Planar multi-degree-of-freedom micro piezoelectric robot with annular structure and excitation method

Abstract

The invention belongs to the technical field of robots, and particularly relates to a planar multi-degree-of-freedom micro piezoelectric robot with an annular structure and an excitation method, the robot comprises an actuating component and a guide mechanism, and the actuating component comprises an annular base body, a piezoelectric ceramic piece assembly and a driving foot assembly; the guide mechanism comprises a support, a locking bolt assembly, a nut assembly and a guide bearing assembly. According to the excitation method, after a special electric signal is applied to the actuating part, three different axial bending modes of the actuating part are excited, and the combination of the modes is utilized to enable the driving foot to generate an oblique straight line or an elliptical track. Through the friction effect between the piezoelectric robot and the ground, the piezoelectric robot can achieve linear motion and rotary motion in the orthogonal direction in the plane. The robot has the advantages of being small in size, simple and convenient in structure, simple in driving mechanism and high in movement efficiency, particularly has the high flexibility characteristic of being capable of achieving plane three-degree-of-freedom movement, and has wide application potential in the fields of narrow environment detection, safety rescue and the like.

Description

Technical Field

[0001] The invention relates to the field of robot technology, in particular to a planar multi-freedom micro piezoelectric robot with an annular structure and an excitation method. Background Art

[0002] At present, robots are able to complete some specific tasks instead of humans, such as smart warehousing, automobile assembly or welding of key industrial components. However, in special environments such as search and rescue in a small space after a disaster, covert reconnaissance or high temperature and high pressure, micro-robots with small size, light weight and excellent movement performance are needed to perform tasks. Traditional robots are mostly driven by electromagnetic motors. Although the driving efficiency is high, the complex transmission system cannot make them miniaturized. The development of micro-robots driven by smart materials has become a hot topic. Most of these robots have complex manufacturing processes and poor movement stability, which greatly affects their application in real scene environments.

[0003] Piezoelectric robots are easy to miniaturize, have fast response and high movement efficiency, and are a relatively high-performance micro-robot implementation solution. However, due to their reliance on vibration modes, most piezoelectric robots, although they can ensure a small size, only have a single degree of freedom of movement, which prevents them from further application; when robots can achieve multi-degree-of-freedom movement, more complex structural designs put forward higher requirements for processing and manufacturing. Summary of the invention

[0004] In view of the problem that the existing piezoelectric robots have a single degree of freedom of movement, the present invention provides a planar multi-degree-of-freedom micro piezoelectric robot with a ring structure, which has the advantages of planar multi-degree-of-freedom.

[0005] The specific technical solutions are as follows:

[0006] A planar multi-freedom micro piezoelectric robot with an annular structure comprises an actuating component and a guiding mechanism; the guiding mechanism is mounted on the actuating component.

[0007] Furthermore, the actuating component includes an annular base, a driving foot assembly and a piezoelectric ceramic sheet assembly; the driving foot assembly includes a first driving foot, a second driving foot, a third driving foot and a fourth driving foot, and the piezoelectric ceramic sheet assembly includes a first piezoelectric ceramic sheet, a second piezoelectric ceramic sheet, a third piezoelectric ceramic sheet and a fourth piezoelectric ceramic sheet; the straight edge of the annular base is used to stick the first piezoelectric ceramic sheet, the second piezoelectric ceramic sheet, the third piezoelectric ceramic sheet and the fourth piezoelectric ceramic sheet, and the first piezoelectric ceramic sheet, the second piezoelectric ceramic sheet, the third piezoelectric ceramic sheet and the fourth piezoelectric ceramic sheet are sequentially stuck to the annular base in a counterclockwise direction. shaped substrate; the first piezoelectric ceramic sheet, the second piezoelectric ceramic sheet, the third piezoelectric ceramic sheet, and the fourth piezoelectric ceramic sheet are all polarized along the thickness direction, and the polarization direction is perpendicular to the upper surface of the annular substrate and upward or downward; the first driving foot, the second driving foot, the third driving foot, and the fourth driving foot are sequentially pasted to the lower surface of the annular substrate in a counterclockwise direction, and the centroids of the first driving foot, the second driving foot, the third driving foot, and the fourth driving foot coincide with the centroids of the corresponding rectangular pasting positions, and correspond one-to-one to the first piezoelectric ceramic sheet, the second piezoelectric ceramic sheet, the third piezoelectric ceramic sheet, and the fourth piezoelectric ceramic sheet.

[0008] Furthermore, the guide mechanism includes a bracket, a locking bolt assembly, a nut assembly and a guide bearing assembly; the locking bolt assembly includes a first locking bolt, a second locking bolt, a third locking bolt and a fourth locking bolt; the nut assembly includes a first nut, a second nut, a third nut and a fourth nut; the guide bearing assembly includes a first guide bearing, a second guide bearing, a third guide bearing and a fourth guide bearing; the bracket has a square disc structure, and the outer side of the sharp corner of the square disc structure has an overhanging portion with an inner hole; the first guide bearing, the second guide bearing, the third guide bearing and the fourth guide bearing are respectively placed horizontally on the overhanging portion of the bracket in a counterclockwise direction, and The centroids of the first guide bearing, the second guide bearing, the third guide bearing and the fourth guide bearing are aligned with the centroid of the inner hole of the protruding part of the bracket, the first locking bolt, the second locking bolt, the third locking bolt and the fourth locking bolt are inserted into the first guide bearing, the second guide bearing, the third guide bearing, the fourth guide bearing and the inner hole of the protruding part of the bracket in a counterclockwise direction, the first nut, the second nut, the third nut and the fourth nut are screwed into the first locking bolt, the second locking bolt, the third locking bolt and the fourth locking bolt respectively, and the other components do not fall off while ensuring the normal rotation of the first guide bearing, the second guide bearing, the third guide bearing and the fourth guide bearing.

