CN1215925C - Robotic anthropomorphic hand variable grasping force mechanical finger device - Google Patents

Abstract

The present invention relates to a mechanical finger device with variable grasp force for simulating a human hand by a robot, which belongs to the technical field of anthropomorphic robots and comprises a basic knuckle, a variable grasp force joint and a variable grasp force knuckle, wherein both of the basic knuckle and the variable grasp force knuckle are in hollow structures; the variable grasp force joint comprises a motor, a speed reducer, a transmission mechanism, a joint shaft, a shifting block, a plate spring. The joint shaft is sheathed between the basic knuckle and the variable grasp force knuckle; the output shaft of the motor is connected with the speed reducer, is arranged in the basic knuckle, and is parallel to the joint shaft. The output shaft of the speed reducer is connected with the transmission mechanism connected with the joint shaft. The shifting block is sheathed on the joint shaft; one end of the plate spring is fixed to the shifting block; and the other end of the plate spring is inserted into the variable grasp force knuckle. The transmission mechanism can be in gear transmission, tendon venation transmission, band wheel transmission, chain wheel transmission and connecting rod transmission. The device has the advantages of simple structure, easy processing and high reliability; the device can be used as different fingers or a part of a finger on a human hand simulated by a robot for realizing different grasp force with high grasping precision in object grasp.

Description

Robotic anthropomorphic hand variable grasping force mechanical finger device

technical field

The invention relates to a manipulator device, in particular to a structural design of a robot anthropomorphic hand variable grasping force mechanical finger device.

Background technique

The main function of the robotic anthropomorphic hand is to grasp objects. According to the weight of the object and the degree of softness and hardness of the surface, the robot hand should use different grasping forces when grasping, that is, the grasping force of the robot anthropomorphic hand should have certain controllability. Therefore, it is of great significance to design robotic fingers with variable grasping force for anthropomorphic hands.

An existing robot anthropomorphic hand variable grasping force mechanical finger device, such as the U.S. invention patent US4946380, consists of a motor, the first and second joints, the first and second knuckles, tendon ropes, a small movable pulley and a large fixed pulley Consisting of a connecting rod and a compression spring, the device is driven by a motor to drive the first joint to rotate (that is, to drive the first knuckle of the finger to rotate), and to drive the tendon rope to drive the second joint to rotate (to drive the second knuckle of the finger to rotate) . In the middle of the tendon rope bypassing the two joints, it is also necessary to bypass the small movable pulley and the large fixed pulley mounted on the connecting rod. The shaft of the large fixed pulley is fixed on the first knuckle of the finger, and the hinge in the middle of the connecting rod Fixedly connected on the large fixed pulley, a stage clip is provided between the small movable pulley on one end of the connecting rod and the first phalanx of the finger. When grabbing an object, when the second knuckle of the finger touches the object and no longer rotates, the motor continues to rotate, making the tendon rope tense, and the tension of the tendon rope makes the connecting rod equipped with the small moving pulley rotate, so that the compression spring After the motor stops rotating, the rebound force of the deformation stage spring will make the second phalanx of the finger maintain the constant grasping force produced on the object. By controlling the size of the angle at which the motor continues to rotate after the second knuckle of the finger touches the object, different grasping forces when grasping the object can be controlled.

The disadvantages of this device are: the device is only suitable for being installed on the robot anthropomorphic hand with tendon transmission; the device mechanism is complicated, requires high manufacturing level, high cost, and low reliability; The force control accuracy is reduced, unless a special material with little deformation is used, which will make the whole hand more expensive.

Contents of the invention

The purpose of the present invention is to design a robot anthropomorphic hand variable grasping force mechanical finger device for overcoming the deficiencies of the prior art. The transmission mechanism of the device can be gear transmission, tendon transmission, pulley transmission, sprocket transmission, and connecting rod transmission. The device is simple, easy to process and reliable, and can be used as a finger or a part of a robot anthropomorphic hand to realize different grasping forces generated when the robot anthropomorphic hand grasps objects, and the control precision of the grasping force is high.

