direction, so by periodically applying strong pressure and scraping force twice per wheel rotation, the rover scrapes the regolith. Even on the lunar surface where there is a lot of debris, it is possible to periodically gain strong thrust and move forward without getting stuck. Note that the above-mentioned angular ranges A1 and A2 can also be defined as angular ranges during which the distance between the axle P and the wheel outer circumference changes from a long state to a short state.
As shown in FIG. 31(b), when the axle P is placed at the center of a polygon (a circle in the illustrated example), for example, when the wheel is rotated clockwise as shown by the arrow, one angle In area A3, a large pressing pressure and a large scraping force act on the regolith in the forward direction of movement, whereas in other angular areas, the regolith in the forward direction of movement acts on the regolith in the forward direction of movement. , a small pressure and a small scraping force are applied, so by periodically applying a strong pressure and scraping force once per rotation of the wheel, the rover can move on the lunar surface where logoliths have accumulated. However, it is possible to periodically obtain strong thrust and move forward without getting stuck. Note that the above-mentioned angular range A3 can also be defined as the angular range during which the distance between the axle P and the wheel outer circumference changes from a long state to a short state.

A rover with such a configuration has a simple configuration of just two left and right wheels and a stabilizer attached to the vehicle body, but it can achieve running and steering operations only by operating the rotary drive unit. be able to. In addition, since each of the left and right wheels and each of the left and right axles have the above-mentioned predetermined relative relationship, even when driving uphill on soft ground such as the moon surface where regolith is deeply deposited, The left and right wheels extend upward and push against and scrape up the regolith in front of them, causing the wheels to float and prevent them from sinking, so the vehicle body intermittently gains large thrust with each rotation of the wheels and moves forward. That is, unlike wheels with concentric axle connections that rely solely on friction between the wheels and the ground to obtain thrust, the wheels do not sink deeply into the regolith as the wheels rotate and become stuck.

Note that the side profile shape of the wheel is not particularly limited, and may be not only circular but also polygonal. Further, its three-dimensional shape is not limited to a hemispherical shape, but may be cylindrical or disc-shaped like a normal automobile wheel. Further, the left and right axles are preferably aligned on a straight line, but may be parallel and eccentric to each other. Furthermore, the stabilizer is not limited to a tail-shaped one whose tip touches the ground, but may also be one that uses a gyro to achieve the stabilizing function without contacting the ground.

In a preferred embodiment,
a first rotation drive unit, wherein the rotation drive unit includes a first motor for rotating one of the axles; and a second rotation drive unit, the rotation drive unit includes a second motor for rotating the other one of the axles. The drive unit may also include a drive unit.

According to such a configuration, by providing a dedicated motor for each of the left and right wheels, it is possible to realize various running modes and steering modes.

In a preferred embodiment,
The motor may include a rotation control section for controlling rotations of the first motor and the second motor in conjunction with each other.

According to such a configuration, various running modes and steering modes can be realized by appropriately controlling the left and right motors in conjunction with each other depending on the control specifications of the rotation control section.

In a preferred embodiment,
The rotation control unit controls the rotations of the first motor and the second motor in conjunction so that the left and right wheels rotate in a manner similar to the rotation of both arms in butterfly swimming. It may be.

According to such a configuration, strong propulsive force can be periodically obtained by realizing a wheel rotation mode similar to butterfly swimming.

In a preferred embodiment,
The rotation control unit controls the rotations of the first motor and the second motor in conjunction so that the left and right wheels rotate in a manner similar to the rotation of both arms in crawl swimming. It may be.

According to such a configuration, by realizing a wheel rotation mode similar to crawl swimming, it is possible to move the vehicle straight forward while scraping the ground frequently.

At this time, a wheel rotation pattern similar to butterfly swimming or a wheel rotation pattern similar to crawl swimming can be realized by controlling the rotational speed or phase of the left and right wheels in conjunction with each other.

In a preferred embodiment,
The stabilizer may be formed of a rigid material, and may be a tail portion that extends rearward from the rear portion of the vehicle body by a predetermined length, and has a tip thereof in contact with a running surface.

According to such a configuration, it is possible to resist the backward movement of the vehicle body and to enable stable step-by-step travel in a state of three-point support by the two left and right wheels and one grounding point of the rigid tail. can.

In a preferred embodiment,
The tail may further include left and right fins extending diagonally backward from the tip of the tail and branching left and right.

According to such a configuration, even in the event of a rollover, the left and right fins can easily assist in getting up.

In a preferred embodiment,
The upper part of the vehicle body may include an observatory section equipped with a camera.
According to such a configuration, in combination with the periodic upward stepping motion, it is possible to acquire an image of a predetermined field of view from a relatively high position.

In a preferred embodiment,
The camera may include a first camera having a field of view forward in the direction of travel and a second camera having a field of view backward in the direction of travel.

According to such a configuration, it is possible to easily approach the target object included in the visual field ahead in the traveling direction while checking the past driving trajectory from the wheel ruts included in the visual field behind the traveling direction. be able to.

In a preferred embodiment,
The vehicle body is
a vehicle body housing that accommodates the rotary drive unit and has left and right axle insertion holes on the left and right sides thereof;
The left and right wheels are
It consists of left and right outer shell halves obtained by dividing the outer shell surrounding the entire circumference of the vehicle body housing into left and right halves, and further inside the vehicle body housing,
When a predetermined activation condition is met, the left and right outer shell halves are moved from the left and right coupled state by causing each of the left and right axles to protrude a predetermined amount from the vehicle body housing through each of the left and right axle insertion holes. It may have an axle protrusion mechanism for shifting to the left-right separated state.

According to such a configuration, before the predetermined starting condition is satisfied, the left and right axles are retracted into the vehicle body housing, and the left and right outer shell halves are in a left-right coupled state, and the entire circumference of the vehicle body housing is On the other hand, after a predetermined starting condition is established, the left and right axles are moved out of the body housing by the action of the axle protruding mechanism. The left and right outer shell halves protrude into a left and right separated state, and the vehicle body housing is exposed through the gap between them, and the left and right outer shell halves function as the left and right wheels, making it possible to run. do.

In a preferred embodiment,
The axle protruding mechanism is
left and right sliding guide members that slidably guide the left and right axles through the left and right axle insertion holes of the vehicle body housing;
left and right driven gears that are fixed to the left and right axles, respectively;
left and right drive gears that are fixed to left and right drive shafts that extend parallel to each of the left and right axles, and that continue to mesh with the driven gear while each of the left and right axles reaches from an initial position to a protruding position; and,
left and right springs that urge each of the left and right axles in a direction to protrude from the left and right insertion holes of the vehicle body housing;
The non-circular hole formed by the axle insertion hole is used as a keyhole, and the large non-circular diameter portion formed at the tip of each of the axle shafts is used as a key, and by relative rotation between the key and the keyhole, a locked state where the two are not aligned and a locked state where both are aligned is changed. It may include a left and right locking mechanism that creates an unlocked state and a left and right locking mechanism.

According to such a configuration, before the predetermined activation condition is satisfied, each of the left and right axles is biased by the left and right springs in a direction in which they protrude from the left and right axle insertion holes. Since protrusion is prevented by the action of the left and right lock mechanisms, when a predetermined activation condition is met, the lock mechanism is activated by the rotation of the left and right drive shafts and the relative rotation between the key and the keyhole. By simply changing from the locked state to the unlocked state, the left and right axles are projected from the left and right axle insertion holes by the action of the spring, and the left and right outer shell halves are changed from the left and right joined state to the left and right separated state. can turn to.