[0009] Furthermore, the annular base is an annular metal structure with straight edges and curved edges; the radial widths of the annular structures where the straight edges and curved edges of the annular base are located are the same; a blind hole is provided at the annular structure with the curved edge of the annular base for carrying a guide mechanism, and a small cylinder is provided at the bottom of the bracket corresponding to the position of the blind hole, and the small cylinder can be inserted into the blind hole, and the small cylinder and the blind hole are gap-matched.

[0010] Furthermore, the first piezoelectric ceramic sheet, the second piezoelectric ceramic sheet, the third piezoelectric ceramic sheet, and the fourth piezoelectric ceramic sheet have the same structure, which are all flat plate structures; the lengths of the first piezoelectric ceramic sheet, the second piezoelectric ceramic sheet, the third piezoelectric ceramic sheet, and the fourth piezoelectric ceramic sheet are consistent with the length of the straight side of the annular substrate.

[0011] Furthermore, the structures of the first driving foot, the second driving foot, the third driving foot and the fourth driving foot are consistent, and they are all combined cylindrical structures with a circular base and a circular toe; the diameters of the bases of the first driving foot, the second driving foot, the third driving foot and the fourth driving foot are smaller than the width of the annular structure in the annular base.

[0012] Furthermore, the inner hole diameters of the first guide bearing, the second guide bearing, the third guide bearing and the fourth guide bearing are larger than the inner hole diameter of the protruding part of the bracket, while the major diameters of the threads of the first locking bolt, the second locking bolt, the third locking bolt and the fourth locking bolt are smaller than the inner hole diameter of the protruding part of the bracket, and the nominal diameters of the first nut, the second nut, the third nut and the fourth nut are consistent with those of the first locking bolt, the second locking bolt, the third locking bolt and the fourth locking bolt.

[0013] The excitation method of the planar multi-degree-of-freedom micro piezoelectric robot with the ring structure comprises the following steps:

[0014] A Cartesian coordinate system o-xyz is set in the piezoelectric robot, the centroid of the actuating component is the origin of the coordinate system, the direction from the centroid of the actuating component to the centroid of the second piezoelectric ceramic sheet is the positive direction of the x-axis; the direction from the centroid of the actuating component to the centroid of the fourth piezoelectric ceramic sheet is the negative direction of the x-axis; the direction from the centroid of the actuating component to the centroid of the third piezoelectric ceramic sheet is the positive direction of the y-axis; the direction from the centroid of the actuating component to the centroid of the first piezoelectric ceramic sheet is the negative direction of the y-axis; the direction from the centroid of the actuating component to the upper surface of the annular substrate is the positive direction of the z-axis, and the direction pointing to the lower surface of the annular substrate as the rotation axis is the negative direction of the z-axis. The linear motion direction of the piezoelectric robot in the plane is consistent with the Cartesian coordinate system; the rotation direction that coincides with the positive direction of the x-axis after rotating 90 degrees from the positive direction of the y-axis is the clockwise rotation direction of the piezoelectric robot, and vice versa.

[0015] The excitation scheme for the micro piezoelectric robot to achieve linear motion along the x-axis:

[0016] A first excitation signal is applied to the first piezoelectric ceramic plate, the third piezoelectric ceramic plate and the fourth piezoelectric ceramic plate, and a second excitation signal is applied to the second piezoelectric ceramic plate; the first and second excitation signals are both sinusoidal AC voltage signals with the same frequency and amplitude, and the second excitation signal lags the first excitation signal by half a cycle in terms of time phase difference;

[0017] Under the action of these excitation signals, a first-order axial bending vibration mode characterized by the simultaneous outward expansion or contraction of the first driving foot, the second driving foot, the third driving foot, and the fourth driving foot is generated, as well as a third-order axial bending vibration mode characterized by the second driving foot and the fourth driving foot vibrating in opposite directions; based on the combination of the first-order axial bending vibration mode and the third-order axial bending vibration mode, the toe tips of the first driving foot, the second driving foot, the third driving foot, and the fourth driving foot generate an oblique linear motion trajectory with a certain angle to the x-axis; using the friction between the first driving foot, the second driving foot, the third driving foot, and the fourth driving foot and the ground, the piezoelectric robot can achieve linear motion in the positive direction of the x-axis;

[0018] When the piezoelectric robot needs to move in the negative direction of the x-axis, it only needs to apply the first excitation signal to the first piezoelectric ceramic sheet, the second piezoelectric ceramic sheet, and the third piezoelectric ceramic sheet, and the second excitation signal to the fourth piezoelectric ceramic sheet;

[0019] The excitation scheme for the micro piezoelectric robot to achieve linear motion along the y-axis:

[0020] Applying a first excitation signal to the first piezoelectric ceramic piece, the second piezoelectric ceramic piece and the fourth piezoelectric ceramic piece, and applying a second excitation signal to the third piezoelectric ceramic piece; the first and second excitation signals are the same as the first and second excitation signals when the robot realizes linear motion in the positive direction of the x-axis;

[0021] Under the action of the first and second excitation signals, the actuating component generates a first-order axial bending vibration mode characterized by the first driving foot, the second driving foot, the third driving foot, and the fourth driving foot simultaneously moving outward or contracting, and a third-order axial bending vibration mode characterized by the first driving foot and the third driving foot vibrating in opposite directions; based on the combination of the first-order axial bending vibration mode and the third-order axial bending vibration mode, the toe tips of the first driving foot, the second driving foot, the third driving foot, and the fourth driving foot generate an oblique linear motion trajectory having a certain angle with the y-axis; by utilizing the friction between the first driving foot, the second driving foot, the third driving foot, and the fourth driving foot and the ground, the piezoelectric robot can move in the positive direction of the y-axis;

[0022] When the micro piezoelectric robot needs to move in the negative direction of the y-axis, the first excitation signal is applied to the second piezoelectric ceramic sheet, the third piezoelectric ceramic sheet, and the fourth piezoelectric ceramic sheet, and the second excitation signal is applied to the first piezoelectric ceramic sheet;

[0023] The excitation scheme for the micro piezoelectric robot to achieve rotational motion around the z-axis:

