A Certain Proportional Multi-way Valve Radial Force And The Friction Analysis And Friction Compensation Research

Proportional multi-way valve can control the different hydraulic circuits to work at the same time, it has the advantages of small volume, saving energy, reducing oil and increaing control precision, it has been widespreadly applicated in the engineering machinery field. The friction of multi-way value loads to valve core sticking, low velocity crawling, large flux hysteresis, pressure pulsation. Therefore, the friction analysis of the multi-way valve, structure improvement and friction compensation are studied to reduce friction harmful effect on the performance of the proportional multi-way value which is of great significance to improve the performance of proportional multi-way valve.Regarding a certain proportional multi-way valve as the research object, taking the friction analysis of the proportional multi-way valve, two aspects of structure improvement and friction compensation are studied, this paper completes the following aspects:Firstly, the structure of the valve which affects the valve core friction and valve core sticking is analyzed. The theoretical model of the radial force that the valve core of the proportional multi-way value suffered is builded when it is eccentric and original tapered. The common rectangular pressure-equalizing groove and O pressure-equalizing groove is analyzed, meanwhile the flow field between the valve core and the valve cover is simulated by use of Fluent software. The two forms of pressure-equalizing groove are studied to find the influence to the valve core radial force,friction force and the leakage.Secondly, by means of the multi-way valve performance testing experiment platform, the relevant data such as friction data and speed acceleration data can be obtained. Lu Gre Model with modified viscous friction(simply “Sticky Lu Gre model”for short) reflects a good realistic friction when the valve core move in the high speed, so this model is used to identify the friction parameter. With the help of the Sticky Lu Gre model we identify the friction parameter characteristics of valve. The static parameters are identified by use of the MATLAB toolbox, the dynamic parameters are identified by use of μPSO algorithm.Finally, the working principle of the proportional multi-way valve is analyzed, proportional multi-way valve physical model is established by use of AMESim software and the model is verified. According to the characters of sticky Lu Gre model the friction state observer is designed and the MATLAB/Simulink module is encapsulated. The friction compensator is added to the multi-way valve physical model in the method of AMESim/MATLAB united simulation. Sticky Lugre model compensation method is used in the simulation and it is compared with traditional PID friction compensation method. The advantages and disadvantages of two kinds of methods are analyzed. It is concluded that the friction compensation based on Sticky Lugre model has better compensation effect.