Piezoelectric stack driven micro piezoelectric mobile robot and driving control method thereof

Abstract

The invention belongs to the technical field of piezoelectric actuators, and provides a piezoelectric stack driven miniature piezoelectric mobile robot and a driving control method thereof, and the technical scheme is that piezoelectric actuators are arranged on two sides of the bottom end of a robot body, piezoelectric stacks and legs are arranged on two sides of each piezoelectric actuator, a driving circuit is arranged in the robot body, and the piezoelectric stacks are connected with the driving circuit. The output end of the driving circuit is connected to the piezoelectric stack, and the two lower metal sheets are respectively adhered to the upper side and the lower side of the piezoelectric ceramic; receiving a target remote control signal, analyzing the target remote control signal, and outputting a corresponding control signal; specific motion control parameters are determined according to the control signal, a driving signal is adjusted based on the motion control parameters, the piezoelectric ceramic vibrates in the length direction under the application of the driving signal, the vibration in the length direction is converted into the thickness direction through the upper and lower metal sheets, and the legs are driven to move. The structure is light and simple, the manufacturing complexity is low, manufacturing / assembling errors are reduced, the controllability is high, and multi-application-scene system integration is easy to achieve.

Description

Technical Field

[0001] The present invention belongs to the technical field of piezoelectric drivers, and in particular relates to a piezoelectric stack-driven micro piezoelectric mobile robot and a driving and controlling method thereof. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Micro-robots integrate multiple disciplines including mechanics, electronics, control and computers. They are a hot research direction for robotics in recent years. Based on their small size, light weight and flexible movement, they can be applied to many fields such as bioengineering, military reconnaissance, cell puncture and optical measurement. Piezoelectric / ultrasonic actuators are actuators that use the reverse piezoelectric effect to generate displacement by applying voltage. Compared with traditional motors and electromagnetic actuators, piezoelectric / ultrasonic actuators have many advantages such as fast response, high reliability, low power consumption, small size and high resolution. Therefore, in intelligent industrial scenarios with high precision, high integration and high power density such as optical focusing equipment, robots, aerospace, micro-machinery, etc., piezoelectric / ultrasonic robots have more significant technical advantages and broad application prospects.

[0004] In order to meet the use requirements in different scenarios, a variety of micro robots have been developed. For example, the publication number CN114935472A proposes a soil detection micro robot, including a soil drilling component, a steering component, a modular peristaltic mechanism, a universal joint and a power supply component connected in sequence, and the outer surfaces of the soil drilling component and the power supply component are provided with a patch type temperature and humidity sensor, and the patch type temperature and humidity sensor outputs the detection signal to the outside through the wireless communication module, and can move forward in a complex and harsh soil environment and perform soil detection activities at the same time; the publication number CN117922722A provides a planar multi-degree-of-freedom three-legged piezoelectric robot and a driving method, including a robot base, a plurality of driving feet are distributed in a circular array on the lower surface of the robot base, and the end of the driving foot away from the robot base is in contact with the ground, and each driving foot is provided with a plurality of groups of inertial driving piezoelectric ceramics, and each group of inertial driving piezoelectric ceramics is respectively installed on the side wall of the driving foot close to the center of the robot base and away from the center of the robot base, and the inertial driving piezoelectric ceramics are used for externally connecting an AC voltage to make the inertial driving piezoelectric ceramics produce deformation along the central axis direction of the robot base. The main components of the entire robot include the robot base, inertial drive piezoelectric ceramics and resonant drive piezoelectric ceramics, which simplify the structure of the robot and facilitate the assembly and repair of the robot. When driven by applied AC voltage, inertial stepping motion and resonant motion are realized, thereby improving the robot's motion accuracy. The micro robots with publication numbers CN218599155U and CN1836848A are also used for walking in special environments to realize operations, data collection, and obstacle crossing.

