时滞对主动悬架幅频特性的影响

Influence of Time-delay on Amplitude-frequency Characteristics of Active Suspension

为探究时滞对主动悬架控制性能的影响,在分析时滞对闭环控制系统传递特性影响的基础上,建立了考虑控制输入时滞的悬架系统模型,并以该模型为研究对象,理论分析了时滞对天棚主动控制和加速度阻尼主动控制下悬架幅频特性的影响,最后通过数值仿真进行了分析与验证。结果表明:时滞导致车体加速度的传递率增大,同时还造成一、二阶主振型频率的变化,并在中、高频区域产生多个共振峰;较大的时滞会造成主动悬架振动控制效果的明显恶化甚至系统的失稳。

In order to explore the influence of time-delay on control characteristics of active suspension,a model of suspension system considering the control input time-delay is established on the basis of analyzing the influence of time-delay on transfer characteristics of a closed loop control system. Taking the model as the research object,the influence of time-delay on amplitude-frequency characteristics of skyhook active control and acceleration driven damping active control is theoretically analyzed. Finally,numerical simulations are carried out to analyze and verify the conclusions. The results show that the timedelay results in the raise of the transfer rate of the vehicle＇s body acceleration,the change of the first and the second order frequency of the main vibration mode,and generates multi-formants in middle and high frequency areas. A large time-delay will result in the obvious deterioration of the vibration control effect of the active suspension,even the instability of the system.