JP2001277175A - Multi-fingered movable robot hand and its gripping control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve controllability so that one driving source moves a plurality of fingers to an object to be gripped including a different diameter material and the robot hand performs a behavior similar to an gripping operation of a living body. SOLUTION: This multi-fingered movable robot hand comprises two or more fingers (the little finger 12, the third finger 14, the middle finger 18, the forefinger 20) arranged in parallel having joints, the other finger (the thumb 30) disposed facing to these fingers, and flexible members (wires 11, 13, 17, 19, 21, 22) for being pulled to bend joints of two or more fingers. For contacting two or more fingers and one finger with the object W to be gripped including the different diameter material to allow the gripping operation, power generated from one driving source 1 is transmitted to two or more flexible members via one or more differential gears 4, 7, 8, and each flexible member is pulled. Thus, a gripping force is generated in two or more fingers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of controlling a plurality of fingers with a single drive source to a grasping object including a different-diameter object, and performing a behavior similar to a grasping operation of a living body. The present invention relates to a multi-fingered robot hand improved in gripping and a gripping control method thereof.

[0002]

2. Description of the Related Art Hitherto, many mechanisms for controlling a robot hand or an artificial hand as an artificial hand have been developed. Generally speaking, when one human hand is viewed as a mechanism, it is said to have about 20 degrees of freedom, but in order to achieve this faithfully, 20 drive sources are required. Not practical. Therefore, the degree of freedom of the robot hand or the artificial hand is usually simplified to about 1 to 3. Normally, the movement of a human holding or opening a hand is defined as one degree of freedom.

[0003]

With a robot hand or a prosthetic hand having one degree of freedom, gripping and opening are performed with only one drive source, so that the finger joint cannot be usually moved.
You can't move your fingers independently. For this reason, there is a problem that not only a human-like movement cannot be performed, but also an object cannot be reliably grasped.

[0004] The present invention has been made in view of such circumstances, and a plurality of fingers are moved by a single driving source with respect to an object to be grasped including an object having a different diameter, and a grasping operation of a living body is performed. It is an object of the present invention to provide a multi-fingered mobile robot hand having improved controllability so as to perform close behavior and a gripping control method thereof.

[0005]

SUMMARY OF THE INVENTION In order to solve the problems, the present invention provides two or more fingers which have joints and are arranged substantially in parallel, and another one which is arranged to face the fingers. And a multi-finger movable robot hand comprising a flexible member that is pulled to bend the joint of the two or more fingers, wherein the two or more fingers and the one finger are Power generated from one drive source is transmitted to two or more flexible members through one or more differential gears in order to enable a gripping operation by contacting a gripping target object including a different diameter object. The gripping force is generated on the two or more fingers by pulling each flexible member.

That is, a multi-fingered mobile robot hand represented by a multi-fingered, multi-jointed myoelectric control prosthesis, which has joints composed of free-rotating pulleys for rotatingly supporting a link member, is arranged substantially in parallel. Two or more fingers, another finger disposed opposite the fingers, and an intermediate pulley between the free-rotating pulleys that is pulled to bend the joints of the two or more fingers. And each of the flexible members is connected in a cross-over manner.
By transmitting to the flexible members of the two or more fingers through two or more differential gears, respectively, and pulling each flexible member from both the bending side and the extension side of the link material, A finger joint drive mechanism for generating a gripping force on more than one finger,
The two or more fingers and the one finger are brought into contact with an object to be gripped including a different diameter object to adjust or hold the tension of the flexible member,
It is provided with a different-diameter object gripping mechanism that controls a gripping operation so that each finger joint wraps around the outer shape of the object to be gripped.

Here, a different-diameter object gripping mechanism uses a tension differential type torque sensor instead of an intermediate pulley, and brings the two or more fingers and the one finger into contact with a gripping object, thereby performing a tension differential. The strain amount or tension difference detected by the torque sensor is fed back to adjust the tension, each finger joint takes individual displacement according to the outer shape of the object to be gripped, and the gripping operation can be performed so as to wrap the object to be gripped. Compliance control is assumed.

In a gripping control method, power generated from one drive source is transmitted to two or more flexible members via one or more differential gears, and the flexible members are linked. By adjusting the tension from both directions of the bending side and the extension side and pulling, the finger joint is driven so as to generate a gripping force on the two or more fingers, and the two or more fingers are connected to the one or more fingers. The finger is brought into contact with the object to be grasped, and the amount of strain or the difference in tension detected by the tension differential torque sensor is fed back to adjust the tension. In particular, compliance control is performed on the gripping operation so as to wrap the gripping object.

Therefore, by moving three or more fingers including the finger joint by one driving source, a movement close to that of a human hand can be performed. It is possible to grip all of the fingers by contacting them with different-diameter objects.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the principle of the mechanism according to the present invention.