[0005] In order to achieve specific functions, untethered microrobots need to be equipped with corresponding wireless devices, storage components and signal transmitters, which requires the microrobot to have a certain load capacity and maintain good movement ability when carrying equipment. However, the above-mentioned traditional electromagnetic-driven robots are driven by electromagnetic motors and complex mechanical structures, which is not conducive to the miniaturization and lightweight of robots. In addition, electromagnetic motors are easily affected by electromagnetic interference and generate serious heat after long-term operation, which is not conducive to continuous and stable operation in extreme environments, limiting their comprehensive performance and application prospects. For piezoelectric microrobots, they are generally excited by transducers or piezoelectric ceramic patches to generate corresponding movements. When transducer excitation is used, it is difficult to achieve large adjustments in geometric parameters due to the influence of the vibration frequency-wavelength relationship. The length of the actuator in the transducer vibration propagation direction (wavelength direction) is limited, the mass / size can be optimized in a small space, and the system integration is difficult. The manufacturing complexity and manufacturing / assembly errors of piezoelectric / ultrasonic actuators using patch-type piezoelectric / ultrasonic actuators seriously affect the performance of the actuators. The piezoelectric / ultrasonic actuators using single longitudinal vibrations have complex structures and are difficult to design. Summary of the invention

[0006] In order to solve at least one technical problem existing in the above-mentioned background technology, the first aspect of the present invention provides a micro piezoelectric mobile robot driven by a piezoelectric stack, which adopts a piezoelectric stack as a driving unit, has a light and simple structure, low manufacturing complexity, reduced manufacturing / assembly errors, strong controllability, and easy to realize system integration in multiple application scenarios.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] A piezoelectric stack-driven micro-piezoelectric mobile robot comprises a robot body, piezoelectric actuators are arranged on both sides of the bottom of the robot body, each piezoelectric actuator has the same structure, piezoelectric stacks and legs are arranged on both sides of each piezoelectric actuator, a driving circuit is arranged inside the robot body, the output end of the driving circuit is connected to the piezoelectric stack, each piezoelectric stack comprises a piezoelectric ceramic and two upper and lower metal sheets, and the lower two metal sheets are respectively adhered to the upper and lower sides of the piezoelectric ceramic;

[0009] The driving circuit is configured to: receive a target remote control signal, analyze the target remote control signal and output a corresponding control signal; determine specific motion control parameters according to the analyzed control signal, and adjust the driving signal based on the motion control parameters. When the driving signal is applied, the piezoelectric ceramic vibrates along the length direction, and the upper and lower metal sheets convert the vibration in the length direction into the thickness direction, thereby driving the leg movement.

[0010] As an embodiment, a rear wheel is also arranged at the bottom of the body, and the piezoelectric actuator includes a first piezoelectric actuator and a second piezoelectric actuator, the first piezoelectric actuator and the second piezoelectric actuator are arranged in parallel, and the first piezoelectric actuator, the second piezoelectric actuator and the landing point of the rear wheel form an equilateral triangle.

[0011] As an embodiment, each piezoelectric actuator includes a supporting structure, which includes a top surface and two side surfaces that are integral with the top surfaces, the top surface has a threaded hole, and the top surface is connected to the body through the threaded hole and bolts; a piezoelectric stack is arranged on each side surface, one end of the leg is fixed to the side surface, and the other end is coupled to each other.

[0012] As an implementation mode, weight-reducing grooves are symmetrically arranged on both sides of the threaded hole, and weight-reducing holes are arranged on both sides.

[0013] As an embodiment, the leg includes two metal sheets and an aluminum alloy foot, one end of each metal sheet is fixed to the side of the supporting structure, and the other end is coupled to the aluminum alloy foot via a coupling agent.

[0014] As an embodiment, the lower end of the aluminum alloy foot is a hemispherical surface.

[0015] As an embodiment, the driving circuit includes a control circuit, a Boost amplifier circuit and an H-bridge circuit. The input end of the control circuit is connected to the remote control signal, the first output end of the control circuit is connected to the Boost amplifier circuit, the second output end is connected to the H-bridge circuit, the output end of the Boost amplifier circuit is connected to the input end of the H-bridge circuit, and the output end of the H-bridge circuit is connected to the corresponding load, namely the piezoelectric stack.

[0016] The second aspect of the present invention provides a driving method for a micro piezoelectric mobile robot driven by a piezoelectric stack, which uses a piezoelectric stack as a driving unit, has a light and simple structure, low manufacturing complexity, reduced manufacturing / assembly errors, strong controllability, and easy implementation of system integration for multiple application scenarios.

