Design of Sliding Mode Control using Proportional-Integral Sliding Variable for Active Suspension System with Different Road Profiles

Active suspension systems enable autonomous vehicles to carry out various functionalities to move on and afford drivability with more safety and comfort. To design a controller, it should attend requirements such satisfactory road holding ability, while still providing comfort when riding over bumps and holes in the road. In this paper, a robust sliding mode control is designed that overcomes the problem of comforts while riding over the bumps and holes for the active suspension system. The sliding variable is designed using a proportional plus integral (PI) approach which guarantees better steady-state performance in the presence of road disturbances. The stability of the closed-loop system is derived using the Lyapunov approach that guarantees the finite convergence of state variables. The simulation outcomes demonstrate the efficacy of the proposed control algorithm in the presence of normal and continuous road disturbances having shorter time duration and high amplitudes. Finally, the simulation results are analyzed and compared with the constant plus proportional rate reaching law in the presence of system uncertainties.