Integration design and parameter optimization for a novel in-wheel motor with dynamic vibration absorbers

To overcome vertical vibration negative effects induced by high unsprung mass of the existing IWM, a novel integrated IWM topology scheme is developed. This scheme aims for the integrated design of hub, rotor housing and brake disk, and the stator is considered as a DVA, which is flexibly isolated from the unsprung system by the suspension elastic sleeve. Primarily, the quarter-vehicle dynamic model with the DVA-based electric wheel is established, and the improved vibration transmission characteristics of the integrated IWM are clarified in the frequency domain. Then, according to the sensitivity analysis theory, the sensitivity of the vertical dynamic response to the association structural parameters such as stator mass, stiffness and damping of rubber bushing and bearing is discussed. On this basis, the MCO of the association structural parameters is carried out by using the adaptive weighted PSO and FEM. After optimization and treatment, the overall mass of stator decreases by 9.35% when the structure strength is satisfied, the vertical dynamic characteristics of the integrated IWM system have been improved to varying degrees; particularly, the motor MGD gets more than 20% improvement. The results demonstrate that the proposed integrated scheme can observably improve the vehicle vertical dynamics and simultaneously the DVA system exhibits excellent performance in terms of wheel and motor vibration suppression.