CN107065919A - Agricultural plant protection unmanned plane back and forth spray back and forth during turning path flight control method, device and unmanned plane - Google Patents

Abstract

The invention provides a turning path flight control method, device and unmanned aerial vehicle during the reciprocating spraying process of an agricultural plant protection unmanned aerial vehicle, which belongs to the field of unmanned aerial vehicle route planning methods and control methods. The man-machine turning strategy does not fully consider the actual maneuvering characteristics of the UAV, nor does it take into account the minimum number of turns, resulting in the UAV being forced to fly for a long time with variable speed, which in turn causes the UAV to be unable to adapt to the variable speed environment, and wastes energy when changing speed. question. The method of the present invention includes: obtaining the spraying radius of the UAV and the minimum turning radius of the UAV; judging that the UAV should perform the first type of turning, the second type of turning or the third type of turning according to the spraying radius and the minimum turning radius, And get the judgment result; adjust the flight state parameters of the drone according to the judgment result, and then control the flight of the drone. The invention also provides a turning path flight control device and an unmanned aerial vehicle. The invention is applicable to plant protection drones.

Description

The turning path flight control method of the agricultural plant protection UAV during the reciprocating spraying process Methods, Devices and UAVs

technical field

The invention relates to a turning path flight control method, device and UAV during the reciprocating spraying process of a plant protection UAV, and belongs to the field of UAV route planning methods and control methods.

Background technique

The area of plant protection UAV spraying operation is generally large, and the UAV is small in size and flexible in response. Therefore, the general plant protection UAV spraying route is planned to be in the shape of "Π" back and forth. As shown in Figure 3(a) and Figure 3(b), this situation will involve the turning problem of the UAV, and the route generated by man-made or offline planner generally does not consider the maneuvering characteristics of the UAV effect on turning. The spraying paths shown in Fig. 3(a) and Fig. 3(b) are more reasonable when flying vertically, but when the first spraying path turns to the second path, the turning path at this time is A right angle, which obviously does not conform to the flight characteristics of the UAV. If you turn according to this route, the UAV needs to decelerate to 0 first, then turn around at 90°, decelerate to 0 after acceleration, and fly to the second path at 90° Turn around and accelerate to speed V, and then spray at a constant speed. A flight path like this requires acceleration and deceleration every time, which is a waste of time and resources.

Figure 3(a) shows a standard rectangular spraying area, and Figure 3(b) shows an irregular spraying area, but their planned routes are all reciprocating. This back-and-forth route is especially good for spraying efficiency and spraying uniformity without obstacles. However, in practical applications, the maneuvering (flight) characteristics of the plant protection UAV itself cannot turn like the routes shown in Figure 3(a) and Figure 3(b).

And when the UAV turns, it will also be affected by various factors, such as the flight speed of the plant protection UAV, the size of the minimum turning radius, and the size of the spraying radius. The turning strategy of the plant protection UAV in the prior art does not fully consider the maneuvering characteristics of the UAV, nor does it take into account the flight speed, minimum turning radius, and spraying radius of the UAV, nor does it reduce the speed of the UAV through the above factors. Flight time, so as to improve the energy saving and endurance of plant protection drones.

Contents of the invention

The purpose of the present invention is to solve the problem that the turning strategy of the plant protection UAV in the prior art does not fully consider the actual maneuvering characteristics of the UAV, nor does it take into account the flight speed, minimum turning radius, and spraying radius of the UAV, and cannot The shortcomings of providing energy-saving turning strategies for plant protection UAVs by reducing the number of speed changes.

A turning path flight control method used in the reciprocating spraying process of a plant protection unmanned aerial vehicle, the turning path is formed by the UAV flying from the turning position of the current straight line spraying path to the next reverse straight line spraying path The arc-shaped path passed through, the method includes the steps of:

Step 1): Obtain the spraying radius R _p of the UAV and the minimum turning radius R _z of the UAV;

Step 2): According to the spraying radius R _p and the minimum turning radius R _z , it is judged that the UAV should perform the first type of turn, the second type of turn or the third type of turn, and obtain the judgment result; One type of turn means that when the UAV flies to a straight line perpendicular to the current flight path through the minimum turn R _z at a constant speed, it does not reach the adjacent straight spraying path; Passing through the minimum turning R _z at a constant speed can just fly to the adjacent spraying path; the third type of turning means that when the drone flies to any straight line perpendicular to the current flight path through the minimum turning R _z at a constant speed, it will Crossing adjacent spray paths or beyond the spray area;

Step 3) Adjust the flight state parameters of the UAV according to the judgment result, and then control the flight of the UAV.

