Robot hand joint based on piezoelectric driving

Abstract

The robot hand joint based on piezoelectric driving comprises a hand shell, the lower end of the hand shell is connected with a piezoelectric rotating motor, a plurality of finger joint units are arranged on the hand shell, and piezoelectric linear motors are arranged in the finger joint units; a first piezoelectric ceramic, a first stator and a rotor are arranged in the piezoelectric rotating motor; the piezoelectric rotating motor excites the first stator to vibrate through the first piezoelectric ceramic, and the rotor is driven to rotate through contact friction between the first stator and the rotor so as to drive the robot hand to rotate. A second piezoelectric ceramic and a linear motion mechanism are arranged in the piezoelectric linear motor; the piezoelectric linear motor excites the coupled bending vibration mode through the second piezoelectric ceramic to generate friction force, and the friction force drives the linear motion mechanism to do linear motion so as to drive the finger joint units to complete corresponding actions. According to the invention, high-precision and quick-response hand action control can be provided while a compact structure is realized.

Description

Technical Field

[0001] The invention relates to a robot hand joint based on piezoelectric drive, belonging to the technical field of robot hand joints. Background Art

[0002] Most existing robot hand joint drive parts use electromagnetic drive or hydraulic drive, which have certain limitations in terms of complexity, response speed, positioning accuracy and weight. In particular, traditional drive methods are difficult to meet the needs of humanoid robots in terms of delicate movements and high-precision control of hand joints. Summary of the invention

[0003] The object of the present invention is to provide a robot hand joint based on piezoelectric drive, which can provide high-precision and fast-response hand motion control while achieving a compact structure.

[0004] The technical solution of the present invention is as follows: a robot hand joint based on piezoelectric drive, comprising a hand shell, a piezoelectric rotary motor is connected to the lower end of the hand shell, a plurality of finger joint units are arranged on the hand shell, and a piezoelectric linear motor is arranged in the finger joint unit; the piezoelectric rotary motor has a first piezoelectric ceramic, a first stator and a rotor built in; the piezoelectric rotary motor excites the first stator to vibrate through the first piezoelectric ceramic, and drives the rotor to rotate by utilizing the contact friction between the first stator and the rotor to drive the robot hand to rotate; the piezoelectric linear motor is provided with a second piezoelectric ceramic and a linear motion mechanism; the piezoelectric linear motor excites the coupled bending vibration mode through the second piezoelectric ceramic to generate friction force, and drives the linear motion mechanism to perform linear motion by the friction force to drive the finger joint unit to complete the corresponding action.

[0005] The above-mentioned piezoelectric-driven robot hand joint, the piezoelectric rotary motor includes a lower end cover, a first circular groove is provided on the lower end cover, and the rotor is arranged in the first circular groove; a rotating column is provided at the center of the rotor; the first stator is provided on the upper side of the rotor; a connecting ring is provided at the center of the first stator; the first piezoelectric ceramic is provided on the upper side of the first stator and fits therewith; the first piezoelectric ceramic has a second circular groove in the center; an upper end cover is provided on the upper side of the first piezoelectric ceramic, and the upper end cover is connected to the lower end cover; the upper end cover has a third circular groove; the rotating column passes through the connecting ring, the second circular groove, and the third circular groove in sequence and is fixedly connected to the hand housing.

[0006] The aforementioned piezoelectrically driven robot hand joint has a plurality of threaded holes on the lower end cover; a plurality of connecting ears on the side of the first stator; a plurality of connecting holes on the upper end cover, screws are arranged in the connecting holes, and the screws pass through the connecting ears and cooperate with the threaded holes.

[0007] The aforementioned piezoelectrically driven robot hand joint has a groove on the upper portion of the upper end cover, the groove being located on the upper portion of the third circular groove; a bearing is provided in the groove.

[0008] The aforementioned piezoelectric-driven robot hand joint, the finger joint unit includes a connecting piece for connecting and fixing to a hand housing, the connecting piece has a notch, a piezoelectric linear motor is arranged in the notch; the connecting piece is provided with a piezoelectric motor fixing block located on the side of the piezoelectric linear motor, the piezoelectric motor fixing block is fixedly connected to the piezoelectric linear motor; the outer end of the linear motion mechanism is connected to a screw, the end of the screw is connected to a slider; a linear slide rod is arranged on both sides of the piezoelectric linear motor in the notch, the linear slide rod is slidably connected to the slider; a spring is provided on the linear slide rod, one end of the spring is fixedly connected to the slider, and the other end of the spring is fixedly connected to the front end surface of the notch.

