Lateral control of autonomous vehicles based on learning driver behavior via cloud model

In order to achieve the lateral control of the intelligent vehicle, use the bi-cognitive model based on cloud model and cloud reasoning, solve the decision problem of the qualitative and quantitative of the lateral control of the intelligent vehicle. Obtaining a number of experiment data by driving a vehicle, classify the data according to the concept of data and fix the input and output variables of the cloud controller, design the control rules of the cloud controller of intelligent vehicle, and clouded and fix the parameter of cloud controller： expectation, entropy and hyper entropy. In order to verify the effectiveness of the cloud controller, joint simulation platform based on Matlab/Simulink/CarSim is established. Experimental analysis shows that： driver＇s lateral controller based on cloud model is able to achieve tracking of the desired angle, and achieve good control effect, it also verifies that a series of mental activities such as feeling, cognition, calculation, decision and so on are fuzzy and uncertain.

人类司机分心行为对无人车纵向速度控制的影响

无人车通常无法探测到人类司机的分心行为,这将导致无人车延迟地采取紧急制动来避免追尾。因此,本文致力于构建无人车控制与人类司机分心监测之间的桥梁,来辅助无人车预测潜在风险并像有经验的人类司机一样避让处于分心的司机,提高无人车的智能化水平和交通系统的安全性。首先,本文提出了一种整合了司机分心监测、车对车信息交换和无人车速度控制的可行系统框架。然后,基于卷积神经网络,本文提供了一种司机分心监测实现。最后,基于模型预测控制策略,本文提出了一种考虑了司机分心行为的无人车纵向速度控制方法,并给出持续可行性分析。仿真结果验证了本文工作的有效性。

基于MPC的自动驾驶车辆横向路径跟踪控制

由于驾驶技能、生理极限等原因,人工驾驶员在转向操作中存在响应迟滞、动作超调等问题,控制性能优良的自动驾驶车辆可以改善上述问题。设计了一种基于模型预测控制(MPC)的自动驾驶车辆横向路径跟踪控制器。基于预瞄跟随理论建立了最优侧向加速度的驾驶员转向模型,以分析驾驶员方向盘操作中预瞄时间和车速对车辆跟踪参考路径的影响。基于模型预测控制算法设计了车辆横向路径跟踪控制器,利用反馈校正机制改进车辆预测模型,以处理参数不完全确定和外部干扰对模型精度带来的影响;采用松弛因子对目标函数进行处理,以保证目标函数具有可行解;进一步地,将所设计的模型预测控制器每一步的优化求解转化为带约束的二次规划问题,利用模型预测控制滚动优化的特点,求解跟踪参考路径所需的方向盘转角,作用于自动驾驶车辆。实验结果表明:预瞄时间和车速对驾驶员操控车辆跟踪参考轨迹的影响较大,MPC控制器下的车辆实际行驶轨迹与参考轨迹之间的最大横向偏差为0.085 m,小于熟练驾驶员操控的车辆,同时,MPC控制器下的车辆转向起始时刻相对于熟练驾驶员操控的车辆提前0.89 s。

Steering control strategy guide by two preview vision cues

Vision cues play an important role in states feedback in motion control.However,the existing driver steering models consider little about vision cues utilized by human drivers during their steering procedure.This paper presents a novel steering control strategy based on two preview points(far point and near point).The far point is used to compensate the steering wheel by predicting the upcoming curvature change with respect to the lane,while the near point as vision feedback,which is used to tune the steering wheel by estimating the errors of vehicle states and lane center.To obtain much smoother lateral acceleration during steering,a forward internal model is established using a second-order yaw dynamics system that captures the influence of yaw angular acceleration caused by steering wheel angle.The input parameter of the second-order system is the vision cues of both the near and far points,and the output parameters are the ideal yaw angle and yaw rate.To calculate suitable the steering wheel angle,an adaptive controller is designed using fuzzy sliding technology,which is used as the input of the vehicle system dynamics.Numerical simulation results show that the proposed method performs better than the existing driver steering models in case of imitating human drivers' behavior,and exhibits excellent adaption to the lane curvature change.