基于分数阶PID控制器的智能车控制

Control of Intelligent Vehicle Based on Fractional Order PID

针对智能车高速行驶下对目标轨迹的快速跟踪要求,结合预瞄跟随理论设计了分数阶PID控制器(FOPID)。分数阶PID比传统PID控制器多两个参数自由度,所以在设计过程中有更大的灵活性。利用改进Oustaloup数字实现算法,框图化实现分数阶PID控制器,通过遗传算法对IAE性能指标寻优整定FOC参数并应用于智能车被控系统。S imu link仿真结果表明,对智能车系统,分数阶PID控制器具有比传统PID控制器更好的动态性能。并且,分数阶PID控制器具有更强的鲁棒性,当模型参数发生变化时,能够更好地保证系统稳定性。通过对比传统PID控制器和分数阶PID控制器的数字实现,证明了分数阶PID控制器在过程控制中的可操作性。

A fractional order PID controller（FOPID） which is used for smart car path-tracking control under high speed condition was designed based on preview-follower theory. A fractional order PID controller has 2 more degrees of freedom than classical PID control- ler, so it is more flexible when designing. Improved Oustaloup algorithm was used to implement the fractional order controller. Parameters of the controller is tuned by IAE performance optimization with genetic algorithm to fit the smart car control system. Simulation results shows that, fractional order PID controller provided better dynamics than classical PID controller. Moreover, fractional PID controller showed stronger robustness, that meant the controller could keep stable when the model parameter changed much. A comparison between the digital implementation of fractional PID and classical PID showed the feasibility of fractional PID controller in practical process control.