A wireless ultrasonic motor drive control system and method

Abstract

The present invention discloses a wireless ultrasonic motor drive control system and method, including a controller, a drive circuit and an ultrasonic motor, wherein the drive circuit drives and controls the ultrasonic motor according to an output signal of the controller, wherein the drive circuit includes: a transmitting end, which includes a high-frequency inverter, a first power compensation circuit and a transmitting coil connected in sequence, wherein the high-frequency inverter converts the direct current generated by a direct current power supply into high-frequency alternating current and transmits it to the transmitting coil through the power compensation circuit; a receiving end, which includes a receiving coil and a second power compensation circuit, wherein the receiving coil is connected to the ultrasonic motor through the second power compensation circuit to form a closed loop; the receiving coil is arranged opposite to the transmitting coil and generates an alternating current in the closed loop according to the alternating magnetic flux generated by the transmitting coil, thereby driving the ultrasonic motor. The present invention adopts wireless power transmission technology to realize the cable-free drive control of the ultrasonic motor.

Description

Technical Field

[0001] The present invention relates to the technical field of ultrasonic motor control, and in particular to a wireless ultrasonic motor drive control system and method. Background Art

[0002] Unlike traditional motors that are driven by electromagnetic force, ultrasonic motors use the inverse piezoelectric effect of piezoelectric ceramics to convert AC power into vibration of the stator in the ultrasonic frequency band, and drive the rotor to rotate or move linearly through the friction between the stator and the rotor. Electromagnetic motors are susceptible to electromagnetic interference and have poor stability in situations with strong electromagnetic interference. Ultrasonic motors have the advantages of compact structure, low speed and high torque, power-off self-locking, fast response speed, high control accuracy, power-off self-locking and no electromagnetic interference. They are widely used in micro-machinery, precision positioning and aerospace.

[0003] The traditional ultrasonic motor drive system consists of two parts: a rectifier circuit and an inverter circuit. The structure of such a drive system is relatively simple and is similar to the drive power supply of the transmission motor. However, this drive system generally requires a large electric energy conversion device, which hinders the overall miniaturization of the ultrasonic motor system. The traditional drive method requires the motor to be connected to a cable, which limits the application of ultrasonic motors in industrial robotic arms and other applications, and cannot achieve high-degree-of-freedom rotation. In addition, in the drive power supply structure of the transmission, the power supply and the motor are not electrically isolated, which leads to reduced system reliability and shortened ultrasonic motor life. Summary of the invention

[0004] The purpose of the present invention is to provide a wireless ultrasonic motor drive control system and method, which adopts wireless power transmission technology to realize cable-free drive control of ultrasonic motors.

[0005] In order to solve the above technical problems, the present invention provides a wireless ultrasonic motor drive control system, including a controller, a drive circuit and an ultrasonic motor, wherein the drive circuit drives and controls the ultrasonic motor according to an output signal of the controller, wherein the drive circuit includes:

[0006] A transmitting end, connected to the controller, comprising a high-frequency inverter, a first power compensation circuit and a transmitting coil connected in sequence, wherein the high-frequency inverter is externally connected to a DC power supply, and the high-frequency inverter converts the DC power generated by the DC power supply into high-frequency AC power and transmits it to the transmitting coil through the power compensation circuit, and the transmitting coil generates an alternating magnetic flux;

[0007] The receiving end includes a receiving coil and a second power compensation circuit, wherein the receiving coil is connected to the ultrasonic motor through the second power compensation circuit to form a closed loop; the receiving coil is arranged opposite to the transmitting coil and generates an alternating current in the closed loop according to the alternating magnetic flux generated by the transmitting coil, thereby driving the ultrasonic motor.