[0009] The aforementioned piezoelectrically driven robot hand joint, the front ends of the connecting parts are respectively provided with L-shaped first joint auxiliary links, the outer side of the first joint auxiliary link is provided with a triangular second link, and the first joint auxiliary link is hinged to the middle part of the second link; the first links are hinged to the two sides of the slider, the other end of the first link is hinged to one end of the second link, and the first joint link is hinged between the other ends of the two second links; the second joint link is hinged to a Y-shaped second joint link at the bending between the first joint auxiliary links, and the other forked end of the second joint link is hinged to the first joint link; the second joint auxiliary link is hinged to the outer side of the first joint auxiliary link, and the other end of the second joint auxiliary link is hinged with an L-shaped third joint link; the long end of the second joint link is hinged to the bending of the third joint link; the front end of the third joint link is provided with a simulated finger.

[0010] In the aforementioned piezoelectric-driven robot hand joint, the piezoelectric linear motor is a hollow linear motor; the linear motion mechanism includes a second stator in a rectangular shape, the interior of the second stator is hollow and provided with threads, and the threads cooperate with the screw.

[0011] In the aforementioned piezoelectrically driven robot hand joint, the number of the second piezoelectric ceramics is 4, and the second piezoelectric ceramics are distributed around the second stator and fit closely.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] 1. In the present invention, the finger joint unit is controlled by the pressure point linear motor to simulate the varicose contraction of the human hand, and the bending of the human wrist is simulated by the piezoelectric rotary motor; compared with the traditional motor, the piezoelectric linear motor can have better size adaptability and can be manufactured in multiple size ranges to meet the market demand for the integration of robot hand joints in a full range of sizes; and the actual motion trajectory of the finger joint can be achieved through a single driving source, which is conducive to the further miniaturization of the robot hand and is easier to meet the actual needs of the robot hand. As a result, the present invention realizes the realization of a compact structure while providing high-precision and fast-response hand motion control, and has the advantages of simple structure and significant effect.

[0014] 2. In the present invention, the piezoelectric rotary motor has a compact structure. The first piezoelectric ceramic is used to excite the first stator to vibrate. The rotating column of the rotor passes through the connecting ring, the second circular groove, and the third circular groove in sequence and is connected to the hand shell. The contact friction between the first stator and the rotor is used to drive the rotating column to rotate, thereby realizing the steering of the hand shell and improving the output torque of the first stator.

[0015] 3. In the present invention, the extension and contraction of the screw is controlled by a piezoelectric linear motor, so that the slider at the end of the screw moves along the linear slide rod, and the slider drives the first connecting rod to move while moving, and the first connecting rod makes the second connecting rod rotate around the connecting piece, and the other end of the second connecting rod makes the first joint connecting rod move, and the first joint connecting rod makes the second joint connecting rod rotate around the first joint auxiliary connecting rod, and the other end of the second joint connecting rod rotates the third joint connecting rod under the cooperation of the second joint auxiliary connecting rod, so as to simulate the varicose contraction of the human hand. Therefore, the present invention can realize the simulation of the varicose contraction of the human hand by the finger joint unit through a single driving source based on a piezoelectric linear motor, which is conducive to the further miniaturization of the robot hand and more easily meets the actual needs of the robot hand. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of the present invention;

[0017] Figure 2 is a cross-sectional view of a piezoelectric rotary motor;

[0018] Figure 3 is an exploded schematic diagram of a piezoelectric rotary motor;

[0019] Figure 4 It is a structural schematic diagram of the finger joint unit;

[0020] Figure 5 It is a structural schematic diagram of the finger joint unit;

[0021] Figure 6 is a schematic diagram of the structure of a piezoelectric linear motor;

[0022] Figure 7 This is the wiring diagram of the piezoelectric linear motor.

[0023] The markings in the accompanying drawings are: 1-hand housing, 2-piezoelectric rotary motor, 3-finger joint unit, 201-connecting piece, 202-piezoelectric linear motor, 203-piezoelectric motor fixing block, 204-screw, 205-linear slide rod, 206-slider, 207-spring, 208-first connecting rod, 209-second connecting rod, 210-first joint auxiliary connecting rod, 211-first joint connecting rod, 212-second joint auxiliary connecting rod, 213-second joint connecting rod, 214-third joint connecting rod, 215-slot, 216-simulated finger, 231-second piezoelectric ceramic, 232-linear motion mechanism, 233-second stator, 234-thread, 301-lower end cover, 302-first circular groove, 303-rotor, 304-rotating column, 305-first stator, 306-connecting ring, 307-first piezoelectric ceramic, 308-second circular groove, 309-upper end cover, 310-third circular groove, 311-groove, 312-bearing, 313-threaded hole, 314-connecting ear, 315-connecting hole, 316-screw. DETAILED DESCRIPTION

[0024] The present invention is further described below in conjunction with the accompanying drawings and embodiments, but they are not intended to limit the present invention.

