摘要
针对时滞减振控制的非线性悬架系统,建立其二自由度系统的动力学方程。首先,对动力系统进行了数值模拟,通过不同控制参数下系统的动力学行为的分岔图、相轨迹、庞加莱截面、功率谱图来研究时滞非线性悬架系统的混沌动力学行为。研究表明,基于系统参数和外在激励,选择适当的时滞控制参数,可避免系统在运行过程中出现混沌现象,改善系统的运行品质。然后,以主系统幅值均方根为目标函数,对系统进行优化得出减振效果最优时的时滞和反馈增益系数,并与无时滞时非线性悬架系统的主振幅响应进行比较。结果表明,时滞对非线性悬架系统减振和系统品质的改善是能够同时实现的。最后,研究了时滞控制参数变化对系统动力学行为的影响,研究发现,同一系统在不同时滞参数下其分岔形式以及通往混沌的形式具有着多样性,会出现倍周期分岔、Hopf分岔、阵发性分岔以及它们各自通往混沌的不同演化模式,这为实现悬架参数的优化控制提供了理论依据。
Based on the damping control of nonlinear suspension system with time-delay, a two-degree-of-freedom dynamics system is established in this paper. Firstly, the chaos dynamic properties of nonlinear suspension system with time-delay are investigated by numerical simulation which includes bifurcation diagrams, the phase traces, Poincare sections and power spectra under different control parameters. The results show that the chaos phenomena can be avoided by selecting suitable time-delay control parameter according to system parameters and intrinsic excitation, and therefore the motion property of vehicle is improved. Then, taking root mean square of the main system amplitude as the objective function, the optimal time-delay and feedback gain are obtained by using optimization method and the corresponding main system amplitude is compared with that of the nonlinear suspension system with no delay. The results indicate that the vibration reduction and the quality improvement of system can be achieved at the same time. At last, the effects of delay control parameters on the behavior of system dynamics are discussed, which verifies different bifurcations(i.e. period-doubling bifurcation, Hopf bifurcation, explosive bifurcation) and their distinct routes to chaos under different control parameters based on the same system. The research in this paper provides theoretical references for optimization of suspension parameters.
出处
《应用力学学报》
CAS
CSCD
北大核心
2016年第5期891-897,941,共7页
Chinese Journal of Applied Mechanics
基金
国家自然科学基金(51275280)
关键词
悬架系统
时滞
非线性动力学
混沌
分岔
suspension system
time-delay
nonlinear dynamics
chaos
bifurcation
