Five-degree-of-freedom piezoelectric robot based on inertial stepping principle

Abstract

The application discloses a five-degree-of-freedom piezoelectric robot driven based on an inertial stepping principle, relates to the technical field of robots, and comprises an upper driving system, a lower driving system, a spherical hinge system, an upper output end, a connecting rod and a driving foot. The spherical hinge system comprises a spherical hinge lower end cover, a joint ball, a joint seat, a spherical hinge friction pair, a pre-tightening bolt and a spherical hinge upper end cover. The upper driving system comprises a plurality of piezoelectric driving units, an upper connecting ring and an upper inertia ring. The lower driving system comprises a plurality of piezoelectric driving units, a lower inertia ring, a lower connecting ring and a lower output end. By applying different sawtooth wave voltage excitation signals to the piezoelectric driving units, the piezoelectric driving units can output bending deformation in different directions, the driving foot and the upper output end are moved under the action of inertial force, and finally, linear motion displacement output of the upper output end in the x-axis direction and the y-axis direction and rotation motion displacement output of the upper output end around the x-axis, the y-axis and the z-axis are realized. The application has wide application potential in the fields of aerospace, optical equipment and the like.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of robots, and particularly relates to a five-degree-of-freedom piezoelectric robot driven based on an inertial stepping principle. BACKGROUND

[0002] Micro robots are a research hotspot in the field of robots at present and have wide application prospects in medical treatment, industrial detection and environmental monitoring. However, the existing robots still have obvious limitations in motion performance. A traditional motor driving scheme is complex in structure and large in size, and is difficult to meet the miniaturization requirement. Piezoelectric driving technology based on the inverse piezoelectric effect is one of ideal driving schemes for realizing micro robots because of its compact structure, fast response, high precision and no electromagnetic interference. At present, part of piezoelectric driving robots can only realize single direction motion, and the flexibility is insufficient, which is difficult to adapt to complex plane environments. Even some piezoelectric robots with multiple degrees of freedom often face problems such as complex driving structure, great control difficulty and high cost, which restricts the actual application. SUMMARY

[0003] The application proposes a five-degree-of-freedom piezoelectric robot driven based on an inertial stepping principle to solve the problems of low motion degree of freedom, complex structure and difficult control of the existing robots.

[0004] The five-degree-of-freedom piezoelectric robot driven based on the inertial stepping principle comprises an upper driving system, a lower driving system, a spherical hinge system, an upper output end, a connecting rod and a driving foot.

[0005] The spherical hinge system comprises a spherical hinge lower end cover, a joint ball, a joint seat, a spherical hinge friction pair and a spherical hinge upper end cover.

[0006] The spherical hinge upper end cover and the spherical hinge lower end cover are fixedly connected to the upper and lower sides of the joint seat, the spherical hinge friction pair is connected to the inside of the joint seat, and the lower surface of the spherical hinge friction pair is in contact with the surface of the joint ball.

[0007] The upper driving system comprises a piezoelectric driving unit A, a piezoelectric driving unit B, a piezoelectric driving unit C, a piezoelectric driving unit D, an upper connecting ring and an upper inertia ring.

[0008] The upper connecting ring is arranged in the inside of the upper inertia ring, the left and right sides of the upper connecting ring are fixedly connected to the upper inertia ring through the piezoelectric driving unit C and the piezoelectric driving unit A, and the front and rear sides of the upper connecting ring are fixedly connected to the joint seat through the piezoelectric driving unit D and the piezoelectric driving unit B.

[0009] The lower driving system comprises a piezoelectric driving unit E, a piezoelectric driving unit F, a piezoelectric driving unit G, a piezoelectric driving unit H, a lower inertia ring, a lower connecting ring and a lower output end.