[0008] As a further improvement of the present invention, the first power compensation circuit adopts an LCC resonant circuit, which includes a first capacitor, a second capacitor and a first inductor, one end of the first inductor is connected to the high-frequency inverter, and the other end of the first inductor is respectively connected to one end of the first capacitor and one end of the transmitting coil; one end of the second capacitor is connected to the other end of the transmitting coil, and the other end of the second capacitor is connected to the other end of the first capacitor and grounded; the first capacitor is connected in parallel with the transmitting coil; the second power compensation adopts a capacitor series resonant circuit, and the capacitor series resonant circuit includes a third capacitor, one end of the third capacitor is connected to the receiving coil, and the other end of the third capacitor is connected to the ultrasonic motor.

[0009] As a further improvement of the present invention, a dual-path wireless energy transmission structure is adopted between the transmitting end and the receiving end, and the dual-path wireless energy transmission structure includes a first transmission channel and a second transmission channel, and the first transmission channel and the second transmission channel both include a first power compensation circuit, a transmitting coil, a receiving coil matching the transmitting coil, and a second power compensation circuit; the first compensation circuits of the first transmission channel and the second transmission channel are both connected to the output end of the high-frequency inverter and the two transmission channels have a phase difference, and the receiving coils are both connected to the ultrasonic motor through the second compensation circuit to form a closed loop.

[0010] As a further improvement of the present invention, the transmitting end of the first transmission channel includes a first inductor, a first capacitor, a second capacitor and a first transmitting coil, one end of the first inductor is connected to the high-frequency inverter, and the other end of the first inductor is respectively connected to one end of the first capacitor and one end of the first transmitting coil; one end of the second capacitor is connected to the other end of the first transmitting coil, and the other end of the second capacitor is connected to the other end of the first capacitor and grounded; the first capacitor is connected in parallel with the transmitting coil; the receiving end of the first transmission channel includes a third capacitor and a first receiving coil, one end of the third capacitor is connected to one end of the first receiving coil, and the other end of the third capacitor is connected to the ultrasonic motor; the other end of the first receiving coil is connected to the ultrasonic motor.

[0011] As a further improvement of the present invention, the transmitting end of the second transmission channel includes a second inductor, a fourth capacitor, a fifth capacitor and a second transmitting coil, one end of the second inductor is connected to the high-frequency inverter, and the other end of the second inductor is respectively connected to one end of the fourth capacitor and one end of the second transmitting coil; one end of the fifth capacitor is connected to the other end of the first transmitting coil, and the other end of the fifth capacitor is connected to the other end of the fourth capacitor and grounded; the fourth capacitor is connected in parallel with the second transmitting coil; the receiving end of the second transmission channel includes a sixth capacitor and a second receiving coil, one end of the sixth capacitor is connected to one end of the second receiving coil, and the other end of the sixth capacitor is connected to the ultrasonic motor; the other end of the second receiving coil is connected to the other end of the first receiving coil and are jointly connected to the ultrasonic motor.

[0012] As a further improvement of the present invention, the high-frequency inverter adopts a full-bridge inverter circuit.

[0013] As a further improvement of the present invention, the controller includes a fuzzy controller and a PID controller. The fuzzy controller is used to provide control parameters for the PID controller according to the speed deviation and error change rate of the ultrasonic motor. The PID controller is used to control the drive circuit according to the control parameters, input speed and speed deviation output control quantity.

[0014] A wireless ultrasonic motor drive control method is used to drive and control the wireless ultrasonic motor drive control system as described above.

[0015] As a further improvement of the present invention, when the transmitting coil, the first power compensation circuit, the receiving coil and the second power compensation circuit work simultaneously, the wireless ultrasonic motor drive control system works in a resonant state; when the frequency of the alternating current induced by the receiving coil meets the ultrasonic motor drive operating frequency, the ultrasonic motor works.

[0016] As a further improvement of the present invention, the controller adopts a fuzzy adaptive PID control method to control the drive circuit. The fuzzy adaptive PID control method includes: using a PID algorithm to control the drive circuit, and at the same time, by calculating the current speed error and error change rate of the ultrasonic motor, using fuzzy rules to adjust the control parameters in the PID algorithm in real time to meet the adaptive setting.

