Study On The H_∞ Controller Of A High-Speed Electro-Hydraulic Propotional System

Hydraulic damper is one of the key components for absorption of the train's vibration. Especially, the requirement of safety and comfort becomes a major problem after a comprehensive increasing the speed of travel of China's railway. Aim at the demand for high-speed trains, many types of hydraulic dampers for high-speed train are being developed in China, but high-speed damper's performance cannot be tested comprehensively because of the restriction of the existing test equipment and test methods, so the further development and improvement of performance is limited.At present, the J95 - damper, used in China widespread, its performance test bench takes the advantages of a mechanical driven device. Because of body movement restrictions, the test bench can only test it by sinusoidal movement with low frequency, but cannot meet damper-tests requirements of the high frequency response to the high-speed performance.After 30 years of development, the manufacture technology for electro-hydraulic proportional valves, hydraulic cylinders, and other hydraulic components has enjoyed all-round development, so research on the damper test platform based on the high-speed electro-hydraulic proportional control technology is feasible. However, high-speed electro-hydraulic proportional system does not meet the demand of stability and tracking ability based on the classic control algorithms. The reasons is that classical control algorithm depends on the description of the precise mathematical models for dynamic performance, but hydraulic pulsation, the system damping, friction and the oil temperature are changing with high-speed travel, so it was not possible to determine the precise mathematical model. Furthermore, actual proportional valve generally has larger zero dead zone, so the work is not stable at zero balance, which leading to severe shaking at high-speed travel.In contrast, H_∞ robust control theory does not need accurate mathematical models, but also can ensure the stability of control systems through H_∞ performance indicators. So research on H_∞controller of high-speed electro-hydraulic proportional control system has important academic and...