[0010] The lower connecting ring is arranged inside the lower inertia ring, and the left and right sides of the lower connecting ring are fixedly connected with the lower inertia ring through the piezoelectric driving units F and H, and the front and rear sides of the lower connecting ring are fixedly connected with the lower output end through the piezoelectric driving units G and E, and the lower output end is provided with a threaded hole;

[0011] The upper output end is fixedly connected with the upper end cover of the spherical hinge;

[0012] The upper end of the connecting rod is coaxially fixedly connected with the joint ball, and the lower end of the connecting rod is connected with the threaded hole on the lower output end.

[0013] The upper end of the driving foot is connected in the threaded hole of the lower output end.

[0014] Preferably, by applying different sawtooth wave voltage excitation signals to the piezoelectric driving units, the piezoelectric driving units can output bending deformation in different directions, and under the action of inertial force, the driving foot and the upper output end are moved, and finally the linear motion displacement output of the upper output end in the x-axis direction and the y-axis direction and the rotary motion displacement output around the x-axis, the y-axis and the z-axis are realized.

[0015] Preferably, the spherical hinge friction pair is vertically slidably connected inside the joint seat, the pre-tightening bolt is threadedly connected in the upper end cover of the spherical hinge, and the lower end of the pre-tightening bolt is in abutting connection with the spherical hinge friction pair, and the pre-tightening bolt can adjust the friction force between the spherical hinge friction pair and the joint ball.

[0016] Preferably, the upper driving system and the lower driving system adopt an axisymmetric arrangement mode respectively.

[0017] Preferably, the piezoelectric driving units in the upper driving system and the lower driving system adopt a perpendicular arrangement mode.

[0018] Preferably, each piezoelectric driving unit is composed of a driving hinge and two piezoelectric chips, and the two piezoelectric chips are symmetrically bonded on the two sides of the driving hinge.

[0019] Preferably, the driving hinge, the lower inertia ring, the lower connecting ring and the lower output end in the lower driving system are integrally processed from a whole piece of elastic metal material; and the driving hinge, the upper connecting ring, the upper inertia ring and the joint seat in the upper driving system are integrally processed from a whole piece of elastic metal material.

[0020] Preferably, the spherical hinge system further comprises a spring pad, a flat pad and a circular ring flat pad, and the spring pad, the circular ring flat pad and the flat pad are sequentially arranged between the spherical hinge friction pair and the pre-tightening bolt from bottom to top.

[0021] Preferably, the threaded hole, the lower inertia ring, the joint ball and the upper inertia ring are coaxially arranged.

[0022] Compared with the prior art, the present application has the following beneficial results:

[0023] The application utilizes eight piezoelectric driving units to bend and deform under sawtooth voltage excitation, and then drives the upper and lower inertia rings to move, and under the action of inertia force, the movement of the lower inertia ring is converted into the friction sliding of the driving foot with the ground and the displacement output of the upper output end, and the movement of the upper inertia ring is converted into the displacement output of the upper output end, and by applying different voltage excitation signals to the piezoelectric driving units, the piezoelectric driving units can output bending deformation in different directions, and then realize the linear motion of the upper output end along the x-axis direction and the y-axis direction and the rotary motion around the x, y and z axes, a total of five degrees of freedom displacement output.

[0024] The application has high structural integration, the driving hinge, the lower connecting ring, the lower inertia ring and the lower output end in the lower driving system can be integrally machined by CNC and wire cutting, the driving hinge, the upper connecting ring, the upper inertia ring and the joint seat in the upper driving system can be integrally machined by CNC and wire cutting, and the structure is simple and the control is flexible, the output end can realize opposite direction linear motion or rotary motion by controlling the sawtooth voltage signals of the eight piezoelectric driving units, and flexible conversion of each degree of freedom can be realized, and then five degrees of freedom displacement output is realized.