The present invention also provides a turning path flight control device used in the reciprocating spraying process of the plant protection drone, including:

The flight parameter acquisition module is used to obtain the spraying radius of the UAV as _Rp and the minimum turning radius of the UAV as _Rz ;

Turning type judging module, for judging that the UAV should perform a first type of turn, a second type of turn or a third type of turn according to the spraying radius R _p and the minimum turning radius R _z , and obtain the judgment result ; When the first type of turning represents that the unmanned aerial vehicle flies through the minimum turning R _z to a straight line perpendicular to the current flight path at a uniform speed, it does not reach the adjacent straight spraying path; the second type of turning represents the The _UAV can just fly to the adjacent spray path through the minimum turn Rz at a constant speed; the third type of turn means that the UAV flies through the minimum turn _Rz at a constant speed to any direction perpendicular to the current flight path. When in a straight line, it will cross the adjacent spraying path or exceed the spraying area;

The flight state control module is used to adjust the flight state parameters of the UAV according to the judgment result, and then control the flight of the UAV.

The present invention also includes an unmanned aerial vehicle, including the above-mentioned turning path flight control device used in the reciprocating spraying process of the plant protection unmanned aerial vehicle.

The beneficial effects of the present invention are: considering the flight speed, the minimum turning radius, and the spraying radius, the turning scheme is planned according to the relationship between the minimum turning radius and the spraying radius, so that the turning path is as small as possible, and the speed change of the drone is minimized. Flight time, so as to achieve the purpose of reducing energy consumption for plant protection drones.

Description of drawings

Fig. 1 is the flowchart of the turning path flight control method used in the reciprocating spraying process of the plant protection unmanned aerial vehicle of the present invention;

Fig. 2 is the schematic diagram of the turning path flight control device used in the reciprocating spraying process of the plant protection drone of the present invention;

Fig. 3 (a) is the schematic diagram of the route of drone spraying in an unobstructed rectangular area;

Fig. 3 (b) is a schematic diagram of the route of the UAV spraying in an unobstructed irregular area;

Fig. 4 is the flight path diagram of the first type turning of the present invention;

Fig. 5 is the flight path diagram of the second type turning of the present invention;

Fig. 6 is the flight path diagram when the spray path is an even number in the third type of turn of the present invention;

Fig. 7 is the flight path diagram when the spray path is an odd number in the third type of turn of the present invention;

Fig. 8 is an overall flowchart of an embodiment of the present invention.

detailed description

Specific implementation mode one: the turning path flight control method used in the reciprocating spraying process of the plant protection drone in this embodiment, the turning path is that the drone flies from the turning position of the current straight line spraying path to the next turning point. The arc path passed by the straight line spraying path, it is characterized in that, described method comprises the following steps:

Step 1): Obtain the spraying radius R _p of the UAV and the minimum turning radius R _z of the UAV;

Step 2): According to the spraying radius R _p and the minimum turning radius R _z , it is judged that the UAV should perform the first type of turn, the second type of turn or the third type of turn, and obtain the judgment result; One type of turn means that when the UAV flies to a straight line perpendicular to the current flight path through the minimum turn R _z at a constant speed, it does not reach the adjacent straight spraying path; Passing through the minimum turning R _z at a constant speed can just fly to the adjacent spraying path; the third type of turning means that when the drone flies to any straight line perpendicular to the current flight path through the minimum turning R _z at a constant speed, it will Crossing adjacent spray paths or beyond the spray area;

Step 3) Adjust the flight state parameters of the UAV according to the judgment result, and then control the flight of the UAV.

Embodiment 2: This embodiment differs from Embodiment 1 in that in step 3), the flight parameters include flight speed, turning position, and turning radius where turning occurs.

Other steps and parameters are the same as those in Embodiment 1.

