基于改进LQR方法的汽车横摆稳定性控制研究

为提高极限工况下汽车行驶的横摆稳定性,提出了一种改进的LQR横摆稳定性控制方法,考虑了路面附着极限的影响。在轮胎特性处于线性区域时,以二自由度线性模型作为参考模型,其稳态横摆角速度及质心侧偏角作为理想状态,当轮胎特性处于非线性区域时,以由路面附着系数决定的横摆角速度作为理想状态。根据线性二次型调节器(LQR)理论计算出维持汽车稳定所需要施加的附加横摆力矩。最后利用所建立的七自由度非线性模型,在正弦转向输入以及单移线工况下对控制方法进行了仿真验证,结果表明所设计的算法能够合理地控制横摆角速度及质心侧偏角,提高行驶的横摆稳定性。

Research on vehicle yaw stability control based on improved LQR method

In order to improve the yaw stability of the vehicle under extreme conditions, an improved LQR yaw stability control method is proposed, which takes into account the influence of the road surface adhesion limit. is established. In the linear region of tire characteristics, with two degrees of freedom linear model as the reference model, the steady-state yaw rate and sideslip angle as the ideal state, and when the tire characteristics are nonlinear, the yaw rate is determined by the road surface adhesion coefficient. The additional yaw moment required to maintain the stability of the vehicle is calculated according to the linear quadratic regulator (LQR) theory. Finally, the performance of the algorithm was simulated using a seven degree of freedom nonlinear model of vehicle in the sinusoidal steering input and single lane condition, and the results show that the designed algorithm can reasonably control the yaw rate and sideslip angle, improve yaw stability.