In a preferred embodiment,
The left and right drive gears have an irregular cross section having a circular cross-section gear portion that meshes with the driven gear at the protruding position and a wide fan-shaped gear portion that meshes with the driven gear on the way from the initial position to the protruding position. It may also be a drive gear.

According to such a configuration, the locking mechanism engages only within a small rotational angle range from the locked state to the unlocked state, and immediately after unlocking, the wide locking mechanism slides while being engaged while linking with the protruding movement of the axle. Since the irregular cross-section drive gear is constructed from the fan-shaped cross-section gear portion and the circular cross-section gear portion that meshes with each other after the axle shaft has been fully extended, the weight of the drive gear can be reduced by reducing the volume.

In a preferred embodiment,
A rod-shaped tail portion corresponding to the stabilizer and an observation deck portion with a camera may be attached to positions along the left-right neutral line of the vehicle body housing so as to be foldable against biasing force in the deployment direction.

According to such a configuration, when the left and right outer shell halves are in the left-right coupled state, the rod-shaped tail portion and the camera-equipped observation deck portion are folded and housed together with the vehicle body in the outer shell body. On the other hand, when the left and right outer shell halves are separated from each other, the rod-shaped tail part and the camera-equipped observation deck part can be expanded to protrude from the gap between the left and right outer shell halves. It can be in an expanded state.

At this time, the rod-shaped tail may further include left and right fins that extend diagonally backward from the tip and are foldable.

According to such a configuration, both the folded left and right fins can be placed in the accommodated state, and the unfolded fins can also be placed in the expanded state.

In a preferred embodiment,
Each of the left and right outer shell halves is formed as a substantially hemispherical outer shell half made of plastic or light metal (for example, aluminum, etc.), and when in the left and right coupled state, surrounds the vehicle body housing. It may also form a substantially spherical outer shell.

With such a configuration, when released onto the lunar surface, it is possible to ensure cushioning properties and also has good rolling properties, so it can roll on the slope of the lunar surface while remaining connected to the left and right sides. By doing so, it is possible to secure the distance traveled on the lunar surface without wasting energy.

In a preferred embodiment,
A large number of openings may be distributed over the entire circumference of each of the left and right outer shell halves. At this time, among the large number of openings, a pair of left and right openings located at the opening edges of the outer shell halves are adjacent to each other when the outer shell halves are in the combined state, so that one imaging A window may be formed to allow a camera to capture images of the surroundings when the observatory section is folded.

According to such a configuration, the center of gravity of the spherical outer shell is placed on the equator to ensure directivity during rolling, and the inner peripheral edge of the opening functions as a non-slip or scraper to reduce the propulsion force. Contributing to the acquisition of regolith that gets inside the outer shell while driving, Naturally discharging the regolith that gets inside the outer shell while driving, Even if the spherical outer shell is in a stored state, by operating the camera, the opening (photographing window) This has effects such as being able to obtain peripheral images through the camera.

In a preferred embodiment,
A recess or a rib may be arranged at an appropriate distance in the outermost circumferential band of the left and right outer shell halves.

According to such a configuration, these depressions or ribs can firmly grip the lunar surface on which regolith is deposited and exhibit an anti-slip effect.

In a preferred embodiment,
Pole protrusions may be formed at both pole parts of the left and right outer shell halves.

According to such a configuration, the center of gravity of the spherical outer shell is placed on the equator to ensure directivity during rolling, and the direction of rolling is regulated so that it rolls centered on the equator. It's also effective.

In a preferred embodiment,
The diameter of the substantially spherical body that appears when the left and right outer shell bodies are joined together may be in the range of 50 mm to 200 mm.

Multiple spheres of this size can be mounted in the limited internal space of the lunar lander, and they can withstand shock even if they are released from the lunar lander onto the lunar surface just before or after landing. It is expected that the system will operate effectively.

According to the present invention, although the vehicle body has a simple configuration in which two left and right wheels and a stabilizer are attached to the vehicle body, it is possible to realize running operation and steering operation only by operating the rotary drive unit. In addition, each of the left and right wheels and each of the left and right axles is designed such that the distance between the ground contact surface of the wheel and the axle varies greatly depending on the rotation angle of the wheel. Therefore, even when driving uphill on soft ground such as the lunar surface where regolith is deeply deposited, the left and right wheels extend upward and rotate in a manner that strongly presses and scrapes the regolith in front of them. (A large pressing pressure and a large raking force are applied.) As a reaction to the raking action, the vehicle body intermittently gains a large thrust with each revolution of the wheels and moves forward. That is, unlike wheels with concentric axle connections that rely solely on friction between the wheels and the ground to obtain thrust, the wheels do not sink deeply into the regolith as the wheels rotate and become stuck.

FIG. 1 is a perspective view of the rover (stored state). FIG. 2 is a perspective view of the rover (in an expanded state) as seen diagonally from the front. FIG. 3 is a perspective view of the rover (in an expanded state) as seen diagonally from the rear. FIG. 4 is an exploded perspective view of the rover (main parts). FIG. 5 is an external perspective view of the vehicle body (axle protruding state). FIG. 6 is a perspective view showing the attachment position of the axle to the wheel. FIG. 7 is an enlarged perspective view showing the shape of the mechanism holding plate. FIG. 8 is a perspective view of the vehicle body (one side housing removed). FIG. 9 is a perspective view of the vehicle body (with housings removed on both sides). FIG. 10 is a perspective view showing the power transmission system from the motor to the axle. FIG. 11 is an enlarged perspective view showing the shape of the irregularly shaped drive gear. FIG. 12 is an explanatory diagram showing the shape of the axle insertion hole. FIG. 13 is an explanatory diagram showing the relationship between the axle insertion hole and the non-circular cross-section shaft portion. FIG. 14 is a perspective view of the entire contents contained within the housing. FIG. 15 is an explanatory diagram of the photographing section assembly. FIG. 16 is a side view of the rover (in an expanded state). FIG. 17 is a side view of the tail and fins (in an expanded state). FIG. 18 is a rear view of the rover (deployed state). FIG. 19 is an explanatory diagram of the support structure of the tail base. FIG. 20 is an explanatory diagram of the unfolded state and the folded state of the fin portion. FIG. 21 is an explanatory diagram of a running state due to concentric wheel rotation on a regolith uphill slope. FIG. 22 is an explanatory diagram of a butterfly running state due to eccentric wheel rotation on a regolith uphill slope. FIG. 23 is a perspective view of the rover in a crawling state (phase difference of 180 degrees). FIG. 24 is a side view of the rover in a crawling state. FIG. 25 is a block diagram showing the electrical hardware configuration of the rover. FIG. 26 is a flowchart showing the operation of the control section. FIG. 27 is a perspective view of a stabilizer (modified example). FIG. 28 is an exploded perspective view of the stabilizer (modified example). FIG. 29 is a projected view of the stabilizer (modified example). FIG. 30 is an explanatory diagram showing a state in which the stabilizer (modified example) is attached. FIG. 31 is an explanatory diagram showing that the distance between the ground plane of the axle and the axle varies greatly depending on the rotation angle of the axle.

