ILC for Precision Servo with Input Non-linearities: Application to a Piezo Actuator

Abstract

Most ILC schemes proposed hithertowere designed and analyzed without taking the input non-linearities, such as deadzone, saturation, backlash, into account. These input non-linearities are non-smooth and non-affine-in-input factor widely existing in actuators or mechatronics devices. They give rise to extra difficulty in control due to the presence of singularity or non-uniqueness in the system input channels. In this chapter, we focus on input deadzone, and show that ILC algorithms remain effective in general for systems with input non-smooth non-linearities that could be unknown and state dependent. In addition, in this chapter we will also briefly discuss the input saturation and input backlash.