The robot anthropomorphic hand variable grasping force mechanical finger device designed by the present invention includes basic knuckles, variable grasping force joints, and variable grasping force knuckles; said basic knuckles and variable grasping force knuckles are hollow structures , the variable grasping force joint is set between the basic knuckle and the variable grasping force knuckle; the variable grasping force joint includes a motor, a reducer, a transmission mechanism, a joint shaft, a sliding bearing, and a shifting block , leaf spring; its connection relationship is: the said joint shaft sleeve is set between the basic knuckle and the variable grasping force knuckle, the output shaft of the motor is connected with the reducer, arranged in the basic knuckle, and parallel to the joint shaft; the output shaft of the reducer is connected with the transmission mechanism, and the transmission mechanism is connected with the joint shaft; the shift block is fixed on the joint shaft; one end of the leaf spring is fixed with the shift block, and the other end is inserted Take force inside the knuckles. After the leaf spring is installed, there is a certain amount of initial bending deformation, so as to ensure that there is no gap between the leaf spring and the variable grasping force knuckle.

Said transmission mechanism can adopt gear transmission mechanism, also can adopt pulley transmission mechanism, chain wheel transmission mechanism, connecting rod transmission mechanism or tendon transmission mechanism etc.

The variable grasping force joint may include a torsion spring, the two ends of which are respectively connected with the joint shaft and the basic knuckles to eliminate the gap generated during the transmission process;

A potentiometer can be installed at one end of the joint shaft to detect the angular position of the joint shaft rotation, and position closed-loop control can be realized.

An encoder can be installed at the tail of the motor to detect the rotation speed of the output shaft of the motor, so that closed-loop speed control can be realized.

Said basic phalanx can comprise basic phalanx frame, bearing plate, gear cover, and the three are affixed together.

Said variable grasping force phalanx may comprise a variable grasping force phalanx frame and a spacer, and the two are affixed together.

Working principle of the present invention is:

When the robot grabs an object with an anthropomorphic hand, assuming that the basic knuckles have touched the surface of the object, the motor output shaft rotates, which drives the output shaft of the reducer to rotate, drives the transmission mechanism to move, drives the joint shaft to rotate, drives the shift block to rotate, and drives the leaf spring The other end of the plate spring moves the variable grasping force knuckle to rotate around the axis of the joint shaft until the variable grasping force knuckle touches the object. At this time, the joint shaft, shift block, leaf spring and variable grasping force finger The knots are rotated by the same angle θ. At this time, the continued rotation of the motor will drive the joint shaft and the shifting block to continue to rotate through the angle α. The fixed end of the leaf spring and the shifting block has also turned through the angle α, while the other end of the leaf spring and the knuckle with variable grasping force cannot rotate due to the obstruction of the object, so the leaf spring is bent and deformed to generate a rebound force. The variable grasping force knuckles are applied to the object, thereby generating the compressive force F exerted by the variable grasping force knuckles on the object. As the motor rotates, the bending deformation angle α of the leaf spring increases, and the pressing force F increases accordingly. By controlling the rotation of the motor, the control of the grasping force can be realized. When the motor stops rotating, the rebound force produced by the bending deformation of the leaf spring not only produces the variable grasping force knuckle to apply the grasping force F to the object, but also has a tendency to rotate the joint shaft in the opposite direction. Since the deceleration ratio of the reducer is large (hundreds to one), and the motor has a certain moment of inertia, the moment of inertia is magnified many times in the reduction transmission with a large reduction ratio, so it is impossible for the leaf spring to realize the reverse rotation of the toggle joint axis. Rotate, so the bending deformation of leaf spring is kept, and the pressing force F of variable grasping force phalanx to object has just been kept. Owing to the existence of this pressing force F and the frictional force f generated by it, the robot anthropomorphic hand can now pick up the object.

When the object is released, the output shaft of the motor reverses, drives the output shaft of the reducer to reverse, drives the transmission mechanism to move in the reverse direction, drives the joint shaft to reverse, and drives the shifting block to reverse, so that the bending deformation of the leaf spring gradually decreases and the grip becomes smaller. The pressing force F exerted by the force-taking knuckle on the object also gradually decreases. When the shift block reverses the angle α, the leaf spring returns to the initial small bending deformation state. The pressing force F has been reduced to zero. The motor continues to rotate to drive the shifting block to rotate, and the gripping force is changed by the leaf spring to reverse and leave the object surface.