[0024] A first excitation signal is applied to the second piezoelectric ceramic sheet, a second excitation signal is applied to the fourth piezoelectric ceramic sheet, a third excitation signal is applied to the first piezoelectric ceramic sheet, and a fourth excitation signal is applied to the third piezoelectric ceramic sheet; the first and second excitation signals are consistent with the first and second excitation signals when the robot realizes linear motion of the y-axis; the third and fourth excitation signals are sinusoidal AC voltage signals, and the frequency amplitudes are consistent with the first and second excitation signals, the third excitation signal lags behind the first excitation signal by a quarter of a cycle in terms of time phase difference, and the fourth excitation signal lags behind the first excitation signal by a quarter of a cycle in terms of time phase difference. The signal is three quarters of a period; under the action of the excitation signal, a third-order axial bending vibration mode characterized by the first driving foot and the third driving foot vibrating in opposite directions is generated, and a third-order axial bending vibration mode characterized by the second driving foot and the fourth driving foot vibrating in opposite directions is generated; based on the coupling of the two third-order axial bending vibration modes, the toe tips of the first driving foot, the second driving foot, the third driving foot, and the fourth driving foot generate tangential elliptical trajectories; using the friction between the first driving foot, the second driving foot, the third driving foot, the fourth driving foot and the ground, the piezoelectric robot can rotate counterclockwise around the z-axis;

[0025] When the micro-piezoelectric robot needs to move clockwise around the z-axis, the signal of the first piezoelectric ceramic piece is changed to the fourth excitation signal, and the signal of the third piezoelectric ceramic piece is changed to the third excitation signal.

[0026] The beneficial effects of the present invention are:

[0027] The planar multi-degree-of-freedom micro-piezoelectric robot with an annular structure of the present invention has small size, simple configuration, simple driving mechanism, high motion efficiency, and especially has the high flexibility feature of being able to realize planar three-degree-of-freedom motion, and has wide application potential in the fields of narrow environment detection, safety rescue, etc.; the annular structure of the present invention combines the efficient actuation characteristics of the piezoelectric beam module and the high efficiency of the traveling wave transmission in the circular ring structure, on the one hand reducing the weight and size of the robot, and on the other hand realizing the robot's three-degree-of-freedom motion in the plane without adding redundant actuating components, thereby reducing the complexity of the robot structure;

[0028] The excitation method of the present invention can stimulate three different axial bending modes of the actuating component by applying a special electrical signal to the actuating component. The combination of these modes can make the driving foot produce an oblique straight line or an elliptical trajectory. The friction between the piezoelectric robot and the ground can enable the piezoelectric robot to realize linear motion and rotational motion in orthogonal directions in the plane; by coupling the required vibration modes, the robot's motion efficiency is enhanced, and in particular, it has the high flexibility feature of being able to realize three-degree-of-freedom motion in the plane. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of the overall structure of a planar multi-degree-of-freedom micro piezoelectric robot with a ring structure according to the present invention;

[0030] Figure 2 It is a structural schematic diagram of the actuating component in the present invention;

[0031] Figure 3 It is a schematic diagram of the top view of the actuating component in the present invention;

[0032] Figure 4 It is a left-side structural schematic diagram of the actuating component in the present invention;

[0033] Figure 5 It is a structural schematic diagram of the guide mechanism in the present invention;

[0034] Figure 6 It is a right side structural schematic diagram of the guide mechanism in the present invention;

[0035] Figure 7 It is a schematic cross-sectional structural diagram of the robot of the present invention;

[0036] Among them, 1. annular base; 2-1. first driving foot; 2-2. second driving foot; 2-3. third driving foot; 2-4. fourth driving foot; 3-1. first piezoelectric ceramic sheet; 3-2. second piezoelectric ceramic sheet; 3-3. third piezoelectric ceramic sheet; 3-4. fourth piezoelectric ceramic sheet; 4-1. first nut; 4-2. second nut; 4-3. third nut; 4-4. fourth nut; 5. bracket; 6-1. first locking bolt; 6-2. second locking bolt; 6-3. third locking bolt; 6-4. fourth locking bolt; 7-1. first guide bearing; 7-2. second guide bearing; 7-3. third guide bearing; 7-4. fourth guide bearing. DETAILED DESCRIPTION

[0037] In order to better explain the present invention and facilitate understanding, the technical solutions and effects of the present invention are described in detail below through specific implementation modes in conjunction with the accompanying drawings.

[0038] like Figure 1As shown, the present invention discloses a ring-shaped planar multi-degree-of-freedom micro piezoelectric robot, including an actuating component and a guide mechanism; the guide mechanism is installed on the actuating component; the actuating component is the main body of the piezoelectric robot, and is composed of an annular base 1, a piezoelectric ceramic sheet assembly and a driving foot assembly; the guide mechanism is composed of a bracket 5, a locking bolt assembly, a nut assembly and a guide bearing assembly. The actuating component generates vibrations to make the driving foot swing in a prescribed mode, and then uses the friction provided by the ground to achieve movement, while the guide mechanism is mainly used to prevent the piezoelectric robot from moving in a narrow path. The role of the guide bearing is to convert the sliding friction of the wall on it into rolling friction when the robot runs in a path with a wall, and finally eliminate the obstruction of the wall to the movement of the robot.