[0017] The beneficial effects of the present invention are as follows: the present invention adopts resonant wireless power transmission technology to drive and control the ultrasonic motor, realizes the cable-free operation of the motor, and can be used for the mechanical arm of an industrial robot to rotate with a high degree of freedom (360 degrees), so that the mechanical arm of an industrial robot using the system can rotate 360 ​​degrees with a high degree of freedom; the motor driving circuit at the receiving end adopts only passive components, which greatly simplifies the existing motor driving circuit and is easy to modularize; the use of ultrasonic motors enables the system to have a strong anti-electromagnetic interference capability; the physical isolation between the power input side and the power receiving side makes the system modular, facilitates the subsequent adjustment and maintenance, and improves the reliability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the driving circuit of the present invention;

[0019] Figure 2 It is a schematic diagram of the principle structure of the control method of the present invention. DETAILED DESCRIPTION

[0020] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0021] refer to Figure 1 The present invention provides a wireless ultrasonic motor drive control system, comprising a controller, a drive circuit and an ultrasonic motor, wherein the drive circuit drives and controls the ultrasonic motor according to an output signal of the controller, wherein the drive circuit comprises:

[0022] A transmitting end, connected to the controller, comprising a high-frequency inverter, a first power compensation circuit and a transmitting coil connected in sequence, wherein the high-frequency inverter is externally connected to a DC power supply, and the high-frequency inverter converts the DC power generated by the DC power supply into high-frequency AC power and transmits it to the transmitting coil through the power compensation circuit, and the transmitting coil generates an alternating magnetic flux;

[0023] The receiving end includes a receiving coil and a second power compensation circuit, wherein the receiving coil is connected to the ultrasonic motor through the second power compensation circuit to form a closed loop; the receiving coil is arranged opposite to the transmitting coil and generates an alternating current in the closed loop according to the alternating magnetic flux generated by the transmitting coil, thereby driving the ultrasonic motor.

[0024] The present invention uses resonant wireless power transmission as the energy transmission means of the wireless ultrasonic motor, because the wireless power transmission mode has a long transmission distance, large transmission power and high transmission efficiency. In the resonant wireless power transmission technology, an alternating current is passed through the coil at the transmitting end to generate an alternating magnetic flux, and the alternating magnetic flux is partially hinged to the coil at the receiving end. After the coil at the receiving end is connected to the load to form a closed loop, the electric energy can be wirelessly transmitted from the transmitting end to the receiving end. Using wireless power transmission technology to drive and control the ultrasonic motor can realize cable-free drive control of the ultrasonic motor. In such a system, the motor end only needs to be combined with the corresponding matching circuit, which greatly simplifies the drive control circuit, which promotes the miniaturization of the ultrasonic motor system and its application in the field of micro-machines, and the anti-electromagnetic interference characteristics of the ultrasonic motor enable the system to be applied to occasions with relatively strong electromagnetic interference.

[0025] Example 1

[0026] The present embodiment provides a wireless ultrasonic motor drive control system. Based on the above implementation mode, the first power compensation circuit adopts an LCC resonant circuit, the LCC resonant circuit includes a first capacitor, a second capacitor and a first inductor, one end of the first inductor is connected to a high-frequency inverter, and the other end of the first inductor is respectively connected to one end of the first capacitor and one end of a transmitting coil; one end of the second capacitor is connected to the other end of the transmitting coil, and the other end of the second capacitor is connected to the other end of the first capacitor and grounded; the first capacitor is connected to the transmitting coil in parallel; the second power compensation adopts a capacitor series resonant circuit, the capacitor series resonant circuit includes a third capacitor, one end of the third capacitor is connected to the receiving coil, and the other end of the third capacitor is connected to the ultrasonic motor.

[0027] The DC power supply is converted into high-frequency AC power by a high-frequency inverter and input into the transmitting coil. The alternating current generates alternating magnetic flux in the transmitting coil, and the alternating magnetic flux is partially hinged to the receiving coil, inducing an alternating electromotive force in the receiving coil, generating an alternating current in the load circuit, thereby realizing wireless transmission of energy.

