Structural Design And Control Study Of A Parallel Micro-vibration Platform

Vibration platforms and other vibration excitation devices are often used to produce vibration in the study of vibration problems. In this paper, a parallel micro-vibration platform was studied thoroughly, three-translational spatial parallel mechanism was used as main mechanism, piezoelectric ceramics were used as driver, traditional rigid motion pairs were taken place by the flexible hinges, thus the parallel micro-vibration platform could realize vibrations from one-one-dimension to three-dimension. The content of this paper mainly covers the following four aspects.Firstly, non-symmetric three-translational 3-RRRP(4R) mechanism was used as main mechanism of the vibration platform according to the design requirements of the parallel micro-vibration platform, motion output and degree-of-freedom of the chosen mechanism were analyzed, position equation of the mechanism was established, motion decoupling analysis was carried out; the first order influence coefficient matrix and the second order influence coefficient matrix were built up, the speed equation and acceleration equation were obtained, all these provided theoretical basis for the design of the parameters of the model.Secondly, parameters of the main mechanism of the parallel micro-vibration platform were analyzed and designed. The flexible hinges that had the characteristics of zero clearance, zero friction, free of friction, free of assembly were used as the kinematic pairs of the mechanism, the material of the flexible hinges was chosen reasonably, the parameters of the mechanism were designed; the finite element model of the mechanism was constructed, the security check was carried out, the feasibility on the design of the mechanism was verified.Thirdly, virtual prototype of the parallel micro-vibration was built up with the software of Solidworks and ADAMS, simulation tests of the vibration characteristics of the vibration platform were carried out on the virtual prototype. The corresponding micro-speed was imposed on the initial revolute pair of the mechanism, and the output displacement curves and output vibration curves of the vibration platform were obtained, correctness of the vibration law was verified.Finally, the control system of the parallel micro-vibration platform was designed, the vibration control of the parallel micro-vibration platform could be realized with the method of fuzzy gain scheduling PID control. The control software of the parallel micro-vibration platform was designed, and the feasibility of the controller was verified through experiments.Through above analysis, we have got specific and in-depth understanding to the characteristics and structural properties of the parallel micro-vibration platform, and these laid a good foundation to the development and application of the parallel micro-vibration platform.