针对汽车主动悬架系统在转向过程中的动力学行为,建立了整车转向模型。从提高汽车转向时的乘坐舒适性和操纵稳定性出发,从时域和频域两方面研究了整车系统的最优控制问题。考虑转向过程中汽车的横摆、侧倾、俯仰及垂直方向的振动和悬架的动挠度,定义了范数评价指标,并根据人体对振动的敏感频率范围引入了适当的频域加权函数,设计出最优控制器。仿真结果表明,该方法能够有效抑制由转向和路面不平引起的振动,明显降低人体敏感频段的垂直和旋转方向振动的幅值,使悬架动挠度有所下降。
Based on the active suspension dynamics in steering, a full vehicle steering model was built. In order to improve the ride comfort and the stability of driving, an optimal control method of the full vehicle was studied in time- and frequency-domains. Considering the yaw, roll, pitch, vertical moment of the vehicle body and the journey of the suspension, the norm index was defined. For the human horizontal and vertical sensitivity frequency ranges, the proper frequency-dependent performance weights were chosen and the optimal controller was designed. The simulation results show that this method can effectively reduce the vibrations of the vehicle body caused by steering and the road roughness. In the human sensitive frequency ranges, the amplitudes of vertical and rotational vibrations are considerably decreased. Also, the suspension deflections are restrained.