摘要
针对底盘关键子系统对车辆行驶稳定性影响能力与有效作用区域的差异,综合考虑轮胎的非线性特性与各子系统间动力学耦合关系,建立整车14自由度非线性动力学模型,分别运用非线性H∞控制和模糊控制对转向、悬架和制动子系统进行控制性能研究,采用多级递阶控制理论设计了组织级、协调级和执行级的车辆稳定性多级协调控制系统。运用滑模控制理论与轮胎逆模型将组织级得到的保持车辆行驶稳定性所需的广义目标控制力和力矩转化为轮胎侧偏角和滑移率,再基于功能分配原理对各子系统控制功能进行协调,实现了底盘复杂系统的功能解耦,并对整车稳定性协调控制系统进行了仿真分析。仿真结果表明:防抱死制动系统与半主动悬架系统联合控制对车辆稳定性的控制效果相对较差,主动前轮转向的加入可以明显改善车辆的操纵稳定性。相对于汽车底盘子系统联合控制,多级递阶协调控制能更好地改善整车行驶稳定性,使制动距离减小,保持滑移率基本在目标值0.2附近。
Based on the differences of chassis key subsystems influences on vehicle stability and effective acting regions, the nonlinear characteristic of tires and the dynamics coupling relation among vehicle chassis subsystems were comprehensively considered, and the 14-DOF full vehicle model was built. Nonlinear H~ control and fuzzy control were separately utilized for chassis steering, braking and suspension to study the control performances. Multi-level hierarchical control theory was adopted to establish vehicle stability coordinated control system including organization, coordination and execution level. Sliding mode control theory and inverse tire model were used to translate the generalized target control forces and moments from organization level into tire sideslip angle and slip ratio. Based on the principle of function distribution, the control function of each subsystem was coordinated, the function deeoupling of vehicle chassis complex system was realized, and full vehicle stability coordinated control system was simulated. Simulation result shows that the control effect on vehicle stability by combined control of ABS （anti-lock braking system） and SAS（semi-active suspension system） is relatively poor, but joining AFS （active front steering） can significantly improve vehicle handling stability. Compared to vehicle chassis subsystem combined control, multi-level hierarchical coordinated control can improve vehicle stability preferably, reduce the braking distance and keep the slip ratio near the target value 0. 2 basically. 2 tabs, 12 figs, 20 refs.
出处
《交通运输工程学报》
EI
CSCD
北大核心
2015年第4期77-85,共9页
Journal of Traffic and Transportation Engineering
基金
国家自然科学基金项目(51278514)
中国博士后科学基金项目(2014M562259)
重庆市基础与前沿研究计划项目(cstc2014jcyjA60007)
关键词
车辆工程
车辆动力学
多级递阶控制
功能分配
稳定性
vehicle engineering
vehicle dynamics
multi-level hierarchical control
function distribution
stability