First, power is transmitted from a driving motor 1 as a driving source to a differential gear 4 via a spur gear 2 and a spur gear 3. The differential gear 4 transmits power to a spur gear 5 and a spur gear 6. The spur gear 5 transmits power to the differential gear 7 and the spur gear 6
Transmits power to the differential gear 8. The differential gear 7 is a pulley 9
And power to the pulley 10. Pulley 9 is wire 1
The wire 11 moves the little finger 12. Similarly, the pulley 10 winds the wire 13, and the wire 13 moves the ring finger 14. The differential gear 8 transmits power to the pulleys 15 and 16. The pulley 15 winds up the wire 17, and the wire 17 moves the middle finger 18. Similarly, the pulley 16 winds up the wire 19, and the wire 19 moves the index finger 20. (Finger joint drive mechanism)

Here, even when the movement of the index finger 20 and the middle finger 18 is restricted, the differential gear 4 to the spur gear 5, the differential gear 7,
Little finger 12 and ring finger 14 via pulley 9 and pulley 10
Power can be transmitted to Further, even if the movement of the ring finger 14 is restricted, power can be transmitted from the differential gear 7 to the little finger 11 via the pulley 9.

Then, two or more fingers and the one finger (thumb 30 described later) are brought into contact with the object W to be gripped, and the amount of strain or the amount of strain detected by a tension differential torque sensor (reference numeral 29 described later) is detected. By adjusting the tension by feeding back the tension difference, each joint takes individual displacement according to the outer shape of the object to be gripped, and controlling the gripping operation so as to wrap the object to be gripped, so that the shape can not be predicted at all. It is possible to realize gripping such that even a different diameter object is wrapped (following) along its shape. (Different-diameter object gripping mechanism)

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a plan view (a) and a side view (b) of the hand [five fingers] of the embodiment.

The mechanism for moving the four fingers other than the thumb 30 in FIG. 2 is the same as in FIG. 1, and the small finger 12, the ring finger 14, the middle finger 18, and the index finger 20 are driven by one drive source, ie, the motor 1.
Can be moved including the finger joints.

In the conventional method, moving at least four fingers requires at least four driving sources. In the present embodiment, however, one driving source is required.
It is realized only by the number of drive sources.

FIG. 3 shows a principle diagram of a mechanism for bending a finger joint by pulling a wire.

Of each of the wires (11, 13, 17, 19), the bent side 21 and the extended side 22 of any one of the wires
Are wound around the first joint pulley 23, the intermediate pulley 24, the second joint pulley 25, and the drive pulley 26 from opposite directions, and both ends of the bending side 21 and the extension side 22 of the wire are fixed to the first phalanx 27, Give proper initial tension.

When the drive pulley 26 is rotated clockwise in this state, the tension on the bending side 21 is large and the tension on the extension side 22 is small, and a tension difference occurs between these two wires. Due to this tension difference, the second phalange 28 rotates about the second joint pulley 25, and the first phalange 27
Rotate around and the knuckle bends.

Further, since the bending and extension of the finger are performed by changing the rotation direction of the drive pulley, the finger operation can be controlled by controlling the rotation speed and torque of the drive source.

For reference, model specifications of the hand [five fingers] of the embodiment are summarized in Table 1.

[0024]

[Table 1]

[0025]

According to the robot hand of the present invention, four fingers other than the thumb can be moved including the finger joint, and can be grasped in accordance with the shape of the object, so that the robot hand can move more like a human hand. Since the operation can be performed with only one driving source, the mechanism is downsized, and a prosthetic hand having substantially the same size as an adult hand can be realized. In addition, the weight of the entire mechanism can be reduced, and a prosthetic hand that is lightly burdened by a forearm amputee with weak muscle can be realized.

As an application field of the present invention, there is a use in a welfare field as a power prosthesis such as a myoelectric prosthesis for a forearm amputee and a prosthesis for an amputee of another part. In addition, control of the robot hand of a remote control robot for extreme work, such as work in outer space, inside the containment vessel of a nuclear power plant, deep sea, fire scene, culture vessel of toxic microorganisms, using a healthy person as the pilot, remote surgery Operation of a robot hand by a doctor at the time, operation of a micro robot hand by a doctor at the time of operation on a micro organ such as a blood vessel, an eyeball, etc., manned operation of a robot hand for handling a micro device such as an LSI device or an unmanned telephone station, unmanned Manned operation of a robotic hand of a remotely controlled robot that performs maintenance and management of facilities that require maintenance and management of radio relay facilities, tunnels, unmanned substations, etc., as well as input devices to the piloting device of aircraft pilots, virtual created by computer CG Application to manipulation in space is possible. .

