为提高自动驾驶车辆在超高速公路行驶的安全性，提出了一种换道轨迹规划策略。首先，采用5次多项式生成一般变道轨迹簇，以车辆动力学极限和周围交通车辆为约束，将轨迹规划问题量化为求解换道行为持续时间；接着，考虑车辆动力学约束，建立了车辆动力学模型和Brush轮胎模型，基于所建立汽车模型的轮胎侧向力数据求解轮胎侧偏刚度，辅以魔术轮胎模型，验证所求轮胎侧偏刚度；然后，引入质心侧偏角-横摆角速度相平面，得到高速车辆安全驾驶包络线，并给定多组车速和附着系数进行CarSim仿真训练，确定满足车辆动力学约束的最短换道时间；最后，考虑与周围交通车辆的避撞约束，分析3种典型的换道场景，基于单障碍车的位置，确定满足避撞要求的最短与最长换道持续时间，建立满足安全换道要求的换道持续时间阈值模型。经多参数安全换道域检验，所建立的车辆安全换道持续时间边界模型能够在给定参数下求解出安全可行的换道轨迹，为超高速公路换道行为提供轨迹参考，提高超高速公路换道行为的安全性。

To improve the driving safety of autonomous vehicles on superhighways, this paper proposed a lane-changing trajectory planning strategy. Firstly, five polynomials were used to generate general lane-changing trajectory clusters, and the trajectory planning problem was quantified as the duration of solving lane-changing behavior with the limit of vehicle dynamics and surrounding traffic vehicles. Then, considering the constraints of vehicle dynamics, the vehicle dynamics model and Brush tire model were established. Based on the tire lateral force data of the established vehicle model, the tire lateral stiffness was solved, and the magic tire model was used to verify the tire lateral stiffness. Next, the phase plane of sideslip angle and yaw rate was introduced to obtain the safe driving envelope of high-speed vehicle. CarSim simulation training was carried out on given multiple groups of vehicle speeds and adhesion coefficients to determine the shortest lane-changing time that meets the vehicle dynamics constraints. Finally, considering the collision avoidance constraints with surrounding traffic vehicles, three typical lane-changing scenarios were analyzed. The shortest and longest lane-changing durations satisfying the collision avoidance requirements were determined based on the position of single obstacle vehicle, and the threshold model of lane-changing duration satisfying the safe lane-changing requirements was established. The multi-parameter safety lane-changing domain test shows that the established vehicle safety lane-changing duration boundary model can solve the safe and feasible lane-changing trajectory under the given parameters, provide trajectory reference for the superhighway lane-changing behavior, and improve the safety of the superhighway lane-changing behavior.