應用比例積分控制器與外擾估測器之電動自走車輪速控制

Abstract

由於近年來環保節能的意識興起，世界各國政府開始訂定車輛碳排放標準，促成了電動車產業的市場蓬勃發展，加上交通載具自動化的提倡，在汽車工業創新領域中掀起自動駕駛車的全新潮流。在此背景之下，將綠色節能的電動車應用至自動駕駛領域，期望能在簡單的環境如校園道路，以低成本實踐車輛巡航自走，讓自動駕駛車成為簡單環境中新的代步工具。本研究基於以馬達為驅動元件的電動車之架構，將目光投注到低速度車輛之自動輪胎速度追隨系統上，結合感測器偵測車輛當下的狀態並回授給控制器，將輪胎受到的外界摩擦力與車體負載視為干擾，加入干擾估測器(DOB，disturbance observer)與比例積分控制器(PI-controller)，並利用嵌入式系統計算補償訊號，以控制車體輪胎速度能追隨給定的輪胎速度為目標，讓駕駛者只須控制車輛的轉向，由控制器來追隨穩定的輪胎速度。 由本研究實驗結果可知，在加入所設計的控制器之後，實際在校園道路上之平緩道路、上坡等不同路況做輪胎速度的追隨，都有顯著的控制效果；在下坡路段的系統響應較慢且誤差較大，但仍能跟隨輪胎速度參考訊號。

In recent years, due to the awareness of energy saving and environment protection, as well as the promotion of automatic transportation, development of electric vehicles (EVs) and automatic driving systems becomes irreversible trends in automotive industry. This study focuses on automatic wheel speed control of an electric golf car for on campus transportation. A PI-controller with a disturbance observer (DOB) is used and implemented in the micro controller TMS-F28335. The PI-controller achieves the desired steady state velocity following response, while the disturbance observer compensates for the load variation of the car and the inference of the road friction to enhance robustness of the system. Experiments were conducted on the campus road at National Chiao Tung University. The results show that the proposed controller significantly improves the wheel speed following performance, regardless of the road conditions and slopes.