Study On The Engineering Machinery 4WS System And Digital Controller

The steering characteristics of vehicles are important aspects that can improve the active safe. Research on the 4-wheel steering (4WS) system has important significance.The structure and working principle of 4WS are researched; 4WS comprehensive test bench is developed independently; The mathematical model of the test bench is setup, simulation model is established using MATLAB, and the dynamic simulations are completed. The control strategy and controlling means of 4WS system are analyzed and studied in detail, the steering controller based on DSP is designed, software are programmed using CC2000. Through the experimental research of test bench and digital controller, the results indicate that 4WS test bench has better dynamic and static characteristics, and the experimental transfer function is derived. The mathematical model established is correct according to the results of experiments and simulation. The indoor test results indicate that the digital controller can complete such functions as front wheel steering, full wheel steering and crab-crawl steering, system selfcheck and faults diagnosis. The steering system can meet the relationship of steering angle and steering time, also the relationship of steering angle and PWM duty ratio. The control scheme of digital steering controller based on DSP is feasible. The research provides theoretical references for application of 4WS in construction machineries and development of digital controller.