運用H∞控制法則降低車輛行經顛簸路面時之震動與耗能

Abstract

近年來由於氣候異常，使得環保意識抬頭。因此環保駕駛(Eco-driving)的觀念也逐漸成形。環保駕駛的概念在國外已推廣有年，環保駕駛提倡不猛踩油門或煞車、有目的的變換車道等等。就大部分駕駛者而言，在通過顛簸路面之前會將車速降低以減少駕駛者所感受到的震動，但沒有經驗或是沒有環保駕駛概念的駕駛者，往往過度剎車以致無法兼顧舒適度與耗能，甚至駕駛者太晚發現前方有顛簸路段而錯失反應時機，造成通過顛簸路面時的不適感。但不管是急速煞車導致耗能過度或是沒有適當的反應而使震動過大皆不是駕駛者想要的結果。 本研究針對後輪驅動車輛，設計輪胎轉矩控制系統，使車輛在行經顛簸路面時，能降低震動，同時避免過度剎車。本論文將控制架構分為上下層控制器，上層控制器採用H∞ Control的方式，配合人體對加速度在頻域上的權重，調整 之頻域權重計算所需要的縱向加速度以盡量少的耗能降低路面顛簸傳至車身的震動。下層控制器則考慮線性輪胎模型與真實輪胎模型間受外界干擾產生的模型不確定性的問題，藉由控制輪胎力矩來產生所需的縱向加速度。最後本研究將以Carsim模擬軟體來驗證車輛行經顛簸路面能透過控制輪胎力矩來降低駕駛者感受到的震動與節能效果。

In recent years, climate anomalies inspire the rise of environmental awareness. Therefore, eco-driving has been promoted for years. Eco-driving suggests that drivers should avoid inefficient deceleration or acceleration. But it is hard for an inexperienced driver to take into consideration both eco-driving and driver comfort at the same time. Hence this paper presents a wheel torque control structure for a vehicle on rugged roads to achieve eco-driving and driver comfort simultaneously. The proposed control structure is separated into the upper controller, input linearization and the lower controller. The input linearization allows a linear time invariant upper controller to be used. The upper controller calculates the desired longitudinal acceleration by H∞ control techniques, because controllers are effective in suppressing model uncertainties and enhancing driver comfort in accordance with the ISO standard. The lower controller is used to calculate the wheel torque for tracking the longitudinal acceleration given by the upper controller. To compensate for the model uncertainty between the Carsim tire model and the liner tire model in use, the sliding mode controller is applied to the lower controller. Then, comparisons of the proposed control structure and normal driver reaction on rugged roads are conducted by Carsim.