ABSTRACT

Rear-wheel steering has seen new popularity in recent years. Many explanations of rear-wheel steering systems use the concept of a ‘virtual wheel base’ to explain in-phase or out-of-phase steering. This paper introduces a novel reference model that realises this metaphor. A reference model is created where its wheelbase can be changed arbitrarily, making the resulting system intuitive and simpler to design and tune. This augments the properties of the reference model whose signals are used for a feedback control system. The real vehicle tracks these signals using active front and rear-wheel steering. This system can be implemented in a vehicle using steer-by-wire or an autonomous vehicle for control. A MIMO controller is derived and results show that the system operates as intended. Finally, a control law is proposed to change the virtual wheelbase using the road curvature. It is shown that it has advantages over conventional rear-wheel steering control.

摘要

近年来，后轮转向新的流行。后轮转向系统的许多解释使用“虚拟轴距”的概念来解释同相或异相转向。本文介绍了一种实现这一隐喻的新颖参考模型。创建了一个参考模型，其轴距可以任意更改，从而使生成的系统直观且易于设计和调整。这增强了参考模型的特性，其信号用于反馈控制系统。实车使用主动前轮和后轮转向来跟踪这些信号。该系统可以在使用线控转向的车辆或用于控制的自动驾驶车辆中实施。导出了 MIMO 控制器，结果表明系统按预期运行。最后，提出了一种利用道路曲率改变虚拟轴距的控制律。结果表明，它比传统的后轮转向控制具有优势。