[0025] Embodiment: A piezoelectric driven robot hand joint, comprising: Figure 1-6 As shown, it includes a hand shell 1, and the lower end of the hand shell 1 is connected to a piezoelectric rotary motor 2; the hand shell 1 is provided with five finger joint units 3, four of which are arranged on the upper end surface of the hand shell 1 and the bending direction is downward, and the remaining one is arranged on the side of the hand shell 1 and the bending direction is upward, so as to better simulate the human hand; the finger joint unit 3 is provided with a piezoelectric linear motor 202; the piezoelectric rotary motor 2 is built with a first piezoelectric ceramic 307, a first stator 305 and a rotor 303; the piezoelectric rotary motor 2 is connected to ... The first stator 305 is excited to vibrate through the first piezoelectric ceramic 307, and the contact friction between the first stator 305 and the rotor 303 is used to drive the rotor 303 to rotate so as to drive the robot hand to rotate; the piezoelectric linear motor 202 is provided with a second piezoelectric ceramic 231 and a linear motion mechanism 232; the piezoelectric linear motor 202 excites the coupled bending vibration mode through the second piezoelectric ceramic 231 to generate friction force, and drives the linear motion mechanism 232 to perform linear motion through the friction force to drive the finger joint unit 3 to complete the corresponding action.

[0026] Preferably, if Figure 2 and 3As shown, the piezoelectric rotary motor 2 includes a lower end cover 301, a first circular groove 302 is provided on the lower end cover 301, and a rotor 303 is arranged in the first circular groove 302; a rotating column 304 is provided at the center of the rotor 303; the first stator 305 is arranged on the upper side of the rotor 303; a connecting ring 306 is provided at the center of the first stator 305, and the connecting ring 306 and the first stator 305 are connected via four spokes; the first piezoelectric ceramic 307 is arranged on the upper side of the first stator 305 and bonded thereto through epoxy resin; a second circular groove 308 is provided at the center of the first piezoelectric ceramic 307; an upper end cover 309 is provided on the upper side of the first piezoelectric ceramic 307, and the upper end cover 309 is connected to the lower end cover 301; a third circular groove 310 is provided on the upper end cover 309; the rotating column 304 passes through the connecting ring 306, the second circular groove 308, and the third circular groove 310 in sequence and is fixedly connected to the hand shell 1. By applying a single-phase excitation signal to the first piezoelectric ceramic 307 , the radial mode of the first stator 305 is excited, and the radial mode of the first stator 305 is converted into the torsional mode of the connecting ring 306 through the spoke connection, thereby generating the rotational motion of the rotor 303 .

[0027] Preferably, if Figure 2 and 3 As shown, the lower end cover 301 is provided with four threaded holes 313; the first stator 305 is provided with four connecting ears 314 on the side; the upper end cover 309 is provided with four connecting holes 315, and screws 316 are provided in the connecting holes 315. The screws 316 are inserted into the connecting holes 315, and the threaded part of the screws 316 passes through the connecting ears 314 and matches with the threaded holes 313, so that the upper end cover 309 is fixedly connected to the lower end cover 301.