[0017] In order to achieve the above object, the present invention adopts the following technical solution:

[0018] A driving method for a piezoelectric stack-driven micro-piezoelectric mobile robot, based on the piezoelectric stack-driven micro-piezoelectric mobile robot described in the first aspect, comprises the following steps:

[0019] Receive the target remote control signal, analyze the target remote control signal and output the corresponding control signal;

[0020] Determine specific motion control parameters based on the control signal obtained by analysis;

[0021] The driving signal is adjusted based on the motion control parameters. When the driving signal is applied, the piezoelectric ceramic vibrates along the length direction. The upper and lower metal sheets convert the vibration in the length direction to the thickness direction, driving the leg movement.

[0022] Furthermore, different remote control signals correspond to corresponding channel parameters. When the remote control signal is changed, the parameters of different channels will change, thereby generating different control signals.

[0023] Furthermore, the method also includes acquiring speed and acceleration information of the robot during the movement of the robot; adjusting the driving signal according to the acquired speed and acceleration information of the robot, and feeding back to the piezoelectric stack to adjust the action of the robot.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. Traditional electromagnetic motor-driven robots require complex mechanical structures to cooperate with the drive, which makes it difficult to achieve miniaturization and modularization. The actuators are susceptible to electromagnetic interference, have poor controllability, and lack application scenarios. The robot of the present invention uses piezoelectric ceramics as a driving unit, and controls the drive circuit to output a driving signal according to the type of signal. Under the application of the driving signal, the same piezoelectric stack vibrates along the length direction and converts the vibration in the length direction to the thickness direction, driving the leg movement. It has low manufacturing complexity, reduces manufacturing / assembly errors, has strong controllability, and is easy to achieve system integration in multiple application scenarios.

[0026] 2. The manufacturing complexity and manufacturing / assembly errors of piezoelectric / ultrasonic actuators using clamping and patch-type piezoelectric / ultrasonic actuators seriously affect the performance of the actuator. The piezoelectric / ultrasonic actuator using a single longitudinal vibration has a complex structure and is difficult to design. A non-resonant drive method is adopted to avoid the difficulty in the design of the vibration body structure. A piezoelectric stack with an amplification mechanism is used as the driving unit to amplify the output displacement on the vibration side, effectively improving the thrust density and power density, and achieving fast speed and high load.

[0027] 3. In view of the high integration of micro-robots, robots using electromagnetic drive will be affected by electromagnetic interference of the circuit, and the operating frequency bandwidth of traditional ultrasonic piezoelectric actuators is large. Untethered work has certain requirements on the power consumption and continuous movement time of the mounted circuit, which affects the load / weight ratio and autonomous working time of the actuator; low-frequency signal drive is used, and the required drive signal frequency is low and the required bandwidth is small. The piezoelectric stack needs to provide stable high power for driving. The circuit design uses a high-power Boost circuit to amplify the input voltage and is connected to four charge-type H-bridges dedicated to the piezoelectric stack. The H-bridge circuit uses MOSFET tubes as switching elements. The low-frequency signal switching energy loss is small, and the resistance of the element itself can be ignored, which does not affect the load voltage, effectively reducing and saving circuit energy consumption and ensuring continuous and stable output of the circuit.

[0028] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0030] Figure 1 It is a schematic diagram of the overall structure of a piezoelectric stack-driven micro piezoelectric mobile robot provided by an embodiment of the present invention;

[0031] Figure 2 is a schematic diagram of the structure of a piezoelectric actuator provided by an embodiment of the present invention;

[0032] Figure 3 is a schematic diagram of the motion principle of a piezoelectric actuator provided by an embodiment of the present invention;

[0033] Figure 4 is a cross-sectional view of a robot provided by an embodiment of the present invention;

[0034] Figure 5 is a schematic diagram of the structure of a driving circuit provided by an embodiment of the present invention;

[0035] Figure 6 is the step mode driving voltage provided by the embodiment of the present invention;

[0036] Figure 7 is a control strategy flow chart provided by an embodiment of the present invention;

[0037] Among them, 1. piezoelectric actuator; 11. supporting structure; 111. threaded hole; 112. weight-reducing groove; 113. weight-reducing hole; 12. piezoelectric stack; 13. leg; 131. metal sheet; 132. aluminum alloy foot; 2. rear wheel; 3. body; 31. outer shell; 32. drive circuit; 33. battery. DETAILED DESCRIPTION

[0038] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0039] It should be noted that the following detailed descriptions are all illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0040] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0041] In the present invention, the directions or positional relationships indicated by terms such as "upper", "lower", "side", "bottom", etc. are based on the directions or positional relationships shown in the accompanying drawings. They are relational words determined only for the convenience of describing the structural relationships of the various parts or elements of the present invention. They do not specifically refer to any part or element in the present invention and cannot be understood as limitations on the present invention.