[0025] The application has small structure volume, fast response, is not affected by electromagnetic interference and has flexible motion, and has wide application potential in the technical fields of aerospace, optical equipment, integrated circuits, microelectromechanical systems and the like, and provides certain reference for the design of five degrees of freedom robots. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is a perspective structural schematic view of the application;

[0027] Figure 2 It is a front view of the application;

[0028] Figure 3 It is a perspective structural schematic view of the upper driving system;

[0029] Figure 4 It is a sectional view of the upper driving system;

[0030] Figure 5 It is a top view of the lower driving system;

[0031] Figure 6 It is an excitation voltage signal waveform diagram of the application;

[0032] Figure 7 It is a deformation process schematic view of the piezoelectric driving unit under different excitation signals; wherein (a) is upward and downward bending, and (b) is left and right bending;

[0033] Figure 8 It is a driving principle diagram of the linear displacement output of the upper output end along the x-axis direction; wherein (a) is a top view of the lower driving system, and (b) is a front view of the robot;

[0034] Figure 9 Figure 2 is a driving principle diagram of the upper output end linear displacement output along the y-axis direction; wherein (a) is a right view of the robot, (b) is a top view of the lower driving system;

[0035] Figure 10 Figure 3 is a driving principle diagram of the upper output end angular displacement output around the z-axis direction; wherein (a) is a top view of the lower driving system, (b) is a top view of the robot;

[0036] Figure 11 Figure 4 is a left view driving principle diagram of the upper output end angular displacement output around the x-axis direction;

[0037] Figure 12 Figure 5 is a rear view driving principle diagram of the upper output end angular displacement output around the y-axis direction.

[0038] In the figure, the various reference signs are as follows:

[0039] 1: upper driving system; 2: lower driving system; 3: spherical hinge system; 4: upper output end; 5: connecting rod; 6: driving foot; 11: piezoelectric driving unit A; 12: piezoelectric driving unit B; 13: piezoelectric driving unit C; 14: piezoelectric driving unit D; 15: upper connecting ring; 16: upper inertia ring; 21: piezoelectric driving unit E; 22: piezoelectric driving unit F; 23: piezoelectric driving unit G; 24: piezoelectric driving unit H; 25: lower inertia ring; 26: lower connecting ring; 27: lower output end; 31: spherical hinge lower end cover; 32: joint ball; 33: joint seat; 34: spherical hinge friction pair; 35: elastic pad; 36: flat pad; 37: fixing bolt; 38: pre-tightening bolt; 39: spherical hinge upper end cover; 310: circular ring flat pad. DETAILED DESCRIPTION

[0040] Example 1: Reference Figures 1 to 5 A five-degree-of-freedom piezoelectric robot driven based on the inertia stepping principle, comprising an upper driving system 1, a lower driving system 2, a spherical hinge system 3, an upper output end 4, a connecting rod 5, and a driving foot 6;

[0041] The spherical hinge system 3 comprises a spherical hinge lower end cover 31, a joint ball 32, a joint seat 33, a spherical hinge friction pair 34, an elastic pad 35, a flat pad 36, a pre-tightening bolt 38, a spherical hinge upper end cover 39, and a circular ring flat pad 310;

[0042] The upper end cap 39 and the lower end cap 31 of the ball joint are fixedly connected to the upper and lower sides of the joint seat 33 by connecting bolts (not shown in the figure). The lower end cap 31 is used to limit the joint ball 32. The ball joint friction pair 34 is vertically slidably connected inside the joint seat 33, and the lower surface of the ball joint friction pair 34 contacts the surface of the joint ball 32 to generate friction. A spring washer 35, a circular flat washer 310, and a flat washer 36 are installed on the ball joint friction pair 34 in sequence. The preload bolt 38 is threadedly connected inside the upper end cap 39 of the ball joint, and the lower end of the preload bolt 38 abuts against the flat washer 36. The preload bolt 38 can adjust the friction between the ball joint friction pair 34 and the joint ball 32.

[0043] The upper drive system includes piezoelectric drive unit A11, piezoelectric drive unit B12, piezoelectric drive unit C13, piezoelectric drive unit D14, upper connecting ring 15, and upper inertial ring 16;

[0044] The upper connecting ring 15 is located inside the upper inertia ring 16, and the upper connecting ring 15 is located on the left and right sides ( Figure 3 In the middle, the positive x-axis direction is the left side) is fixed to the upper inertial ring 16 through piezoelectric drive unit C13 and piezoelectric drive unit A11, and the front and rear sides of the upper connecting ring 15 (the positive y-axis direction is the front side) are fixed to the joint seat 33 through piezoelectric drive unit D14 and piezoelectric drive unit B12.

