Adaptive actuator failure compensation for multivariable feedback linearizable systems

A feedback linearization based adaptive control scheme is developed for multivariable nonlinear systems subject to uncertain failures. The use of a direct adaptive actuator failure compensator and a linear feedback controller leads to error equations suitable for deriving adaptive update laws for the direct control signal. The key new design feature is the estimation of both the failure patterns and the failure values, for direct adaptive actuator failure compensation, newly developed for multivariable feedback linearizable nonlinear systems. Closed-loop stability and asymptotic output tracking in the presence of actuator failure uncertainties is proved and desired system performance is shown by simulation results from an application to attitude control of a vehicle dynamic model.