Model reference adaptive control for an ionic polymer metal composite in underwater applications

Ionic polymer metal composite (IPMC) materials are in an early stage of development. Their response as actuators is still very unpredictable. Their dynamic response is still subjected to several critical parameters that vary with time, thus extracting an accurate and repeatable model is very difficult. This paper presents the design and implementation of an adaptive efficient position control system for an IPMC actuator working in underwater conditions. The control system is an model reference adaptive control (MRAC) based on a reference model and an adaptation that controls a 1 cm × 0.5 cm length IPMC strip based on a Nafion 117 Na+ membrane. As the reference model a second-order empirical model of the plant is used. The control system is first simulated and then experimentally implemented within the LabVIEW framework.