Multi-Objective Optimisation of Restricted Complexity Controllers

Restricted complexity controller design for the active suspension benchmark problem [1] is considered. The control design specifications of the benchmark is firstly recast into a mixed H∞/l1 optimisation problem, which is solved via a convex optimisation approach. A globally optimal Pareto curve is produced via the optimisation. It presents the limits of performance and is served as a reference for restricted complexity controller design. Then, controllers with different complexity are designed via a direct optimisation approach. The performance indices of these controllers are compared with the global Pareto curve. Based on the comparison, the controller with three parameters is determined as the one achieving acceptable performance with lowest complexity. Experimental results on the real system confirm the satisfactory performance achieved by the controller.