Closed-loop Subspace Predictive Control for Fault Tolerant MPC Design

Subspace predictive control (SPC) is recently seen in the literature for joint system identification and control design. This combination enables automatically tuning the parameters in conventional model predictive control (MPC); and therefore provides a solution to the problem of fault tolerant MPC design. The existing SPCs either deal with open-loop data or depend on the information of the controller in a closed loop. In this paper we introduce a new closed-loop SPC method, which is independent of any controller information. Both the analytic solution to the unconstrained case and the quadratic programming problem for the constrained case are formulated. A recursive solution for updating the SPC control law is proposed. A fault tolerant MPC scheme is then developed based on the recursive algorithm, whose effectiveness is demonstrated on tolerating a fault in a steer-by-wire actuator.