基于改进LQR的四轮独立驱动-转向汽车稳定性控制

Stability Control of Four-Wheel Independent Drive Steering Vehicle Based on Improved LQR

摘要:

针对四轮独立驱动-转向汽车在多速域工况下的转向稳定性控制需求,提出了一种基于自适应LQR的多轮协同分层控制策略。在二自由度理想模型与四轮转向非线性动力学模型的复合架构基础上,引入车速关联的自适应权重系数调节机制,建立“上层优化-下层分配”的分层控制框架,并利用Carsim与Simulink联合开展仿真实验,实现了不同车速下车辆横摆角速度与质心侧偏角的协同优化。结果表明:在低速和中高速下的DLC以及角阶跃工况场景中,A-LQR控制策略能够有效抑制质心侧偏角和横摆角速度的跟踪误差,结合分层控制架构能够有效提高车辆轨迹跟踪精度与行驶稳定性。研究为提升车辆转向轨迹精度和稳定性控制方法提供了参考。

Abstract:

A multi wheel cooperative hierarchical control strategy based on adaptive LQR is proposed to address the steering stability control requirements of four-wheel independent drive steering vehicles in multi speed domain conditions. On the basis of the composite architecture of the two degree of freedom ideal model and the four-wheel steering nonlinear dynamic model, an adaptive weight coefficient adjustment mechanism related to vehicle speed is introduced, and a hierarchical control framework of "upper layer optimization lower layer allocation" is established. Carsim and Simulink are jointly used to conduct simulation experiments, achieving the coordinated optimization of vehicle yaw rate and center of mass lateral angle at different vehicle speeds. The results indicate that in DLC and angular step working scenarios at low and medium to high speeds, The A-LQR control strategy can effectively suppress the tracking errors of the center of mass sideslip angle and yaw rate, and combined with a layered control architecture, it can effectively improve the accuracy of vehicle trajectory tracking and driving stability. The research provides a reference for improving the accuracy and stability control methods of vehicle steering trajectories.