The play of the transmission mechanism is eliminated by using the torsion spring connected between the joint shaft and the base knuckle. Through the encoder, the rotation speed of the motor can be detected, so that the closed-loop control of the rotation speed of the finger with variable grasping force can be realized. Through the potentiometer, the angular position of the joint shaft and the shifting block can be detected; the closed-loop control of the angular position of the joint shaft and the shifting block can be realized.

The feature of the present invention is: the mechanical finger device of the robot anthropomorphic hand with variable grasping force. The device includes basic knuckles, joints with variable grasping force, and knuckles with variable grasping force, and its transmission mechanism can be gear transmission, tendon transmission, belt wheel transmission, sprocket transmission, and connecting rod transmission. The device is simple, easy to process and reliable. It can be used as a finger or a part of a finger on an anthropomorphic hand of a robot to realize different grasping forces generated when the anthropomorphic robot grasps an object, and the control precision of the grasping force is high.

Description of drawings

Fig. 1 is a side appearance view of an embodiment of a robot anthropomorphic hand variable grasping force mechanical finger device of the present invention.

Fig. 2 is the front appearance view of the robot anthropomorphic hand variable grasping force mechanical finger device of this embodiment.

Fig. 3 is a schematic diagram of the robotic anthropomorphic hand of this embodiment when the mechanical finger device with variable grasping force grasps an object.

Fig. 4 is a side view of the application of this embodiment to the robot anthropomorphic hand, at this time the thumb has swung to the position facing the palm.

Fig. 5 is the front appearance view of this embodiment applied to the robot anthropomorphic hand, at this time the thumb has swung to the side of the palm.

Fig. 6 is a schematic diagram of a robot anthropomorphic hand holding a cylindrical object in this embodiment.

In Figures 1 to 8:

1 is the basic knuckle, 2 is the variable grasping force knuckle, 3 is the variable grasping force joint,

4 is the gear cover, 5 is the knuckle frame with variable gripping force, 6 is the spacer,

7 is the leaf spring, 8 is the basic knuckle frame, 9 is the motor,

10 is an encoder, 11 is a bearing, 12 is a potentiometer,

13 is a torsion spring, 14 is a sleeve, 15 is a shift block,

16 is a taper pin, 17 is a joint gear shaft, 18 is a pinion,

19 is a reducer, 20 is a bearing plate, 21 is a bearing plate,

22 is the first knuckle of the index finger, 23 is the second knuckle of the index finger, 24 is the first knuckle of the thumb,

25 is the second knuckle of the thumb, 26 is the first joint of the index finger, 27 is the second joint of the index finger,

28 is the first joint of the thumb, 29 is the second joint of the thumb, 30 is the wrist connecting plate,

31 is an object.

Detailed ways

Content of the present invention is described in detail as follows in conjunction with embodiment and accompanying drawing:

An embodiment of a robotic anthropomorphic hand variable grasping force mechanical finger device designed by the present invention is shown in FIGS. Both the basic knuckle 1 and the variable grasping force knuckle 2 are hollow structures, and the variable grasping force joint 3 is set between the sub-basic knuckle 1 and the variable grasping force knuckle 2 .

The basic phalanx 1 includes a basic phalanx frame 8, a bearing plate 20, and a gear cover 4, and the three are fixed together by screws.

The variable grasping force knuckle 2 includes a variable grasping force knuckle skeleton 5 and a pad 6, and the two are fixed together by screws.