[0028] Furthermore, the transmitting coil and the receiving coil must work together with the power compensation circuit to achieve a resonant state to transmit wireless power. The transmitting coil and the LCC type resonant circuit form a resonant cavity, and the receiving coil uses a capacitor series resonant circuit, which makes the system have a higher power transmission power and efficiency. When the system works in a resonant state, the power transmission efficiency is the highest. The ultrasonic motor is capacitive to the outside, and the inductor series matching circuit plays the role of impedance matching, which can reduce the reactive power of the system and improve the system power factor, thereby improving the power and efficiency of power transmission.

[0029] Example 2

[0030] like Figure 1As shown, this embodiment provides a wireless ultrasonic motor drive control system. Based on the above implementation, the high-frequency inverter adopts a full-bridge inverter circuit, which consists of four MOSFETs (S 1 , S 2 , S 3 , S 4 ) to achieve the conversion of DC to AC. A dual-path wireless energy transmission structure is used between the transmitter and the receiver. The dual-path wireless energy transmission structure includes a first transmission channel and a second transmission channel. The first transmission channel includes a resonant compensation network at the transmitter: L T1 , C P1 , C T1 , L P1 is the No. 1 transmitting coil, C R1 is the resonant compensation network at the receiving end, L R1 is the first receiving coil; the second transmission channel includes the resonant compensation network at the transmitting end: L T2 , C P2 , C T2 , L P2 It is the No. 2 transmitting coil, C R2 is the resonant compensation network at the receiving end, L R2 The input ends of the first transmission channel and the second transmission channel are both connected to the output end of the high-frequency inverter and the two transmission channels have a phase difference. The receiving coils are both connected to the ultrasonic motor through the second compensation circuit to form a closed loop.

[0031] Specifically, the first transmission channel: inductor L T1 One end is connected to the S of the high frequency inverter 1 and S 2 Between, the inductor L T1 The other end is connected to capacitor C P1 One end and the transmitting coil L P1 One end of the capacitor C T1 One end is connected to the transmitting coil L P1 The other end of the capacitor C T1 The other end of the capacitor C P1 The other end of the capacitor C P1 With the transmitting coil L P1 Parallel connection; capacitor C R1 One end is connected to the receiving coil L R1 One end of the capacitor C R1 The other end is connected to the ultrasonic motor; the receiving coil L R1 The other end is connected to an ultrasonic motor;

[0032] Second transmission channel: inductor L T2 One end is connected to the S of the high frequency inverter 3 and S 4 Between, inductor LT2 The other end is connected to capacitor C P2 One end and the transmitting coil L P2 One end of the capacitor C T2 One end is connected to the transmitting coil L P2 The other end of the capacitor C T2 The other end of the capacitor C P2 The other end of the capacitor C P2 With the second transmitting coil L P2 Parallel connection; capacitor C R2 One end is connected to the receiving coil L R2 One end of the capacitor C R2 The other end is connected to the ultrasonic motor; the receiving coil L R2 The other end is connected to the receiving coil L R1 The other end is connected to the ultrasonic motor.

[0033] The DC power supply is converted into high-frequency AC power by a full-bridge inverter and input into the transmitting coil. The alternating current generates an alternating magnetic flux in the transmitting coil, and the alternating magnetic flux is partially hinged to the receiving coil, inducing an alternating electromotive force in the receiving coil, generating an alternating current in the load circuit, thereby realizing wireless energy transmission. In this embodiment, the transmitting coil and the receiving coil of the power transmission unit adopt a dual-channel wireless energy transmission channel structure. Driving a wireless ultrasonic motor requires two sinusoidal voltages with a certain phase difference. If the frequency of the high-frequency AC voltage induced by the receiving coil meets the ultrasonic motor driving operating frequency, the wireless ultrasonic motor can be directly driven.

