车辆主动悬架系统的舒适性优化控制

Ride Comfort Control of Active Suspension System Via Optimization Design Method

为提高非线性主动悬架系统控制性能,提出一种分数阶模糊控制与PID控制输出端并联结合的复合控制方法,利用分数阶模糊控制输出对PID控制进行补偿。研究根据1/4车非线性悬架模型,考虑路面冲击载荷作用,采用控制系统综合性能指标函数方法,对分数阶次参数进行离线优化设计。复合控制方法具有算法简单、控制律计算量较少的特点,不仅能弥补PID控制自适应性差的不足,且可避免传统模糊PID参数在线整定优化控制方法中,因存在控制延迟导致实时控制悬架系统效果不佳的问题。不同等级路面和车速的仿真研究结果表明,与单一PID控制、整数阶模糊控制以及整数阶模糊PID复合控制这三种方法相比较,上述方法能获得更好控制效果,有效提高了车辆的乘坐舒适性。

ABSTRACT ： For improving the control performances of nonlinear active suspension, a parallel hybrid control method is proposed in the paper, which consists of PID controller and fractional-order controller. The fractional-order con- troller in the hybrid control sc.heme was used to compensate the output of the PID controller. From the dynamical model of a nonlinear quarter vehicle, using the impulsive load, the fractional order was designed via off-line optimiza- tion search based on the minimum criteria of the suspension system comprehensive performance index function. This method has some characteristics of simplicity and less calculation, which can not only compensate the adaptability of the traditional PID controller, but also overcome the problem that the control performance can be decreased because of the control time-delay effect in the fuzzy-PID method through on-line optimizing PID parameters. Simulation results demonstrate that under the driving cycles with various grade roads and vehicle speed, the presented hybrid control method has better control effect than the PID control and the hybrid scheme with integral-order fuzzy controller, and can further improve the ride comfort and safety of vehicle.