Variable grasping force joint 3 includes motor 9, reducer 19, pinion 18, joint gear shaft 17, sliding bearing 11, taper pin 16, sleeve 14, potentiometer 12, encoder 10, torsion spring 13, dial block 15 , leaf spring 7. Its connection relationship is: said joint gear shaft 17 is sheathed between the basic phalanx 1 and the variable gripping force phalanx 2 . The output shaft of the motor 9 is connected with the speed reducer 19, and is arranged in the position closest to the joint gear shaft in the basic phalanx 1, and is parallel to the joint gear shaft. The output shaft of the speed reducer 19 and the pinion 18 are fixedly connected by set screws, and the pinion meshes with the joint gear shaft. The torsion spring 13 is connected to the joint gear shaft 17 and the basic knuckle frame 8 respectively. The shifting block 15 is sleeved and fixed on the joint gear shaft through a conical pin 16 . One end of leaf spring 7 is fixedly connected with shifting block by screw, and the other end is inserted in the knuckle of variable grasping force, contacts with cushion block 6. A sliding bearing 11 is provided between the basic knuckle 1 and the joint gear shaft 17 . A potentiometer 12 is housed at one end of the joint gear shaft 17 away from the gear. Sleeve 14 is sleeved on the joint gear shaft. The encoder 10 is installed at the tail of the motor. Because the pad is thicker, the leaf spring 7 has a certain amount of initial bending deformation after installation, thereby ensuring that there is no gap between the leaf spring 7 and the knuckle 2 with variable grasping force.

The working principle of the present embodiment, with reference to Fig. 3, is described as follows:

When the robot anthropomorphic hand grabs an object, assuming that the basic knuckle 1 has touched the surface of the object 36, the output shaft of the motor 9 rotates, which drives the output shaft of the reducer 19 to rotate, drives the pinion gear 18 to rotate, drives the joint gear shaft 17 to rotate, and drives the The dial block 15 rotates, driving the rotation of the leaf spring 7, and the other end of the leaf spring presses the cushion block 6, and the variable grasping force knuckle 2 rotates around the axis of the joint gear shaft 17 until the variable grasping force knuckle 2 contacts Object, now the joint gear shaft 17, shift block 16, leaf spring 7 and variable grasping force phalanx 2 have turned through the same angle θ. At this time, the continued rotation of the motor 9 will drive the joint gear shaft 17 and the shifting block 15 to continue to rotate through the angle α. The one end of the flat spring 7 and the shifting block 15 is also rotated through the angle α, and the other end of the flat spring 7 and the knuckle 2 with variable grasping force cannot rotate because of the blocking constraint of the object 36, so the flat spring 7 is bent and deformed. , to generate a rebound force, which is applied to the object through the pad 6 and the variable grasping force knuckle skeleton 5, thereby generating the pressing force F exerted by the variable grasping force knuckle 2 on the object 36. As the motor 9 rotates, the bending deformation angle α of the leaf spring 7 increases, and the pressing force F increases accordingly. By controlling the rotation of the motor 9, the grasping force can be controlled. When the motor 9 stopped rotating, the rebound force produced by the bending deformation of the leaf spring 7 not only produced the variable grasping force knuckle 2 to apply the grasping force F to the object, but also had a tendency to reversely rotate the knuckle gear shaft 17. Because the deceleration ratio of the speed reducer 19 is relatively large (several hundreds to one), and the motor 9 has a certain moment of inertia, which is amplified many times in the reduction transmission with a large reduction ratio, so it is impossible for the leaf spring 7 to realize the toggle joint Gear shaft 17 counter-rotates, so the bending deformation of leaf spring 7 is kept, and the compressing force F of variable grasping force phalanx 2 to object 36 has just been kept. Owing to the existence of this pressing force F and the frictional force f generated by it, the robot anthropomorphic hand can now pick up the object.

When the object is released, the output shaft of the motor 9 reverses, drives the output shaft of the reducer 19 to reverse, drives the pinion gear 18 to reverse, drives the joint gear shaft 17 to reverse, and drives the shift block 15 to reverse, so that the bending deformation of the leaf spring 7 Decrease gradually, and the pressing force F exerted by variable grasping force knuckles 2 on the object 36 also gradually decreases. When the shifting block 15 reverses the angle α, the leaf spring 7 returns to the initial small bending deformation state. The time-varying grasping force The pressing force F of the knuckle 2 on the object 36 has been reduced to zero. The motor 9 continues to rotate, drives the shifting block 15 to rotate, stirs and changes the grasping force phalanx 2 by leaf spring 7 and reverses and leaves object 36 surfaces.