Hereinafter, one preferred embodiment of the rover according to the present invention will be described in detail with reference to the accompanying drawings (FIGS. 1 to 30). Incidentally, the embodiment described below is one of the results of joint research at JAXA's Space Exploration Innovation Hub.

<<Overview of overall configuration>>
As shown in FIG. 4, the rover 1 according to this embodiment includes a vehicle body 10, left and right wheels 20, 30, a stabilizer 40 including left and right tail parts 401, 403, left and right fin parts 402, 404, and a camera. It is roughly composed of an observation deck section 50 that includes an observation deck section 50, and is moved from a predetermined stowed state (see Fig. 1) to a predetermined unfolded state (see Figs. 2 and 3) by the operation of left and right axle protruding mechanisms (details will be described later). It is believed that it is possible to move to

Here, the "storage state" means that the left and right hemispherical outer shell halves 201 and 301 are joined facing each other to form a spherical outer shell, in which the vehicle body 10, the stabilizer 40, and the observatory part 50 are arranged. It is in a state where it is stored. At this time, the left and right tail parts 401, 403, the left and right fin parts 402, 404, and the observatory part 50 are in a predetermined folded state (details will be described later) in which the spherical outer shell is urged in the restoration direction. be accommodated in.

In addition, the "deployed state" means that the left and right hemispherical outer shell halves 201, 301 are separated from each other by a predetermined distance to form a gap S between them, and from this gap S, the left and right tail parts 401, 403 and This is a state in which the left and right fins 402, 404 and the viewing platform 50 are expanded and protruded. In this unfolded state, the left and right hemispherical outer shell halves 201, 301 also function as the left and right wheels 20, 30.

Left and right axles 114 and 214 can protrude from left and right axle insertion holes 11b and 12b provided on the left and right side surfaces of the vehicle body housing 10A (see FIGS. 5 and 9). Left and right wheels 20 and 30 are attached to the tips of these axles 114 and 214, respectively. The important point here is that the left and right axles 114, 214 and the left and right wheels 20, 30 are not mounted concentrically but eccentrically to each other (see FIG. 6).

According to such an eccentric mounting structure, even when driving uphill on soft ground such as the moon surface where regolith (fine sand) is deeply deposited, the left and right wheels 20, 30 do not extend upward. , rotates while strongly pressing the regolith in front of it while raking it up (a large pressure and a large raking force are applied), so as a reaction to the raking action, the vehicle body 10 rotates one rotation of the wheels 20,0. Each time, the robot moves forward with a large thrust intermittently (see Fig. 22). In other words, as with wheels with concentric axles that rely solely on the friction between the wheels 10 and 20 and the ground to obtain thrust, as the wheels 20 and 30 rotate, they sink deeply into the regolith and become stuck. (See Figures 21, 22, and 23).

<<Detailed explanation of the vehicle body>>
The vehicle body 10 includes a drive unit assembly 10B (see FIG. 10) including an axle protrusion mechanism in a vehicle body housing 10A (see FIGS. 5 and 7) formed by joining left and right housing halves 11, 12 and a bottom plate 13. Contains and consists of. Left and right axle insertion holes 11b and 12b are provided on the left and right side surfaces of the vehicle body housing 10A. As shown in FIG. 12, the shape of the inner peripheral edge of the axle insertion holes 11b and 12b is, for example, in the case of the axle insertion hole 12b on the right side, a pair of rectangular recesses 12d and 12d that face each other and a circle that faces each other. It is a non-circular hole surrounded by arcuate recesses 12c, 12c. This non-circular hole functions as a keyhole in the lock mechanism described later. The same applies to the axle insertion hole on the left side.

The drive assembly 10B is constructed by integrally connecting various components of the drive assembly via a support plate 14, as shown in FIG. As shown in FIG. 7, this support plate 14 is fixed to the vehicle body housing 10A by being held between the left and right vehicle body housing halves 11 and 12.

The support plate 14 has three through holes 14a, 14b, and 14c, as shown in FIG. The through hole 14a is for inserting and holding the rod-shaped motor 111 (see FIG. 10) for driving the left wheel, and a boss portion 14a' for holding the front end of the motor 111 extends from the exit of the hole. It will be done. As shown in FIG. 8, the through hole 14b is for inserting and holding the rod-shaped motor 121 for driving the right wheel, and a boss portion 14b' (for holding the front end of the motor 121) is provided at the exit of the hole. (see FIG. 9) are extended. A guide rod 101 (see FIG. 8) for guiding concentric linear motion of the left and right axles 114, 124 is inserted and held through the through hole 14c. This guide rod 101 is inserted into the center hole of the left and right axles 114, 124, so the left and right axles 114, 124 are inserted into the left and right axle insertion holes 11b (see FIG. 5), 12b (see FIG. 5) by the action of the guide rod 101. (see 14) allows for linear sliding.

The illustrated motors 111 and 121 are DC motors capable of forward and reverse rotation, and the rotational force obtained from the motor rotor is decelerated via a planetary gear built into the motor, and then the motor shaft 111a, It is output from 121a. In FIG. 10, reference numerals 111b and 121b are encoders that are incorporated into the motors 111 and 121 to detect the rotation of these motors 111 and 121. Note that these encoders 111 and 121 may be separate parts independent from the motor.

As shown in FIG. 10, left and right irregular drive gears 112 and 122 are attached to motor shafts (drive shafts) 111a and 121a (see FIG. 11) of the left and right rod-shaped motors 111 and 121, respectively. As shown in FIG. 11, each of the irregularly shaped drive gears includes, for example, the right irregularly shaped drive gear 122, a gear portion 122a with a circular cross section located at the tip, and a gear portion 122a with a circular cross section that continues in the axial direction from the gear portion 122a with a circular cross section. It has a fan-shaped wide gear portion 122b in cross section. The same applies to the left side irregularly shaped drive gear. On the other hand, driven gears 113 and 123 each having a circular cross section are attached to the rear end portions of the left and right axles 114 and 124, respectively, as shown in FIG.

When the left and right axles 114, 124 are in the initial position where they do not protrude from the axle insertion holes 11b, 12b, the left and right circular driven gears 113, 123, respectively, are fan-shaped wide gear portions 112b in cross section of the left and right irregularly shaped drive gears 112, 122. , 122b, and contributes to a substantially half-rotation motion for shifting the relative angle between the key and the keyhole from the misaligned angle to the aligned angle. On the other hand, when the left and right axles 114, 124 are in the protruding position where they protrude to the limit from the axle insertion holes 11b, 12b, the left and right driven gears 113, 123 with a circular cross section, respectively, 122 with circular cross-section gears 112a, 122a, and contributes to rotational movement for traveling. Furthermore, from the initial position to just before the protrusion limit position, the irregularly shaped drive gears 112, 122 and the left and right circular driven gears 113, 123 are maintained in a meshed state while sliding against each other.

