基于Gauss伪谱法的紧急避让汽车操纵逆动力学

汽车高速紧急避让行驶安全性是汽车自主开发亟待解决的关键问题，也是汽车主动安全的前提和必要条件之一。提出一种汽车操纵逆动力学求解方法，该方法能够用于汽车高速紧急避让性能的客观评价。基于一种求解最优控制问题的新方法——Gauss伪谱法(Gauss pseudospectral method, GPM)，以驾驶员对汽车施加的转角输入和驱动力/制动力为控制变量，以最短时间完成双移线过程为控制目标，通过Gauss伪谱法将最优控制问题转化为非线性规划问题之后，运用序列二次规划方法求解。仿真结果表明，相对于间接法和传统直接法，Gauss伪谱法具有求解效率高，对初值依赖性小的优势。采用该方法解决汽车的最速操纵问题，边值约束和路径约束均得到很好的满足，可以客观评价不同汽车以最短时间完成双移线过程的操纵性能。通过实车试验，仿真值和试验值的变化趋势基本一致，从而验证了模型的正确性。

Vehicle Handling Inverse Dynamics Based on Gauss Pseudospectral Method while Encountering Emergency Collision Avoidance

Vehicle driving safety is the urgent key problem to be solved of automobile independent development while encountering emergency collision avoidance with high speed. And it is also the premise and one of the necessary conditions of vehicle active safety. A new technique for vehicle handling inverse dynamics which can evaluate the emergency collision avoidance performance is proposed. Based on a new optimal control method-Gauss pseudospectral method(GPM), the steering angle input and the traction/ brake force imposed by driver are the control variables, the minimum time required to complete the double lane change is the control object. By using the Gauss pseudospectral method, the optimal control problem is converted into a nonlinear programming problem that is then solved by means of the sequential quadratic programming(SQP). The simulation results show that the proposed method is not sensitive to the initial value and the optimization efficiency is higher compared with indirect methods and traditional direct methods. When solving the vehicle minimum time maneuver problem with the method, boundary constrains and path constrains are well satisfied. Utilizing the method, the maneuverability of two different vehicles that complete double lane change with minimum time can be evaluated objectively. The correctness of the model is verified through real vehicle test.