Utilize the torsion spring 13 connected between the joint gear shaft 17 and the basic knuckle frame 5 to eliminate the backlash of the gear transmission. Through the encoder 10, the rotation speed of the motor 9 can be detected, so that the closed-loop control of the rotation speed of the finger 2 with variable grasping force can be realized. Through the potentiometer 12, the rotational angular positions of the joint gear shaft 17 and the shifting block 15 can be detected, and the position closed-loop control of the rotational angles of the joint gear shaft 17 and the shifting block 15 can be realized.

The structure of this embodiment for the robot anthropomorphic hand is shown in Figures 4 and 5.

The robot anthropomorphic hand applying the two structures of the present embodiment includes a palm 21, a first knuckle 22 of the index finger, a second knuckle 23 of the index finger, a first knuckle 24 of the thumb, a second knuckle 25 of the thumb, a first knuckle 26 of the index finger, The second joint 27 of the index finger, the first joint 28 of the thumb, the second joint 29 of the thumb, and the connecting plate 30 of the wrist.

Among them, the structure of the present embodiment is applied to the palm 21, the first joint 26 of the index finger and the first knuckle 22 of the index finger, wherein the palm 21 is used as the basic knuckle, the first joint 26 of the index finger is a joint with variable grasping force, and the first knuckle of the index finger Joint 22 is variable grasping force phalanx.

The first knuckle 22 of the index finger, the second knuckle 27 of the index finger and the second knuckle 23 of the index finger apply yet another structure of this embodiment, wherein the first knuckle 22 of the index finger is used as the basic knuckle, and the second knuckle 27 of the index finger is used as the variable grab The force joint 23 is used as variable grasping force phalanx.

The principle of grabbing an object by the robot anthropomorphic hand applying the two structures of this embodiment is shown in FIG. 6 . Rotate the first knuckle 22 of the index finger and the second knuckle 23 of the index finger to cooperate with the first knuckle 24 of the thumb and the second knuckle 25 of the thumb to realize grabbing the object 31 .

Claims (6)

1, a kind of mechanical finger with variable grasp force simulating human hand for robot device is characterized in that: comprise basic dactylus, changeable grasping force joint, changeable grasping force dactylus; Said basic dactylus and changeable grasping force dactylus are hollow structure, and said changeable grasping force joint is sheathed between basic dactylus and the changeable grasping force dactylus; Said changeable grasping force joint comprises motor, decelerator, transmission mechanism, joint shaft, sliding bearing, shifting block, leaf spring; Its annexation is: said joint shaft is sheathed between basic dactylus and the changeable grasping force dactylus, and the output shaft of motor links to each other with decelerator, is arranged in the basic dactylus, and is parallel to joint shaft; Said reducer output shaft links to each other with transmission mechanism, and transmission mechanism links to each other with joint shaft; Said shifting block is fixed on the joint shaft; Said leaf spring one end and shifting block are affixed, and the other end inserts in the changeable grasping force dactylus; Said transmission mechanism adopts a kind of of gear drive or tendon network transmission mechanism.

2, mechanical finger with variable grasp force simulating human hand for robot device as claimed in claim 1 is characterized in that: said changeable grasping force joint comprises torsion spring, and its two ends link to each other with basic dactylus with joint shaft respectively.

3, the described mechanical finger with variable grasp force simulating human hand for robot device of claim 1, it is characterized in that: the end at said joint shaft is equipped with potentiometer.

4, mechanical finger with variable grasp force simulating human hand for robot device as claimed in claim 1, it is characterized in that: the afterbody at motor is equipped with encoder.

5, mechanical finger with variable grasp force simulating human hand for robot device as claimed in claim 1 is characterized in that: said basic dactylus comprises basic dactylus skeleton, shaft bearing plate, gear cap, and the three is fixed together.

6, mechanical finger with variable grasp force simulating human hand for robot device as claimed in claim 1 is characterized in that: said changeable grasping force dactylus comprises changeable grasping force dactylus skeleton, cushion block, and the two is fixed together.

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