Design of a robust quantitative feedback theory position controller for an ionic polymer metal composite actuator using an analytical dynamic model

Nowadays, ionic polymer metal composite actuators are widely used in many fields such as biometric, biomedical, and micro-manipulator devices. Although extensive research exists on control of the ionic polymer metal composite actuators, not much research has been done on robust control considering the nonlinear dynamics of the ionic polymer metal composite. In this study, for the first time, a closed-loop robust controller based on quantitative feedback theory is designed to overcome the actuation performance degradation of the ionic polymer metal composite actuators. First, an analytical electromechanical model is developed to fully describe dynamics of the flexible ionic polymer metal composite actuator. The model is based on the Euler–Bernoulli beam theory and includes structural damping to model viscoelastic behavior of the ionic polymer metal composite actuator. Considering the highly nonlinear and uncertain dynamics of the ionic polymer metal composite actuator, a feedback controller based on quantitative feedback theory is designed to suppress the arbitrary external disturbances and consistently track desired input. Results indicate that the robust quantitative feedback theory control techniques can significantly improve the ionic polymer metal composite performance against nonlinearity and parametric uncertainties.