Specific embodiment three: the difference between this embodiment and specific embodiment one or two is: in step 3), when the judgment result is the first type of turn, the drone performs the following steps in sequence:

Step 3A.1) At the turning position, turn 90 degrees at a constant speed and fly through the minimum turning R _z to a straight line perpendicular to the current flight path;

Step 3A.2) Fly along a straight line to an adjacent straight spraying path;

Step 3A.3) Fly to the adjacent spraying path through the minimum turning R _z at a constant speed at the turning position;

Step 3A.4) Fly in a straight line along said adjacent spray paths.

Other steps and parameters are the same as those in Embodiment 1 or Embodiment 2.

Specific embodiment four: the difference between this embodiment and one of the specific embodiments one to three is: in step 3), when the judgment result is the second type of turning, the drone performs the following steps in sequence:

Step _3B.1 ) Turn 180 degrees at a constant speed and fly to the adjacent spraying path through the minimum turn Rz;

Step 3B.2) Fly in a straight line along the adjacent spray paths.

Other steps and parameters are the same as those in Embodiments 1 to 3.

Specific embodiment five: the difference between this embodiment and one of the specific embodiments one to four is: in step 3), when the judgment result is the third type of turn, the drone performs the following steps in sequence:

Step 3C.1) Acquiring information on the number of preset spraying paths;

Step 3C.2) According to the number information of the spraying paths, it is identified that the spraying paths are odd or even; when the spraying paths are even, record the number of spraying paths as 2k; when the spraying paths When there are an odd number of paths, record the number of spraying paths as 2k+1; k is a positive integer;

Step 3C.3) When the number of the spraying paths is odd, execute the flight route of type A; when the number of the spraying paths is even, execute the flight route of type B;

The characteristics of the Class A flight route are: whenever it reaches the turning point of the k spraying path, it turns 180° at a constant speed and flies to the k+2 path; and when the UAV flies to the 2k-1 When spraying the path, it is necessary to turn 180° at a constant speed and fly from the 2k-1 spraying path to the 2k spraying path;

The characteristics of the B-type flight route are: whenever it reaches the turn of the k spraying path, turn 180° at a constant speed and fly to the k+2 path; and when the drone flies to the 2k+1 path When spraying paths, it is necessary to turn 180° at a constant speed and fly from the 2k+1 path to the 2k path.

Other steps and parameters are the same as in one of the specific embodiments 1 to 4.

Specific implementation mode six: the difference between this implementation mode and one of specific implementation modes one to five is:

The method for determining the obstacle-avoiding spraying path for the plant protection drone of the present embodiment includes the following steps:

In step 3C.3), the execution of the category A flight route is specifically:

Step A1) At the turning position, turn 180° at a constant speed and fly from the first spraying path to the third spraying path;

Step A2) Fly in a straight line at a constant speed at the third spraying path until reaching the turning position of the third spraying path;

Step A3) Repeat step A1) to step A2) until the spraying of the 1st, 3...2k-1 spraying paths is completed;

Step A4) At the turn of the 2k-1 spraying path, fly to the 2k spraying path through variable speed;

Step A5) Fly in a straight line at a constant speed on the 2k spraying path until reaching the turning position of the 2k spraying path;

Step A6) At the turning position of the 2k spraying path, turn 180° at a constant speed and fly from the 2k spraying path to the 2k-2 spraying path;

Step A7) Repeat step A4) to step A6), until the 2k, 2k-2... 2 spraying paths are all sprayed.

Other steps and parameters are the same as one of the specific embodiments 1 to 5.

Specific implementation mode seven: the difference between this implementation mode and one of specific implementation modes one to six is:

In step 3C.3), the execution of the category B flight route is specifically:

Step B1) Fly from the first spraying path to the third spraying path by turning 180° at a constant speed at the turning position;

Step B2) Fly in a straight line at a constant speed at the third spraying path until reaching the turning position of the third spraying path;

Step B3) Repeat step B1) to step B2), until all the spraying paths of the 1st, 3rd...2k+1 spraying paths are completed;

Step B4) At the turn of the 2k+1 spraying path, fly at a variable speed to the 2k spraying path;

Step B5) Fly in a straight line at a constant speed on the 2k spraying path until reaching the turning position of the 2k spraying path;

Step B6) At the turning position of the 2k spraying path, turn 180° at a constant speed and fly from the 2k spraying path to the 2k-2 spraying path;

Step B7) Step B4) to Step B6) are repeated until the 2k, 2k-2... 2 spraying paths are all sprayed.