[0034] The present invention also provides a wireless ultrasonic motor drive control method, which drives and controls the wireless ultrasonic motor drive control system as described above. Figure 2 As shown in the figure, the system adopts fuzzy adaptive PID control strategy as the speed control method of ultrasonic motor. Fuzzy adaptive PID regulation is a control strategy that combines fuzzy control with PID control. It applies the basic theories and methods of fuzzy mathematics, expresses the conditions and operations of the rules with fuzzy sets, and stores these fuzzy control rules and related information as knowledge in the knowledge base of DSP. Then DSP uses fuzzy reasoning to automatically achieve the optimal adjustment of PID parameters according to the actual response.

[0035] The control quantity output by the PID controller in the control system can be the frequency, amplitude or phase difference between the voltage signals of each phase, and the input quantity is the deviation e(k); the input quantity of the fuzzy controller is the speed deviation e(k) and error change rate of the ultrasonic motor. The output is the control parameters Kp, Ki and Kd of the PID controller. Based on the PID algorithm, the system calculates the current speed error e(k) and the error change rate The fuzzy rules are used to adjust the control parameters of the PID controller in real time to meet the requirements of its parameter adaptive setting. The present invention adopts a high-performance fuzzy PID controller, which is more advanced, accurate,

[0036] Specifically, the radio motor is controlled by a digital signal processor, and a DSP is commonly used. The digital signal processor sets a fixed frequency switching signal according to the operating frequency requirements of the radio motor. The duty cycle of the switching signal is calculated by a fuzzy PID controller, and the obtained switching signal is used to drive the MOSFET.

[0037] Since the traditional cabled motor system is restricted by the cable, it cannot achieve high-degree-of-freedom rotation; and the cabled motor requires a large electric energy conversion device, which is not conducive to the miniaturization of the system. Electromagnetic motors are susceptible to electromagnetic interference and have poor stability in situations where point magnetic interference is strong. The present invention uses wireless power transmission technology to drive and control the ultrasonic motor, realizing the cable-free operation of the motor, so that the industrial robot arm using the system can rotate 360 ​​degrees with high degrees of freedom; and the present invention uses a high-frequency inverter for direct drive. The present invention also improves the system power factor through a power compensation circuit; simplifies the system structure and is easy to modularize; the use of ultrasonic motors enables the system to have a strong ability to resist electromagnetic interference.

[0038] The above-described embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or changes made by those skilled in the art based on the present invention are within the protection scope of the present invention. The protection scope of the present invention shall be subject to the claims.

Claims

1. A wireless ultrasonic motor drive control system, characterized in that: It includes a controller, a driving circuit and an ultrasonic motor, wherein the driving circuit drives and controls the ultrasonic motor according to the output signal of the controller, wherein the driving circuit includes: a transmitting end, connected to the controller, which includes a high-frequency inverter connected in sequence, a first power compensation, and converts the direct current generated by the direct current into high-frequency alternating current and transmits it to the transmitting coil through the power compensation circuit, and the transmitting coil generates an alternating magnetic flux; a receiving end, which includes a receiving coil and a second power compensation circuit, and the receiving coil is connected to the ultrasonic motor through the second power compensation circuit to form a closed loop; the receiving coil is arranged opposite to the transmitting coil and generates an alternating current in the closed loop according to the alternating magnetic flux generated by the transmitting coil, thereby driving the ultrasonic motor; the first power compensation circuit adopts an LCC resonant circuit, and the LCC The resonant circuit includes a first capacitor, a second capacitor and a first inductor, one end of the first inductor is connected to the high-frequency inverter, and the other end of the first inductor is respectively connected to one end of the first capacitor and one end of the transmitting coil; one end of the second capacitor is connected to the other end of the transmitting coil, and the other end of the second capacitor is connected to the other end of the first capacitor and grounded; the first capacitor is connected in parallel with the transmitting coil; the second power compensation adopts a capacitor series resonant circuit, the capacitor series resonant circuit includes a third capacitor, one end of the third capacitor is connected to the receiving coil, and the other end of the third capacitor is connected to the ultrasonic motor; a dual-path wireless energy transmission structure is adopted between the transmitting end and the receiving end, the dual-path wireless energy transmission structure includes a first transmission channel and a second transmission channel, the first transmission channel and the second transmission channel both include a first power compensation circuit, a transmitting coil, a receiving coil matched with the transmitting coil, and a second power compensation circuit; the first compensation circuits of the first transmission channel and the second transmission channel are both connected to the output end of the high-frequency inverter and the two transmission channels have a phase difference, and the receiving coils are both connected to the ultrasonic motor through the second compensation circuit to form a closed loop.

