線控四輪轉向系統之車輛穩定控制研究

Development of Four-wheel-steering for a Vehicle with a Steer-by-wire System

張舜長(Shun-Chang Chang) ； 林裕翔(Yu-Shiang Lin) ； 蘇育斌(Yu-Bin Su)

《科學與工程技術期刊》 6卷2期 (2010/06) Pp. 61-70

https://doi.org/10.7117/JSET.201006.0061

摘要

本文主要探討線控四輪轉向系統之車輛穩定控制，由於線控四輪轉向系統是由馬達驅動轉向取代傳統轉向柱，因此可在其控制核心內加入車輛穩定控制之策略，使車輛能達到四輪轉向之效果，同時控制車輛之重心側滑角及橫擺率，使車輛在行駛時都能保持在最低的重心側滑角及橫擺率的範圍內，以增加車輛在低速的機動性和高速過彎時的安全性、操控性以及穩定性。本研究利用模擬軟體CarSim，分析模擬車輛行駛時之穩定性。
本研究運用分散式架構以及CAN Bus通訊協定技術，建構線控轉向系統實驗平台。線控四輪轉向控制實現於線控轉向系統實驗平台上，驗證線控前輪轉向與線控後輪轉向，利用閉迴路控制，除了精準控制前輪轉向，依據車速判斷，達到後輪低速逆相位轉向及高速同相位轉向之控制目標。在控制器中，加入主動轉向之可變轉向比功能，依據車速高低、方向盤角度、前輪轉向角度及加減速力道等的訊號，整合辨識判斷後，調整轉向比，因應車輛動態狀況進行適度調整。

關鍵字

線控轉向系統 ； 四輪轉向 ； 車輛穩定控制 ； 重心側滑角 ； CarSim

並列摘要

This study focuses on the stability control of a vehicle by a four-wheel steer-by-wire system. Vehicles with this type of steering are not subject to the limitations of traditional steering systems. The stability control of a vehicle commands the front and rear steering angles with the objective of referencing the sideslip angle and yaw-rate signals corresponding to the desired handling behavior. Under this control system, the vehicle can be stably handled at high or low speeds in cornering. In this study, CarSim software is used to verify the proposed method for stability control.
The construction of the distributed steer-by-wire system experimental platform is based on the CAN (controller area network) bus technique, which uses this platform to verify the system. Use of closed-loop control is studied, wherein the rear-wheel steering direction depends on the speed of the vehicle. At slow speeds, the rear wheels move in the opposite direction from the front wheels; whereas, at high speeds, the four wheels all move in the same direction. The controller features an active steering function aimed toward optimal control of the front-wheel steering angle via a variable steering-gear ratio.

並列關鍵字

steer-by-wire system ； four-wheel-steering ； stability control ； sideslip angle ； CarSim