基于分数阶PID理论的汽车线控转向的主动控制

Active control of steering-by-wire of vehicle based on fractional-order PID theory

为实现更好的车辆稳定性,提出一种基于分数阶比例积分微分(PID)理论的线控转向(SBW)主动控制方法。建立了SBW系统Simulink动力学模型,设计了定横摆角速度增益的理想变传动比曲线;基于横摆角速度反馈的状态跟踪校正控制策略,提出该算法;利用Oustaloup滤波器和粒子群优化算法,进行了有理化和参数整定处理。在高速双移线和鱼钩工况下,进行了离线Carsim/Simulink联合仿真分析。结果表明:相比于传统PID控制和模糊控制,该控制方法的横摆角速度降低了4.7%和9%,侧向加速度降低了6.3%和7.7%,质心侧偏角降低了9.8%和19.5%;因而,该控制器具有较好的SBW主动控制性能。

An active control method of steering-by-wire(SBW) was proposed based on a fractional-order proportional-integral-differential(PID) theory to have a better vehicle running stability. The authors stablished a Simulink dynamic model of the SBW system, and designed a control strategy of state-tracking-correction with yaw-rate-feedback using an ideal variable transmission ratio curve with constant yaw rate gain. Some rationalization and parameter tuning were processed out by using an Oustaloup filter and a particle swarm optimization algorithm. The automobile SBW with a fractional-order PID controller was analyzed by an off-line simulation using a Carsim/Simulink joint simulation under the conditions of high-speed double-shift line and the conditions of fish hook. The results show that the fractional order PID controller reduces the yaw angular velocity by 4.7% and 9%, reduces the lateral acceleration by 6.3% and 7.7%, and reduces the sideslip angle of center of mass by 9.8% and 19.5%, compared with the traditional PID control and with the fuzzy control. Therefore, the controller has better SBW active control performance.