Steering Controller for SBW Vehicle with Trajectory Curvature as Controlled Variable

在本研究项目中，我们研究了一种使用线控转向系统的前置主动转向系统。讨论基于我们的曲率输出驱动器模型和D^*控制的概念，其中曲率命令被转换为考虑车速的参考D^*值，并被馈送到车辆控制器。在第一年(2001)，我们利用这种转向控制概念和基本版本的曲率输出驱动器模型进行了路径跟踪巡航的仿真实验。仿真得到了多自由度车辆仿真软件(CarSim)的支持。例如，对紧急刹车时非故意急转弯的预防效果进行了测试。2002年，我们扩展了我们的驱动程序模型。它的框架与传统的一阶预览模型非常相似。该模型不再考虑实际车辆动态特性的变化，而是假设转向控制器实现曲率指令。这种简单的预览模型对于路径跟踪是足够有效的，这意味着即使在路面状况剧烈波动的情况下，主动前置转向车辆也可以很容易地驾驶。对驾驶员响应时间、车辆延误和相位超前补偿的影响进行了仿真实验。我们构建了一个基于VR技术的实时模拟器，用于对人体进行实验。主动前轮转向也通过牵引力/制动力分配得到了增强。加强在严酷的驾驶条件下是有效的，并将防止较大的侧滑角。

In this research project, we have studied a front active steering using a steer-by-wire system. The discussion is based on our curvature output driver model and the concept of D^* control, where the curvature command is translated into the reference D^* value taking accounts of the vehicle speed, and is fed to the vehicle controller. In the first year (2001), we have performed simulation experiments of path following cruising using this steering control concept and the basic version of curvature output driver model. The simulations were supported by a multi-degree-of-freedom vehicle simulation software (CarSim). For example, prevention effects for unwilled steep turns at hard brakings are tested. In 2002, we extended our driver model. Its framework is very similar to the conventional first order preview model . Our model no longer cares variation of dynamical characteristics of the real vehicle but assumes that the steering controller will realize the curvature command. This simple preview model is sufficiently effective for the path following and then the fact implies that the active front steered vehicle will be easily driven even with a violent fluctuation of road surface condition. We have experimented simulations to evaluate the effect of driver response time, the vehicle delay, and the phase-leading compensation. We constructed a real-time simulator based on VR technologies to experiment with human subjects. The active front steering was also augmented by a traction / braking force distribution. The augmentation is effective under severe driving conditions and will prevent large sideslip angles.