A NOVEL MODEL-BASED STEERING CONTROL FOR HYDRA-POWERED ARTICULATED STEERING VEHICLES

摘要

The hydra-power articulated steering vehicles possess brilliant maneuverability and efficiency, and they were widely applied in mining, construction, agriculture, and forestry. However, the steering characteristic also deduced a serious handling stability problem of this type of vehicle, i.e., oscillation in yaw motion. Previous research only analyzed the stability of the vehicle dynamical system or provided a passive structural method to suppress the oscillation of articulated vehicles. This work presents a novel model-based steering control of articulated steering vehicles. A coupled nonlinear dynamic model was established firstly, in which nonlinear models of the hydraulic system and dynamic model of articulated frames were included. Then the coupled model was validated in time and frequency domain by a field test. The susceptibility of different factors of the system oscillation was investigated by simulation based on the validated model. On this foundation, an optimized scheme of the hydraulic steering system was provided. Further a novel control strategy, in which the articulation angle and corresponding angular velocity were considered together as the control variables of the system, was embedded into the optimized system. Comparing results in dynamic responses of articulated frames, ripples in the hydraulic steering system shown the effectiveness and superiority of the presented method.