According to such irregularly shaped drive gears 112, 122, the shape of the drive gear required to transmit the rotation of the drive shafts 114, 124 of the motor to the driven gears 113, 123 of the slidable axles 114, 124 is cylindrical. Rather than using wide gears, we have provided wide gear sections 112b and 122b with fan-shaped cross sections, leaving gear teeth only in the approximately half-turn portion required for unlocking the lock mechanism, and omitting the other portions. It is possible to significantly reduce the weight of the drive gear, which is a heavy component of the product. Note that, of course, if the weight of the drive gear is mounted on a landing craft having a thrust for which the weight is not a problem, a normal wide cylindrical gear can be used instead of the irregularly shaped drive gears 112 and 122.

Left and right coil springs 116, 126 are compressed between the driven gears 113, 123 and the support plate 14. These coil springs 116, 126 provide a biasing force for causing the left and right axles 114, 124 to protrude from the left and right axle insertion holes 11b, 12b.

Next, the lock mechanism will be explained. The lock mechanism uses the non-circular holes formed by the left and right axle insertion holes 11b and 12b as a keyhole, and uses the non-circular cross-section shaft portions formed by the respective tips of the left and right axles 114 and 124 as a key, and allows relative rotation between the key and the keyhole. This realizes a locked state in which the two do not match, and the lock cannot be inserted, and an unlocked state, in which the two match, and the lock can be inserted.

In this example, as for the above-mentioned non-circular cross-section shaft portion, as shown in FIG. , 124b projecting from each other at 180 degree intervals. On the other hand, regarding the non-circular holes, as described above, as shown in FIG. This is realized by forming it so as to be surrounded by the rectangular recesses 11d, 11d, 12d, and 12d.

According to such a locking mechanism, as shown in FIG. 13, a pair of protrusions 114a, 114b, 124a, 124b constituting the non-circular cross-section shaft portions of the left and right axles 114, 124 and the left and right axle insertion holes 11b. , 12b do not align with each other, a locked state is achieved in which the left and right axles 114, 124 cannot be inserted into the axle insertion holes 11b, 12b, respectively. can do. On the other hand, a pair of protrusions 114a, 114b, 124a, 124b forming non-circular cross-section shaft portions of the left and right axles 114, 124 and a pair of rectangular recesses 11d, 11d of the left and right axle insertion holes 11b, 12b, By aligning the axles 12d and 12d, it is possible to realize an unlocked state in which the left and right axles 114 and 124 can be inserted into the axle insertion holes 11b and 12b, respectively.

Therefore, if the above-mentioned lock mechanism is set to the locked state with the left and right axles 114, 124 pushed into the axle insertion holes 11b, 12b against the repulsive force of the left and right coil springs 116, 126, the left and right Immediately after starting the motors 111, 121, the locking mechanism switches from the locked state to the unlocked state within half a rotation of the axle, and the left and right axles 114, 124 are moved by the repulsive forces of the left and right springs 116, 126, respectively. The meshing partners of the driven gears 113, 123, which protrude out of the vehicle body housing 10A from the axle insertion holes 11b, 12, and have a circular cross section and are attached to the axle at the same time, are the fan-shaped cross-sectional gear portions 112b, 122b of the irregular drive gears 112, 122. By switching from the cross-sectional circular gear portions 112a, 122a, it becomes possible to rotationally drive the left and right wheels 20, 30 by the left and right motors 111, 121.

Inside the vehicle body housing 10A, in addition to the various mechanical parts described above, as shown in FIG. For example, two to three 1.5V batteries 16, 16, 16, which serve as a power source for the circuit, are housed. Note that details of the electrical hardware constituted by various electronic components mounted on the circuit board 15 will be described in detail later with reference to the block diagram of FIG. 25 and the flowchart of FIG. 26.

<<Detailed explanation of wheels>>
As shown in FIG. 4, the left and right wheels 20, 30 have approximately spherical outer shells surrounding the housing 10A of the vehicle body 10 (for example, in the case of resin, the wall thickness is 1.0 mm to 2.0 mm; in the case of aluminum, the wall thickness is 1.0 mm to 2.0 mm). It is composed of left and right hemispherical outer shell halves 201 and 301, which are equally divided into two halves (wall thickness: 0.7 mm to 1.0 mm, diameter: 50 mm to 200 mm). The hemispherical outer shell halves 201 and 301 are made of a material that is lightweight and has a certain degree of elasticity (for example, light metal such as aluminum or resin such as polyimide), with the intention of reducing the impact upon landing. will be adopted.

An important point in relation to the present invention is that the hemispherical outer shell halves 201, 301 and the left and right axles 114, 124 are eccentrically attached to each other, as shown in FIG. In other words, the left and right axles 114 and 124 are attached to the back surfaces of the left and right hemispherical outer shell halves 201 and 301, with the centers of these halves 201 and 301 shifted by a predetermined amount.

More specifically, as shown in FIG. 10, left and right brackets 115 and 125 are attached to the tips of the left and right axles 114 and 124, respectively. Each of the brackets 115, 125 is provided with a pair of screw holes 115a, 115b, 125a, 125b. On the other hand, on the back surfaces of the left and right hemispherical outer shell halves 201 and 301, as shown in FIG. is provided. The left and right axles 114 and 124 are screwed to parts of annular ribs 206 and 306 on the back surfaces of the left and right hemispherical outer shell halves 201 and 301 via left and right brackets 115 and 125, respectively. As a result, the left and right wheels 20, 30 are eccentrically and firmly attached to the left and right axles 114, 124. At this time, the amount of eccentricity between the axle center and the wheel center may be determined in consideration of the maximum turning radius of the wheels required for uphill travel, etc. in the assumed state of the regolith.

As shown in FIG. 1, a large number of openings are symmetrically distributed in the hemispherical outer shell halves 201, 301. That is, in the illustrated example, the left hemispherical outer shell half 201 is provided with a pole protrusion 202, and in order of proximity to the pole protrusion 202, a first circumferential band 203, a second circumferential band 204, A third lap band 205 is defined. Each of the three circumferential bands 203, 204, and 205 has a large number of openings (windows) 203a, 204a, and 205a separated by appropriate distances in the circumferential direction so as to avoid continuity between adjacent circumferential bands. It is arranged as follows. In addition, a recess 205b and a rib 205b' are arranged in the third circumferential band 205 so as to fill the gap between the adjacent openings 205a. Similarly, first to third circumferential bands 303, 304, and 305 are defined in the right hemispherical outer shell half 301, and each of these circumferential bands includes a plurality of openings (windows) 303a, 304a and 305a are arranged, and in addition to the opening, a recess 305b and a rib 305b' are arranged in the third circumferential band (see FIG. 18).

These openings 203a to 205a, 303a to 305a are arranged symmetrically around the equator of the spherical outer shell, and left and right polar protrusions 202, 302 are arranged in both local parts. (see Fig. 18), the center of gravity of the sphere in the stored state (see Fig. 1) is distributed almost on the equator, and the left and right polar protrusions 202, 302 also function as balancers in the left-right direction. . Therefore, when the spherical rover 1 lands on an inclined surface in the stowed state (see Fig. 1), although it initially depends on the posture at the time of landing, the horizontal axis of rotation is the straight line connecting both protrusions 202 and 302. This makes it possible to travel relatively long distances while rolling while maintaining a posture with the spherical equator as the landing surface. Note that the left and right pole protrusions 202 and 302 not only function as left and right balancers, but also function as gripping parts for the ejector (not shown), for example, when the spherical rover 1 is released from the lunar module. .

