Modeling and Control of Artificial Muscles Actuated Systems with Applications to Biomedical Systems

点击翻译按钮获取中文摘要

Over the last decade, electroactive polymers, a novel family of smart materials, have received tremendous interests for their potential applications in sensing, actuation, and energy harvesting. Therein, ionic polymer-metal composites (IPMCs) form an important category of electroactive polymers and have built-in actuation and sensing capabilities. Owing to the IPMCs' softness, resilience, biocompatibility and the capability of producing large deformation under a low action voltage, IPMCs are highly attractive as a material for actuators or sensors in biomedical applications and for developing artificial muscles or biomimetic robots. However, the IPMC actuated systems reflect highly nonlinear characteristics observed in both electrical and mechanical responses including creep, hysteresis, structural nonlinearity, and time-varying behaviors, and so on, which severely limits system performance. Without the aid of feedback control techniques to overcome the these effects, it is only possible to achieve limited positioning accuracy. Control of the IPMC actuated systems including hysteresis nonlinearity are very difficult problems because the vast majority of existing control methods are only applicable to systems that are smooth and differentiable. New methods, however, are greatly needed because hysteresis nonlinearities often severely limit the performance of feedback systems if they are not controlled properly. Therefore, the development of characterizing and control techniques for IPMC actuated systems is of significant theoretical and practical interest for their applications. The objective of this research is to conduct fundamental research related to modeling and control of the IPMC actuated systems involving complex hysteresis in the presence of model uncertainties. The targeted applications includes biomedical systems such as artificial muscle actuating units and biomimetic robots.