Design and Control of a Novel Geared Electromagnetic Active Suspension

A novel geared electromagnetic active suspension is proposed in this paper. A pushing rod and a rocker are introduced to transfer the suspension vertical motion to the rotational motion of the motor. Comparing with the common ball-screw active suspension, it presents advantages of simple structure, easy manufacturing and module design. As the state variables of the suspension system cannot be all obtained for the sake of cost, taking the suspension deflection as the measurement, an output feedback LQR optimal controller is adopted, and it is concluded that the system can be stable with damping. Considering the nonlinearity of equivalent stiffness and unsprung mass caused by the system structure, parameter perturbation ranges are concluded through dynamic analysis, and robust H_∞ control algorithm is proposed to realize the multi-objective optimization. The performance comparisons of both controllers mentioned above are carried out in the ADAMS/MATLAB co-simulation to reflect the influence of the nonlinearity of real time in practice. The results conclude that, in real system containing nonlinearity and parameter perturbations, the robust H_∞ controller performs better in robustness of improving the ride comfort and handling stability.