2. A wireless ultrasonic motor drive control system as claimed in claim 1, characterized in that: The transmitting end of the first transmission channel includes a first inductor, a first capacitor, a second capacitor and a first transmitting coil, one end of the first inductor is connected to the high-frequency inverter, and the other end of the first inductor is respectively connected to one end of the first capacitor and one end of the first transmitting coil; one end of the second capacitor is connected to the other end of the first transmitting coil, and the other end of the second capacitor is connected to the other end of the first capacitor and grounded; the first capacitor is connected in parallel with the transmitting coil; The receiving end of the first transmission channel includes a third capacitor and a first receiving coil, one end of the third capacitor is connected to one end of the first receiving coil, and the other end of the third capacitor is connected to the ultrasonic motor; the other end of the first receiving coil is connected to the ultrasonic motor.

3. A wireless ultrasonic motor drive control system as claimed in claim 2, characterized in that: The transmitting end of the second transmission channel includes a second inductor, a fourth capacitor, a fifth capacitor and a second transmitting coil, one end of the second inductor is connected to the high-frequency inverter, and the other end of the second inductor is respectively connected to one end of the fourth capacitor and one end of the second transmitting coil; one end of the fifth capacitor is connected to the other end of the first transmitting coil, and the other end of the fifth capacitor is connected to the other end of the fourth capacitor and grounded; The fourth capacitor is connected in parallel with the second transmitting coil; The receiving end of the second transmission channel includes a sixth capacitor and a second receiving coil, one end of the sixth capacitor is connected to one end of the second receiving coil, and the other end of the sixth capacitor is connected to the ultrasonic motor; the other end of the second receiving coil is connected, and the other end of the first receiving coil is jointly connected to the ultrasonic motor.

4. A wireless ultrasonic motor drive control system as claimed in claim 1, characterized in that: The high frequency inverter adopts a full-bridge inverter circuit.

5. The wireless ultrasonic motor drive control system according to claim 1, characterized in that: The controller includes a fuzzy controller and a PID controller. The fuzzy controller is used to provide control parameters for the PID controller according to the speed deviation and error change rate of the ultrasonic motor. The PID controller is used to control the drive circuit according to the control parameters, input speed and speed deviation output control quantity.

6. A wireless ultrasonic motor drive control method, characterized in that: A wireless ultrasonic motor drive control system according to any one of claims 1 to 5 is driven and controlled.

7. A wireless ultrasonic motor driving control method as claimed in claim 6, characterized in that: When the transmitting coil, the first power compensation circuit, the receiving coil and the second power compensation circuit work simultaneously, the wireless ultrasonic motor drive control system works in a resonant state; when the frequency of the alternating current induced by the receiving coil meets the ultrasonic motor drive operating frequency, the ultrasonic motor works.

8. A wireless ultrasonic motor driving control method as claimed in claim 6, characterized in that: The controller adopts a fuzzy adaptive PID control method to control the drive circuit. The fuzzy adaptive PID control method includes: using a PID algorithm to control the drive circuit, and at the same time, by calculating the current speed error and error change rate of the ultrasonic motor, using fuzzy rules to adjust the control parameters in the PID algorithm in real time to meet the adaptive setting.

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