前馈多源信息下异构动力学卡车队列协同控制系统

Cooperative control system of truck platoon with heterogeneous dynamics under feedforward multi-source information

针对目前卡车队列动力学异构性所导致的系统弦稳定性、内部稳定性以及队列耦合性降低的问题,提出了一种异构协同自适应巡航系统控制器设计方法,建立了基于前馈多源信息的异构动力学卡车队列闭环耦合系统;考虑由异构车型所构成的卡车队列存在发动机执行器的饱和态异构问题,建立了发动机饱和性和状态约束条件;在上层协同控制器的基础上,建立了一种非线性下层异构发动机扭矩输出控制模型,用于控制车辆动力学仿真软件TruckSim中的真实车辆模型;建立了基于三维燃油特性图的车辆能耗模型,用于计算实时车辆油耗和节能性分析;通过频域分析法,结合已知异构动力学参数量化标定了协同自适应巡航系统控制器的增益,确保系统满足弦稳定条件。分析结果表明:相比同构动力学控制器,异构协同自适应巡航系统控制器可以确保距离误差在-0.01~0.15 m内,优于同构控制器作用下的-0.3~0.5 m,且当领航车进入匀速行驶状态时,跟随车辆能立刻收敛至相同的行驶状态,收敛性能优于同构协同自适应巡航控制系统;卡车队列节油率最大可达8.15%,随着车头时距减小至0.5 s,平均节油率最大可达8.10%。由此可见,多源前馈信息异构控制系统能有效降低车辆的状态误差传递,设计的前馈多源信息下异构动力学卡车队列协同控制系统能提升队列的弦稳定性,也能保证系统的燃油经济性。

A controller design method for the heterogeneous cooperative adaptive cruise system was proposed to deal with the problems of reduced system string stability,internal stability,and platoon coupling caused by the heterogeneity of truck platoon dynamics.A closed-loop coupling system was established for the truck platoon with heterogeneous dynamics under the feedforward multi-source information.Considering the heterogeneous saturation problem of engine actuators in a truck platoon composed of heterogeneous vehicle models,the engine saturation and state constraints were established.Based on the upper cooperative controller,a nonlinear control model for the lower heterogeneous engine torque output was built to control the real vehicle models in the vehicle dynamics simulation software TruckSim.An energy consumption model of vehicles based on the three-dimensional fuel characteristic map was constructed to calculate the real-time fuel consumption and analyze the energy saving of vehicles.By the frequency-domain analysis method and the known heterogeneous dynamics parameters,the gains of the controller for the cooperative adaptive cruise system were quantitatively calibrated to guarantee that the string stability conditions were satisfied.Analysis results show that compared with the controller with homogeneous dynamics,the controller for the heterogeneous cooperative adaptive cruise system is able to keep the distance error within the range of-0.01-0.15 m,better than the range of-0.3-0.5 m under the action of a homogeneous controller.In addition,when the leading vehicle keeps a constant velocity,the convergence to the same driving state can be achieved by all following vehicles immediately.The convergence performance is better than that of the homogeneous cooperative adaptive cruise system.The maximum fuel-saving rate of the truck platoon is up to 8.15%.As the time headway reduces to 0.5 s,the maximum average fuel-saving rate is 8.10%.Thus,it can be seen that the heterogeneous control system under the feedforward multi-source information is capable of effectively reducing the propagation of vehicle state errors.The designed cooperative control system for the truck platoon with heterogeneous dynamics under the feed-forward multi-source information is able to enhance the string stability of the platoon and guarantee the fuel economy of the system.