Speed control of ultrasonic motors using neural network

Abstract

Ultrasonic motor (USM) is a newly developed motor and it has an excellent performance and many useful features, so it has been expected to be of practical use. However, this motor has a heavy nonlinearity which varies with driving conditions. Therefore, precise speed control of ultrasonic motor is difficult. This paper proposes a new speed control scheme for ultrasonic motor using a neural network. The proposed controller can approximate the nonlinear input-output mappings of the motor using the neural network, and can compensate the characteristic variations by online learning. The usefulness and validity of the proposed control scheme is examined by experiments.

Neuro-fuzzy speed tracking control of traveling-wave ultrasonic motor drives using direct pulsewidth modulation

“…into (13), can be obtained as (17) By using (11) and (12), can be obtained as (18) Hence, by substituting (17) and (18) into (15), and then using (14), is updated by (19) Similarly, by using (11), (12), (14), (16), and (17), is updated by (20)…”

“…Although many attempts have been made to model the TWUM, the resulting models are so complex or data demanding that they are impractical for real-time control [9]- [11]. Alternatively, many empirical approaches, such as proportional integral (PI) control [12], fuzzy logic control [13], adaptive control [14], and neural network control [15], have been proposed for motion control of the TWUM. The PI control is simple and offers a wide stability margin.…”

Design and performance evaluation of an exponentially weighted moving average–based adaptive control for piezo-driven motion platform

“…Besides the problems of inaccurate assembly or improper preload, these piezoelectric motors are sensitive to temperature rise and their performance becomes worse during long-time operation. 1,2 These negative factors are the disadvantages and serious concerns of using piezoelectric motors. Miscellaneous wedge-type piezoelectric motors usually driven by standing wave to propel a carriage via the contact tip were designed to improve the positioning capability and accuracy.…”

Neuro-fuzzy speed tracking control of traveling-wave ultrasonic motor drives using direct pulse width modulation

“…Basically, the speed of the TUSM can be manipulated by controlling the frequency, phase difference and the voltage amplitude of the two sinusoidal voltage waveforms which input to the TUSM. Many researchers have opted for the frequency of the sinusoidal voltage waveforms as the control variable [1]- [5]. It can easily be controlled digitally and spans the whole speed range the TUSM allows.…”

“…However, the resulting models are so complex or data demanding that they are impractical for real-time control [14]- [16]. Alternatively, many empirical approaches for speed control, such as classical PI control [7], [12], fuzzy logic control [1], adaptive control [2], [17], neural network control [5] have been proposed. PI controller is simple and offers wide stability margin.…”