A Control Strategy for Ultrasonic Motor Speed under High Temperature Condition
Ultrasonic motor (USM) is a new principle motor,which applies piezoelectric vibration and frictional force as the driving source.Piezoelectric motors exhibit a number of advantages compared to conventional electromagnetic (stepping) motors,e.g.superior force/mass ratio,improved direct drive capability,and they often do not require any reduction gear.Piezoelectric motors offer several outstanding characteristics that may be very interesting for new scientific instruments in space applications.Therefore,it is an important question how ultrasonic motors perform under high temperature condition and how to control the speed of ultrasonic motor under high temperature condition.Using traditionally method to control ultrasonic motors,the speed fluctuates rapidly.In this paper,we analyze the speed of ultrasonic motor.Traditionally,we control speed by frequency.Theoretically,ultrasonic motor working frequency is at anti-resonant.But,because of material and manufacture error,the working frequency is not at anti-resonan.Usually,the working frequency places at left anti-resonant and ultrasonic motor can work well.When ultrasonic motor work,the temperature of it rise and its anti-resonant frequency deceases.Therefore,the working frequency of ultrasonic motor is change with the anti-resonant frequency in order to keep the speed steady.This method performs well under normal environment.But under high temperature condition,this method does not control speed of ultrasonic motor well as showing Fig.1.In order to keep the speed steady,when the antiresonant frequency deceases at high temperature,we keep the frequency closely to anti-resonant frequency to keep the speed fluctuates little.Using this control method,under different high temperature environment,the speed fluctuates at 9 percent in experiment.
Wei Zheng Chunsheng Zhao Weiqing Huang
Precision Driving Laboratory,Nanjing University of Aeronautics & Astronautics,Nanjing 210016,China
国际会议
南京
英文
301-306
2007-09-09（万方平台首次上网日期，不代表论文的发表时间）