Feedback linearization and decoupling of steering cylinder system

YUAN Zhao-hui， DONG Sheng， LIU Wen-feng
（Department of Automatic Control， Northwestern Polytechnical University， Xi'an 710072， China）

Abstract： In order to solve the problems in the vehicle steering cylinder load control，such as the strong position of interference，multi-channel coupling，nonlinear，linear systems and nonlinear systems theory was introduced in the design of the system controller. For each channel coupling，problem，a decoupling controller based on the feed-forward compensation was designed. Feed-forward compensation structure is simple and decoupling network order low. Combining feedback linearization technology and the optimal control theory，a nonlinear optimal controller based on the precise feedback linearization was investigated. Then the complicated nonlinear problems were transformed to linear problems. The system performances were achieved using asymptotic output tracking. The simulations demonstrate feed-forward compensation decoupling controller can effectively eliminate the coupling. But when the system is highly nonlinear，only the feed-forward compensation decoupling control could not achieve high quality performance requirements. However，the optimal controller is designed based on exact feedback linearization，when considering the system of nonlinear，it can quickly and accurately achieve the preset.
Key words： steering cylinder loading； electro-hydraulic servo system； feed-forward decoupling control； feedback linearization