[0045] The lower drive system includes piezoelectric drive unit E21, piezoelectric drive unit F22, piezoelectric drive unit G23, piezoelectric drive unit H24, lower inertia loop 25, lower connecting loop 26, and lower output terminal 27;

[0046] The lower connecting ring 26 is located inside the lower inertia ring 25, and the left and right sides of the lower connecting ring 26 ( Figure 5 In the middle, the positive x-axis direction is the left side) is fixed to the lower inertia ring 25 through piezoelectric drive unit F22 and piezoelectric drive unit H24. The front and rear sides of the lower connecting ring 26 (the positive y-axis direction is the front side) are fixed to the lower output end 27 through piezoelectric drive unit G23 and piezoelectric drive unit E21. The lower output end 27 is provided with a screw hole. The screw hole, lower inertia ring 25, articulated ball 32, and upper inertia ring 16 are coaxially arranged.

[0047] The upper output end 4 is fixedly connected to the upper end cover 39 of the ball joint by fixing bolt 37;

[0048] The upper end of the connecting rod 5 is coaxially fixed to the joint ball 32, and the lower end of the connecting rod 5 is connected to the screw hole on the lower output end 27.

[0049] The upper end of the drive foot 6 is threaded into the screw hole of the lower output end 27;

[0050] By applying different sawtooth wave voltage excitation signals to the piezoelectric driving units, the piezoelectric driving units can output bending deformation in different directions, and under the action of inertial force, the driving feet 6 and the upper output end 4 are moved, and finally the linear motion displacement output of the upper output end 4 along the x-axis direction and the y-axis direction and the rotary motion displacement output of the upper output end 4 around the x-axis, the y-axis and the z-axis are realized.

[0051] Further, the upper driving system 1 and the lower driving system 2 adopt axisymmetric arrangement modes respectively.

[0052] Further, the piezoelectric driving units in the upper driving system 1 and the lower driving system 2 adopt a perpendicular arrangement mode.

[0053] Further, each piezoelectric driving unit is composed of one driving hinge and two piezoelectric chips, and the two piezoelectric chips are symmetrically bonded on both sides of the driving hinge.

[0054] Further, the driving hinge, the lower inertia ring 25, the lower connecting ring 26 and the lower output end 27 in the lower driving system are integrally processed from one whole piece of elastic metal material; the driving hinge, the upper connecting ring 15, the upper inertia ring 16 and the joint seat 33 in the upper driving system are integrally processed from one whole piece of elastic metal material.

[0055] Further, the driving feet 6 realize the planar motion of the upper output end 4 by sliding friction with the ground.

[0056] Further, the joint ball 32 realizes the rotary motion of the upper output end 4 by rotating friction with the spherical hinge friction pair 34.

[0057] Working principle of the application:

[0058] Referring to Figures 1 to 12 , in the embodiment 1, each piezoelectric chip adopts the sawtooth wave voltage as shown in Figure 6 as an excitation signal, and taking one piezoelectric driving unit as an example, as shown in Figure 7 (a), the single driving hinge is fixed on the right side, only the left end can be moved, and the polarity of the piezoelectric chip is from bottom to top, that is, the bottom is negative and the top is positive, when the two piezoelectric chips are simultaneously applied with the waveform one voltage excitation signal as shown in Figure 6 , the lower piezoelectric chip is shortened, the upper piezoelectric chip is elongated, the driving hinge is bent downward, and the whole piezoelectric driving unit is bent downward, when the two piezoelectric chips are simultaneously applied with the waveform two voltage excitation signal as shown in Figure 6 , the lower piezoelectric chip is elongated, the upper piezoelectric chip is shortened, the driving hinge is bent upward, and the whole piezoelectric driving unit is bent upward; as shown in Figure 7 (b), the single driving hinge is fixed on the upper side, only the lower end can be moved, and the polarity of the piezoelectric chip is from right to left, that is, the right side is negative and the left side is positive, when the two piezoelectric chips are simultaneously applied with the waveform one voltage excitation signal as shown inFigure 6 When the waveform one voltage excitation signal shown in the figure is applied, the right piezoelectric wafer is shortened and the left piezoelectric wafer is elongated, so that the driving hinge is bent to the right and the whole piezoelectric driving unit is bent to the right. When the same voltage excitation signal is applied to the two piezoelectric wafers at the same time, Figure 6 When the waveform two voltage excitation signal shown in the figure is applied, the right piezoelectric wafer is elongated and the left piezoelectric wafer is shortened, so that the driving hinge is bent to the left and the whole piezoelectric driving unit is bent to the left.

