全車主動式懸吊系統之非線性遞迴步階控制設計

由於近幾年來高科技產業與汽車工業的蓬勃發展，愈來愈多新的科技技術被應用到車輛的設計上。因此，以舒適安全性設計為考量的主動式懸吊系統，已成為各類高級車種的研究發展目標。在設計汽車的懸吊系統時，一個主要的雙重目標是既要減少傳送到乘客座的垂直作用力來增進乘坐的舒適度，另外一方面也需要增加車輪與路面的接觸藉此增進汽車的操控性與安全性。因此，在考慮主動式懸吊系統的設計時，就必須解決多個存在控制目標的衝突及無法完全妥協的情形－車體移動量( body motion )、乘坐舒適度( ride quality )、路面操控性能( road handling )、懸吊移動距離( suspension travel )。本文主要是將主動式懸吊運用在全車系統的控制設計，並利用非線性遞迴步階控制設計( nonlinear backstepping design )來達到控制目的。藉此能夠有效的改善乘坐舒適度與懸吊移動距離之間無法同時改善的衝突。乘座舒適度與車體的垂直位移和角度位移密切的關係，所以主動式懸吊的控制器必須有能力減少路面傳達到車體的垂直位移與角度位移量。懸吊移動距離即車體與車輪之間的相對位移，為了避免懸吊系統碰撞到車體，所以控制器必須有能力避免懸吊移動超過其最大限制進而產生更大的不舒適感。由於此種新的方法使用了一種比較特別的非線性濾波器( nonlinear filter )，而此種濾波器的有效頻寬會隨著懸吊移動距離的大小來改變，所以在控制器中加入此種非線性特性，能夠有效的調節懸吊系統的彈性特徵，換句話說，就可以很平順的轉移兩個具有衝突性的控制目標－乘坐舒適度與懸吊移動限制。

關鍵字

主動式懸吊系統；非線性遞迴步階設計；全車模型；乘坐舒適度；懸吊移動距離

並列摘要

In recent years, due to the prosperous developments of high technologies and automobile industries, lots of new technologies are applied in the design of vehicles. Therefore, the comfortable security design for active suspension system has become the researchful goal of all kinds of advanced car. The dual objective is to minimize the vertical forces transmitted to the passengers for improving the ride quality and to maximize the tire-to-road contact for enhancing the handling performance and driving safety, when designing the automotive vehicle suspension. In the design of vehicle suspension systems, the various performance parameters which should be considered are given as follows: body motion, ride quality, road handling and suspension travel. This thesis develops a novel nonlinear backstepping design for the control of full-vehicle active suspension systems to improve the conflicting objectives which are inherent tradeoff between ride quality and suspension travel. Suspension travel means the space variation between body and tire. In order to avoid the suspension hits the vehicle body, the controllers must have the ability to prevent the suspension form hitting its travel limitation. The novelty is in use of nonlinear filter whose effective bandwidth depends on the magnitudes of suspension travel. Therefore, this kind of design allows the close-loop system with the ability to execute in different operating regions. In other words, the nonlinear controller can smoothly transfer its priority between the conflicting objectives of ride comfort and suspension travel.