汽车电子稳定控制系统控制策略仿真分析

为了避免汽车在低附着路面上高速转弯或者紧急避障时易发生不稳定现象,设计了基于模糊理论和滑模理论的模糊滑模控制策略。建立车辆二自由度理想模型,选择横摆角速度和质心侧偏角作为控制变量,对其理想值进行计算；基于车辆运动参数对失稳状态做出分析；并对失稳状态下的车辆进行横摆力矩控制。基于等效控制法设计了积分滑模控制器,对横摆角速度和质心侧偏角的偏差采用质心侧偏角协调加权法调节比例权重,并通过模糊控制规则调节滑模控制器切换系统的切换增益大小,建立模糊滑模控制器。在MATLAB/Simulink中对控制策略进行仿真分析,仿真结果表明：在阶跃工况下,横摆角速度的稳态值与理想值仅差0.005 rad/s,质心侧偏角与理想值几乎重合,仅差0.003 rad；正弦工况下,横摆角速度超调值与理想值仅差0.04 rad/s,质心侧偏角也仅差0.008 rad。与参数自整定模糊PI控制策略相比,模糊滑模控制响应速度更快,能够较好地跟踪理想曲线,达到稳态效果更好；同时能产生更大的横摆力矩,更好地控制汽车的稳定性,验证了控制模型的正确性。

Simulation and Analysis of Control Strategy for Automotive Electronic Stability Control System

The fuzzy sliding mode control strategy based on the fuzzy theory and the synovium theory was designed to avoid the unstable phenomenon when the vehicle turned at high speed or avoided the obstacle in an emergency on the low adhesion road surface. The ideal two-degree-of-freedom model of the vehicle was established. The yaw angular velocity and the side slip angle of the center of mass were selected as the control variables, and the ideal values of the two control variables were calculated. The instability state was analyzed based on vehicle motion parameters. And the yaw moment control of the vehicle in the unstable state was carried out. An integral sliding mode controller was designed based on the equivalent control method, and the proportional weight was adjusted by the side slip angle coordination weighted method to adjust the deviation between yaw velocity and side slip angle. The switching gain of the sliding mode controller switching system was adjusted by fuzzy control rules, and the fuzzy synovial controller was established. The control strategy was simulated and analyzed in MATLAB/Simulink. The simulation results show that the steady-state value of the yaw rate is only 0.005rad/s from the ideal value under the step condition, and the lateral slip angle of the center of mass almost coincides with the ideal value, only a difference of 0.003rad; under the sine condition, the yaw rate exceeds the ideal value. The difference between the overshoot value and the ideal value is only 0.04rad/s, and the slip angle of the center of mass is also only a difference of 0.008rad. Compared with parameter self-tuning fuzzy PI control strategy, the response speed of fuzzy sliding mode control is faster, and it can track the ideal curve better, and achieve better steady-state effect. At the same time, a larger yaw moment can be generated to better control the stability of the vehicle, which verifies the correctness of the control model.