[0059] The specific working process of the present application is as follows:

[0060] 1. As shown in the figure, the above output end 4 is taken as an object, and the process can generate a linear displacement output of the output end 4 along the positive direction of the x-axis; Figures 1 to 8 In stage (I), the eight piezoelectric driving units are in an unpowered state, and the upper output end 4 has no displacement output;

[0061] In stage (II), the piezoelectric driving unit E21 and the piezoelectric driving unit G23 are applied with the waveform two voltage excitation signal shown in the figure; when the voltage slowly decreases from 0 to -U, the piezoelectric driving unit E21 and the piezoelectric driving unit G23 are slowly deformed and bent to the left, driving the lower inertia ring 25 to move in the positive direction of the x-axis, at this time, the lower inertia ring 25 moves in the positive direction of the x-axis by a distance of Δ

[0062] 1; Figure 6 x In stage (III), when the voltage rapidly rises from -U to 0, the piezoelectric driving unit E21 and the piezoelectric driving unit G23 quickly recover to the non-bent deformation state, and under the action of the inertial force, the driving foot 6 slides and moves in the positive direction of the x-axis by a distance of Δ 1;

[0063] The lower inertia ring 25 moves in the negative direction of the x-axis by a distance of Δ x 2,where Δ x 1-Δ x 2, the final robot moves in the positive direction of the x-axis by a distance of Δ x 1+Δ x 2, that is, the linear displacement output of the upper output end 4 in the positive direction of the x-axis is Δ x 1+Δ x 2.

[0064] If the process is repeated continuously, the upper output end 4 can realize large-stroke step linear displacement output in the positive direction of the x-axis. By applying the waveform one voltage excitation signal in the figure to the piezoelectric driving unit E21 and the piezoelectric driving unit G23, the upper output end 4 can generate linear displacement output in the negative direction of the x-axis. Figure 6

[0065] 2. As shown in the figure, Figures 1 to 7 and Figure 9As shown, the above output end 4 is the object, the process of the above output end 4 can produce the linear displacement output along the positive direction of the y axis;

[0066] In stage (I), the eight piezoelectric drive units are in the unpowered state, and the output end 4 has no displacement output;

[0067] In stage (II), the piezoelectric drive unit F22 and the piezoelectric drive unit H24 are applied to the waveform two voltage excitation signal as shown Figure 6 When the voltage slowly decreases from 0 to -U, the piezoelectric drive unit F22 and the piezoelectric drive unit H24 are slowly curved and deformed upward, driving the lower inertia ring 25 to move in the positive direction of the y axis, at this time the lower inertia ring 25 moves in the positive direction of the y axis Δ y 1 distance;

[0068] In stage (III), when the voltage rapidly rises from -U to 0, the piezoelectric drive unit F22 and the piezoelectric drive unit H24 quickly recover to the non-bending deformation state, under the action of the inertial force, the driving foot 6 slides with the ground friction to move in the positive direction of the y axis Δ y distance, the lower inertia ring 25 moves in the negative direction of the y axis Δ y 2 distance, wherein Δ y = Δ y 1- Δ y 2, finally the robot moves in the positive direction of the y axis Δ y distance, that is, the linear displacement output of the output end 4 in the positive direction of the y axis is Δ y ;

[0069] If the process is repeated, the output end 4 can realize large-stroke step linear displacement output in the positive direction of the y axis, by applying the reverse voltage excitation signal to the piezoelectric drive unit F22 and the piezoelectric drive unit H24, that is Figure 6 the waveform one voltage excitation signal in the above formula, the output end 4 can produce linear displacement output in the negative direction of the y axis.