[0042] In the present invention, terms such as "connected" and "connection" should be understood in a broad sense, indicating that the connection can be fixed, integral or detachable; it can be directly connected or indirectly connected through an intermediate medium. Relevant scientific research or technical personnel in this field can determine the specific meaning of the above terms in the present invention according to specific circumstances, and they should not be understood as limiting the present invention.

[0043] Traditional electromagnetic motor-driven robots require complex mechanical structures to cooperate with the drive, which makes it difficult to achieve miniaturization and modularization. The actuators are susceptible to electromagnetic interference, have poor controllability, and lack application scenarios. The robot uses piezoelectric ceramics as the driving unit. The piezoelectric actuator consists of three parts. The piezoelectric actuator adopts a triangular structure, which has a stable and simple structure, low manufacturing complexity, reduced manufacturing / assembly errors, strong controllability, and easy system integration for multiple application scenarios.

[0044] In view of the problems that traditional electromagnetic motor-driven robots require complex mechanical structures to cooperate with the drive, are difficult to achieve miniaturization and modularization, and the actuators are susceptible to electromagnetic interference, have poor controllability, and lack application scenarios, the present invention adopts a piezoelectric stack as a driving unit, which has a light and simple structure, low manufacturing complexity, reduced manufacturing / assembly errors, strong controllability, and easy to achieve system integration in multiple application scenarios.

[0045] In order to address the problems that the manufacturing complexity and manufacturing / assembly errors of piezoelectric / ultrasonic actuators using clamping and patch-type piezoelectric / ultrasonic actuators seriously affect the performance of the actuator, and the piezoelectric / ultrasonic actuators using single longitudinal vibration have complex structures and are difficult to design, the present invention adopts a non-resonant driving method to avoid the difficulties in the design of the vibration body structure, uses a piezoelectric stack with an amplification mechanism for actuation, amplifies the output displacement on the vibration side, effectively improves the thrust density and power density, and achieves fast speed and high load.

[0046] Due to the high integration of micro-robots, robots using electromagnetic drive will be affected by electromagnetic interference of the circuit. The operating frequency bandwidth of traditional ultrasonic piezoelectric actuators is large. Untethered work has certain requirements on the power consumption and continuous movement time of the mounted circuit, which affects the load / weight ratio and autonomous working time of the actuator; low-frequency signal drive is used, and the required drive signal frequency is low and the required bandwidth is small. The piezoelectric stack needs to provide stable high power for driving. The circuit design uses a high-power Boost circuit to amplify the input voltage and connect it to four charge-type H-bridges dedicated to the piezoelectric stack. The H-bridge circuit uses MOSFET tubes as switching elements. The low-frequency signal switching energy loss is small, and the resistance of the element itself can be ignored, which does not affect the load voltage, effectively reducing and saving circuit energy consumption and ensuring continuous and stable output of the circuit.

[0047] Embodiment 1

[0048] like Figure 1As shown, this embodiment provides a piezoelectric stack-driven micro-piezoelectric mobile robot, including two piezoelectric actuators 1, rear wheels 2 and a body 3; the piezoelectric actuators 1 and the rear wheels 2 are arranged at the bottom of the body 3; the two piezoelectric actuators 1 are arranged in parallel, and the landing points of the two piezoelectric actuators 1 and the rear wheels 2 form an equilateral triangle, realizing an imitation wooden ox and horse configuration, ensuring that the robot structure is stable and minimized.

[0049] In this embodiment, the piezoelectric actuator 1 is connected to the machine body 3 via bolts, and the rear wheel 2 is connected to the machine body via a socket.

[0050] like Figure 2 The figure shows a schematic diagram of the structure of the piezoelectric actuator 1. Each piezoelectric actuator includes a support structure 11, a piezoelectric stack 12 and a leg 13. The support structure 11 includes a top surface and two sides with the top surfaces being integrated. The top surface is provided with a threaded hole 111, and is connected to the body 3 through the threaded hole 111 and a bolt. Weight reduction grooves 112 are symmetrically arranged on both sides of the threaded hole, and a piezoelectric stack 12 is arranged on each side. One end of the leg 13 is fixed to the side, and the other end is coupled to each other.

