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A major deficiency of piezoelectric actuators is that their open-loop control accuracy is seriously limited by hysteresis. In this paper, a novel mathematical model is proposed to describe hysteresis precisely and a new parameter called turning voltage is introduced. It was found experimentally that the shapes of hysteresis curves are decided by the value of the turning voltage. A computer-based inverse control approach under open-loop operation based on the mathematical model was applied to suppress the inherent hysteresis to within ±1% full span range of a stack piezoelectric actuator and the performance of the piezoelectric actuator is noticeably improved.

The drive power supply for micro-positioning platform is an integral part of the control system of micro-positioning platform. In order to achieve the purpose of accomplishing precise positioning, the micro-positioning platform not only needs nice positioning accuracy, but also has good controllability and stability. This makes a high requirement for drive power supply for micro-positioning platform. With the development of electronic technology, FPGA has been applied widely. As FPGA has a very good application flexibility, FPGA have been widely used in control systems today. According to the above characteristics, I designed a drive power supply for micro-positioning platform. The drive power supply used closed-loop feedback as control mode, in order to achieve the purpose of outputting highly precise voltage. In terms of hardware, the drive power supply made FPGA as the main controller, combined with A/D converters, D/A converters and operational amplifiers made up control circuits and amplifier circuits. The control circuits and amplifier circuits constituted of multiple modules separately. This paper discussed mainly the design and realization of each module of the control circuits and amplifier circuits.

Piezoelectric actuator controlled by voltage shows serious hysteresis phenomena, which severely degrades the positioning accuracy. Based on Prandtle-Ishlinskii hysteresis operator, an adaptive inverse control approach is presented for reducing hysteresis. The weights of the model are identified by using LMS algorithm. The realization of an inverse feedforward controller for the linearization of a piezoelectric actuator is formulated. Experiments were performed on a micro-positioning system driven by piezoelectric actuators. The results show that the presented adaptive inverse control lowers the non-linearity error from about 17.3 to about 2% in comparison to the conventionally open-loop control.

The compact precise tilt positioning mechanism (PTPM) determines the performance of inter-satellite optical communication systems. This paper presents a novel structural design of a PTPM in which the tilt movement is implemented by the elastic deformation of a flexure ring. The flexure ring promises zero friction and zero clearance. The stiffness model of the flexible ring was built based on an analysis of the structural mechanics. Then a dynamic model is presented based on the Lagrange equation. A modal analysis and an experimental investigation were performed. The error between the three methods is less than 10%.

The need for a precision fast positioning technique is drawing significant attention from optical engineering, semiconductor industry, biotechnology, and nanotechnology, etc. This paper presents a novel piezoelectric (PZT) actuated precision fast positioning system (PFPS), which consists of a control module, PZT driving module, a precision fast positioning mechanism (PFPM), and a micro-displacement measure module. It controls the tilt and piston movements quickly and precisely. The driving, mechanism and measure integrative model of the PFPS has been built. The methods of digital proportional integral differential (PID) feedback control and self-tuning fuzzy PID control are studied. Simulation results prove that the proposed self-tuning fuzzy PID controller has good dynamic and static performances. A dynamic performance test system has been established. The experimental results confirm the validity of the design and the theoretical analysis of the PFPS.