Guaranteeing preselected tracking quality for uncertain strict-feedback systems with deadzone input nonlinearity and disturbances via low-complexity control

A continuous, low-complexity, static, state-feedback controller is proposed for strict-feedback systems with deadzone input nonlinearity and disturbances, utilizing the Prescribed Performance Control methodology. The scheme achieves preselected bounds on the transient and steady state output error performance despite the uncertainty in system nonlinearities and deadzone characteristics. Regarding the latter, a general class of admissible deadzones is considered compared to the current state-of-the-art, permitting nonsmooth and even locally decreasing behavior outside the dead-band. Furthermore, approximating structures, i.e., neural networks, fuzzy systems, etc., are not utilized and, moreover, the backstepping “explosion of complexity” issue is eliminated without residing in filtering, thus deriving a low-complexity design. The proposed controller evades the construction of a deadzone inverse and does not employ a special analytical deadzone representation. Simulations are performed to verify the theoretical findings.