An Optimal Approximation Technique for Fractional-order Lead Compensator Applied to a Car Suspension Problem

This paper deals with the optimal approximation of fractional-order lead compensator (FOLC). Stable, minimum-phase FOLC rational approximants are guaranteed using a constrained optimization procedure. The optimization is carried out using a state-of-the-art metaheuristic to approximate the frequency characteristics of the FOLC. Variation of the approximation order on the accuracy of the proposed FOLC, when applied to a car suspension compensation problem, is investigated. The efficacy of the algorithm in terms of convergence rate and computational time is evaluated. Comparison with the published literature demonstrates the lower approximation error achieved by the proposed approach.