[0070] 3. As shown in Figures 1 to 7 and Figure 10 , the above output end 4 is the object, the process of the above output end 4 can produce the linear displacement output along the positive direction of the y axis;

[0071] In stage (I), the eight piezoelectric drive units are in the unpowered state, and the output end 4 has no displacement output;

[0072] In stage (II), the piezoelectric drive unit E21 and the piezoelectric drive unit F22 are applied to the waveform two voltage excitation signal as shown Figure 6 , the piezoelectric drive unit G23 and the piezoelectric drive unit H24 are applied to the waveform two voltage excitation signal as shown Figure 6The waveform one voltage excitation signal shown; when the voltage slowly decreases from 0 to -U and the voltage slowly increases from 0 to U, the piezoelectric driving unit F22 slowly bends and deforms upwards, the piezoelectric driving unit G23 slowly bends and deforms to the right, the piezoelectric driving unit H24 slowly bends and deforms downwards, and the piezoelectric driving unit E21 slowly bends and deforms to the left, driving the lower inertia ring 25 to rotate clockwise around the z-axis by an angle of θ z1 ;

[0073] In stage (III), when the voltage rapidly increases from -U to 0 and the voltage rapidly decreases from U to 0, the piezoelectric driving unit E21, the piezoelectric driving unit F22, the piezoelectric driving unit G23 and the piezoelectric driving unit H24 rapidly recover to the non-bending deformation state, under the action of the inertial force, the driving foot 6 rotates with the ground to make the robot rotate clockwise around the z-axis by an angle of θ z , and the lower inertia ring 25 rotates counterclockwise around the z-axis by an angle of θ z2 , wherein θ z = θ z1 - θ z2 , and finally the robot rotates clockwise around the z-axis by an angle of θ z , that is, the rotation angle displacement output of the upper output end 4 around the z-axis clockwise is θ z .

[0074] If the process is continuously repeated, the upper output end 4 can realize large-stroke step rotation angle displacement output clockwise around the z-axis. By applying reverse voltage excitation signals to the piezoelectric driving unit E21, the piezoelectric driving unit F22, the piezoelectric driving unit G23 and the piezoelectric driving unit H24, that is, applying the waveform one voltage excitation signal shown in Figure 6 to the piezoelectric driving unit E21 and the piezoelectric driving unit F22, and applying the waveform two voltage excitation signal shown in Figure 6 to the piezoelectric driving unit G23 and the piezoelectric driving unit H24, the upper output end 4 can generate large-stroke step rotation angle displacement output counterclockwise around the z-axis.

[0075] 4. As shown in Figures 1 to 7 and Figure 11 , the above output end 4 is taken as the object, and in this process, the upper output end 4 can generate rotation angle displacement output clockwise around the x-axis;

[0076] In stage (I), the eight piezoelectric driving units are in an unpowered state, and the upper output end 4 has no displacement output;

[0077] In stage (II), the piezoelectric driving unit B12 is applied with a waveform one voltage excitation signal as shown in Figure 6 , and the piezoelectric driving unit D14 is applied with a waveform two voltage excitation signal as shown in Figure 6 ; when the voltage slowly rises from 0 to U, the piezoelectric driving unit B12 slowly bends and deforms downward, and when the voltage slowly falls from 0 to -U, the piezoelectric driving unit D14 slowly bends and deforms upward, driving the upper inertia ring 16 to rotate clockwise around the x axis by an angle of θ x1 ;

