Inversion-free adaptive control of uncertain systems with shape-memory-alloy actuation

We apply retrospective cost adaptive control (RCAC) to a command-following problem for an uncertain shape-memory-alloy (SMA) actuator. The SMA actuator is characterized by a Wiener model consisting of linear dynamics that convert the input voltage or current to a temperature, and a hysteresis model that characterizes the relationship between the temperature and the output displacement. We use the generalized Prandtl-Ishlinskii model to characterize the input-output relationship between the temperature and the output displacement in the SMA actuator.