[0051] In this embodiment, the side piezoelectric stack 12 is fixed to the bottom of the side surface by double-sided adhesive;

[0052] In this embodiment, weight-reducing holes 113 are provided on both sides, and the weight-reducing holes 113 are distributed in the center.

[0053] In this embodiment, the piezoelectric stack 12 includes a piezoelectric ceramic and two upper and lower metal sheets, which are respectively attached to the piezoelectric ceramic to form a parallelogram structure with an amplifying effect. In this embodiment, the upper and lower metal sheets are made of stainless steel sheets.

[0054] A piezoelectric stack with an amplifying mechanism is used for actuation to amplify the output displacement on the vibration side, effectively increasing the thrust density and achieving fast speed and high load. Piezoelectric ceramics stretch and contract along the length direction, and the displacement and thrust converted to the thickness direction are about ten times the displacement and thrust generated by the ceramic stretching. Piezoelectric actuation accumulates tiny displacements, and after a single displacement is amplified, the speed will be increased while the frequency remains unchanged. With the presence of an amplifying mechanism, the displacement and thrust per unit time at low frequencies are increased, the thrust density is increased, and the upward support force is increased.

[0055] The leg 13 includes two metal sheets 131 and an aluminum alloy foot 132. One end of each metal sheet 131 is fixed to the upper support side, and the other end is coupled to the aluminum alloy foot 132 through a coupling agent. Preferably, the metal sheet 131 is made of stainless steel sheet, and the lower end of the aluminum alloy foot 132 is a hemispherical surface to ensure that the contact point with the ground is as small as possible.

[0056] Figure 3This is a working principle diagram of the piezoelectric actuator 1. When working, the driving circuit applies a square wave signal with a phase difference of π / 2 to the two piezoelectric stacks of a piezoelectric actuator 1. The piezoelectric stack on one side is stretched along the length direction and contracted in the thickness direction, driving the legs upward. At the same time, the piezoelectric stack on the other side is contracted along the length direction and stretched in the thickness direction, driving the legs downward. The aluminum alloy foot 132 of the piezoelectric actuator 1 produces an elliptical motion with a braking effect.

[0057] At the same time, there is a phase difference of π between the two piezoelectric actuators 1, which makes the robot move in a specified direction similar to the posture of a human walking with two legs alternately. When the signal phase of the two piezoelectric stacks of a single piezoelectric actuator is changed, the robot will move in the opposite direction.

[0058] Figure 4 It is a cross-sectional view of the robot, wherein the body 3 includes a shell 31, and a driving circuit 32 and a battery 33 are arranged in the shell cavity;

[0059] like Figure 5 As shown, the driving circuit 32 includes a control circuit, a Boost amplifier circuit and an H-bridge circuit. The input end of the control circuit is connected to the remote control signal, the first output end of the control circuit is connected to the Boost amplifier circuit, the second output end is connected to the H-bridge circuit, the output end of the Boost amplifier circuit is connected to the input end of the H-bridge circuit, and the output end of the H-bridge circuit is connected to the corresponding load, i.e., the piezoelectric stack;

[0060] The battery 33 is connected to the control circuit and the Boost amplifier circuit respectively to supply power to the control circuit and the Boost amplifier circuit;

[0061] The control signal output by the control circuit is two opposite square wave signals, one of which is input to the Boost amplifier circuit. The input end of the Boost amplifier circuit is connected to the battery voltage, and the output end uses a pure resistor in series with an isolation amplifier and another pure resistor. The output signal of the control circuit changes the current size of the isolation amplifier circuit, thereby changing the output voltage size of the Boost amplifier circuit, so the output drive signal voltage acting on the piezoelectric stack also produces the same change;

[0062] The other input is to the H-bridge circuit to control the opening and closing of the switch element of the H-bridge circuit. By changing the frequency of the control signal, the switching frequency of the switch element changes accordingly, and the output drive signal frequency also changes in the same way.

[0063] In this embodiment, the H-bridge circuit adopts a micro H-bridge circuit. By designing a micro H-bridge circuit specifically driving the piezoelectric stack, it adopts a low-frequency signal drive, which is suitable for high-voltage and high-charge piezoelectric drive elements. The high-power amplifier circuit and the four H-bridge circuits ensure efficient motion output, reduce circuit energy consumption, and improve the robot's deadweight / load ratio.