Other steps and parameters are the same as one of the specific embodiments 1 to 6.

Embodiment 8: This embodiment is implemented based on any one of Embodiments 1 to 7, and the difference is:

The single flight path length of the first type of turn is:

D _{turn 1} = 2R _p -2R _z +πR _z ;

The single flight path length of the second type of turn is:

D _{turn 2} = πR _z ;

The single flight path length of the third type of turn is:

D _{turn 3} = πR _z .

Specific embodiment nine: This embodiment provides a turning path flight control device used in the reciprocating spraying process of the plant protection drone, including:

The flight parameter acquisition module is used to obtain the spraying radius of the UAV as _Rp and the minimum turning radius of the UAV as _Rz ;

Turning type judging module, for judging that the UAV should perform a first type of turn, a second type of turn or a third type of turn according to the spraying radius R _p and the minimum turning radius R _z , and obtain the judgment result ; When the first type of turning represents that the unmanned aerial vehicle flies through the minimum turning R _z to a straight line perpendicular to the current flight path at a uniform speed, it does not reach the adjacent straight spraying path; the second type of turning represents the The _UAV can just fly to the adjacent spray path through the minimum turn Rz at a constant speed; the third type of turn means that the UAV flies through the minimum turn _Rz at a constant speed to any direction perpendicular to the current flight path. When in a straight line, it will cross the adjacent spraying path or exceed the spraying area;

The flight state control module is used to adjust the flight state parameters of the UAV according to the judgment result, and then control the flight of the UAV.

Embodiment 10: This embodiment provides an unmanned aerial vehicle, including the turning path flight control device used in the reciprocating spraying process of the plant protection drone as described in Embodiment 9:

<Example>

This embodiment mainly relates to the derivation process of the formulas appearing in the specific implementation manner.

1. Symbol definition

Assume that the plant protection UAV is spraying on an ideal rectangular ground without obstacles (other situations are similar, such as the irregular shape in Figure 3(b)), assuming that the length of the rectangle is a and the width is b, also That is, the length of the single flight path of the plant protection UAV is b, the starting point of the single flight path of the plant protection UAV is named S(i), and the end point is named T(i). For example, S(1)T(1) represents the first The start and end points on the flight path.

The relevant parameters of the plant protection UAV spraying operation are: the spraying radius of the plant protection UAV is R _p , the flight speed V, and the minimum turning radius R _z of the plant protection UAV at the current speed.

2. Analysis of the turning situation during the spraying operation of the plant protection drone

There are many factors that need to be considered when turning. First, the influence of the minimum turning radius R _z ; second, the influence of UAV flight speed V on the minimum turning radius; third, the influence of UAV spraying radius R _p . In addition, there are many external factors, such as wind interference, electromagnetic interference, obstacle interference, etc. Here we only discuss the impact of the first three items, without considering other external factors. The following discusses the size relationship between R _p and R _z .

The Dubins path used in the present invention is the prior art, and the author has given a proof in the article that when two directed vectors are connected, the path obtained by using the Dubins path is the shortest. The invention applies it to the research on the turning problem of the spraying operation process of the plant protection drone. This not only takes into account the length of the turning route, but also improves the efficiency of turning.

(1) Category 1 turns

When Rp>Rz, the plant protection UAV can fly through the Dubins path from a straight line at speed V through the minimum turning circle generated by the minimum turning radius Rz to a straight line perpendicular to the first flight path, and then fly through the horizontal line at speed V After a straight line, fly through the minimum turning circle to the second spraying operation path. The common spraying radius of plant protection drones is about 6-8 meters. At this time, the minimum turning radius of plant protection drones should be less than this value. Its specific flight is shown in Figure 4.