[0039] like Figure 2 As shown, the driving foot assembly includes a first driving foot 2-1, a second driving foot 2-2, a third driving foot 2-3, and a fourth driving foot 2-4, and the piezoelectric ceramic sheet assembly includes a first piezoelectric ceramic sheet 3-1, a second piezoelectric ceramic sheet 3-2, a third piezoelectric ceramic sheet 3-3, and a fourth piezoelectric ceramic sheet 3-4; the straight edge of the annular substrate 1 is used to paste the first piezoelectric ceramic sheet 3-1, the second piezoelectric ceramic sheet 3-2, the third piezoelectric ceramic sheet 3-3, and the fourth piezoelectric ceramic sheet 3-4, and the first piezoelectric ceramic sheet 3-1, the second piezoelectric ceramic sheet 3-2, the third piezoelectric ceramic sheet 3-3, and the fourth piezoelectric ceramic sheet 3-4 are pasted to the upper surface of the annular substrate 1 in a counterclockwise direction. The first piezoelectric ceramic sheet 3-1, the second piezoelectric ceramic sheet 3-2, the third piezoelectric ceramic sheet 3-3, and the fourth piezoelectric ceramic sheet 3-4 are all polarized along the thickness direction to excite the vibration mode of the driving foot; the polarization direction is also perpendicular to the upper surface of the annular substrate 1 and is upward or downward. The first driving foot 2-1, the second driving foot 2-2, the third driving foot 2-3, and the fourth driving foot 2-4 are pasted to the lower surface of the annular base 1 in a counterclockwise direction, and the centroids of the first driving foot 2-1, the second driving foot 2-2, the third driving foot 2-3, and the fourth driving foot 2-4 coincide with the centroids of the corresponding rectangular pasting positions; and correspond one-to-one with the first piezoelectric ceramic sheet 3-1, the second piezoelectric ceramic sheet 3-2, the third piezoelectric ceramic sheet 3-3, and the fourth piezoelectric ceramic sheet 3-4.

[0040] like Figure 3As shown, the annular base 1 is an annular metal structure with straight edges and curved edges; the radial widths of the annular structures where the straight edges and curved edges of the annular base 1 are located are the same; the annular structure with curved edges in the annular base 1 has a blind hole for carrying a guide mechanism, wherein the straight edges of the annular metal structure have the vibration characteristics of the piezoelectric beam module, which improves the actuation characteristics of the first driving foot 2-1, the second driving foot 2-2, the third driving foot 2-3, and the fourth driving foot 2-4 connected to the bottom of the annular base 1, which is beneficial for the robot to achieve efficient linear motion; the curved edges of the annular metal structure have good traveling wave transmission characteristics in the circular ring structure, which is very beneficial for the robot to achieve rotational motion around its own axis; so far, the annular base 1 of the robot combines the comprehensive advantages of the piezoelectric beam module and the circular ring structure, so that the robot can achieve three-degree-of-freedom motion in the plane, thereby maximizing the robot's motion flexibility. The first piezoelectric ceramic sheet 3-1, the second piezoelectric ceramic sheet 3-2, the third piezoelectric ceramic sheet 3-3, and the fourth piezoelectric ceramic sheet 3-4 have the same structure, and are all thin flat plate structures; the lengths of the first piezoelectric ceramic sheet 3-1, the second piezoelectric ceramic sheet 3-2, the third piezoelectric ceramic sheet 3-3, and the fourth piezoelectric ceramic sheet 3-4 are consistent with the length of the straight side of the annular substrate 1;

[0041] like Figure 4 As shown, the structures of the first driving foot 2-1, the second driving foot 2-2, the third driving foot 2-3, and the fourth driving foot 2-4 are consistent, and are all combined cylindrical structures with a circular base and a circular toe; the diameter of the base of the first driving foot 2-1, the second driving foot 2-2, the third driving foot 2-3, and the fourth driving foot 2-4 is smaller than the width of the annular structure in the annular base 1;

[0042] like Figure 5As shown, the locking bolt assembly includes a first locking bolt 6-1, a second locking bolt 6-2, a third locking bolt 6-3, and a fourth locking bolt 6-4; the nut assembly includes a first nut 4-1, a second nut 4-2, a third nut 4-3, and a fourth nut 4-4; the guide bearing assembly includes a first guide bearing 7-1, a second guide bearing 7-2, a third guide bearing 7-3, and a fourth guide bearing 7-4; the first guide bearing 7-1, the second guide bearing 7-2, the third guide bearing 7-3, and the fourth guide bearing 7-4 are horizontally placed on the protruding part of the bracket 5 in a counterclockwise direction, and the centroids of the first guide bearing 7-1, the second guide bearing 7-2, the third guide bearing 7-3, and the fourth guide bearing 7-4 are aligned with the outer edge of the bracket 5. The centroids of the inner holes of the extending parts are aligned, and the first locking bolt 6-1, the second locking bolt 6-2, the third locking bolt 6-3, and the fourth locking bolt 6-4 are inserted into the inner holes of the first guide bearing 7-1, the second guide bearing 7-2, the third guide bearing 7-3, the fourth guide bearing 7-4 and the extending part of the bracket 5 in a counterclockwise direction, and the first nut 4-1, the second nut 4-2, the third nut 4-3, and the fourth nut 4-4 are screwed into the first locking bolt 6-1, the second locking bolt 6-2, the third locking bolt 6-3, and the fourth locking bolt 6-4. While ensuring that the first guide bearing 7-1, the second guide bearing 7-2, the third guide bearing 7-3, and the fourth guide bearing 7-4 can rotate normally, the remaining components do not fall off;

[0043] like Figure 6 As shown, the inner diameters of the first guide bearing 7-1, the second guide bearing 7-2, the third guide bearing 7-3, and the fourth guide bearing 7-4 are larger than the inner diameter of the protruding portion of the bracket 5, while the major diameters of the threads of the first locking bolt 6-1, the second locking bolt 6-2, the third locking bolt 6-3, and the fourth locking bolt 6-4 are smaller than the inner diameter of the protruding portion of the bracket 5, so that the guide bearings can rotate freely. The nominal diameters of the first nut 4-1, the second nut 4-2, the third nut 4-3, and the fourth nut 4-4 are consistent with those of the first locking bolt 6-1, the second locking bolt 6-2, the third locking bolt 6-3, and the fourth locking bolt 6-4.

[0044] like Figure 7 As shown, a small cylinder is provided at the bottom of the bracket 5 corresponding to the position of the blind hole. The small cylinder can be inserted into the blind hole, and the small cylinder and the blind hole are gap-matched so that the two are connected together.

