Robust H∞ Control Design for Improving Handling and Ride Comfort in Semi-Active Suspension Systems

Abstract

This study investigates the application of robust H∞ control design for semiactive suspension systems. The goal is to achieve a balance between ride comfort and handling. A quartercar model is used to simulate the system's dynamics. The findings demonstrate that the robust H∞ control approach with μ-synthesis offers significant advantages compared to traditional passive control and nominal H∞ control methods. When compared to the passive system, the robust H∞ controller with μ-synthesis results in a 50% reduction in body displacement (from 0.04 meters to 0.02 meters) during a simulated road bump. It also achieves a 25% reduction in peak body acceleration (from 4 m/s2 to 3 m/s2) and a 37.5% reduction in suspension deflection (from 0.04 meters to 0.025 meters). These improvements translate to a smoother ride with less body movement and improved handling due to better tire contact with the road. The μ-synthesis method specifically addresses uncertainties like passenger weight and road conditions. This leads to more consistent performance in real-world driving scenarios. Overall, this study highlights the effectiveness of robust H∞ control design in achieving a well-balanced suspension system that enhances both ride comfort and handling.