[0078] In stage (III), when the voltage quickly rises from -U to 0 and the voltage quickly falls from U to 0, the piezoelectric driving unit B12 and the piezoelectric driving unit D14 quickly recover to the non-bending deformation state, under the action of the inertial force, the spherical hinge friction pair 34 frictionally rotates with the joint ball 32, rotates clockwise around the x axis by an angle of θ x ; θ x2 ; θ x = θ x1 - θ x2 , and finally the upper driving system 1 rotates clockwise around the x axis by an angle of θ x ; θ x ;

[0079] If the process is continuously repeated, the upper output end 4 can realize large-stroke step rotation angular displacement output clockwise around the x axis. By applying reverse voltage excitation signals to the piezoelectric driving unit B12 and the piezoelectric driving unit D14, i.e. applying the waveform two voltage excitation signal in Figure 6 to the piezoelectric driving unit B12 and applying the waveform one voltage excitation signal in Figure 6 to the piezoelectric driving unit D14, the upper output end 4 can generate large-stroke step rotation angular displacement output counterclockwise around the x axis.

[0080] 5. As shown in Figures 1 to 7 and Figure 12 , the upper output end 4 is the object, and in this process, the upper output end 4 can generate rotation angular displacement output clockwise around the y axis;

[0081] In stage (I), the eight piezoelectric driving units are in an unpowered state, and the upper output end 4 has no displacement output;

[0082] During stage (II), an application such as... is applied to the piezoelectric drive unit A11. Figure 6 The waveform shown is a two-sawtooth voltage signal, which applies a voltage to the piezoelectric drive unit C13 as follows: Figure 6 The waveform shown is a sawtooth voltage signal; when the voltage slowly rises from 0 to U, the piezoelectric drive unit C13 slowly bends and deforms downwards; when the voltage slowly drops from 0 to -U, the piezoelectric drive unit A11 slowly bends and deforms upwards, causing the upper inertial ring 16 to rotate clockwise around the y-axis. At this time, the upper inertial ring 16 rotates clockwise around the y-axis. θ y1 Angle;

[0083] During stage (III), when the voltage rapidly rises from -U to 0 and rapidly drops from U to 0, piezoelectric drive units A11 and C13 quickly return to their non-bending deformation state. Under the action of inertial force, the ball joint friction pair 34 and the articulated ball 32 rotate clockwise around the y-axis. θ y The upper inertial ring 16 rotated counterclockwise around the y-axis at an angle. θ y2 Angle, among which θ y = θ y1 - θ y2 Ultimately, the upper drive system 1 rotated clockwise around the y-axis. θ y The angle, that is, the angular displacement output of the upper output terminal 4 around the y-axis in a clockwise direction, is... θ y ;

[0084] If this process is repeated continuously, the upper output terminal 4 can achieve a large-stroke step rotational angular displacement output around the y-axis in a clockwise direction. This is achieved by applying a reverse voltage excitation signal to the piezoelectric drive unit A11 and the piezoelectric drive unit C13, i.e., applying a voltage excitation signal to the piezoelectric drive unit A11 such as... Figure 6 The waveform shown is a sawtooth voltage signal, which applies a voltage to the piezoelectric drive unit C13 as follows: Figure 6 The waveform shown is a sawtooth voltage signal. The upper output terminal 4 can generate a large-stroke stepping rotational angular displacement output around the y-axis in the counterclockwise direction.

