Design of Fractional-Order Lead Compensator for a Car Suspension System Based on Curve-Fitting Approximation

Abstract

An alternative procedure for the implementation of fractional-order compensators is presented in this work. The employment of a curve-fitting-based approximation technique for the approximation of the compensator transfer function offers improved accuracy compared to the Oustaloup and Padé methods. As a design example, a lead compensator intended for usage in car suspension systems is realized. The open-loop and closed-loop behavior of the system is evaluated by post-layout simulation results obtained using the Cadence IC design suite and the Metal Oxide Semiconductor (MOS) transistor models provided by the Austria Mikro Systeme 0.35 μm Complementary Metal Oxide Semiconductor (CMOS) process. The derived results verify the efficient performance of the introduced implementation.

Keywords

• fractional-order controllers
• motion control systems
• Oustaloup approximation
• Padé approximation
• CMOS analog integrated circuits
• operational transconductance amplifiers