[0064] like Figure 5 and Figure 7 As shown, the specific control process includes:

[0065] The control circuit is used to receive the target remote control signal, analyze the target remote control signal and output the corresponding control signal; determine the specific motion control parameters according to the analyzed control signal, and adjust the Boost amplifier circuit and the H-bridge circuit based on the motion control parameters to generate a drive signal. When the drive signal is applied, the piezoelectric ceramic vibrates along the length direction, and the upper and lower metal sheets convert the vibration in the length direction to the thickness direction, thereby driving the leg movement.

[0066] In this embodiment, receiving the target remote control signal and analyzing the target remote control signal to output the corresponding control signal specifically includes:

[0067] The remote control signals sent by the remote control handle include various commands for controlling the robot's movement, such as forward, backward, speed adjustment, and steering. Different remote control signals correspond to corresponding channel parameters. When the remote control signal is changed, the parameters of different channels will change, thus generating different control signals. Therefore, the control signal categories are distinguished according to the different parameters of each channel.

[0068] The following is an example to explain how to distinguish control signal categories based on the different parameters of each channel;

[0069] The remote control handle includes two left and right joysticks that can move along the XY axes, a left front pulley and a left toggle switch, a right trigger key and a right front button.

[0070] For example, channel 1 is the corresponding value when the right joystick moves on the Y axis. The remote sensing is at the top of the Y axis, that is, the joystick is pushed to the top, which is defined as a straight signal. The control circuit receives a signal from channel 1 of 200, and if the joystick is at the bottom, the signal is 1400.

[0071] Channel 2 is the value corresponding to the right joystick moving on the X axis. The remote sensing is on the far left of the X axis, that is, the joystick is pushed to the far left, which is defined as a left turn signal. The signal received by the control circuit from channel 2 is 200. If the joystick is on the far right, the signal is 1400. In order to ensure fault tolerance, the value will have a certain range. The actual limit values ​​of the two joysticks are 200-1400.

[0072] For example, when going straight, the corresponding value of channel 1 will be less than 800, and the corresponding value of channel 2 will be between 800-1200. In addition, the smaller the value of channel 1, the faster the forward speed. At this time, set the value of channel 1 to 400-1000, and the value of channel 2 to 700-1000 to define it as a straight signal. When turning left, the corresponding value of channel 1 is between 800-1200, and the value of channel 2 is less than 400. At this time, set the value of channel 2 to less than 400, and the value of channel 1 to 700-1000 to define it as a left turn signal.

[0073] Generate a pressure drive signal based on the motion control parameters, specifically including:

[0074] The robot has two piezoelectric actuators. Controlling one piezoelectric actuator requires two square wave signals with a phase difference of 90°, and is controlled via four signals.

[0075] When going straight, the four signals are turned on at the same time, and the two piezoelectric actuators move forward at the same time. The turning range is determined by the channel parameters. Different voltages are applied to the two legs for different ranges. For example, when turning left slightly, the right leg maintains a high voltage and the left leg voltage decreases; when turning sharply, the right leg maintains a high voltage and the left leg signal is turned off. When stepping, you need to press the setting button. After pressing it, the robot outputs Figure 6 Sawtooth wave signal.

[0076] In this embodiment, under the application of the adjusted driving signal, the piezoelectric stack is controlled to vibrate along the length direction, and the vibration in the length direction is converted to the thickness direction, driving the legs to move to realize the movement of the robot.

[0077] Apply the following pressure to the two piezoelectric actuators of the robot: Figure 5 The excitation voltage is , during the stage of slow voltage rise, the piezoelectric stack 12 stretches along the thickness direction, pushing the aluminum alloy foot 132 slowly forward in the target direction; during the stage of rapid voltage drop, the piezoelectric stack 12 contracts along the thickness direction, pushing the aluminum alloy foot 132 forward in the opposite direction, and the piezoelectric stack on the other side contracts along the thickness direction, pulling the foot up from the ground, reducing the friction between the aluminum alloy foot 132 and the ground, so that the aluminum alloy foot 132 basically remains stationary, realizing the resonant "stick-slip" alternating stepping motion, and achieving high-precision resolution micro-displacement.

