摘要
为提高四轮转向汽车的操纵稳定性,提出一种联合后轮转向和横摆力矩的最优控制方法.从7自由度四轮转向整车模型出发,建立车辆转向的线性化简化模型和理想模型,并基于二次型最优控制理论推导出前馈控制器和反馈控制器.仿真结果表明:在低速和高速行驶工况下,相比传统的前馈控制,基于最优设计的前馈控制器能改善车辆的行驶姿态,而实施前馈加反馈的最优控制方法可获得更优的理想模型跟踪控制性能,实现了零侧偏角控制目标,同时横摆角速度的控制误差也很小,使得汽车具有更好的行驶轨迹、速度保持能力和稳定状态,进一步提高了车辆的操纵稳定性.
In order to improve the steering stability of four-wheel-steering （4WS） vehicle, an optimal control method is presented to realize integrated control of the rear steer angle and direct yaw moment. From a 4WS vehicle model with seven degrees of freedom, a simplified linear model and ideal model are introduced to describe vehicle steering, and the feed-forward and feedback controller are designed based on the linear quadratic optimal control theory. Simulation results demonstrate that under the driving cycles with low speed and high speed, compared with the traditional feed-forward control, not only the feed-forward controller based on optimal control design can improve the vehicle steering attitude, but also the proposed optimal control method including feed-forward and feedback controllers has better control performances, such as zero slip angle and the smaller error of yaw velocity, and can further enhance the path tracking ability and steering stability of 4WS vehicle.
出处
《广西科技大学学报》
CAS
2015年第1期1-6,17,共7页
Journal of Guangxi University of Science and Technology
基金
广西教育厅科研项目(201204LX657
201202ZD068)
广西自然科学基金项目(2013GXNSFAA019351)
关键词
四轮转向车辆
横摆力矩
后轮转向
最优控制
操纵稳定性
four-wheel-steering vehicle
yaw moment
rear wheel steering
optimal control
steering stability
