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

Abstract

The invention discloses a five-degree-of-freedom piezoelectric robot driven based on the inertia stepping principle, and relates to the technical field of robots, the five-degree-of-freedom piezoelectric robot 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; different sawtooth wave voltage excitation signals are applied to the piezoelectric driving unit, the piezoelectric driving unit can output bending deformation in different directions, the driving foot and the upper output end are made to move under the action of inertia force, and finally linear motion displacement output of the upper output end in the x-axis direction and the y-axis direction and rotary motion displacement output around the x-axis, the y-axis and the z-axis are achieved. The method has wide application potential in the fields of aerospace, optical equipment and the like.

Description

Technical Field

[0001] This invention relates to the field of robotics, specifically to a five-degree-of-freedom piezoelectric robot driven by the principle of inertial stepping. Background Technology

[0002] Miniature robots are a current research hotspot in the field of robotics, with broad application prospects in medical, industrial inspection, and environmental monitoring. However, existing robots still have significant limitations in motion performance. Traditional motor-driven solutions are complex in structure and large in size, making it difficult to meet miniaturization requirements. Piezoelectric actuation technology based on the inverse piezoelectric effect has become one of the ideal actuation solutions for miniature robots due to its compact structure, fast response, high precision, and absence of electromagnetic interference. Currently, some piezoelectric-driven robots can only achieve unidirectional movement, lacking flexibility and struggling to adapt to complex planar environments. Even some multi-degree-of-freedom piezoelectric robots often face problems such as complex actuation structures, high control difficulty, and high cost, which restrict their practical application. Summary of the Invention

[0003] This invention addresses the problems of low degrees of freedom, complex structure, and difficult control of existing robots by proposing a five-degree-of-freedom piezoelectric robot driven by the inertial stepping principle.

[0004] A five-degree-of-freedom piezoelectric robot driven by the inertial stepping principle includes an upper drive system, a lower drive system, a ball joint system, an upper output end, a connecting rod, and drive legs; The ball joint system includes a lower ball joint cap, a ball joint, a ball joint seat, a ball joint friction pair, and an upper ball joint cap; The upper and lower end caps of the ball joint are fixedly connected to the upper and lower sides of the joint seat. The ball joint friction pair is connected inside the joint seat, and the lower surface of the ball joint friction pair is in contact with the spherical surface of the joint. The upper drive system includes piezoelectric drive unit A, piezoelectric drive unit B, piezoelectric drive unit C, piezoelectric drive unit D, upper connecting ring, and upper inertial ring; The upper connecting ring is located inside the upper inertial ring, and the left and right sides of the upper connecting ring are fixed to the upper inertial ring through piezoelectric drive unit C and piezoelectric drive unit A, and the front and rear sides of the upper connecting ring are fixed to the joint seat through piezoelectric drive unit D and piezoelectric drive unit B. The lower drive system includes piezoelectric drive unit E, piezoelectric drive unit F, piezoelectric drive unit G, piezoelectric drive unit H, lower inertial loop, lower connecting loop, and lower output terminal; The lower connecting ring is located inside the lower inertial ring, and the left and right sides of the lower connecting ring are fixed to the lower inertial ring through piezoelectric drive unit F and piezoelectric drive unit H. The front and rear sides of the lower connecting ring are fixed to the lower output end through piezoelectric drive unit G and piezoelectric drive unit E. The lower output end is provided with screw holes. The upper output end is fixedly connected to the upper end cover of the ball joint; The upper end of the connecting rod is coaxially fixed to the joint ball, and the lower end of the connecting rod is connected to the screw hole on the lower output end. The upper end of the drive foot is connected to the screw hole at the lower output end.

[0005] Preferably, by applying different sawtooth wave voltage excitation signals to the piezoelectric drive unit, the piezoelectric drive unit can output bending deformation in different directions, causing the drive foot and upper output end to move under the action of inertial force, ultimately realizing linear motion displacement output of the upper output end along the x-axis and y-axis and rotational motion displacement output around the x, y, and z axes.

[0006] Preferably, the ball joint friction pair is vertically slidably connected inside the joint seat, and the preload bolt is threadedly connected inside the upper end cover of the ball joint, with the lower end of the preload bolt in contact with the ball joint friction pair. The preload bolt can adjust the friction force between the ball joint friction pair and the joint ball.