[0078] Furthermore, a sinusoidal wave signal is input for excitation, and the piezoelectric ceramic vibrates along the length direction. The stainless steel sheet on the surface amplifies the vibration in the length direction and converts it to the thickness direction. The leg is coupled by two stainless steel sheets 131 and the aluminum alloy foot 132 through a coupling agent. The lower end of the aluminum alloy foot 132 is a hemispherical surface to ensure that the contact point with the ground is as small as possible.

[0079] Figure 7This is the control strategy flow chart of the robot. After the robot is powered on, it receives the signal sent by the remote control device. If no signal is received, the robot enters the standby state. If a signal is received, the robot outputs the corresponding drive signal according to the different received signals, and reads the current speed / acceleration information of the robot at the same time, adjusts the drive signal according to the real-time information, and optimizes the robot's actions.

[0080] Embodiment 2

[0081] This embodiment provides a driving method for a micro-piezoelectric mobile robot driven by a piezoelectric stack according to the first embodiment, comprising:

[0082] Step 1: Receive the target remote control signal, analyze the target remote control signal and output the corresponding control signal;

[0083] In this embodiment, different remote control signals correspond to corresponding channel parameters. When the remote control signal is changed, the parameters of different channels will change, thereby generating different control signals.

[0084] For example, when going straight, the corresponding value of channel 1 is less than 800, and the corresponding value of channel 2 is between 800-1200. In addition, the smaller the value of channel 1, the faster the forward speed. At this time, the program defines the value of channel 1 between 400-1000 and the value of channel 2 between 700-1000 as a straight signal. When turning left, the corresponding value of channel 1 is between 800-1200, and the value of channel 2 is less than 400. At this time, the program defines the value of channel 2 less than 400 and the value of channel 1 between 700-1000 as a left turn signal.

[0085] Step 2: Determine specific motion control parameters according to the control signal obtained by analysis, and adjust the drive signal based on the motion control parameters;

[0086] Determine specific motion parameters according to the channel parameters corresponding to the control signal, the piezoelectric stack on each piezoelectric actuator corresponds to one drive signal, and adjust the voltage of each drive signal based on the motion parameters;

[0087] The robot has two piezoelectric actuators. Controlling one piezoelectric actuator requires two square wave signals with a phase difference of 90°, which are controlled by 4 signals. When going straight, the 4 signals are turned on at the same time, and the two piezoelectric actuators move forward at the same time. The turning amplitude is determined according to the channel parameters. Different amplitudes apply different voltages to the two legs. For example, when turning left slightly, the right leg maintains a high voltage and the voltage of the left leg decreases; when turning sharply, the right leg maintains a high voltage and the left leg signal is turned off. When stepping, you need to press the setting button. After pressing it, the robot outputs as follows Figure 5 Sawtooth wave signal.

[0088] Step 3: When the driving signal is applied, the piezoelectric ceramic vibrates along the length direction, and the upper and lower metal sheets convert the vibration in the length direction to the thickness direction, driving the leg movement;

[0089] In this embodiment, during the stage of slow voltage rise, the piezoelectric stack 12 stretches along the thickness direction, pushing the aluminum alloy foot 132 slowly forward in the target direction; during the stage of rapid voltage drop, the piezoelectric stack 12 contracts along the thickness direction, pushing the aluminum alloy foot 132 forward in the opposite direction, and the piezoelectric stack on the other side contracts along the thickness direction, pulling the foot up from the ground, reducing the friction between the aluminum alloy foot 132 and the ground, so that the aluminum alloy foot 132 basically remains stationary, realizing a resonant "stick-slip" alternating stepping motion, and achieving high-precision resolution micro-displacement.

[0090] Step 4: Get the speed and acceleration information of the robot;

[0091] Step 5: According to the obtained speed and acceleration information of the robot, adjust the drive signal to optimize the robot's action;

[0092] In this embodiment, according to the acquired speed and acceleration information of the robot, when adjusting the drive signal, the existing PID algorithm is used for optimization;

[0093] For example, when the robot moves straight, when there is a speed difference between the two legs, an acceleration to the left and right will be generated. The deviation is obtained by subtracting the initial set value. The voltage of the two leg drive signals is readjusted according to the deviation. Assuming that it is an acceleration to the left, the voltage of the right leg drive signal will be reduced, so that the speed of the two legs can be kept consistent and move forward in a straight line.

