Space With Three Translations Of Ultra-precision Positioning Platform And Control Methods

With the development of science and technology, ultra-precise positioning technology gets rapid development in recent years. The micro-robot's which can realize ultra-precise operation is concerned by more and more people. What's more, it has promising application and great development potential.Based on the typical spatial 3-DOF parallel mechanism- Delta mechanism, a new 3-DOF parallel robot which called 3-DOF spatial translational ultra-precision parallel robot is designed. The robot using elastic supporting structure, and with piezoelectric actuators as its drives. It has high resolution, stiffness, low energy consumption and compact structure.The flexible hinge is designed from conventional kinematic pair according to the characteristics of micro-robot which can realize ultra-precise operation. The flexible chain is designed according to the flexible hinge and its elastic supporting. A compliant 3-DOF spatial translational ultra-precise positioning platform is designed according to the flexible chain. The theoretical analysis is proceed, including its location and pose,forward and inverse solutions of its positions. And the finite element analysis to the model is implemented, including the analysis of flexible hinges, flexible chain and the whole platform. Also the model analysis is implemented. The results shows that the positioning designed can achieve precise positioning in nanoscale. The research to the characteristics of piezoelectric actuators is implemented based on the drive mechanism of piezoelectric actuators, including capacitive, temperature, hysteresis, creep and nonlinear characteristics. The transfer function of the ultra-precise positioning platform is deduced. The neural network PID control algorithm is used to control the platform accurately. And simulation curves are gived through Matlab after some experimental researches. The results show the platform designed can well realize ultra-precise positioning. The result shows the control method can well meet the requirements in overstrike, accommodation time and stability.