[0085] The above-described embodiments are only used to illustrate the technical solutions of the present application, but not limit them; although the present application is described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A five-degree-of-freedom piezoelectric robot driven based on the principle of inertial stepping, characterized in that: The upper driving system, the lower driving system, the spherical hinge system, the upper output end, the connecting rod and the driving foot are included. The spherical hinge system includes a spherical hinge lower end cover, a joint ball, a joint seat, a spherical hinge friction pair and a spherical hinge upper end cover. The spherical hinge upper end cover and the spherical hinge lower end cover are fixedly connected on the upper and lower sides of the joint seat, the spherical hinge friction pair is connected inside the joint seat, and the lower surface of the spherical hinge friction pair is in contact with the surface of the joint ball. The upper driving system includes a piezoelectric driving unit A, a piezoelectric driving unit B, a piezoelectric driving unit C, a piezoelectric driving unit D, an upper connecting ring and an upper inertia ring. The upper connecting ring is arranged inside the upper inertia ring, and the left and right sides of the upper connecting ring are fixedly connected with the upper inertia ring through the piezoelectric driving unit C and the piezoelectric driving unit A, and the front and rear sides of the upper connecting ring are fixedly connected with the joint seat through the piezoelectric driving unit D and the piezoelectric driving unit B. The lower driving system includes a piezoelectric driving unit E, a piezoelectric driving unit F, a piezoelectric driving unit G, a piezoelectric driving unit H, a lower inertia ring, a lower connecting ring and a lower output end. The lower connecting ring is arranged inside the lower inertia ring, and the left and right sides of the lower connecting ring are fixedly connected with the lower inertia ring through the piezoelectric driving unit F and the piezoelectric driving unit H, and the front and rear sides of the lower connecting ring are fixedly connected with the lower output end through the piezoelectric driving unit G and the piezoelectric driving unit E, and the lower output end is provided with a threaded hole. The upper output end is fixedly connected with the spherical hinge upper end cover. The upper end of the connecting rod is coaxially fixedly connected with the joint ball, and the lower end of the connecting rod is connected with the threaded hole on the lower output end. The upper end of the driving foot is connected in the threaded hole of the lower output end.

2. The five-degree-of-freedom piezoelectric robot driven based on the principle of inertia stepping according to claim 1, characterized in that: By applying different sawtooth wave voltage excitation signals to the piezoelectric driving units, the piezoelectric driving units can output bending deformation in different directions, and under the action of inertial force, the driving foot and the upper output end are moved, and finally the linear motion displacement output of the upper output end in the x-axis direction and the y-axis direction and the rotary motion displacement output around the x-axis, the y-axis and the z-axis are realized.

3. The five-degree-of-freedom piezoelectric robot driven based on the principle of inertia stepping according to claim 1, characterized in that: The spherical hinge friction pair is vertically slidably connected inside the joint seat, the pre-tightening bolt is threadedly connected in the spherical hinge upper end cover, and the lower end of the pre-tightening bolt is in contact with the spherical hinge friction pair, and the pre-tightening bolt can adjust the friction force between the spherical hinge friction pair and the joint ball.

4. The five-degree-of-freedom piezoelectric robot driven based on the principle of inertia stepping according to claim 1, characterized in that: The upper driving system and the lower driving system adopt an axisymmetric arrangement respectively.

5. The five-degree-of-freedom piezoelectric robot driven based on the principle of inertia stepping according to claim 4, characterized in that: The piezoelectric driving units in the upper driving system and the lower driving system are arranged in a perpendicular manner.

6. The five-degree-of-freedom piezoelectric robot driven based on the principle of inertia stepping according to claim 1, characterized in that: Each piezoelectric driving unit is composed of a driving hinge and two piezoelectric chips, and the two piezoelectric chips are symmetrically bonded on both sides of the driving hinge.

7. The five-degree-of-freedom piezoelectric robot driven based on the principle of inertia stepping according to claim 6, characterized in that: The driving hinge, the lower inertia ring, the lower connecting ring and the lower output end in the lower driving system are integrally processed from a whole piece of elastic metal material; the driving hinge, the upper connecting ring, the upper inertia ring and the joint seat in the upper driving system are integrally processed from a whole piece of elastic metal material.

8. The five-degree-of-freedom piezoelectric robot driven based on the principle of inertia stepping according to claim 1, characterized in that: The spherical hinge system further includes a spring pad, a flat pad and a circular ring flat pad, and the spring pad, the circular ring flat pad and the flat pad are sequentially arranged between the spherical hinge friction pair and the pre-tightening bolt from bottom to top.

9. The five-degree-of-freedom piezoelectric robot driven based on the principle of inertia stepping according to claim 1, characterized in that: The threaded hole, the lower inertia ring, the joint ball and the upper inertia ring are coaxially arranged.

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