CN-121984378-A - Self-starting prevention method for ultrasonic motor

CN121984378ACN 121984378 ACN121984378 ACN 121984378ACN-121984378-A

Abstract

The invention relates to the technical field of ultrasonic motor driving, and discloses an ultrasonic motor self-starting prevention method, wherein the operation of a motor is controlled by comparing a target position P m with a current position P in real time, and the motor is kept if the positions are consistent; if the rotation directions are inconsistent, a distance difference D is calculated, and the rotation directions are dynamically switched according to the comparison of the D and the threshold value N. And then judging the relation between P m and P again, and deciding to continue to run or enter a setting stage. And (3) regularly judging the position relation during the setting period, gradually approaching the target position, and finally stopping the motor and clearing the marker bit after the setting time exceeds 5-10 s. The invention realizes the correction of the error of the target position and the actual position of the motor by controlling the pulse operation of the motor and the accurate switching of the continuous operation mode and reasonably and timely clearing the control mark position after the closed loop movement of the motor position is finished, thereby avoiding the self-starting risk of the ultrasonic motor in the using process and improving the using reliability of the ultrasonic motor.

Inventors

TANG SIYU
YANG LIN
ZHAO CHUNSHENG

Assignees

南京航达超控科技有限公司

Dates

Publication Date: 20260505
Application Date: 20260210

Claims (8)

1. An ultrasonic motor self-starting prevention method is characterized by comprising the following steps: s1, acquiring a target position P m and a current position P of an ultrasonic motor; S2, judging whether the target position P m is consistent with the current position P, if so, controlling the ultrasonic motor to keep the current state, and if not, executing S3; S3, calculating and comparing a distance difference D between the current position P of the ultrasonic motor and the target position P m , and controlling the positioning direction of the ultrasonic motor to enter a first rotation direction positioning or a second rotation direction positioning; S4, dynamically switching the rotation positioning direction of the ultrasonic motor based on a comparison result of the distance difference D and a first distance threshold N; S5, judging whether the target position P m of the ultrasonic motor is smaller than the current position P again, namely judging that P m is smaller than P; if so, continuing to operate in the second rotation direction pulse mode; if not, stopping the ultrasonic motor, and entering a setting stage; S6, judging whether the target position P m of the ultrasonic motor is smaller than the current position P or not every 1-5ms in a setting stage, if so, switching the motion mode of the ultrasonic motor into a second rotation direction pulse motion mode to slowly approach the current position P to the target position P m , and if not, entering the setting stage; when the setting period is longer than 5-10s, the ultrasonic motor is stopped, and the zone bit is cleared.
2. The method for preventing self-starting of an ultrasonic motor according to claim 1, wherein in step S4, when D > N, the ultrasonic motor enters a second rotation direction pulse mode to slowly approach a target position P m , and the current position of the ultrasonic motor moves in a small direction; When D < N, the ultrasonic motor enters a second rotation direction pulse mode, and is switched to a continuous mode after waiting for a pulse time t, if the pulse time t > t Presetting , , after being switched to the continuous mode, the ultrasonic motor continues to judge that D < N, the ultrasonic motor is switched to the second rotation direction pulse mode to slowly approach the target position P m , and the motor position moves towards a small direction.
3. The method for preventing self-starting of an ultrasonic motor according to claim 2, wherein the step S3 comprises the following steps: S301, judging whether the target position P m of the ultrasonic motor is smaller than the current position P, namely judging that P m is smaller than P; if not, entering a first rotation direction to position the ultrasonic motor; If yes, entering a second rotation direction to position the ultrasonic motor; s302, positioning the ultrasonic motor in a second rotation direction, and calculating a distance difference D between the target position P m of the ultrasonic motor and the current position P.
4. The method for preventing self-starting of an ultrasonic motor according to claim 3, wherein the pulse preset time t Presetting in the step S4 is 1-3S.
5. The method of claim 4, wherein the first distance threshold N of the distance difference D between the target position P m and the current position P of the ultrasonic motor in the step S302 is 12-16.
6. The method for preventing self-starting of an ultrasonic motor according to claim 5, wherein the method comprises the following steps: the self-starting prevention method of the ultrasonic motor further comprises a setting stage of the step S6, wherein the step of the setting stage comprises the following steps: S61, judging whether the distance difference D between the current position P of the ultrasonic motor and the target position P m is smaller than M and M is larger than N, if so, stopping the ultrasonic motor and clearing the motor mark position; If not, calculating a distance difference D between the current position P and the target position P m , wherein D=P-P m , and judging whether the distance difference D is a positive error or a negative error; S62, when the positive error is judged, the motion mode of the ultrasonic motor is switched to a second rotation direction pulse motion mode, so that the current position P of the ultrasonic motor is gradually approximated to the target position P m ; S63, when the negative error is judged, the motion mode of the ultrasonic motor is switched into a first rotation direction pulse motion mode, so that the current position P of the ultrasonic motor is gradually approximated to the target value P m ; And then continuously monitoring the distance difference D between the current position P of the motor and the target position P m until the distance difference D is smaller than the second distance threshold M, stopping the ultrasonic motor, and clearing the ultrasonic motor to mark the position.
7. The method for preventing self-starting of an ultrasonic motor according to any one of claims 1 to 6, wherein the second distance threshold M between the current position P and the target position P m in the setting stage is 21 to 25.
8. The method for preventing self-starting of an ultrasonic motor according to claim 7, wherein the first rotation direction and the second rotation direction are CW direction and CCW direction, respectively, and the directions are opposite.

