减速带及发动机联合激励下车辆混沌识别与智能抑制

摘要

针对非线性悬架车辆通过连续型减速带时,在减速带和发动机的联合激励下可能产生的混沌,以考虑发动机激励的车辆五自由度车辆模型为研究对象,通过车身Poincaré截面图和车辆系统最大Lyapunov指数对车辆在联合激励下产生的混沌进行识别,并利用基于粒子群算法搜索最优反馈增益系数的反馈控制对车辆混沌进行抑制.结果表明,车辆在各车速工况下均处于混沌状态,中低速工况下车辆进入混沌的途径是多频率激励下系统振动的耦合,高速工况下车辆由分岔途径进入混沌状态;利用粒子群算法搜索全局最优反馈增益系数的反馈控制能够有效抑制车辆混沌.揭示了非线性悬架车辆在联合激励下的混沌特性,为混沌的智能抑制提供一种新的思路.%The possible chaos under speed bump and engine combined excitation when the vehicle passing through the speed bump is studied.The 5-DOF model of the vehicle is established with the speed bump and engine combined excitation considered.The Poincaré section and the maximum Lyapunov exponent of vehicle system are used to identify the vehicle chaos. The particle swarm optimization (PSO) is used to search the best feedback gain, which is utilized to suppress the vehicle chaos.The results indicate that the vehicle is in chaos state in all speed range. Under low and medium speed, the route to chaos of the vehicle is the system coupling vibration under multi-frequency excitation. While in the high speed condition,the vehicle approaches the chaos through the bifurcation.Chaos of the vehicle can be effectively suppressed by feedback control with the best feedback gain searched by PSO. The chaos characteristics of the vehicles with nonlinear suspension have been revealed and a new thought of chaos intelligent suppression has been provided.