[0007] Preferably, the upper drive system and the lower drive system are arranged in an axisymmetric manner.

[0008] Preferably, the piezoelectric drive units in the upper drive system and the lower drive system are arranged perpendicularly to each other.

[0009] Preferably, each piezoelectric drive unit consists of a drive hinge and two piezoelectric wafers, with the two piezoelectric wafers symmetrically bonded to both sides of the drive hinge.

[0010] Preferably, the drive hinge, lower inertia ring, lower connecting ring, and lower output end in the lower drive system are machined from a single piece of elastic metal material; the drive hinge, upper connecting ring, upper inertia ring, and joint seat in the upper drive system are machined from a single piece of elastic metal material.

[0011] Preferably, the ball joint system further includes a spring washer, a flat washer, and a circular flat washer, which are arranged sequentially from bottom to top between the ball joint friction pair and the preload bolt.

[0012] Preferably, the screw hole, lower inertia ring, joint ball, and upper inertia ring are coaxially arranged.

[0013] Compared with the prior art, the present invention has the following advantages: This invention utilizes eight piezoelectric drive units to bend and deform under sawtooth wave voltage excitation, thereby driving the upper and lower inertial rings to move. Under the action of inertial force, the motion of the lower inertial ring is converted into frictional sliding between the driving foot and the ground and displacement output of the upper output end, and the motion of the upper inertial ring is converted into displacement output of the upper output end. Furthermore, by applying different voltage excitation signals to the piezoelectric drive units, the piezoelectric drive units can output bending deformation in different directions, thereby realizing linear motion of the upper output end along the x-axis and y-axis and rotational motion around the x, y, and z axes, for a total of five degrees of freedom of displacement output. The present invention has a high degree of structural integration. The drive hinge, lower connecting ring, lower inertia ring and lower output end in the lower drive system can be integrally machined by CNC and wire cutting. The drive hinge, upper connecting ring, upper inertia ring and joint seat in the upper drive system can be integrally machined by CNC and wire cutting. The structure is simple and the control is flexible. By controlling the sawtooth wave voltage signal of the eight piezoelectric drive units, the output end can realize linear motion or rotational motion in opposite directions, and can realize flexible conversion of each degree of freedom, thereby realizing five-degree-of-freedom displacement output. The invention features a small size, fast response, immunity to electromagnetic interference, and flexible movement, and has broad application potential in aerospace, optical equipment, integrated circuits, microelectromechanical systems and other technical fields, providing a certain reference for the design of five-degree-of-freedom robots. Attached Figure Description

[0014] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is the front view of the present invention; Figure 3 This is a three-dimensional structural diagram of the upper drive system; Figure 4 This is a cross-sectional view of the upper drive system; Figure 5 Top view of the lower drive system; Figure 6 This is a waveform diagram of the excitation voltage signal of the present invention; Figure 7 This is a schematic diagram of the deformation process of the piezoelectric drive unit under different excitation signals; where (a) represents vertical bending and (b) represents horizontal bending. Figure 8 The diagram shows the driving principle of the upper output terminal outputting linear displacement along the x-axis; where (a) is the top view of the lower drive system and (b) is the front view of the robot. Figure 9 This is a schematic diagram of the driving principle for linear displacement output along the y-axis at the upper output end; where (a) is the right view of the robot and (b) is the top view of the lower driving system. Figure 10The diagram shows the driving principle of the upper output terminal rotating angular displacement output around the z-axis; where (a) is the top view of the lower drive system and (b) is the top view of the robot. Figure 11 The schematic diagram of the left-view drive principle for the output of angular displacement around the x-axis at the upper output terminal; Figure 12 This is a schematic diagram of the rear-view drive principle, which outputs angular displacement around the y-axis from the upper output terminal.

