侧向运动控制是自动驾驶车辆实现精确路径跟踪的核心技术,然而实际控制系统中存在的多种延迟源会显著恶化控制性能,甚至导致系统失稳.传统延迟补偿方法在车辆参数变化和不确定工况下的适应性不足.针对此问题,本文提出了一种基于自适应...侧向运动控制是自动驾驶车辆实现精确路径跟踪的核心技术,然而实际控制系统中存在的多种延迟源会显著恶化控制性能,甚至导致系统失稳.传统延迟补偿方法在车辆参数变化和不确定工况下的适应性不足.针对此问题,本文提出了一种基于自适应模型预测控制(Adaptive Model Predictive Control,AMPC)的侧向控制延迟补偿策略.首先建立了车辆-延迟集成动力学模型,同时在MPC框架中显式考虑延迟影响,并设计参数自适应机制在线调整补偿器参数.在Matlab与CarSim联合仿真平台上的验证结果表明:与传统状态预测方法和固定参数补偿相比,本文方法能将最大横向跟踪误差降低37%-70%,同时生成更平滑的前轮转角指令,有效抑制高频抖振,在低附着路面(μ=0.3)等极限工况下仍保持稳定的路径跟踪能力.此外,本文于双移线工况下进行了实车道路测试,进一步验证了该策略的工程有效性.本研究为自动驾驶车辆在多变工况下提供了高鲁棒性的延迟补偿方案,显著提升了系统的控制精度与平顺性.展开更多
To compare the suitable working conditions of polypropylene(PP)and polycaprolactam(PA6)materials in actual use in automobiles,the effects of different temperature aging and different reagents on the mechanical propert...To compare the suitable working conditions of polypropylene(PP)and polycaprolactam(PA6)materials in actual use in automobiles,the effects of different temperature aging and different reagents on the mechanical properties of the two materials,such as tensile,bending,compression,and impact were studied.The results indicate that the short⁃term low⁃temperature environment had no much effect on the mechanical properties of PP and PA6.After long⁃term thermal aging at 80℃,the strength of PP and PA6 increased while their toughness decreased.After short⁃term thermal aging at 120℃,PP strength decreases and toughness increases,while PA6 strength increases and toughness decreases.The soaking of glass water and car shampoo had no much effect on the mechanical properties of PP,but had a significant impact on the mechanical properties of PA6.With the increase of soaking time,the strength of PA6 significantly decreases and the toughness significantly increases.The soaking of 95#gasoline had no much effect on the mechanical properties of PA6,but has a significant impact on the mechanical properties of PP.After 720 h of soaking,the retention rates of the tensile strength,bending strength,and compressive strength of PP were all less than 80%,while the retention rate of the impact strength of the cantilever beam was 160.4%.展开更多
文摘侧向运动控制是自动驾驶车辆实现精确路径跟踪的核心技术,然而实际控制系统中存在的多种延迟源会显著恶化控制性能,甚至导致系统失稳.传统延迟补偿方法在车辆参数变化和不确定工况下的适应性不足.针对此问题,本文提出了一种基于自适应模型预测控制(Adaptive Model Predictive Control,AMPC)的侧向控制延迟补偿策略.首先建立了车辆-延迟集成动力学模型,同时在MPC框架中显式考虑延迟影响,并设计参数自适应机制在线调整补偿器参数.在Matlab与CarSim联合仿真平台上的验证结果表明:与传统状态预测方法和固定参数补偿相比,本文方法能将最大横向跟踪误差降低37%-70%,同时生成更平滑的前轮转角指令,有效抑制高频抖振,在低附着路面(μ=0.3)等极限工况下仍保持稳定的路径跟踪能力.此外,本文于双移线工况下进行了实车道路测试,进一步验证了该策略的工程有效性.本研究为自动驾驶车辆在多变工况下提供了高鲁棒性的延迟补偿方案,显著提升了系统的控制精度与平顺性.
文摘To compare the suitable working conditions of polypropylene(PP)and polycaprolactam(PA6)materials in actual use in automobiles,the effects of different temperature aging and different reagents on the mechanical properties of the two materials,such as tensile,bending,compression,and impact were studied.The results indicate that the short⁃term low⁃temperature environment had no much effect on the mechanical properties of PP and PA6.After long⁃term thermal aging at 80℃,the strength of PP and PA6 increased while their toughness decreased.After short⁃term thermal aging at 120℃,PP strength decreases and toughness increases,while PA6 strength increases and toughness decreases.The soaking of glass water and car shampoo had no much effect on the mechanical properties of PP,but had a significant impact on the mechanical properties of PA6.With the increase of soaking time,the strength of PA6 significantly decreases and the toughness significantly increases.The soaking of 95#gasoline had no much effect on the mechanical properties of PA6,but has a significant impact on the mechanical properties of PP.After 720 h of soaking,the retention rates of the tensile strength,bending strength,and compressive strength of PP were all less than 80%,while the retention rate of the impact strength of the cantilever beam was 160.4%.
