The intelligent vehicle corner module system,which integrates four-wheel independent drive,independent steering,independent braking and active suspension,can accurately and efficiently perform vehicle driving tasks an...The intelligent vehicle corner module system,which integrates four-wheel independent drive,independent steering,independent braking and active suspension,can accurately and efficiently perform vehicle driving tasks and is the best carrier of intelligent vehicles.Nevertheless,too many angle/torque control inputs make control difficult and non-real-time.In this paper,a hierarchical real-time motion control framework for corner module configuration intelligent electric vehicles is proposed.In the trajectory planning module,an improved driving risk field is designed to describe the surrounding environment’s driving risk.Combined with the kinematic vehicle-road model,model predictive control(MPC)method,spline curve method,the local reference trajectory of safety,comfort and smoothness is planned in real time.The optimal steering angle is determined using MPC method in path tracking module.In the motion control module,a feedforward-feedback controller assigns the optimal steering angle to the front/rear axles,and an angle allocation controller distributes the target angles of the front/rear axles to four steered wheels.Finally,the PreScan-Simulink-CarSim joint simulation environment is established for conducting the human-in-the-loop emergency obstacle avoidance experiment.It took only 0.005 s for the hierarchical motion control system to determine its average solution time.This proves the effectiveness of the hierarchical motion control system.展开更多
为解决基于模块化多电平换流器的柔性直流输电系统(modular multilevel converter based high voltage direct current,MMC-HVDC)在陆上交流电网故障时出现的盈余功率问题,首先计算验证了能量预警值的合理性,并设计了自适应动作能量值,...为解决基于模块化多电平换流器的柔性直流输电系统(modular multilevel converter based high voltage direct current,MMC-HVDC)在陆上交流电网故障时出现的盈余功率问题,首先计算验证了能量预警值的合理性,并设计了自适应动作能量值,解决距离和控制转换时延造成子模块过电压的问题;然后分析网侧变流器(grid-side converter,GSC)在低压穿越期间的动态输出特性,提出了基于直流电压变化率反馈的海上换流站精准降压控制用以进行风机减载;最终通过整定协同控制的逻辑与控制参数,提出了一种基于风机精准减载与子模块电容能量协同控制的低电压故障穿越策略,解决故障期间系统能量裕度利用率低与耗能装置投资大的问题。在MATLAB/Simulink中搭建系统仿真模型验证方法有效性,并与现有方法比较。仿真结果表明,所提方法可显著减少甚至避免耗能装置的投入,且具有自适应性,可在不同故障工况下尽可能利用MMC-HVDC系统的能量裕度,尤其在故障程度较轻的工况下,能在故障消除时保留部分能量裕度,有效应对电压二次跌落,提高系统低压穿越能力。展开更多
基金Supported by National Natural Science Foundation of China(Grant No.52332013)。
文摘The intelligent vehicle corner module system,which integrates four-wheel independent drive,independent steering,independent braking and active suspension,can accurately and efficiently perform vehicle driving tasks and is the best carrier of intelligent vehicles.Nevertheless,too many angle/torque control inputs make control difficult and non-real-time.In this paper,a hierarchical real-time motion control framework for corner module configuration intelligent electric vehicles is proposed.In the trajectory planning module,an improved driving risk field is designed to describe the surrounding environment’s driving risk.Combined with the kinematic vehicle-road model,model predictive control(MPC)method,spline curve method,the local reference trajectory of safety,comfort and smoothness is planned in real time.The optimal steering angle is determined using MPC method in path tracking module.In the motion control module,a feedforward-feedback controller assigns the optimal steering angle to the front/rear axles,and an angle allocation controller distributes the target angles of the front/rear axles to four steered wheels.Finally,the PreScan-Simulink-CarSim joint simulation environment is established for conducting the human-in-the-loop emergency obstacle avoidance experiment.It took only 0.005 s for the hierarchical motion control system to determine its average solution time.This proves the effectiveness of the hierarchical motion control system.
文摘为解决基于模块化多电平换流器的柔性直流输电系统(modular multilevel converter based high voltage direct current,MMC-HVDC)在陆上交流电网故障时出现的盈余功率问题,首先计算验证了能量预警值的合理性,并设计了自适应动作能量值,解决距离和控制转换时延造成子模块过电压的问题;然后分析网侧变流器(grid-side converter,GSC)在低压穿越期间的动态输出特性,提出了基于直流电压变化率反馈的海上换流站精准降压控制用以进行风机减载;最终通过整定协同控制的逻辑与控制参数,提出了一种基于风机精准减载与子模块电容能量协同控制的低电压故障穿越策略,解决故障期间系统能量裕度利用率低与耗能装置投资大的问题。在MATLAB/Simulink中搭建系统仿真模型验证方法有效性,并与现有方法比较。仿真结果表明,所提方法可显著减少甚至避免耗能装置的投入,且具有自适应性,可在不同故障工况下尽可能利用MMC-HVDC系统的能量裕度,尤其在故障程度较轻的工况下,能在故障消除时保留部分能量裕度,有效应对电压二次跌落,提高系统低压穿越能力。
