多源时变延误下考虑信息同步的智能网联车队控制策略

Control Strategy for Connected and Automated Vehicle Platoon Considering Information Synchronization under Time-varying Delays of Multiple Sources

为解决多前车-后车通信拓扑结构车队中多源时变信息延误影响下的车队稳定性问题,本文提出一种考虑信息同步的智能网联车队控制策略。为此,首先梳理车队中车辆间交互存在的信息延误方式,设计追溯时间项,应用线性前馈-反馈控制器构建状态信息同步的车辆跟驰控制器模型。其次,采用关于间距误差的l2范数稳定性概念,应用控制领域的频域法推导确保车队稳定性控制的稳定性条件。最后,基于推导条件,通过数值计算给出不同通信结构和固定时距下确保车队稳定性的控制参数组合区域。针对领队车周期性震荡和自然驾驶震荡场景,采用数值仿真实验分析所提出的控制策略对于提升车队稳定性的有效性,以及针对减速场景下车队系统的安全表现进行验证。结果表明:对于相同通信结构,车辆控制参数的可行区域随固定时距的增大而变大;提供信息的车辆越多,临界固定时距越小,当控制参数范围为[0,2]时,提供信息的车辆数为1、2和3所对应的固定时距临界值分别为0.43 s、0.24 s和0.16 s;扰动实验结果验证了应用信息同步策略有效抵消延误影响从而保证间距误差随扰动传播而衰减;在加速度为-3.0 m/s^(2)和-4.0 m/s^(2)的减速情况下,基于TIT数值可知信息同步策略能够降低碰撞风险分别超过48%和45%;在加速度为-5.0 m/s^(2)情况下,采用信息同步策略不会发生追尾事故,表明信息同步策略对于紧急制动情况的有效性。基于信息同步的车队控制策略能够为智能网联车队应用提供理论支撑。

To improve the stability of the connected and automated vehicle(CAV)platoons with a multiple-predecessor-follower communication topology under time-varying information delays of multiple sources,a control strategy is proposed herein for the CAV platoon while considering information synchronization of the vehicles in the platoons.In this regard,the information delays occurring in the communications between vehicles in the platoons are first summarized.Traceable time terms are designed and a car-following control model with the synchronizations of state information is formulated using the linear feedback and feedforward controller.The definition of string stability on spacing error based on l_(2)-norm string stability criteria is adopted,and the frequency domain method in the control field is used to derive the stability conditions for ensuring the string-stable platoon control.Based on the derived conditions,the feasible regions of control parameters to ensure the stability of the platoon are provided through numerical computation for different communication topologies and time gaps.Numerical experiments are designed to analyze the effectiveness of the proposed control strategy in improving stability under the periodic and natural driving-based disturbance scenarios of the leader.Additionally,the safety performance of the vehicle platoon is verified under deceleration scenarios.The results show that the feasible regions of the control parameters increase with the time gaps for the same communication topology;the higher the number of predecessors to which the subject vehicle can communicate,the smaller is the critical time gap,the critical time gap is 0.43 s,0.24 s,and 0.16 s for 1,2,and 3 predecessors respectively while the values of the parameters are within[0,2];the results show that,by implementing the information synchronization strategy(ISS),the magnitude of the spacing error can effectively attenuate as the disturbance propagates to the upstream vehicles;the collision risks are reduced by more than 48%and 45%using the ISS as compared with using the platoon without the ISS under decelerations of-3.0 m/s^(2) and-4.0 m/s^(2) based on Time Integrated Time-to-collision(TIT)values;the safety can be guaranteed when using the ISS under a deceleration of-5.0 m/s^(2),which suggests the applicability of the ISS under urgent braking conditions.The information-synchronization-based control strategy provides theoretical support for the application of the CAV platoon.