[0028] Preferably, if Figure 4 and 5As shown, the finger joint unit 3 includes a connecting piece 201 for connecting and fixing with the hand housing 1, the connecting piece 201 has a notch 215, and the piezoelectric linear motor 202 is arranged in the notch 215; the connecting piece 201 is provided with a piezoelectric motor fixing block 203 located on the side of the piezoelectric linear motor 202, and the piezoelectric motor fixing block 203 is fixedly connected to the piezoelectric linear motor 202; the outer end of the linear motion mechanism 232 is connected to a screw rod 204, and the end of the screw rod 204 is connected to a slider 206; the notch 215 is provided with a linear slide rod 205 located on both sides of the piezoelectric linear motor 202, and the linear slide rod 205 is slidably connected to the slider 206; the linear slide rod 205 is provided with a spring 207, one end of the spring 207 is fixedly connected to the slider 206, and the other end of the spring 207 is fixedly connected to the front end surface of the notch 215. The front end of the connecting member 201 is provided with an L-shaped first joint auxiliary link 210 on both sides, and a triangular second link 209 is provided on the outside of the first joint auxiliary link 210, and the first joint auxiliary link 210 is hinged to the middle of the second link 209; the slider 206 is hinged with a first link 208 on both sides, the other end of the first link 208 is hinged to one end of the second link 209, and the other ends of the two second links 209 are hinged with a first joint link 211; the first joint auxiliary link 2 10 is hinged with a Y-shaped second joint link 213 at the bending point between the two ends, and the other forked end of the second joint link 213 is hinged with the first joint link 211; the outer side of the first joint auxiliary link 210 is hinged with a second joint auxiliary link 212, and the other end of the second joint auxiliary link 212 is hinged with an L-shaped third joint link 214; the long end of the second joint link 213 is hinged with the bending point of the third joint link 214; the front end of the third joint link 214 is provided with a simulated finger 216. The extension and retraction of the screw 204 is controlled by a piezoelectric linear motor, so that the slider 206 at the end of the screw 204 moves along the linear slider 205, and the slider 206 drives the first connecting rod 208 to move while moving. The first connecting rod 208 causes the second connecting rod 209 to rotate around the connecting piece 201, and the other end of the second connecting rod 209 causes the first joint connecting rod 211 to move, and the first joint connecting rod 211 causes the second joint connecting rod 213 to rotate around the first joint auxiliary connecting rod 210, and the other end of the second joint connecting rod 213, with the cooperation of the second joint auxiliary connecting rod 212, causes the third joint connecting rod 214 to rotate, thereby realizing the simulation of varicose vein of the human hand.

[0029] Preferably, if Figure 6As shown, the piezoelectric linear motor 202 is a hollow linear motor; the linear motion mechanism 232 includes a second stator 233 in a rectangular shape, the interior of the second stator 233 is hollow and provided with a thread 234, and the thread 234 cooperates with the screw 204. Further, the number of the second piezoelectric ceramics 231 is 4, and the second piezoelectric ceramics 231 are distributed around the second stator 233 and bonded by epoxy resin. Figure 7 As shown, the second piezoelectric ceramics 231 on the upper and lower sides apply a signal E1, E1 = Vsin (ωt), and the second piezoelectric ceramics 231 on the left and right sides apply a signal E2, E2 = Vcos (ωt), which can excite the first-order bending modes of the x and y axes. The first-order bending modes on the x and y axes are theoretically modes of the same type and close in frequency. When E1 and E2 are applied at the same time, the superposition of the two working modes can cause the driving surface of the thread 234 in the second stator to produce an out-of-plane traveling wave motion, which drives the screw to rotate through friction, thereby realizing the linear motion of the screw 204. The forward and backward directions of the screw 204 can be determined by the phase difference between the two-phase signals E1 and E2, that is, a phase difference of π / 2 causes the screw 204 to move forward, and a phase difference of -π / 2 causes the screw 204 to move backward.

[0030] Working principle:

[0031] The finger joint unit 3 is controlled by a piezoelectric linear motor to simulate the flexion of a human hand, and the piezoelectric rotary motor 2 is used to simulate the bending of a human wrist; wherein the piezoelectric rotary motor 2 has a compact structure, and uses the first piezoelectric ceramic 307 to excite the first stator 305 to vibrate, and the rotating column 304 of the rotor 303 passes through the connecting ring 306, the second circular groove 308, and the third circular groove 310 in sequence and is connected to the hand housing 1, and the contact friction between the first stator 305 and the rotor 303 is used to drive the rotating column 304 to rotate, so as to realize the steering of the hand housing 1, and at the same time, the output torque of the first stator 305 can be increased. The piezoelectric linear motor 202 excites the coupled bending vibration mode through the second piezoelectric ceramic 231 to generate friction force, and the linear motion mechanism 232 drives the screw 204 to perform linear motion through the friction force to drive the finger joint unit 3 to complete the corresponding action.

Claims

1. A piezoelectrically driven robot hand joint, characterized in that: The invention comprises a hand housing (1), the lower end of which is connected to a piezoelectric rotary motor (2), the hand housing (1) being provided with a plurality of finger joint units (3), the finger joint units (3) being provided with a piezoelectric linear motor (202); the piezoelectric rotary motor (2) being provided with a first piezoelectric ceramic (307), a first stator (305) and a rotor (303); the piezoelectric rotary motor (2) excites the first stator (305) to vibrate through the first piezoelectric ceramic (307), and utilizes the first stator (305) to vibrate. The contact friction between the piezoelectric linear motor (202) and the rotor (305) drives the rotor (303) to rotate so as to drive the robot hand to rotate; a plurality of second piezoelectric ceramics (231) and a linear motion mechanism (232) are provided in the piezoelectric linear motor (202); the piezoelectric linear motor (202) excites coupled bending vibration modes through the second piezoelectric ceramics (231) to generate friction force, and drives the linear motion mechanism (232) to perform linear motion through the friction force to drive the finger joint unit (3) to complete the corresponding action.