[0015] The following are the labeling elements in the figure: 1: Upper drive system; 2: Lower drive system; 3: Ball joint system; 4: Upper output end; 5: Connecting rod; 6: Drive foot; 11: Piezoelectric drive unit A; 12: Piezoelectric drive unit B; 13: Piezoelectric drive unit C; 14: Piezoelectric drive unit D; 15: Upper connecting ring; 16: Upper inertia ring; 21: Piezoelectric drive unit E; 22: Piezoelectric drive unit F; 23: Piezoelectric drive unit G; 24: Piezoelectric drive unit H; 25: Lower inertia ring; 26: Lower connecting ring; 27: Lower output end; 31: Lower end cap of ball joint; 32: Articulated ball; 33: Articulated seat; 34: Ball joint friction pair; 35: Spring washer; 36: Flat washer; 37: Fixing bolt; 38: Preload bolt; 39: Upper end cap of ball joint; 310: Circular flat washer. Detailed Implementation

[0016] Example 1: Reference Figures 1 to 5 A five-degree-of-freedom piezoelectric robot driven by the inertial stepping principle includes an upper drive system 1, a lower drive system 2, a ball joint system 3, an upper output end 4, a connecting rod 5, and a drive leg 6. The ball joint system 3 includes a lower ball joint cover 31, a ball joint 32, a joint seat 33, a ball joint friction pair 34, a spring washer 35, a flat washer 36, a preload bolt 38, an upper ball joint cover 39, and a circular flat washer 310. 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. 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; 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. 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; 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. The upper output end 4 is fixedly connected to the upper end cover 39 of the ball joint by fixing bolt 37; 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. The upper end of the drive foot 6 is threaded into the screw hole of the lower output end 27; By applying different sawtooth wave voltage excitation signals to the piezoelectric drive unit, the piezoelectric drive unit can output bending deformation in different directions. Under the action of inertial force, the drive foot 6 and the upper output end 4 move, ultimately realizing the linear motion displacement output of the upper output end 4 along the x-axis and y-axis and the rotational motion displacement output around the x, y, and z axes.

[0017] Furthermore, the upper drive system 1 and the lower drive system 2 are arranged in an axisymmetric manner.

[0018] Furthermore, the piezoelectric drive units in the upper drive system 1 and the lower drive system 2 are arranged perpendicularly to each other.

[0019] Furthermore, each piezoelectric drive unit consists of a drive hinge and two piezoelectric wafers, which are symmetrically bonded to both sides of the drive hinge.

[0020] Furthermore, the drive hinge, lower inertia ring 25, lower connecting ring 26, and lower output end 27 in the lower drive system are machined from a single piece of elastic metal material; the drive hinge, upper connecting ring 15, upper inertia ring 16, and joint seat 33 in the upper drive system are machined from a single piece of elastic metal material.

[0021] Furthermore, the driving foot 6 achieves planar motion of the upper output end 4 by sliding against the ground through friction.

[0022] Furthermore, the joint ball 32 achieves the rotational motion of the upper output end 4 through frictional rotation with the ball joint friction pair 34.

[0023] Working principle of the invention: Reference Figures 1 to 12 In this embodiment 1, each piezoelectric chip adopts the following... Figure 6 The sawtooth wave voltage shown is used as the excitation signal. Taking a piezoelectric drive unit as an example, such as... Figure 7 As shown in (a), the right side of a single drive hinge is fixed, and only the left end can move. The polarity of the piezoelectric crystal is from bottom to top, that is, the bottom is the negative electrode and the top is the positive electrode. When two piezoelectric crystals are simultaneously applied... Figure 6 When the waveform shown is subjected to a voltage excitation signal, the lower piezoelectric wafer shortens and the upper piezoelectric wafer lengthens, causing the drive hinge to bend downwards and the entire piezoelectric drive unit to bend downwards. When a voltage excitation signal is applied to both piezoelectric wafers simultaneously... Figure 6 When the waveform shown is subjected to a voltage excitation signal, the lower piezoelectric crystal elongates and the upper piezoelectric crystal shortens, causing the drive hinge to bend upwards, and the entire piezoelectric drive unit to bend upwards; as shown... Figure 7 As shown in (b), the upper part of a single drive hinge is fixed, and only the lower end can move. The polarity of the piezoelectric crystal is from right to left, that is, the right side is the negative electrode and the left side is the positive electrode. When two piezoelectric crystals are simultaneously applied... Figure 6 When the waveform shown is subjected to a voltage excitation signal, the right piezoelectric crystal shortens and the left piezoelectric crystal lengthens, causing the drive hinge to bend to the right, and the entire piezoelectric drive unit to bend to the right. When both piezoelectric crystals are simultaneously subjected to a voltage excitation signal... Figure 6 When the waveform shown is subjected to a voltage excitation signal, the piezoelectric crystal on the right elongates and the piezoelectric crystal on the left shortens, causing the drive hinge to bend to the left and the entire piezoelectric drive unit to bend to the left.

