Position control of ultrasonic motors using neural network

Abstract

Ultrasonic motor is a newly developed rnokar and it has excellent performance and many useful features, therefore, the ultrasonic motor i s expected for many practical applications. However, the drive principle of ultrasanic motor is diEeserit from that of other electromagnetic type motors, and the ~a t~~~i a~~~a~ model of the motor $evetoped yet. Furthermore, the spee tics 0% the motor hold heavy n o~~~n~~~~y and they rive conditions. Therefore, the precise position control of ~ltrasonic motor is generally difficult. h i this paper. we propose a new position control scheme for ultrasonic matex using a neural network. The proposed controller can ~p p~~x~~a t e the nonlinear input-output mappings of the motor using the neural network, and can compensate the characteristic variations by online learning based on &he general ~~~~~~o~a~a t~o~ algorithm. The trained network A n d y makes an inverse model of the plant. 'The usefulness and validity of the praposed control scheme is examined in experiments, 0-7803-3334-9/96/$5.00 0 1996 IEEE. 368

Modeling and RST position controller of rotary traveling wave ultrasonic motor

“…This condition can be rewritten according to the final limit theorem by [20]: (17) Where; L (z -1 ) is a polynomial to be determined. The sinusoidal reference waveform is a particular type of polynomial signals because the theorem of final limit can`t be applied.…”

“…In parallel with TWUSM models, different control methods appeared in the literature [14][15][16][17][18][19]. The most used control variable was the driving frequency because it`s the simplest method.…”

“…Focusing on the position control of USM, this has been also widely reported in research works. These techniques can be generally classified into five categories: PID controller with fixed and variable gains [12][13], adaptive controller [14][15], Fuzzy Logic (FL) controller [16], Neural Network (NN) controller [17], and mixed controller [18][19]. The PID controller is simple and easy to be implemented it suffers from the lower bandwidth and the risk of system instability.…”

Position Control of Ultrasonic Motor Using IMC-PID Combined with Tribes Type NN Algorithm

“…Secondly, USMs possess characteristic variations and nonlinearity which are associated with temperature and load conditions. In order to compensate for characteristics of USM, some intelligent approaches based on NN have been proposed in recent years [5][6][7][8][9][10]. In these intelligent methods, it is not hard to find the following two facts.…”

Precise position control of an ultrasonic motor using the PID controller combined with NN

“…Therefore, in the conventional fixed-gain PID controller, gain adjustment is difficult, and it is not possible to obtain high-quality control performance. To overcome this problem, control methods using neural networks (NN) [1,2] and fuzzy [3,4] and hybrid controllers (a combination of an adaptive controller and a PI controller) [5] have been studied in recent years. However, fuzzy and hybrid control methods have not achieved precise position control.…”