The left and right openings 205a and 305a arranged in the third circumferential band 205 (305) together form a horizontally medium-large photographing window. This photographing window is provided for photographing the surroundings of the spherical rover 1 in the stored state (see FIG. 1) using a camera. That is, by providing this relatively large horizontally long photographing window, even when the left and right hemispherical outer shell halves 201 and 301 are closed, surrounding images can be captured by a camera (for example, a wide-angle camera or a 360-degree camera). It is possible to obtain

On the other hand, in the unfolded state where the left and right hemispherical outer shell halves 201, 301 are opened (see FIGS. 2 and 3), the recesses 205b or ribs 205b' present in the third circumferential zone 205 are mainly It acts as a non-slip grip. In addition, the inner peripheral edges of the openings 204a and 205a present in the second circumferential band 204 and the third circumferential band 205 also function as scrapers that scrape up regolith. In addition, the openings 203a and 204a present in the first circumferential zone 203 and the second circumferential zone 204 naturally discharge regolith that has entered the interior during driving to the outside of the left and right hemispherical outer shell halves 201 and 301. It also functions as an outlet for water.

<<Detailed explanation of stabilizer>>
As shown in FIG. 4, the stabilizer 40 includes left and right tail portions 401, 403 and left and right fin portions 402, 404. The left and right tail portions 401, 403 are formed into a downwardly convex arch using relatively hard plastic (for example, polyamide resin, etc.) or light metal (for example, aluminum, etc.), and the base portions are as shown in FIGS. As shown in FIG. 19, it is rotatably attached to the rear part of the vehicle body housing 10A via horizontal hinge shafts 11e and 12e. While traveling, as shown in FIG. 22, the vehicle is configured so that the vehicle travels mainly with its downwardly convex abdomen or rear portion touching the sand.

Note that these left and right tail portions 401, 403 are urged in the deployment direction by a biasing device such as a spring (not shown). Therefore, in the accommodated state in which the two hemispherical outer shells 201, 301 are combined (see FIG. 1), the two hemispherical outer shells 201, 301 are folded inside the spherical outer shell, and the two hemispherical outer shells 201, 301 are In the deployed state where they are separated (see FIGS. 2 and 3), they are deployed by themselves due to the urging force and protrude from the gap S between the two halves 201 and 301.

The left and right fins 402, 404 extend diagonally backward from the rear ends of the left and right arched tails 401, 403, and are formed of a light metal such as aluminum or a resin such as polyamide. And it is said to be foldable. More specifically, the fins 402 and 404 are hinged to the rear ends of the left and right tails, respectively, as shown by imaginary lines in FIG. It is designed to automatically change its posture from the folded state shown by the solid line in the figure to the unfolded state shown by the imaginary line in the figure. In the unfolded state, as shown in FIGS. 3 and 8, by extending left and right to approximately the same width as the left and right width of the hemispherical outer shell halves 201, 301 in the unfolded state, When the rover 1 is in an overturned state, the rover 1 is bent and its repulsive force supports the right and left wheels 20, 30 of the rover 1 to rotate to help it stand up. In fact, in an experiment conducted by the applicant in collaboration with JAXA, it was confirmed that the left and right fins 402 and 404 are effective in recovering from a rollover state.

Note that these left and right fins 402, 404 are also folded into the inside of the spherical outer shell when the two hemispherical outer shells 201, 301 are in the housed state (see FIG. 1). When the two hemispherical outer shells 201, 301 are in the deployed state separated from each other (see FIGS. 2 and 3), they are automatically deployed together with the two tails 401, 403 by the biasing force, and both halves 201, It will be in a state where it protrudes from the gap S of 301.

By the way, in the stabilizer 40 described above, the left and right tails 401 and 403 may be realized by a single tail that is integrated with them. Examples (modifications) of such a stabilizer using one tail are shown in FIGS. 27 to 30.

As shown in FIG. 27, this stabilizer 40A includes one tail section 411 formed by integrally forming the left and right tail sections 401 and 403 described above, left and right fin sections 412 attached to the rear part of this tail section 411, 413.

As shown in FIGS. 28 and 29, the tail portion 411 includes a main body portion 411a that is a downwardly convex arched plate piece, and a base located at the base end of the main body portion 411a that corresponds to the rear bracket of the main body housing 10A. It has an end side attachment portion and a tip side attachment portion located at the tip of the main body portion 411a and corresponding to the left and right fins. In the illustrated example, the proximal attachment portion is constituted by a pair of left and right boss portions 411b, 411b each having a horizontal axis hole into which a hinge shaft is inserted.

The stabilizer 40A is rotated to the bracket at the rear of the main body housing 10A, as shown in FIG. Fixed for free movement.

The distal end mounting portion has a pair of left and right boss portions 411c, 411c having diagonal shaft holes through which the left and right hinge shafts should be inserted, respectively, and a pair of boss portions 411c, 411c located at the center in the left and right direction, through which the left and right hinge shafts should be inserted, respectively. It is constituted by a central boss portion 411d having an oblique shaft hole.

In this stabilizer 40A, as shown in FIG. 29(c), with the intention of reducing sand resistance during turning (lateral movement), the cross-sectional profile shape of the tail portion 411 is flat on the vertical left and right sides. It has an outline shape surrounded by three flat surfaces: side surfaces, a relatively narrow and horizontal flat bottom located at the center, and left and right inclined flat bottoms connecting them. However, if you prioritize the difficulty of being buried in sand, instead of a relatively narrow flat bottom, you should adopt a wide and horizontal flat bottom that spans almost the entire width of the bottom, and in addition, for the left and right sides, It may also be a curved side surface that bulges outward.

The left and right fins 412, 413 have main body parts 412a, 413a which are slightly twisted arched plate pieces, and a proximal attachment part located at the base end of the main body parts 412a, 413a and corresponding to the rear part of the tail part 411. has. In the illustrated example, the proximal attachment portion is constituted by a pair of left and right boss portions 412b, 412b, 413b, and 413b, each having a horizontal axis hole.

The left and right fins 412, 413 align the hinge shaft holes of the proximal end attachment portions (412b, 413b) with the hinge shaft holes of the distal end attachment portions (411c, 411d) of the tail portion 411, and then align the hinge shaft holes with the hinge shaft holes of the distal end attachment portions (411c, 411d) of the tail portion 411. By inserting long screws 431 and 441, the screws are fixed to the rear end of the tail portion 411 so as to be rotatable while turning diagonally.

In addition, when assembling the tips of the left and right fins 412, 413 to the rear part of the tail 411, springs 432, 442 are incorporated to bias the left and right fins in the direction of expansion. Therefore, as mentioned above, when transitioning from the stored state (see FIG. 1) to the unfolded state (see FIGS. 2 and 3), the tail portion 411 The left and right fins 412, 413 will expand and protrude on their own.

<<Detailed explanation of the observation deck section>>
As shown in FIG. 4, the observatory section 50 is configured by housing a camera assembly (not shown) in a housing formed by joining left and right housing halves 51 and 52, and has left and right hinge holes 51a and 52a. By inserting and fitting the hinge shafts 11a and 12a (see FIG. 5) on the vehicle body housing side, it is rotatably attached to the vehicle body housing 10A. Note that the housing of the observatory section 50 can be folded while being urged in the unfolding direction by a biasing mechanism (not shown).