Description

Self-starting prevention method for ultrasonic motor Technical Field The invention relates to the technical field of ultrasonic motor driving, in particular to an ultrasonic motor self-starting prevention method. Background The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art. The ultrasonic motor is used as a novel micro-special motor based on the piezoelectric ceramic inverse piezoelectric effect and high-frequency mechanical vibration, and has the remarkable advantages of compact structure, high moment density, quick response, power failure self-locking, no electromagnetic interference and the like. However, its high performance implementation is highly dependent on the dedicated driver to which it is matched. The driver not only needs to generate an alternating current excitation signal with high frequency (usually several kilohertz to hundreds kilohertz), but also needs to precisely control the frequency, the phase and the amplitude of the signal so as to effectively excite the specific mode vibration of the stator, thereby driving the rotor to realize precise motion. The ultrasonic motor is used as a special motor based on ultrasonic vibration driving, and is widely applied to the fields of precise positioning, servo control and the like by virtue of the characteristics of low speed, large torque, high response speed and the like. In practical engineering application of an ultrasonic motor, the operation control flow is usually that after a positioning instruction is issued to the ultrasonic motor, the motor executes a motion action and stops in place, and at the moment, a driver keeps a power-on standby state. However, the control logic of the existing ultrasonic motor has the defect that the ultrasonic motor still automatically enters a pulse motion mode to generate a self-starting abnormal operation phenomenon after a period of non-instruction standby time under the conditions that the motor is positioned and stopped and a driver is continuously electrified even if no motion control instruction is issued to the motor. The abnormal phenomenon can lead the ultrasonic motor to deviate from a preset control logic, lose controllability, further cause the problems of equipment positioning deviation, operation faults and the like, and seriously influence the application reliability of the ultrasonic motor in precision equipment. Disclosure of Invention In order to overcome the defects in the prior art, the invention provides the method for preventing the self-starting of the ultrasonic motor, which is used for reasonably and timely clearing the control mark position after the closed loop movement of the motor position is finished, correcting the errors of the target position and the actual position of the motor, avoiding the self-starting risk of the ultrasonic motor in the using process and improving the using reliability of the ultrasonic motor by controlling the pulse work and the accurate switching of the continuous working mode of the motor. The technical scheme adopted by the invention is that the self-starting prevention method of the ultrasonic motor comprises the following steps: s1, acquiring a target position P m and a current position P of an ultrasonic motor; S2, judging whether the target position P m is consistent with the current position P, if so, controlling the ultrasonic motor to keep the current state, and if not, executing S3; S3, calculating and comparing a distance difference D between the current position P of the ultrasonic motor and the target position P m, and controlling the positioning direction of the ultrasonic motor to enter a first rotation direction positioning or a second rotation direction positioning; S4, dynamically switching the rotation positioning direction of the ultrasonic motor based on a comparison result of the distance difference D and a first distance threshold N; S5, judging whether the target position P m of the ultrasonic motor is smaller than the current position P again, namely judging that P m is smaller than P; if so, continuing to operate in the second rotation direction pulse mode; if not, stopping the ultrasonic motor, and entering a setting stage; S6, judging whether the target position P m of the ultrasonic motor is smaller than the current position P or not every 1-5ms in a setting stage, if so, switching the motion mode of the ultrasonic motor into a second rotation direction pulse motion mode to slowly approach the current position P to the target position P m, and if not, entering the setting stage; when the setting period is longer than 5-10s, the ultrasonic motor is stopped, and the zone bit is cleared. In the technical scheme, in the step S4, when D is larger than N, the ultrasonic motor enters a second rotation direction pulse mode to slowly approach the target position P m, and the current position of the ultrasonic motor moves in a small dire