Low order robust controllers for active vehicle suspensions

This paper considers an H_∞ control scheme for active suspensions. A quarter car model, which captures many features of real structures, is used in this study and a pragmatic approach to select the uncertainty and performance weights is proposed. The controller improves ride comfort without sacrificing ride safety and is robust to parametric uncertainties of the model. To decrease the costs of implementation, various controller reduction tools, are applied to reach the same performance by a lower order controller. System performance using reduced controllers are assessed and compared with each other. Numerical data, time and frequency domain simulations demonstrate the effectiveness of the reduced order controller.