Electromechanical Model And Inverse Model Control Of Bending Conducting Polymer Actuators

Conducting polymer is a class of potential materials, actuators base on conducting polymer with low driving voltage, volume deformation, biocompatibility, light weight, simple structure, working in liquid or air medium, has become the focus of the research such as bionic micro operation system, intelligent mechanical system and bionic robot. But since it is complicated that the electro- chemical- mechanical coupling mechanism of conducting polymer actuators in the driven process, and the influence of nonlinear character including hysteresis, positon drift limit the establishment of accurate system model and effective control method.This paper take the trilayer bending conducting polymer actuators as the research object. In order to provide theoretical basis for its practical application, the preparation process, eletro-mechanical modeling and control algorithms has studied. It mainly includes the following aspects:(1) Analysis of the principles of the actuator, the reversible redox reaction in the internal structure of the conducting polymer in its response process; The process of the conversion of electrical energy into mechanical energy has described at the molecular level.(2) It is discussed preliminarily on the preparation process and optimization method of actuators by using ion implantation and electrochemical deposition PPy experiments on PVDF membrane.(3) Based on the theory of diffusive-elastic-metal model for conducting polymer films in electrolyte solution, we extend this model to trilayer conducting actuators and have a transmission line circuit of the trilayer conducting polymer actuators(PPy/PVDF/PPy). By analyzing the electrical and electromechanical coupling model, the relationship between the curvature and the input voltage is obtained, and the linear high-order transfer function base on the relationship as well.(4) Through the frequency characteristics test of 10 mm 2mm actuators, it is identified that the parameters of linear high-order transfer function by frequency response approach based on test data. We obtained respectively the parameters of N=2, 4, 6 order transfer function, and compared the model output with the actual displacement output of actuators system. Finally, zero-pole distribution of actuators is drawn.(5) N=4 order transfer function G(s) of 10 mm 2mm actuators was chosen to calculate the inverted transfer function G-1(s). Combination of compensation of nonlinear character and the inverted transfer function, a direct inverse model control method for actuator with position drift compensation is established. In order to validate the control method of the inverse model, we built control module in the Matlab/Simulink and carried out the testing and analysis experimental verification and analysis in displacement measurement platform.