[0024] The specific working process of this invention is as follows: 1. For example Figures 1 to 8 As shown, output terminal 4 is the object above. In this process, output terminal 4 can generate linear displacement output along the positive x-axis. During stage (I), the eight piezoelectric drive units are in an unpowered state, and there is no displacement output at the upper output terminal 4; During stage (II), the piezoelectric drive unit E21 and piezoelectric drive unit 23G are subjected to the following: Figure 6 The waveform shown is a voltage excitation signal; when the voltage slowly decreases from 0 to -U, both piezoelectric drive units E21 and G23 slowly bend and deform to the left, causing the lower inertia ring 25 to move in the positive x-axis direction. At this time, the lower inertia ring 25 moves Δ in the positive x-axis direction. x A distance of 1; During stage (III), when the voltage rapidly rises from -U to 0, piezoelectric drive unit E21 and piezoelectric drive unit G23 quickly return to their non-bending deformation state. Under the action of inertial force, the drive foot 6 slides against the ground in the positive x-axis direction Δ. x The distance, the lower inertial ring 25 moves Δ in the negative x-axis direction. x The distance of 2, where Δ x =Δ x 1-Δ x 2. Finally, the robot moves Δ along the positive x-axis. x The distance, that is, the linear displacement output of the upper output terminal 4 along the positive x-axis, is Δ. x ; If this process is repeated continuously, the upper output terminal 4 can achieve a large-stroke linear displacement output along the positive x-axis by applying a reverse voltage excitation signal to the piezoelectric drive unit E21 and the piezoelectric drive unit G23. Figure 6 The waveform of the voltage excitation signal can generate a linear displacement output along the negative x-axis at the upper output terminal 4.

[0025] 2. For example Figures 1 to 7 and Figure 9 As shown, output terminal 4 is the object above. In this process, output terminal 4 can generate linear displacement output along the positive y-axis. During stage (I), the eight piezoelectric drive units are in an unpowered state, and there is no displacement output at the upper output terminal 4; During stage (II), the piezoelectric drive unit F22 and the piezoelectric drive unit H24 are subjected to the following: Figure 6 The waveform shown is a voltage excitation signal. When the voltage slowly decreases from 0 to -U, both piezoelectric drive units F22 and H24 slowly bend and deform upwards, causing the lower inertia ring 25 to move in the positive y-axis direction. At this time, the lower inertia ring 25 moves Δ in the positive y-axis direction. y A distance of 1; During stage (III), when the voltage rapidly rises from -U to 0, piezoelectric drive unit F22 and piezoelectric drive unit H24 quickly return to their non-bending deformation state. Under the action of inertial force, the drive foot 6 slides against the ground in the positive y-axis direction Δ. y The distance, the lower inertial ring 25 moves Δ in the negative y-axis direction. y The distance of 2, where Δ y =Δ y 1-Δ y 2. Finally, the robot moves Δ along the positive y-axis. y The distance, that is, the linear displacement output of the upper output terminal 4 along the positive y-axis, is Δ. y ; If this process is repeated continuously, the upper output terminal 4 can achieve a large-stroke linear displacement output along the positive y-axis by applying a reverse voltage excitation signal to the piezoelectric drive unit F22 and the piezoelectric drive unit H24. Figure 6 The waveform of the voltage excitation signal can generate a linear displacement output along the negative y-axis at the upper output terminal 4.

