Ionic polymer metal composites have been demonstrated to offer great potential as versatile actuators. However, the low force output of these actuators continues to be an inhibiting factor in their development. Researchers have begun to investigate thicker ionic polymer metal composite actuators that offer greater force output. An alternative approach is to use multiple strips of actuator in parallel to increase the force output.
In this paper the development of such an actuator is detailed. Issues of parallel or series electrical connection are discussed. Experimental results from the actuator are presented showing the unblocked position response and blocked force response. Losses within the system are considered for various numbers of strips. Finally PID control is applied to the actuator to demonstrate the controlled actuator performance.
New actuator technologies are moving closer towards the creation of artificial muscles. For these muscles to behave in synergy with natural human muscle then they must be controlled in a similar manner. It has been postulated that the control of human motion is achieved through a force and position control strategy termed impedance control. An impedance controller has been developed for implementation on an ionic polymer-metal composite (IPMC) actuator. The basis for this controller is a PID position controller that is demonstrated to accurately control the position response of the IPMC actuator. This position controller is extended to form an impedance controller with a force control loop and impedance filter. Inspite of identified non-linearities in the polymer force output during motion, the impedance controller has been successfully implemented demonstrating the controller design process and good performance of the control strategy.