Algebraic adaptive discontinuous control for trajectory tracking in a perturbed 1-DOF suspension system

This work deals with the control, and the on line algebraic identification, for an unknown perturbed 1 degree of freedom (DOF) suspension system. The algebraic identifier is provided with an automatic disconnection strategy of the fast on-line identification subsystem. The automatic disconnection is achieved by assessing an extra auxiliary parameter, called the “sentinel” parameter, that monitors the convergence of the rest of the system parameters estimation process. The estimated values of mass, stiffness and damping is realized via an adaptive algebraic estimator, with great rapidity and robustness to noise process signals present in the input and output signals measurements. A generalized proportional integral (GPI) controller was designed for the trajectory tracking task and for the rejection of a constant disturbance input. The switched implementation of the average input in the form of a bounded discontinuous control signal is based on the use of a Σ-Δ sliding mode based modulator. In an average sense, this modulation allows us preserve the desirable features of the dynamic output feedback controller and to be close to a real implementation. The efficiency of the complete procedure is demonstrated via digital computer simulations.