[0094] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A piezoelectric stack-driven micro piezoelectric mobile robot, characterized in that: The robot comprises a robot body, piezoelectric actuators are arranged on both sides of the bottom of the robot body, each piezoelectric actuator has the same structure, a piezoelectric stack and legs are arranged on both sides of each piezoelectric actuator, a driving circuit is arranged inside the robot body, an output end of the driving circuit is connected to the piezoelectric stack, each piezoelectric stack comprises a piezoelectric ceramic and two upper and lower metal sheets, and the lower two metal sheets are respectively adhered to the upper and lower sides of the piezoelectric ceramic; The driving circuit is configured to: receive a target remote control signal, analyze the target remote control signal and output a corresponding control signal; determine specific motion control parameters according to the analyzed control signal, and adjust the driving signal based on the motion control parameters. When the driving signal is applied, the piezoelectric ceramic vibrates along the length direction, and the upper and lower metal sheets convert the vibration in the length direction into the thickness direction, thereby driving the leg movement.

2. A piezoelectric stack driven micro piezoelectric mobile robot as claimed in claim 1, characterized in that: A rear wheel is also arranged at the bottom of the robot body. The piezoelectric actuator includes a first piezoelectric actuator and a second piezoelectric actuator. The first piezoelectric actuator and the second piezoelectric actuator are arranged in parallel. The first piezoelectric actuator, the second piezoelectric actuator and the landing point of the rear wheel form an equilateral triangle.

3. A piezoelectric stack driven micro piezoelectric mobile robot as claimed in claim 1, characterized in that: Each piezoelectric actuator includes a supporting structure, which includes a top surface and two side surfaces that are integrated with the top surfaces, and a threaded hole is left on the top surface. The top surface is connected to the body through the threaded hole and bolts; a piezoelectric stack is arranged on each side surface, one end of the leg is fixed to the side surface, and the other end is coupled to each other.

4. A piezoelectric stack driven micro piezoelectric mobile robot as claimed in claim 3, characterized in that: Weight-reducing grooves are symmetrically arranged on both sides of the threaded hole, and weight-reducing holes are arranged on both sides.

5. A piezoelectric stack driven micro piezoelectric mobile robot as claimed in claim 3, characterized in that: The legs include two metal sheets and an aluminum alloy foot. One end of each metal sheet is fixed to the side of the supporting structure, and the other end is coupled to the aluminum alloy foot through a coupling agent.

6. A piezoelectric stack driven micro piezoelectric mobile robot as claimed in claim 5, characterized in that: The lower end of the aluminum alloy foot is a hemispherical surface.

7. A piezoelectric stack driven micro piezoelectric mobile robot as claimed in claim 1, characterized in that: The driving circuit includes a control circuit, a Boost amplifier circuit and an H-bridge circuit. The input end of the control circuit is connected to a remote control signal, the first output end of the control circuit is connected to the Boost amplifier circuit, the second output end is connected to the H-bridge circuit, the output end of the Boost amplifier circuit is connected to the input end of the H-bridge circuit, and the output end of the H-bridge circuit is connected to the corresponding load, namely the piezoelectric stack.

8. A driving method for a piezoelectric stack-driven micro-piezoelectric mobile robot, based on the robot according to any one of claims 1 to 7, characterized in that: The steps include: Receive the target remote control signal, analyze the target remote control signal and output the corresponding control signal; Determine specific motion control parameters based on the control signal obtained by analysis; The driving signal is adjusted based on the motion control parameters. When the driving signal is applied, the piezoelectric ceramic vibrates along the length direction. The upper and lower metal sheets convert the vibration in the length direction to the thickness direction, driving the leg movement.

9. The driving method of the piezoelectric stack driven micro piezoelectric mobile robot as claimed in claim 8, characterized in that: Different remote control signals correspond to corresponding channel parameters. When the remote control signal is changed, the parameters of different channels will change, thereby generating different control signals.

10. The driving method of the piezoelectric stack driven micro piezoelectric mobile robot according to claim 8, characterized in that: The method also includes obtaining speed and acceleration information of the robot during the movement of the robot; adjusting the driving signal according to the obtained speed and acceleration information of the robot, and feeding back the information to the piezoelectric stack to adjust the action of the robot.

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