As shown in FIGS. 15(a) and 15(b), the housing of the observatory section 50 includes a front side light receiving window composed of a left light receiving window half 51b and a right light receiving window half 52b; As shown in (a) and (c), a rear side light receiving window is provided which is composed of a left side light receiving window half 51c and a right side light receiving window 52c, and from the front side light receiving window, a front side board 53c is provided. The front side light receiving section 53a mounted on the back side substrate 53d is configured to face from the back side light receiving window (see FIGS. 15(b) and 15(c)). Note that the front side light receiving section 53a and the back side light receiving section 53b are configured by integrally combining a lens and an image sensor, as is well known to those skilled in the art. The front substrate 53c and the rear substrate 53d are integrally coupled with the support substrate 53d in between, thereby forming a camera assembly. Here, the camera assembly may be configured not only as a normal wide-angle camera but also as a 360-degree camera.

According to the above configuration, when the rover 1 is in the stored state (see FIG. 1), the observatory part 50 is folded and stored inside the spherical outer shell, but the rear light receiving part 53b Since a horizontally long photographing window formed by combining the left and right openings 205a and 305a is located on the front of the rover, images of the area around the rover can be captured through this photographing window with a wide-angle camera or a 360-degree camera. can be obtained. As a result, as will be described later, it is also possible to obtain images of the surroundings from the time the rover is released until the time it lands on the lunar surface (for example, images including the appearance of the lunar lander during or after landing).

On the other hand, when the rover 1 is in the deployed state (see FIGS. 2 and 3), the observation deck section 50 restores itself from the folded state to the unfolded state, and the left and right hemispherical shell halves 201 and 301 It protrudes upward from the vehicle body housing 10A through a gap S formed therebetween. Therefore, in this unfolded state, images within a predetermined field of view in the forward and backward directions of the rover 1 can be simultaneously acquired via the front side light receiving section 53a and the back side light receiving section 53b. Based on the track image included in the rear image, it is possible to efficiently reach the target included in the front image while checking the past travel trajectory and appropriately correcting the driving direction.

<<Detailed explanation of electrical hardware configuration and software configuration>>
The electrical hardware configuration mounted on the circuit board 15 will be described in detail with reference to FIG. 25. As shown in FIG. 25, the electrical hardware configuration of the rover 1 includes a drive section 601, a communication section 602, an input/output section 603, a control section 604, a storage section 605, and an imaging section 606. It consists of connecting through buses. These control elements operate using the battery 16 as a power source.

The drive unit 601 includes left and right motors 111, 121, their drive circuits, etc., and by individually driving the left and right motors 111, 121 via this drive unit 601, the drive unit 601 is eccentrically attached to the axle. The wheels rotate with a rotational trajectory similar to butterfly stroke or crawl stroke.

The communication unit 602 includes a wireless transceiver and performs transmission and reception with a communication unit mounted on, for example, a lunar lander (not shown). At this time, the received data includes various control commands sent from the lunar module, and the transmitted data includes information obtained from the front and rear cameras (front side light receiving section 53, back side light receiving section 53b). Contains video data.

The input/output unit 603 is for managing the exchange of input/output data for various setting operations, and is used to exchange various data between the built-in input/output unit or remotely connected input/output. It is meant to be done.

The control unit 604 is mainly composed of a microprocessor (MPU) for controlling the entire rover and a picture processor (GPU) for processing camera images, and corresponds to control commands sent from the lunar module. and processing the video obtained from the camera for transmission.

The storage unit 605 includes a ROM that stores various system programs to be executed by the MPU and GPU of the control unit 604, a RAM used as a work area when executing the system programs, and an image for temporarily storing camera images. It consists of memory, etc.

The imaging unit 606 is configured to include image sensors included in the front and rear cameras (front side light receiving unit 53, back side light receiving unit 53b), their drive circuits, and the like.

Next, the configuration of the system program executed by the microprocessor (MPU) included in the control unit 604 will be described in detail with reference to the flowchart in FIG. 26. In the figure, when the process is started, first, in the initialization process (step 101), various flags, counters, and registers necessary for calculation are initialized. This initialization process also includes initialization of counters for detecting the rotational positions of the left and right encoders 111b and 121b.

In the following step 102, continuous photographing by the front and rear cameras (front side light receiving section 53a, back side light receiving section 53b) is started. Thereby, the rover 1 starts photographing with the camera while remaining in the stored state (see FIG. 1). Therefore, the rear side camera (rear side light receiving section 53b) can acquire an image of a predetermined field of view around the rover via the horizontally elongated photographing window (openings 205a, 305a) of the spherical outer shell.

In the following step 103, various data are transmitted and received through communication with the lunar lander. Here, the transmitted data includes video data captured by the front and rear cameras (front side light receiving section 53a, back side light receiving section 53b) and encoders of the left and right motors (encoders 111b, 121b).
This includes detection data, etc. In addition, the received data includes various control commands (for example, startup commands, various running mode designation commands, etc.) from the lunar lander.

In the following step 104, the content of the command received from the lunar lander is decoded. In addition, although only two typical decoding results ("crawl running" and "butterfly running") are illustrated in the figure, it goes without saying that there are various other deciphering results. That is, if the result of decoding the received command is that it does not mean starting the left and right motors 111, 121, then steps 103 and 104 are repeated without doing anything, and the rover 1 is placed in the stowed state (see FIG. 1). It remains in standby mode.

Thereafter, when the start command is decoded and a running mode similar to butterfly swimming is specified as the running mode (step 105 "butterfly running"), the process proceeds to step 106, where the left and right motors 111 and 121 are started. Then, as explained earlier, while the left and right axles 114 and 124 rotate half a rotation, the lock mechanism switches from the locked state to the unlocked state, and the left and right The axles 114, 124 protrude from the left and right axle insertion holes 11b, 12b of the vehicle body housing 10A, and in conjunction with this, the rover 1 transitions from the stowed state (see Fig. 1) to the deployed state (see Figs. 2 and 3). do.

Subsequently, in step 107, servo control for predetermined butterfly travel is executed. In this servo control for butterfly running, the left and right wheels 20, 30 are rotated at the same speed and in the same phase based on the detection signals from the left and right encoders 111b, 121b. (see FIG. 22). Thereafter, the above operations (steps 103, 104, 105 ("butterfly running"), 106, 107, 110 NO) are repeated as long as butterfly running is specified until a predetermined stop condition is satisfied.

On the other hand, as a result of decoding the received command (step 104), if it is a start command and the running mode designation is crawl running (step 105 "crawl running"), the process proceeds to step 108. The left and right motors 111 and 121 are activated. Then, as explained earlier, while the left and right axles 114 and 124 rotate half a rotation, the locking mechanism switches from the locked state to the unlocked state, and the left and right springs 116 and 126 are biased. The axles 114, 124 protrude from the left and right axle insertion holes 11b, 12b of the vehicle body housing 10A, and in conjunction with this, the rover 1 transitions from the stowed state (see Fig. 1) to the deployed state (see Figs. 2 and 3). do.

Subsequently, in step 109, servo control for predetermined crawling is executed. In this servo control for crawling, the left and right wheels 20 and 30 are rotated at the same speed and with 180 degree different phases based on the detection signals from the left and right encoders 111b and 121b. This realizes running (see FIGS. 23 and 24). Thereafter, the above operations (steps 103, 104, 105 ("crawl"), NO in steps 108, 109, 110) are repeated as long as crawling is specified until a predetermined stop condition is satisfied.