[Brief description of the drawings]

FIG. 1 is a block diagram showing the principle of a mechanism according to the present invention.

FIG. 2A is a plan view and FIG. 2B is a side view showing an embodiment of the present invention.

FIG. 3 is a block diagram illustrating a principle of a mechanism according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Drive motor 2 Spur gear 3 Spur gear 4 Differential gear 5 Spur gear 6 Spur gear 7 Differential gear 8 Differential gear 9 Pulley 10 Pulley 11 Wire 12 Little finger 13 Wire 14 Ring finger 15 Pulley 16 Pulley 17 Wire 18 Middle finger 19 Wire 20 index finger 21 wire (bending side) 22 wire (extending side) 23 first joint pulley 24 intermediate pulley 25 second joint pulley 26 drive pulley 27 first phalange 28 second phalanx 29 tension differential torque sensor 30 thumb W grip Object

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Akira Koike 3-2-239 Higashi-Fukatsu-cho, Fukuyama City, Hiroshima Prefecture Inside the Hiroshima Prefectural Eastern Industrial Technology Center (72) Inventor Sadaji Shiraga 1-8 Midoricho, Fukuyama City, Hiroshima Prefecture No. F term (reference) in Yamahishi Technica Corporation 3C007 DS01 DS06 ES09 EU06 EU11 EU20 EW14 HS27 3F059 BA08 DA07 DC04 FC04 3F061 AA04 BA09 BC07 BC15 BC19 BD04 BF14 4C097 AA12 BB06 CC01 CC17 TA03 TB01 TB05

Claims (4)

[Claims] 1. An articulation for two or more fingers having joints and arranged substantially in parallel, another finger arranged to face the fingers, and a joint of the two or more fingers. For a multi-fingered robot hand composed of a flexible member to be pulled, the two or more fingers and the one finger are brought into contact with a gripping target object including a different-diameter object to enable a gripping operation. The power generated from one drive source is transmitted to two or more flexible members via one or more differential gears, and each of the flexible members is pulled, whereby the two or more fingers are moved. A multi-fingered robot hand characterized in that a gripping force is generated on the robot. 2. A multi-fingered robotic hand represented by a multi-fingered, multi-joint myoelectric control prosthesis, comprising two joints comprising free-rotating pulleys for pivotally supporting a link member and arranged substantially in parallel. The above-mentioned fingers, another one of the fingers arranged opposite to those fingers, and a crossed-between free-rotating pulley via an intermediate pulley which is pulled to bend the joint of the two or more fingers. A plurality of flexible members connected to the hook, and transmitting power generated from one drive source to the two or more finger flexible members via one or more differential gears, A finger joint drive mechanism for generating a gripping force on the two or more fingers by pulling each flexible member from both directions of the bending side and the extension side of the link material; and A single finger is brought into contact with an object to be grasped including a different-diameter object to form a flexible member. A multi-finger movable robot hand, comprising: a different-diameter object gripping mechanism that controls or holds a tension so that each finger joint wraps around the outer shape of an object to be gripped. 3. A different-diameter object gripping mechanism uses a tension differential torque sensor instead of an intermediate pulley to bring said two or more fingers and said one finger into contact with an object to be gripped. The amount of strain or the difference in tension detected by the torque sensor is fed back to adjust the tension, and each finger joint takes individual displacement in accordance with the outer shape of the object to be grasped, and the gripping operation is performed so as to enclose the object to be grasped. The multi-fingered robot hand according to claim 2, wherein the hand is controlled. 4. A gripping control method for a multi-fingered mobile robot hand represented by a multi-fingered, multi-jointed myoelectric control prosthesis, comprising a joint composed of a free-rotating pulley for rotatably supporting a link member and arranged substantially in parallel. Two or more fingers, another one of the fingers arranged opposite to those fingers, and an intermediate pulley between the free-rotating pulleys that is pulled to bend the joint of the two or more fingers. Gripping control of a multi-fingered robot hand configured to behave like a biological gripping operation on a gripping target object including a different-diameter object, which is configured by respective flexible members connected in a crossed manner through A method for transmitting power generated from one drive source to two or more flexible members via one or more differential gears, and connecting the flexible members to the bending side and the extension side of the link member. By adjusting the tension from both directions and pulling, The finger joint is driven to generate a gripping force on two or more fingers, and the two or more fingers and the one finger are brought into contact with a gripping target, and detected by a tension differential torque sensor. The strain amount or the tension difference is fed back to adjust the tension, each joint takes individual displacement according to the outer shape of the object to be grasped, and compliance control is performed on the grasping operation so as to wrap the object to be grasped. A grip control method for a multi-fingered mobile robot hand.