At this time, the calculated length of the turning path is as follows (the length is the length from the beginning of the turn to the end of the turn):

First calculate the two arc lengths, because the two minimum turning circles are the same size and are tangent to the two vertical line segments, and the arcs corresponding to the two arcs are both 90° with geometric knowledge, so the two arc lengths can be calculated The sum is

And because of

L _{horizontal straight line segment} = 2R _p -2R _z

In summary, the total path length when turning is obtained as

D _{turn 1} ＝2R _p -2R _z +πR _z

(2) Type 2 turns

When Rp=Rz, at this time, the plant protection drone can happen to make a small turning circle with the minimum turning radius, and fly to the second spraying path after a straight line passes through the arc, so that it can turn 180° and enter the next spraying path. A spray path. However, due to environmental factors and the flight characteristics of the drone itself, this is less likely to happen. Its flight route diagram is shown in Figure 5. At this time, when calculating the length of the turning route, there is no horizontal straight line segment in the first case, so the route length during the turning process in this case is:

D _{turn 2} = πR _z

(3) Class 3 turns

When Rp<Rz (in the present embodiment, the preset Rz maximum value is Rz=4Rp, and the value of Rz increases again and will fly to the fourth spraying path, because it is not continued to discuss like this), at this time, It is impossible for the plant protection drone to fly to the next spraying path while the current speed remains constant. In this case, the drone must decelerate to the next spraying path after each flight. flight path. However, acceleration and deceleration will be carried out every time, which will inevitably cause unnecessary waste (such as fuel, pesticides, liquid fertilizers, etc.). The method adopted in this paper is as follows

When the plant protection drone finds that Rp<Rz before the spraying operation, the flight path adopted is no longer to traverse each path in turn, but to turn directly from the first flight path to the third flight path until the completion of 1 , 3, 5, 7...2N+1 and other paths, after a speed change, fly to the 2Nth spraying path, and then repeat the above method until the operation is completed.

The specific flight routes are shown in Fig. 6 and Fig. 7, wherein Fig. 6 shows the situation of even spraying paths, and Fig. 7 shows the situation of odd spraying paths.

The present invention can also have other various embodiments, without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention, but these corresponding changes and deformations are all Should belong to the scope of protection of the appended claims of the present invention.

Claims (10)

