Control of Electro-active Polymer Actuators with Considering Characteristics Changes

Electro-active polymers (EAPs) are functional polymeric materials which respond to electrical stimuli with shape change. Since EAPs can be activated by electric field, driving equipment and control system are able to be easily implemented. Simple feedback control methods such as PID control and optimal control with identified model are effective; however, actuator characteristics of EAPs are likely to change depending on environmental conditions such as temperature and humidity or on material fatigue by iterative actuation. Therefore, feedback control methods considering the characteristics changes are desired. In this chapter, we explain two effective control methods for characteristics changes. One is a self-tuning control, which is a type of adaptive control, and another is cellular actuator control method for an integrated actuator. As example cases of the applied results, experimental results of feedback control of ionic polymer-metal composite (IPMC) actuators are demonstrated.