Toward Industrial Process Control Applications of the Backstepping

This paper addresses practical aspects of the application of the backstepping method to the control of industrial processes. The limitations are emphased and solutions are proposed. The steady-state performances of the backstepping-based controllers are enhanced via the introduction of an integral action in the controller. In presence of non-zero mean perturbations, this modification guarantees vanishing residual errors. The manipulated variable behavior is also improved by the introduction of a new Lyapunov-based filter. In noisy contexts, the later ensures a small variance of the control, without altering the closed-loop stability. Finally, it is shown that an appropriate time scale selection is needed to obtain the desired closed-loop dynamics specification. The proposed scheme is applied to the control of a flotation column.