[0045] The present invention also discloses a method for exciting the planar multi-degree-of-freedom micro-piezoelectric robot having a ring structure, comprising the following steps:

[0046] A Cartesian coordinate system o-xyz is pre-set in the annular structure quadruped micro piezoelectric robot, such as Figure 2As shown. Among them, the centroid of the actuating component is the origin of the coordinate system, and the direction from the centroid of the actuating component to the centroid of the second piezoelectric ceramic sheet 3-2 is the positive direction of the x-axis; the direction from the centroid of the actuating component to the centroid of the fourth piezoelectric ceramic sheet 3-4 is the negative direction of the x-axis; the direction from the centroid of the actuating component to the centroid of the third piezoelectric ceramic sheet 3-3 is the positive direction of the y-axis; the direction from the centroid of the actuating component to the centroid of the first piezoelectric ceramic sheet 3-1 is the negative direction of the y-axis; the direction from the centroid of the actuating component to the upper surface of the annular substrate 1 is the positive direction of the z-axis, and vice versa is the negative direction of the z-axis; the linear motion direction of the annular structure quadruped micro piezoelectric robot in the plane is consistent with the Cartesian coordinate system. In addition, with the z-axis as the rotation axis, the rotation direction that coincides with the positive direction of the x-axis after rotating 90 degrees from the positive direction of the y-axis is the clockwise rotation direction of the piezoelectric robot, and vice versa is the counterclockwise rotation direction;

[0047] In this embodiment, the excitation scheme for the ring-shaped quadruped micro piezoelectric robot to achieve linear motion along the x-axis direction is as follows:

[0048] A first excitation signal is applied to the first piezoelectric ceramic piece 3-1, the third piezoelectric ceramic piece 3-3 and the fourth piezoelectric ceramic piece 3-4 in the actuating component, and a second excitation signal is applied to the second piezoelectric ceramic piece 3-2; the first and second excitation signals are both sinusoidal AC voltage signals of the same frequency and amplitude, but the second excitation signal lags behind the first excitation signal by half a cycle in terms of time phase difference; under the action of these excitation signals, the actuating component generates a first-order axial bending vibration mode characterized by the first driving foot 2-1, the second driving foot 2-2, the third driving foot 2-3 and the fourth driving foot 2-4 simultaneously expanding or contracting outward. , and a third-order axial bending vibration mode characterized by the second driving foot 2-2 and the fourth driving foot 2-4 vibrating in opposite directions; based on the combination of the first-order axial bending vibration mode and the third-order axial bending vibration mode, the toe tips of the first driving foot 2-1, the second driving foot 2-2, the third driving foot 2-3 and the fourth driving foot 2-4 generate an oblique linear motion trajectory with a certain angle to the x-axis; using the friction between the first driving foot 2-1, the second driving foot 2-2, the third driving foot 2-3 and the fourth driving foot 2-4 and the ground, the piezoelectric robot can achieve linear motion in the positive direction of the x-axis;

[0049] In this embodiment, when the four-legged micro piezoelectric robot needs to move in the negative direction of the x-axis, it is only necessary to apply the first excitation signal to the first piezoelectric ceramic sheet 3-1, the second piezoelectric ceramic sheet 3-2, and the third piezoelectric ceramic sheet 3-3, and the second excitation signal to the fourth piezoelectric ceramic sheet 3-4; wherein the first and second excitation signals and the generated vibration modes are consistent with those when the robot moves in the positive direction of the x-axis; but the difference is that, in the plane o-zx, the trajectory form of the fourth driving foot 2-4 when the robot moves in the positive direction of the x-axis is different from the trajectory form of the second driving foot 2-2 when the robot moves in the negative direction of the x-axis with respect to the plane o -yz symmetry; in the plane o-zx, the trajectory form of the second driving foot 2-2 when the robot moves in the positive direction of the x-axis and the trajectory form of the fourth driving foot 2-4 when the robot moves in the negative direction of the x-axis are symmetric about the plane o-yz; in the plane o-zx, the trajectory form of the first driving foot 2-1 when the robot moves in the positive direction of the x-axis and the trajectory form of the first driving foot 2-1 when the robot moves in the negative direction of the x-axis are symmetric about the plane o-yz; in the plane o-zx, the trajectory form of the third driving foot 2-3 when the robot moves in the positive direction of the x-axis and the trajectory form of the third driving foot 2-3 when the robot moves in the negative direction of the x-axis are symmetric about the plane o-yz;

[0050] In this embodiment, the excitation scheme for the ring-shaped quadruped micro piezoelectric robot to achieve linear motion along the y-axis is as follows:

[0051] A first excitation signal is applied to the first piezoelectric ceramic piece 3-1, the second piezoelectric ceramic piece 3-2 and the fourth piezoelectric ceramic piece 3-4 in the actuating component, and a second excitation signal is applied to the third piezoelectric ceramic piece 3-3; the first and second excitation signals are consistent with the first and second excitation signals when the robot realizes the positive linear motion of the x-axis; under the action of the first and second excitation signals, the actuating component generates a first-order axial bending vibration mode characterized by the first driving foot 2-1, the second driving foot 2-2, the third driving foot 2-3 and the fourth driving foot 2-4 simultaneously moving outward or contracting, and the characteristic The first driving foot 2-1 and the third driving foot 2-3 vibrate in opposite directions in a third-order axial bending vibration mode; based on the combination of the first-order axial bending vibration mode and the third-order axial bending vibration mode, the toe tips of the first driving foot 2-1, the second driving foot 2-2, the third driving foot 2-3 and the fourth driving foot 2-4 generate an oblique linear motion trajectory having a certain angle with the y-axis; by using the friction between the first driving foot 2-1, the second driving foot 2-2, the third driving foot 2-3 and the fourth driving foot 2-4 and the ground, the piezoelectric robot can move in the positive direction of the y-axis;