[0026] 3. For example Figures 1 to 7 and Figure 10 As shown, output terminal 4 is the object above. In this process, output terminal 4 can generate a rotational angular displacement output around the z-axis in a clockwise direction. During stage (I), the eight piezoelectric drive units are in an unpowered state, and there is no displacement output at the upper output terminal 4; During stage (II), the piezoelectric drive unit E21 and the piezoelectric drive unit F22 are subjected to the following: Figure 6 The waveform shown is a voltage excitation signal that applies a voltage to piezoelectric drive unit G23 and piezoelectric drive unit H24 as follows: Figure 6 The waveform shown is a voltage excitation signal. When the voltage slowly decreases from 0 to -U and slowly increases from 0 to U, piezoelectric drive unit F22 slowly bends upward, piezoelectric drive unit G23 slowly bends to the right, piezoelectric drive unit H24 slowly bends downward, and piezoelectric drive unit E21 slowly bends to the left, causing the lower inertia ring 25 to rotate clockwise around the z-axis. At this time, the lower inertia ring 25 rotates clockwise around the z-axis. θ z1 Angle; During stage (III), when the voltage rapidly rises from -U to 0 and then rapidly drops from U to 0, piezoelectric drive units E21, F22, G23, and H24 quickly return to their non-bending deformation state. Under the action of inertial force, the drive foot 6 rotates due to friction with the ground, causing the robot to rotate clockwise around the z-axis. θ z The lower inertial ring 25 rotated counterclockwise around the z-axis at an angle of [value missing]. θ z2 Angle, among which θ z = θ z1 - θ z2 Ultimately, the robot rotated clockwise around the z-axis. θ z The angle, that is, the angular displacement output of the upper output terminal 4 around the z-axis in a clockwise direction, is... θ z ; If this process is repeated continuously, the upper output terminal 4 can achieve a large-stroke step rotational angular displacement output around the z-axis in a clockwise direction. This is achieved by applying a reverse voltage excitation signal to the piezoelectric drive units E21, F22, G23, and H24, specifically by applying a voltage excitation signal to piezoelectric drive units E21 and F22. Figure 6 The waveform shown is a voltage excitation signal that applies a voltage to piezoelectric drive unit G23 and piezoelectric drive unit H24 as follows: Figure 6 The waveform shown is a voltage excitation signal. The upper output terminal 4 can generate a large-stroke stepping rotational angular displacement output in the counterclockwise direction around the z-axis.

[0027] 4. For example Figures 1 to 7 and Figure 11 As shown, output terminal 4 is the object above. In this process, output terminal 4 can generate a rotational angular displacement output around the x-axis in a clockwise direction. During stage (I), the eight piezoelectric drive units are in an unpowered state, and there is no displacement output at the upper output terminal 4; During stage (II), an application such as... is applied to the piezoelectric drive unit B12. Figure 6 The waveform shown is a voltage excitation signal that applies a voltage to the piezoelectric drive unit D14 as follows: Figure 6 The waveform shown is a voltage excitation signal. When the voltage slowly rises from 0 to U, the piezoelectric drive unit B12 slowly bends and deforms downwards. When the voltage slowly drops from 0 to -U, the piezoelectric drive unit D14 slowly bends and deforms upwards, causing the upper inertial ring 16 to rotate clockwise around the x-axis. At this time, the upper inertial ring 16 rotates clockwise around the x-axis. θ x1 Angle; During stage (III), when the voltage rapidly rises from -U to 0 and rapidly drops from U to 0, piezoelectric drive unit B12 and piezoelectric drive unit D14 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 frictionally, rotating clockwise around the x-axis. θ x The upper inertial ring 16 rotated counterclockwise around the x-axis at an angle. θ x2 Angle, among which θ x = θ x1 - θ x2 Ultimately, the upper drive system 1 rotated clockwise around the x-axis. θ x The angle, that is, the angular displacement output of the upper output terminal 4 around the x-axis in a clockwise direction, is... θ x ; If this process is repeated continuously, the upper output terminal 4 can achieve a large-stroke step rotational angular displacement output around the x-axis in a clockwise direction. A reverse voltage excitation signal is applied through the piezoelectric drive unit B12 and the piezoelectric drive unit D14, that is, an excitation signal is applied to the piezoelectric drive unit B12. Figure 6 The waveform two voltage excitation signal applies to the piezoelectric drive unit D14. Figure 6 The waveform of the voltage excitation signal can generate a large-stroke stepping rotational angular displacement output in the counterclockwise direction around the x-axis at the upper output terminal 4.