1. A turning path flight control method in the reciprocating spraying process of an agricultural plant protection drone, the turning path is that the UAV flies from the turning position of the current straight line spraying path to the next reverse straight line spraying path The arc-shaped path passed is characterized in that the method comprises the steps of: Step 1): Obtain the spraying radius R _p of the UAV and the minimum turning radius R _z of the UAV; Step 2): According to the spraying radius R _p and the minimum turning radius R _z , it is judged that the UAV should perform the first type of turn, the second type of turn or the third type of turn, and obtain the judgment result; One type of turn means that when the UAV flies to a straight line perpendicular to the current flight path through the minimum turn R _z at a constant speed, it does not reach the adjacent straight spraying path; Passing through the minimum turning R _z at a constant speed can just fly to the adjacent spraying path; the third type of turning means that when the drone flies to any straight line perpendicular to the current flight path through the minimum turning R _z at a constant speed, it will Crossing adjacent spray paths or beyond the spray area; Step 3) Adjust the flight state parameters of the UAV according to the judgment result, and then control the flight of the UAV. 2. The method according to claim 1, characterized in that, in step 3), the flight parameters include flight speed, turning position and turning radius where turning occurs. 3. The method according to claim 2, characterized in that, in step 3), when the judgment result is the first type of turning, the unmanned aerial vehicle performs the following steps successively: Step 3A.1) At the turning position, turn 90 degrees at a constant speed and fly through the minimum turning R _z to a straight line perpendicular to the current flight path; Step 3A.2) Fly along a straight line to an adjacent straight spraying path; Step 3A.3) Fly to the adjacent spraying path through the minimum turning R _z at a constant speed at the turning position; Step 3A.4) Fly in a straight line along said adjacent spray paths. 4. The method according to claim 2, characterized in that, in step 3), when the judged result is the second type of turning, the unmanned aerial vehicle performs the following steps successively: Step _3B.1 ) Turn 180 degrees at a constant speed and fly to the adjacent spraying path through the minimum turn Rz; Step 3B.2) Fly in a straight line along the adjacent spray paths. 5. The method according to claim 2, characterized in that, in step 3), when the judged result is the third type of turn, the unmanned aerial vehicle performs the following steps successively: Step 3C.1) Acquiring information on the number of preset spraying paths; Step 3C.2) According to the number information of the spraying paths, it is identified that the spraying paths are odd or even; when the spraying paths are even, record the number of spraying paths as 2k; when the spraying paths When there are an odd number of paths, the number of spraying paths is 2k+1; k is a positive integer; Step 3C.3) When the number of the spraying paths is odd, execute the flight route of type A; when the number of the spraying paths is even, execute the flight route of type B; The characteristics of the Class A flight route are: whenever it reaches the turning point of the k spraying path, it turns 180° at a constant speed and flies to the k+2 path; and when the UAV flies to the 2k-1 When spraying the path, it is necessary to turn 180° at a constant speed and fly from the 2k-1 spraying path to the 2k spraying path; The characteristics of the B-type flight route are: whenever it reaches the turn of the k spraying path, turn 180° at a constant speed and fly to the k+2 path; and when the drone flies to the 2k+1 path When spraying paths, it is necessary to turn 180° at a constant speed and fly from the 2k+1 path to the 2k path. 6. The method according to claim 5, characterized in that, in the step 3C.3), the execution of the Class A flight route is specifically: Step A1) At the turning position, turn 180° at a constant speed and fly from the first spraying path to the third spraying path; Step A2) Fly in a straight line at a constant speed at the third spraying path until reaching the turning position of the third spraying path; Step A3) Repeat step A1) to step A2) until the spraying of the 1st, 3...2k-1 spraying paths is completed; Step A4) At the turn of the 2k-1 spraying path, fly to the 2k spraying path through variable speed; Step A5) Fly in a straight line at a constant speed on the 2k spraying path until reaching the turning position of the 2k spraying path; Step A6) At the turning position of the 2k spraying path, turn 180° at a constant speed and fly from the 2k spraying path to the 2k-2 spraying path; Step A7) Repeat step A4) to step A6), until the 2k, 2k-2... 2 spraying paths are all sprayed. 7. The method according to claim 5, characterized in that, in the step 3C.3), the execution of the Class B flight route is specifically: Step B1) Fly from the first spraying path to the third spraying path by turning 180° at a constant speed at the turning position; Step B2) Fly in a straight line at a constant speed at the third spraying path until reaching the turning position of the third spraying path; Step B3) Repeat step B1) to step B2), until all the spraying paths of the 1st, 3rd...2k+1 spraying paths are completed; Step B4) At the turn of the 2k+1 spraying path, fly at a variable speed to the 2k spraying path; Step B5) Fly in a straight line at a constant speed on the 2k spraying path until reaching the turning position of the 2k spraying path; Step B6) At the turning position of the 2k spraying path, turn 180° at a constant speed and fly from the 2k spraying path to the 2k-2 spraying path; Step B7) Step B4) to Step B6) are repeated until the 2k, 2k-2... 2 spraying paths are all sprayed. 8. A method according to any one of claims 1 to 7, characterized in that, The single turn path length of the first type of turn is: D _{turn 1} = 2R _p -2R _z +πR _z ; The single turn path length of the second type of turn is: D _{turn 2} = πR _z ; The total length of the single turn path of the third type of turn is: D _{turn 3} = πR _z . 9. A turning path flight control device used in the reciprocating spraying process of a plant protection drone, characterized in that it includes: The flight parameter acquisition module is used to obtain the spraying radius R _p of the drone and the minimum turning radius R _z of the drone; A turning type judging module, used to judge that the UAV should perform a first type of turn, a second type of turn or a third type of turn according to the spraying radius R _p and the minimum turning radius R _z , and obtain a judgment result; The first type of turn means that when the UAV flies to a straight line perpendicular to the current flight path through the minimum turn R _z at a uniform speed, it does not reach the adjacent straight spraying path; the second type of turn means that the unmanned The man-machine can just fly to the adjacent spraying path through the minimum turn _Rz at a constant speed; the third type of turn means that the UAV flies through the minimum turn _Rz at a constant speed to any straight line perpendicular to the current flight path , will cross the adjacent spraying path or exceed the spraying area; The flight state control module is used to adjust the flight state parameters of the UAV according to the judgment result, and then control the flight of the UAV. 10. An agricultural plant protection drone, characterized in that it comprises a turning path flight control device during the reciprocating spraying process of the agricultural plant protection drone according to claim 9.