[0052] In this embodiment, when the quadruped micro piezoelectric robot needs to move in the negative direction of the y-axis, the first excitation signal is applied to the second piezoelectric ceramic sheet 3-2, the third piezoelectric ceramic sheet 3-3, and the fourth piezoelectric ceramic sheet 3-4, and the second excitation signal is applied to the first piezoelectric ceramic sheet 3-1; wherein the first and second excitation signals and the generated vibration modes are consistent with those when the robot moves in the positive direction of the y-axis; however, the difference is that, in the plane o-yz, the trajectory form of the first driving foot 2-1 when the robot moves in the positive direction of the y-axis and the trajectory form of the third driving foot 2-3 when the robot moves in the negative direction of the y-axis are different with respect to the plane o-z x symmetry; in the plane o-yz, the trajectory form of the third driving foot 2-3 when the robot moves in the positive direction of the y-axis is symmetric with the trajectory form of the first driving foot 2-1 when the robot moves in the negative direction of the y-axis about the plane o-zx; in the plane o-yz, the trajectory form of the second driving foot 2-2 when the robot moves in the positive direction of the y-axis is symmetric with the trajectory form of the second driving foot 2-2 when the robot moves in the negative direction of the y-axis about the plane o-zx; in the plane o-yz, the trajectory form of the fourth driving foot 2-4 when the robot moves in the positive direction of the y-axis is symmetric with the trajectory form of the fourth driving foot 2-4 when the robot moves in the negative direction of the y-axis about the plane o-zx;

[0053] In this embodiment, the excitation scheme for the ring-shaped quadruped micro piezoelectric robot to achieve rotational motion around the z-axis is as follows:

[0054] A first excitation signal is applied to the second piezoelectric ceramic plate 3-2 in the actuating component, a second excitation signal is applied to the fourth piezoelectric ceramic plate 3-4, a third excitation signal is applied to the first piezoelectric ceramic plate 3-1, and a fourth excitation signal is applied to the third piezoelectric ceramic plate 3-3; the first and second excitation signals are consistent with the first and second excitation signals when the robot realizes linear motion of the y-axis; the third and fourth excitation signals are still sinusoidal AC voltage signals, and the frequency amplitudes are consistent with the first and second excitation signals, but the third excitation signal lags behind the first excitation signal by one quarter of a cycle in terms of time phase difference, and the fourth excitation signal lags behind the first excitation signal by three quarters of a cycle in terms of time phase difference; Under the action of the excitation signal, the actuating component generates a third-order axial bending vibration mode characterized by the first driving foot 2-1 and the third driving foot 2-3 vibrating in opposite directions, and a third-order axial bending vibration mode characterized by the second driving foot 2-2 and the fourth driving foot 2-4 vibrating in opposite directions; based on the coupling of the two third-order axial bending vibration modes, the toe tips of the first driving foot 2-1, the second driving foot 2-2, the third driving foot 2-3, and the fourth driving foot 2-4 generate tangential elliptical trajectories; using the friction between the first driving foot 2-1, the second driving foot 2-2, the third driving foot 2-3, and the fourth driving foot 2-4 and the ground, the piezoelectric robot can rotate counterclockwise around the z-axis;

[0055] In this embodiment, when the four-legged micro piezoelectric robot needs to move clockwise around the z-axis, the signal of the first piezoelectric ceramic plate 3-1 is changed to the fourth excitation signal, and the signal of the third piezoelectric ceramic plate 3-3 is changed to the third excitation signal; wherein the first, second, third, and fourth excitation signals and the generated vibration modes are consistent with when the robot rotates clockwise around the z-axis; but the difference is that, in the plane o-yz, the trajectory form of the second driving foot 2-2 when the robot rotates clockwise is symmetrical with the trajectory form of the fourth driving foot 2-4 when the robot rotates counterclockwise about the plane o-yz; In the plane o-yz, the trajectory form of the second driving foot 2-2 when the robot rotates counterclockwise is symmetrical with the trajectory form of the fourth driving foot 2-4 when the robot rotates clockwise about the plane o-yz; in the plane o-zx, the trajectory form of the first driving foot 2-1 when the robot rotates clockwise is symmetrical with the trajectory form of the third driving foot 2-3 when the robot rotates counterclockwise about the plane o-zx; in the plane o-zx, the trajectory form of the first driving foot 2-1 when the robot rotates counterclockwise is symmetrical with the trajectory form of the third driving foot 2-3 when the robot rotates clockwise about the plane o-zx.

Claims

1. A planar multi-degree-of-freedom micro piezoelectric robot with a ring structure, characterized in that: It includes an actuating component and a guiding mechanism; the guiding mechanism is mounted on the actuating component.

2. The planar multi-degree-of-freedom micro-piezoelectric robot with an annular structure according to claim 1, characterized in that: The actuating component comprises an annular base (1), a driving foot assembly and a piezoelectric ceramic sheet assembly; the driving foot assembly comprises a first driving foot (2-1), a second driving foot (2-2), a third driving foot (2-3) and a fourth driving foot (2-4); the piezoelectric ceramic sheet assembly comprises a first piezoelectric ceramic sheet (3-1), a second piezoelectric ceramic sheet (3-2), a third piezoelectric ceramic sheet (3-3) and a fourth piezoelectric ceramic sheet (3-4); the straight edge of the annular base (1) is used to adhere the first piezoelectric ceramic sheet (3-1), the second piezoelectric ceramic sheet (3-2), the third piezoelectric ceramic sheet (3-3) and the fourth piezoelectric ceramic sheet (3-4), and the first piezoelectric ceramic sheet (3-1), the second piezoelectric ceramic sheet (3-2), the third piezoelectric ceramic sheet (3-3) and the fourth piezoelectric ceramic sheet (3-4) are adhered to the annular base (1) in sequence in a counterclockwise direction. 1); the first piezoelectric ceramic sheet (3-1), the second piezoelectric ceramic sheet (3-2), the third piezoelectric ceramic sheet (3-3), and the fourth piezoelectric ceramic sheet (3-4) are all polarized along the thickness direction, and the polarization direction is perpendicular to the upper surface of the annular base (1) and is upward or downward; the first driving foot (2-1), the second driving foot (2-2), the third driving foot (2-3), and the fourth driving foot (2-4) are sequentially pasted to the lower surface of the annular base (1) in a counterclockwise direction, and the centroids of the first driving foot (2-1), the second driving foot (2-2), the third driving foot (2-3), and the fourth driving foot (2-4) coincide with the centroids of the corresponding rectangular pasting positions, and correspond one-to-one with the first piezoelectric ceramic sheet (3-1), the second piezoelectric ceramic sheet (3-2), the third piezoelectric ceramic sheet (3-3), and the fourth piezoelectric ceramic sheet (3-4).

