The Research Of Highly Precise Integrated Control Method Applied To The Wind Tunnel Hydraulic Servo Cylinders

In this paper, we study the Hydraulic Servo system that controls the supportingmechanism in the Wind Tunnel test model. We focus on accurately positioning themodel attitude, and collecting data from continuous variable attitude angle instead oftraditional model attitude ladder angle with fixed air, which improves the efficiency ondata collection and enriches the data and information provided in the wind tunnelexperiments.This paper studies the wind tunnel and its main components, the structure and theprinciple of tail abdomen support mechanism device, the electro-hydraulic servotechnique and the different types of electro-hydraulic servo valves, the valve controlledhydraulic cylinder, the hydraulic simulation, and many other techniques that are used inwind tunnel experiments. It introduces the establishment and the control technique ofthe hydraulic axis dynamic model under dynamic friction conditions, furthermore,analyzes the related research works that have been done domestically and globally.This paper proposes a single hydraulic axis control algorithm, and then describesits calculation model and implementation. It uses the rod supported agencieselectrohydraulic servo system as the example for simulation and experiment. The resultsshow that the multi-strategy method that involves speed forward feedback and positionfeedback is an effective method to achieve accurate control. That is on the basis of theposition feedback, the speed feed forward control before adding the desired speedcorresponding to the control signal superimposed on the servo valve control signal。Thebasic principle of this algorithm is that during dynamic operation, the speed forwardfeedback will be the main factor to control the cylinder operating speed to follow theexpected velocity curve, on the other hand, when approaching the expected position, theposition feedback will take charge of protecting position accuracy and preventingexternal interruption. This algorithm can help the single degree freedom hydraulicpressure servo system realizing nonlinear velocity curve dynamic control under variousload conditions, and the precision of the speed control is better than0.5%.This paper establishes a double hydraulic pressure axis simultaneously controlexperimental platform, and studies the double hydraulic axes linkage control techniqueand the two high-precision servo cylinder linkage control technique. The simulation andexperimental results show the effectiveness of using the speed and position combined control method and the virtual spindle control method the hydraulic nonlinear highprecision linkage control, and proves that the first the second levels of the twohigh-precision servo cylinder can follow the “Virtual spindle” to realize high precisionlinkage control. This achieves the method of tandem nonlinear hydraulic pressure servocylinder speed and positioning precision synthesis method for controlling. The precisionof the speed control is better than0.5%, and the precision of positioning is better than0.05mm.