2. The piezoelectric driven robot hand joint according to claim 1, characterized in that: The piezoelectric rotary motor (2) comprises a lower end cover (301), the lower end cover (301) is provided with a first circular groove (302), the rotor (303) is arranged in the first circular groove (302); a rotating column (304) is arranged at the center of the rotor (303); the first stator (305) is arranged on the upper side of the rotor (303); a connecting ring (306) is arranged at the center of the first stator (305); the first piezoelectric ceramic (307) is arranged at the first stator (305) ) and fits with the upper side of the hand housing (1); the center of the first piezoelectric ceramic (307) has a second circular groove (308); the upper side of the first piezoelectric ceramic is provided with an upper end cover (309), and the upper end cover (309) is connected to the lower end cover (301); the upper end cover (309) has a third circular groove (310); the rotating column (304) passes through the connecting ring (306), the second circular groove (308), and the third circular groove (310) in sequence and is fixedly connected to the hand housing (1).

3. The piezoelectric driven robot hand joint according to claim 2, characterized in that: The lower end cover (301) is provided with a plurality of threaded holes (313); the first stator (305) is provided with a plurality of connecting ears (314) on its side; the upper end cover (309) is provided with a plurality of connecting holes (315), each of the connecting holes (315) being provided with a screw (316), the screw (316) passing through the connecting ears (314) and matching with the threaded holes (313).

4. The piezoelectric driven robot hand joint according to claim 2, characterized in that: The upper end cover (309) is provided with a groove (311) at the upper part, and the groove (311) is located at the upper part of the third circular groove (310); a bearing (312) is provided in the groove (311).

5. The piezoelectric driven robot hand joint according to claim 1, characterized in that: The finger joint unit (3) comprises a connecting piece (201) for being connected and fixed to a hand housing (1); the connecting piece (201) has a notch (215), and the piezoelectric linear motor (202) is arranged in the notch (215); the connecting piece (201) is provided with a piezoelectric motor fixing block (203) located on the side of the piezoelectric linear motor (202), and the piezoelectric motor fixing block (203) is fixedly connected to the piezoelectric linear motor (202); the linear motion mechanism (232) The outer end is connected to a screw rod (204), and the end of the screw rod (204) is connected to a slider (206); a linear slider (205) is arranged in the notch (215) and is located on both sides of the piezoelectric linear motor (202), and the linear slider (205) is slidably connected to the slider (206); a spring (207) is arranged on the linear slider (205), one end of the spring (207) is fixedly connected to the slider (206), and the other end of the spring (207) is fixedly connected to the front end surface of the notch (215).

6. The piezoelectric driven robot hand joint according to claim 5, characterized in that: The front end of the connecting member (201) is provided with an L-shaped first joint auxiliary connecting rod (210) on both sides, and a triangular second connecting rod (209) is provided on the outer side of the first joint auxiliary connecting rod (210), and the first joint auxiliary connecting rod (210) is hinged to the middle part of the second connecting rod (209); the first connecting rod (208) is hinged to both sides of the slider (206), the other end of the first connecting rod (208) is hinged to one end of the second connecting rod (209), and the other ends of the two second connecting rods (209) are hinged to the first joint connecting rod (211); the first joint auxiliary connecting rod ( A Y-shaped second joint connecting rod (213) is hinged at the bending point between the first joint auxiliary connecting rod (210), and the other bifurcated end of the second joint connecting rod (213) is hinged to the first joint connecting rod (211); a second joint auxiliary connecting rod (212) is hinged to the outer side of the first joint auxiliary connecting rod (210), and an L-shaped third joint connecting rod (214) is hinged between the other ends of the second joint auxiliary connecting rod (212); the long end of the second joint connecting rod (213) is hinged to the bending point of the third joint connecting rod (214); and a simulated finger (216) is provided at the front end of the third joint connecting rod (214).

7. The piezoelectric driven robot hand joint according to claim 5, characterized in that: The linear motion mechanism (232) comprises a second stator (233) in a rectangular shape. The interior of the second stator (233) is hollow and provided with a thread (234). The thread (234) matches the screw rod (204).

8. The piezoelectric driven robot hand joint according to claim 7, characterized in that: The number of the second piezoelectric ceramics (231) is four, and the second piezoelectric ceramics (231) are distributed around the second stator (233) and are in close contact with each other.

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