3. The planar multi-degree-of-freedom micro-piezoelectric robot with an annular structure according to claim 2, characterized in that: The guide mechanism comprises a bracket (5), a locking bolt assembly, a nut assembly and a guide bearing assembly; the locking bolt assembly comprises a first locking bolt (6-1), a second locking bolt (6-2), a third locking bolt (6-3) and a fourth locking bolt (6-4); the nut assembly comprises a first nut (4-1), a second nut (4-2), a third nut (4-3) and a fourth nut (4-4); the guide bearing assembly comprises a first guide bearing (7-1), a second guide bearing (7-2), a third guide bearing (7-3) and a fourth guide bearing (7-4); the bracket (5) has a square disc structure, and the outer side of the sharp corner of the square disc structure has an overhanging part with an inner hole; the first guide bearing (7-1), the second guide bearing (7-2), the third guide bearing (7-3) and the fourth guide bearing (7-4) are respectively placed horizontally on the overhanging part of the bracket (5) in a counterclockwise direction, and the first guide bearing (7-1), the second guide bearing (7-2) and the third guide bearing (7-3) are respectively placed on the overhanging part of the bracket (5) in a counterclockwise direction. 2), the centroids of the third guide bearing (7-3) and the fourth guide bearing (7-4) are aligned with the centroid of the inner hole of the protruding part of the bracket (5), the first locking bolt (6-1), the second locking bolt (6-2), the third locking bolt (6-3), and the fourth locking bolt (6-4) are inserted into the inner holes of the first guide bearing (7-1), the second guide bearing (7-2), the third guide bearing (7-3), the fourth guide bearing (7-4) and the protruding part of the bracket (5) in a counterclockwise direction, and the first nut (4-1), the second nut (4-2), the third nut (4-3), and the fourth nut (4-4) are screwed into the first locking bolt (6-1), the second locking bolt (6-2), the third locking bolt (6-3), and the fourth locking bolt (6-4) respectively, and the other components do not fall off while ensuring the normal rotation of the first guide bearing (7-1), the second guide bearing (7-2), the third guide bearing (7-3), and the fourth guide bearing (7-4).

4. The planar multi-degree-of-freedom micro-piezoelectric robot with an annular structure according to claim 3, characterized in that: The annular base (1) is an annular metal structure having a straight edge and an arc-shaped edge; the radial widths of the annular structures where the straight edge and the arc-shaped edge of the annular base (1) are located are the same; a blind hole is provided at the annular structure with the arc-shaped edge of the annular base (1) for carrying a guide mechanism, and a small cylinder is provided at the bottom of the bracket (5) corresponding to the position of the blind hole, and the small cylinder can be inserted into the blind hole, and the small cylinder and the blind hole are gap-matched.

5. The planar multi-degree-of-freedom micro-piezoelectric robot with an annular structure according to claim 2, characterized in that: The first piezoelectric ceramic sheet (3-1), the second piezoelectric ceramic sheet (3-2), the third piezoelectric ceramic sheet (3-3), and the fourth piezoelectric ceramic sheet (3-4) have the same structure, and are all flat plate structures; the lengths of the first piezoelectric ceramic sheet (3-1), the second piezoelectric ceramic sheet (3-2), the third piezoelectric ceramic sheet (3-3), and the fourth piezoelectric ceramic sheet (3-4) are consistent with the length of the straight side of the annular base (1).

6. The planar multi-degree-of-freedom micro-piezoelectric robot with an annular structure according to claim 2, characterized in that: The first driving foot (2-1), the second driving foot (2-2), the third driving foot (2-3), and the fourth driving foot (2-4) have the same structure, and are all combined cylindrical structures with a circular base and a circular toe; the diameter of the base of the first driving foot (2-1), the second driving foot (2-2), the third driving foot (2-3), and the fourth driving foot (2-4) is smaller than the width of the annular structure in the annular base (1).

7. The planar multi-degree-of-freedom micro-piezoelectric robot with an annular structure according to claim 3, characterized in that: The inner hole diameters of the first guide bearing (7-1), the second guide bearing (7-2), the third guide bearing (7-3) and the fourth guide bearing (7-4) are larger than the inner hole diameter of the protruding portion of the bracket (5), while the thread major diameters of the first locking bolt (6-1), the second locking bolt (6-2), the third locking bolt (6-3) and the fourth locking bolt (6-4) are smaller than the inner hole diameter of the protruding portion of the bracket (5), and the nominal diameters of the first nut (4-1), the second nut (4-2), the third nut (4-3) and the fourth nut (4-4) are consistent with those of the first locking bolt (6-1), the second locking bolt (6-2), the third locking bolt (6-3) and the fourth locking bolt (6-4).