[0028] 5. For example Figures 1 to 7 and Figure 12 As shown, output terminal 4 is the object above. In this process, output terminal 4 can generate a rotational angular displacement output around the y-axis in a clockwise direction. During stage (I), the eight piezoelectric drive units are in an unpowered state, and there is no displacement output at the upper output terminal 4; 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; 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 ; 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.

[0029] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A five-degree-of-freedom piezoelectric robot driven by the inertial stepping principle, characterized in that: It includes an upper drive system, a lower drive system, a ball joint system, an upper output end, a connecting rod, and a drive foot; The ball joint system includes a lower ball joint cap, a ball joint, a ball joint seat, a ball joint friction pair, and an upper ball joint cap; The upper and lower end caps of the ball joint are fixedly connected to the upper and lower sides of the joint seat. The ball joint friction pair is connected inside the joint seat, and the lower surface of the ball joint friction pair is in contact with the spherical surface of the joint. The upper drive system includes piezoelectric drive unit A, piezoelectric drive unit B, piezoelectric drive unit C, piezoelectric drive unit D, upper connecting ring, and upper inertial ring; The upper connecting ring is located inside the upper inertial ring, and the left and right sides of the upper connecting ring are fixed to the upper inertial ring through piezoelectric drive unit C and piezoelectric drive unit A, and the front and rear sides of the upper connecting ring are fixed to the joint seat through piezoelectric drive unit D and piezoelectric drive unit B. The lower drive system includes piezoelectric drive unit E, piezoelectric drive unit F, piezoelectric drive unit G, piezoelectric drive unit H, lower inertial loop, lower connecting loop, and lower output terminal; The lower connecting ring is located inside the lower inertial ring, and the left and right sides of the lower connecting ring are fixed to the lower inertial ring through piezoelectric drive unit F and piezoelectric drive unit H. The front and rear sides of the lower connecting ring are fixed to the lower output end through piezoelectric drive unit G and piezoelectric drive unit E. The lower output end is provided with screw holes. The upper output end is fixedly connected to the upper end cover of the ball joint; The upper end of the connecting rod is coaxially fixed to the joint ball, and the lower end of the connecting rod is connected to the screw hole on the lower output end. The upper end of the drive foot is connected to the screw hole at the lower output end.

2. The five-degree-of-freedom piezoelectric robot driven by the inertial stepping principle according to claim 1, characterized in that: By applying different sawtooth wave voltage excitation signals to the piezoelectric drive unit, the piezoelectric drive unit can output bending deformation in different directions. Under the action of inertial force, the drive foot and the upper output end move, ultimately realizing the linear displacement output of the upper output end along the x-axis and y-axis and the rotational displacement output around the x, y, and z axes.

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

4. A five-degree-of-freedom piezoelectric robot driven by the inertial stepping principle according to claim 1, characterized in that: The upper drive system and the lower drive system are arranged in an axisymmetric manner.

5. A five-degree-of-freedom piezoelectric robot driven by the inertial stepping principle according to claim 4, characterized in that: The piezoelectric drive units in the upper and lower drive systems are arranged perpendicularly to each other.

6. A five-degree-of-freedom piezoelectric robot driven by the inertial stepping principle according to claim 1, characterized in that: Each piezoelectric drive unit consists of a drive hinge and two piezoelectric wafers, which are symmetrically bonded to both sides of the drive hinge.

7. A five-degree-of-freedom piezoelectric robot driven by the inertial stepping principle according to claim 6, characterized in that: The drive hinge, lower inertia ring, lower connecting ring, and lower output end in the lower drive system are machined from a single piece of elastic metal material; the drive hinge, upper connecting ring, upper inertia ring, and joint seat in the upper drive system are machined from a single piece of elastic metal material.

8. A five-degree-of-freedom piezoelectric robot driven by the inertial stepping principle according to claim 1, characterized in that: The ball joint system also includes spring washers, flat washers, and annular flat washers, which are arranged sequentially from bottom to top between the ball joint friction pair and the preload bolt.

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

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