Output feedback control of a tractor with N-trailer with a guaranteed performance

This paper proposes a saturated output-feedback trajectory tracking controller for an autonomous tractor with N-trailer with guaranteed desired performance specifications. At first, an input-output model of the tractor with N-trailer system is presented by a proper selection of the output variables vector. Based on a prescribed performance technique, a nonlinear transformation between the constrained errors to unconstrained ones is used to develop an open-loop error dynamic model in terms of the unconstrained filtered tracking error. Then, a saturated neural adaptive input-output feedback linearizing controller with a nonlinear observer is proposed to stabilize the tracking errors to the vicinities of the zero with a guaranteed prescribed performance in the presence of model uncertainties while avoiding the velocity measurements and reducing the risk of the actuator saturation simultaneously. Finally, a semi-global uniform ultimate boundedness stability of the closed-loop control system is proved via Lyapunov's direct method. At last, a computer simulation example will be provided to demonstrate the controller effectiveness for practical applications.