Then, while repeating the above operations, if it is determined that a predetermined stop condition is satisfied (step 110 YES), the process proceeds to step 111, where the left and right motors 111, 121 stop their rotations, and the rover 1 is rotated. Running stops. In addition, the stop conditions include receiving a predetermined stop command as a received command, the remaining capacity of the battery 16 serving as a power source falling to a predetermined value, a preset timer reaching a specified time, etc. A condition exists.

<<Rover operation example or detailed explanation of operation>>
An example of operation and operation of the rover 1 will be described in detail. One example of how Rover 1 could be used is to be separated from a mother ship flying in orbit around the moon and mounted on a lunar lander (manned or unmanned) heading for the lunar surface. In that case, since the rover 1 of the embodiment can be configured to be lightweight and compact, it is also possible to preferably mount a plurality of them. After landing on the lunar surface or just before landing on the lunar surface (for example, at an altitude of 1 m to 2 m), the rover 1 mounted on the lunar lander is moved from the lunar lander to a predetermined attitude and a predetermined position, for example, in the horizontal direction. is released with an initial velocity of In this way, the rover 1 released from the lunar lander will perform continuous photography using a 360-degree camera (rear side light receiving unit 53b) and wireless communication with the lunar lander immediately after its release, so the release attitude and release speed are appropriately set. This will also allow the lunar module to capture a so-called self-portrait of itself and send it to the lunar module. In this way, the transmitted image of the lunar lander is sent to the control center on Earth via the mother ship in orbit, and is used, for example, to confirm whether the lunar lander has landed normally. can do.

On the other hand, each of the multiple rovers 1 released from the lunar module is under the gravity of 1/6 of the Earth, draws a predetermined parabola, and lands gently on the lunar surface where regolith is deeply deposited. , while remaining in the contained state with a roughly spherical appearance (see Figure 1), it rolls naturally at a speed that corresponds to the slope of the landing surface, and then hits a certain obstacle or reaches a place with a gentle slope. This will stop the rolling. As explained earlier, the center of gravity of the rover 1 is distributed on the equator, and the left and right polar protrusions 202, 302 act as balancers, so ideally, the rover 1 should maintain a certain posture. Rover 1 is expected to stop at .

After that, predetermined startup conditions (for example, receiving a startup command from the lunar module, expiry of a preset timer, and environmental conditions obtained by sensors separately installed in the rover itself) are set to specified values. , etc.), the left and right motors 111 and 121 are started, and while the left and right axles 114 and 124 rotate half a rotation, the locking mechanism switches from the locked state to the unlocked state. , the rover transitions from the stowed state (see FIG. 1) to the deployed state (see FIGS. 2 and 3), and becomes ready to travel.

Here, since the left and right axles 114, 124 of the rover are installed eccentrically with respect to the left and right wheels 20, 30 (see Fig. 6), the radius from the farthest point on the outer circumference of the wheel is R1, and the radius to the nearest point is R1. It rotates while drawing a rotation locus whose radius is R2 (see FIG. 16). Then, as explained earlier, even when driving uphill on soft ground such as the lunar surface where regolith is deeply deposited, the left and right wheels 20 and 30 extend upward and forcefully move the regolith in front of them. Since the vehicle body 10 rotates in a raking manner while pressing against it (a large pressing pressure and a large raking force are applied), as a reaction to the raking action, the vehicle body 10 is intermittently rotated with each rotation of the wheels 20 and 30. Gain great thrust and move forward. In other words, unlike wheels with concentric axles that rely solely on the friction between the wheels and the ground to obtain thrust, they do not sink deeply into the regolith as the wheels rotate and become stuck (for example, as shown in Fig. 23).

Taking into account the gravity on the moon and the physical properties of regolith, we created an inclined surface on which sand similar to regolith was deposited on the earth, and in that state, we traveled between conventional concentrically coupled wheels and the eccentrically coupled wheels of the present invention. The results of a comparison between the running time and the running time are shown in FIGS. 21 and 22.

According to the rover 1 of the same structure using concentrically coupled wheels, thrust is obtained by relying on the friction between the wheels and the ground, as shown in FIGS. 21(a), (b), and (c). Although the wheels rotated, they slipped, so it was not possible to obtain sufficient thrust, and Rover 1 remained in a fixed position and could hardly move forward.

On the other hand, according to the rover 1 using the eccentrically coupled wheels of the present invention, the left and right wheels 20, 30 extend upward, as shown in FIGS. 22(a), (b), and (c). The robot rotates as if raking up the regolith in front of it while strongly pressing it (large contact pressure and large raking force are applied), so regardless of whether it is butterfly running or crawling, the raking action is It has been confirmed that as a reaction to this, the vehicle body 10 intermittently gains a large thrust for each revolution of the wheels 20, 30 and moves forward.

In particular, in the case of butterfly running, a strong propulsive force can be obtained by simultaneously scraping up the regolith in front with the left and right wheels 20 and 30, as shown in Figure 22, while in the case of crawling, As shown in Figure 23, even though it is done alternately on the left and right, the regolith in front can be scraped up more frequently, so depending on the viscosity of the regolith and the amount of accumulation, it is not possible to efficiently obtain propulsive force. It is considered possible.

According to the rover 1 according to the embodiment, the left and right tail portions 401 and 403 made of a relatively hard material are integrally formed to prevent the rover from slipping backward during the uphill movement when traveling uphill. , effectively supports the stretching motion.

In addition, the left and right fins 402 and 404 extending diagonally rearward from the rear ends of the left and right tails 401 and 403 bend and bend as appropriate when the rover 1 rolls over, while the wheels 20 and 30 Together with the forward rolling motion, the repulsive force effectively supports the standing up motion.

Furthermore, according to the rover 1 according to the embodiment, since it is possible to take pictures from a high position with a camera when it is extended greatly, it is expected that it will be able to capture a wide range of images covering a long distance even when traveling on the moon.

<<Others>>
The gist of the present invention is that each of the left and right wheels and each of the left and right axles are configured such that the distance between the ground contact surface of the wheel and the axle varies greatly depending on the rotation angle of the wheel. For other configurations, features of previous lunar wheels could be combined as desired.

Therefore, the three-dimensional shape of the wheel is not limited to a hemispherical shape, and may be a cylindrical wheel employed in ordinary passenger vehicles. Further, a lug for preventing slipping may be appropriately protruded from the ground contact surface of the wheel. Further, the shape of the side surface of the wheel is not limited to a circular shape, but may be a polygonal shape having any number of angles.

Furthermore, the rover 1 according to the embodiment described above alternates between two states, such as a stowed state (see FIG. 1) → deployed state (see FIGS. 2 and 3) → stowed state (see FIG. 1). It can also be configured so that it can be automatically switched. In that case, a so-called ball screw mechanism can be used instead of the left and right springs 116, 126 as a mechanism for automatically moving the left and right axles 114, 124 in and out.

