Optimization of a Pseudo-Active Suspension Network

The immittance concept of electrical networks corresponds to that of mechanical networks. Immittance method is one of the important methods for mechanical network optimization. That is, the mechanical network is represented by immittance function. The performance index is taken as the optimization objective function. The parameter optimization method or linear matrix inequality is applied to optimize the solution. The immittance function can be implemented passively through network synthesis, which can greatly reduce the structure complexity and production cost. For vehicle suspension composed of passive components, immittance method can only be limited to passive networks. Correspondingly, the optimization results obtained are not ideal enough or deviate from reality because of the complexity of the resulting network. In this paper, a pseudo-active actuator is introduced into vehicle suspension to realize pseudo-active suspension. The pseudo-active actuator introduces negative stiffness and negative damping characteristics through gears, which makes the immittance of the suspension network break through the limitation of “positive-real”. Based on the cubic immittance function, the pseudo-active suspension is obtained and compared with the traditional network suspension obtained by using the traditional network optimization. Under the same working condition, the pseudo-active suspension provides better vertical vibration suppression performances.