8. The method for exciting a planar multi-degree-of-freedom micro-piezoelectric robot with a ring structure according to any one of claims 1 to 7, characterized in that: The following steps are involved: A Cartesian coordinate system o-xyz is set in the piezoelectric robot, the centroid of the actuating component is the origin of the coordinate system, the direction from the centroid of the actuating component to the centroid of the second piezoelectric ceramic sheet (3-2) is the positive direction of the x-axis; the direction from the centroid of the actuating component to the centroid of the fourth piezoelectric ceramic sheet (3-4) is the negative direction of the x-axis; the direction from the centroid of the actuating component to the centroid of the third piezoelectric ceramic sheet (3-3) is the positive direction of the y-axis; the direction from the centroid of the actuating component to the centroid of the first piezoelectric ceramic sheet The direction of the centroid of (3-1) is the negative direction of the y-axis; the direction from the centroid of the actuating component to the upper surface of the annular substrate (1) is the positive direction of the z-axis, and as the rotation axis, the direction pointing to the lower surface of the annular substrate (1) is the negative direction of the z-axis. The linear motion direction of the piezoelectric robot in the plane is consistent with the Cartesian coordinate system; the rotation direction that coincides with the positive direction of the x-axis after rotating 90 degrees from the positive direction of the y-axis is the clockwise rotation direction of the piezoelectric robot, and the opposite is the counterclockwise rotation direction. The excitation scheme for the micro piezoelectric robot to achieve linear motion along the x-axis: A first excitation signal is applied to the first piezoelectric ceramic plate (3-1), the third piezoelectric ceramic plate (3-3) and the fourth piezoelectric ceramic plate (3-4), and a second excitation signal is applied to the second piezoelectric ceramic plate (3-2); the first and second excitation signals are both sinusoidal alternating voltage signals of the same frequency and amplitude, and the second excitation signal lags behind the first excitation signal by half a cycle in terms of time phase difference; Under the action of these excitation signals, a first-order axial bending vibration mode characterized by the simultaneous outward expansion or contraction of the first driving foot (2-1), the second driving foot (2-2), the third driving foot (2-3), and the fourth driving foot (2-4) is generated, as well as a third-order axial bending vibration mode characterized by the second driving foot (2-2) and the fourth driving foot (2-4) vibrating in opposite directions. Based on the combination of the first-order axial bending vibration mode and the third-order axial bending vibration mode, the toe tips of the first driving foot (2-1), the second driving foot (2-2), the third driving foot (2-3), and the fourth driving foot (2-4) generate an oblique linear motion trajectory with a certain angle to the x-axis. By utilizing the friction between the first driving foot (2-1), the second driving foot (2-2), the third driving foot (2-3), and the fourth driving foot (2-4) and the ground, the piezoelectric robot can achieve linear motion in the positive direction of the x-axis. When the piezoelectric robot needs to move in the negative direction of the x-axis, it is only necessary to apply the first excitation signal to the first piezoelectric ceramic sheet (3-1), the second piezoelectric ceramic sheet (3-2), and the third piezoelectric ceramic sheet (3-3), and the second excitation signal to the fourth piezoelectric ceramic sheet (3-4); The excitation scheme for the micro piezoelectric robot to achieve linear motion along the y-axis: A first excitation signal is applied to the first piezoelectric ceramic sheet (3-1), the second piezoelectric ceramic sheet (3-2) and the fourth piezoelectric ceramic sheet (3-4), and a second excitation signal is applied to the third piezoelectric ceramic sheet (3-3); the first and second excitation signals are the same as the first and second excitation signals when the robot realizes linear motion in the positive direction of the x-axis; Under the action of the first and second excitation signals, the actuating component generates a first-order axial bending vibration mode characterized by the first driving foot (2-1), the second driving foot (2-2), the third driving foot (2-3), and the fourth driving foot (2-4) simultaneously moving outward or contracting, and a third-order axial bending vibration mode characterized by the first driving foot (2-1) and the third driving foot (2-3) vibrating in opposite directions; based on the combination of the first-order axial bending vibration mode and the third-order axial bending vibration mode, the toe tips of the first driving foot (2-1), the second driving foot (2-2), the third driving foot (2-3), and the fourth driving foot (2-4) generate an oblique linear motion trajectory having a certain angle with the y-axis; by utilizing the friction between the first driving foot (2-1), the second driving foot (2-2), the third driving foot (2-3), and the fourth driving foot (2-4) and the ground, the piezoelectric robot can move in the positive direction of the y-axis; When the micro-piezoelectric robot needs to move in the negative direction of the y-axis, the first excitation signal is applied to the second piezoelectric ceramic sheet (3-2), the third piezoelectric ceramic sheet (3-3), and the fourth piezoelectric ceramic sheet (3-4), and the second excitation signal is applied to the first piezoelectric ceramic sheet (3-1); The excitation scheme for the micro piezoelectric robot to achieve rotational motion around the z-axis: A first excitation signal is applied to the second piezoelectric ceramic plate (3-2), a second excitation signal is applied to the fourth piezoelectric ceramic plate (3-4), a third excitation signal is applied to the first piezoelectric ceramic plate (3-1), and a fourth excitation signal is applied to the third piezoelectric ceramic plate (3-3); the first and second excitation signals are consistent with the first and second excitation signals when the robot realizes linear motion of the y-axis; the third and fourth excitation signals are sinusoidal AC voltage signals, and are consistent with the frequency amplitudes of the first and second excitation signals; the third excitation signal lags behind the first excitation signal by one quarter of a cycle in terms of time phase difference, and the fourth excitation signal lags behind the first excitation signal by three quarters of a cycle in terms of time phase difference; under the action of the excitation signals, A third-order axial bending vibration mode characterized by opposite vibration directions of the first driving foot (2-1) and the third driving foot (2-3) is generated, as well as a third-order axial bending vibration mode characterized by opposite vibration directions of the second driving foot (2-2) and the fourth driving foot (2-4); based on the coupling of the two third-order axial bending vibration modes, the toe tips of the first driving foot (2-1), the second driving foot (2-2), the third driving foot (2-3), and the fourth driving foot (2-4) generate tangential elliptical trajectories; and by utilizing the friction between the first driving foot (2-1), the second driving foot (2-2), the third driving foot (2-3), the fourth driving foot (2-4) and the ground, the piezoelectric robot can rotate counterclockwise around the z-axis; When the micro piezoelectric robot needs to move clockwise around the z-axis, the signal of the first piezoelectric ceramic piece (3-1) is changed to the fourth excitation signal, and the signal of the third piezoelectric ceramic piece (3-3) is changed to the third excitation signal.

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