That is, this ball screw mechanism has one ball screw with reverse threads cut in each half of its total length, and moves in opposite directions while being threadedly engaged with this ball screw, and while being loosely engaged with the axles 114 and 124. It could be realized by an axle holder that holds this and one motor that can rotate the ball screw in forward and reverse directions. As the above-mentioned motor, either the left or right motor 111 or 121 may be used by interposing a suitable gear train. Further, in order to fold up the protruding tail, fin, and observatory part, it is only necessary to fold them while pulling in their tips using an appropriate tension string winding mechanism.

The present invention can be widely used, for example, in the space industry that develops and produces rovers for lunar surface exploration.

1 Rover 10 Vehicle body 10A Vehicle housing 10B Drive unit assembly 11 Left housing half 11a Hinge shaft 11b Axle insertion hole 11e Hinge shaft 12 Right housing half 12b Axle insertion hole 12c Arc-shaped recess 12d Rectangular recess 12e Hinge shaft 13 Housing bottom plate 14 Support plate 14a Through hole 14b Through hole 14c Through hole 14a' Boss portion 15 Circuit board 16 Battery 20 Left wheel 30 Right wheel 40 Stabilizer 40A Stabilizer 50 Observation deck portion 51 Left half of holder 51a Hinge hole 51b Left half of light receiving window 52 Right half of holder 52a Hinge hole 52b Right half of light receiving window 53 Optical element mounting board 53a Front side light receiving part 53b Back side light receiving part 53c Front side board 53d Back side board 53e Support plate 51a Hinge hole 52a Hinge hole 111 Left wheel motor 111a Motor shaft 112 Irregular drive gear 112a Circular cross-section gear part 112b Fan-shaped wide cross-section gear part 113 Driven gear 114 Left axle 114a Projection 114b Projection 115 Bracket 115a Screw hole 115b Screw hole 116 Coil spring 111b Encoder 121 Right wheel motor 121b Engine coder 121a motor Shaft 122 Irregular drive gear 122a Circular cross-section gear part 122b Fan-shaped wide cross-section gear part 123 Driven gear 124 Right axle 124a Projection 124b Projection 125 Bracket 125a Screw hole 125b Screw hole 126 Coil spring 201 Hemispherical outer shell half 202 Polar projection 203 First circumferential zone 203a Opening 204 Second circumferential zone 204a Opening 205 Third circumferential zone 205a Opening 205b Recess 301 Hemispherical outer shell half 302 Polar protrusion 303a Opening 304a Opening 305a Opening 305b Recess 401 Left tail 402 Left Fin part 403 Right tail portion 404 Right fin portion 411 Single tail portion 411a Main body portion 411b Boss portion serving as the proximal side attachment portion 411c, 411d Boss portion serving as the distal side attachment portion 412 Left fin portion 412a Main body portion 412b Proximal side attachment portion and 413 Right fin part 413a Main body part 413b Boss part which becomes the proximal end mounting part 421 Screw which becomes the hinge shaft 431, 441 Screw which becomes the hinge shaft

Claims (16)

The car body and
left and right wheels,
left and right axles supported by the vehicle body and coupled to each of the left and right wheels;
a rotation drive unit for rotating each of the left and right axles;
a stabilizer for preventing the vehicle body from rotating along with the rotation of the wheels;
The left and right wheels have a polygonal shape including a circle, and each of the left and right wheels and each of the left and right axles are eccentrically connected to each other,
The vehicle body is
A vehicle body housing that accommodates the rotary drive unit and has left and right axle insertion holes on the left and right sides thereof,
The left and right wheels are
It consists of left and right outer shell halves obtained by dividing the outer shell surrounding the entire circumference of the vehicle body housing into left and right halves, and further inside the vehicle body housing,
When a predetermined activation condition is met, each of the left and right axles is caused to protrude by a predetermined amount from the vehicle body housing through each of the left and right axle insertion holes, thereby bringing the left and right outer shell halves into a left-right coupled state ( It has an axle protrusion mechanism that moves from the stored state to the left and right separated state (deployed state),
In the rover, a bowed rod-shaped tail portion corresponding to the stabilizer is attached to a position along a left-right neutral line of the vehicle body housing so as to be foldable against a biasing force in a deployment direction. a first rotation drive unit, wherein the rotation drive unit includes a first motor for rotating one of the axles; and a second rotation drive unit, the rotation drive unit includes a second motor for rotating the other one of the axles. The rover according to claim 1, further comprising a drive section. The rover according to claim 2, further comprising a rotation control unit for controlling rotations of the first motor and the second motor in conjunction with each other. The rotation control unit controls the rotations of the first motor and the second motor in conjunction so that each of the left and right wheels rotates imitating the movement of both hands in butterfly swimming. The rover described in 3. 4. The rotation control unit controls rotations of the first motor and the second motor in conjunction with each other so that the left and right wheels rotate in a manner similar to the movement of both hands in crawl swimming. Rover as described. According to claim 4 or 5, the rotation control unit controls rotations of the first motor and the second motor in conjunction so that the left and right wheels rotate at a predetermined rotation speed and phase. Rover as described. The rover according to claim 1, further comprising left and right fins that extend diagonally backward from the tip of the arched rod-like tail and have left and right elasticity. 2. The rover according to claim 1, wherein an observation deck section including a camera is attached to an upper position of the vehicle body housing along a left-right neutral line so as to be foldable against biasing force in the deployment direction. The rover according to claim 8, wherein the camera includes a first camera having a field of view forward in the direction of travel and a second camera having a field of view backward in the direction of travel in the unfolded state. The axle protruding mechanism is
left and right sliding guide members that linearly and slidably guide each of the left and right axles through the left and right axle insertion holes of the vehicle body housing;
left and right driven gears that are fixed to the left and right axles, respectively;
left and right drive gears that are fixed to left and right drive shafts that extend parallel to each of the left and right axles, and that continue to mesh with the driven gear while each of the left and right axles reaches from an initial position to a protruding position; and,
left and right springs that urge each of the left and right axles in a direction to protrude from the left and right insertion holes of the vehicle body housing;
The non-circular hole formed by the axle insertion hole is used as a keyhole, and the non-circular shaft portion formed at the tip of each of the axle shafts is used as a key, and by relative rotation between the key and the keyhole, a locked state where the two do not align and cannot be inserted is achieved. 2. The rover of claim 1, including a locking mechanism that creates an aligned, penetrable unlocked state. Each of the left and right outer shell halves is formed as a substantially hemispherical outer shell half, and in the left and right combined state, forms a substantially spherical outer shell that surrounds the vehicle body housing. The rover according to item 8 . The rover according to claim 11, wherein each of the left and right substantially hemispherical outer shell halves has a large number of openings distributed over the entire circumference thereof. Among the large number of openings, a pair of left and right openings located at the opening edges of the left and right substantially hemispherical outer shell halves form one imaging window when they are adjacent to each other when in the left-right combined state. 13. The rover according to claim 12, wherein the observation deck part is configured to allow the camera to capture surrounding images when the observation deck part is folded. A recessed portion or a rib is disposed on the outermost circumferential band portion of the left and right substantially hemispherical outer shell halves, corresponding to an angular range where a large pressing force and a large scraping force act. 11. The rover according to claim 11, wherein pole protrusions are formed at pole parts of the left and right substantially hemispherical outer shell halves. The rover according to claim 11, wherein the diameter of the substantially spherical body that appears in the left and right combined state of the left and right substantially hemispherical outer shells is in the range of 50 mm to 200 mm.

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