Researchment On Pneumatic Measurement Of Valve Sleeve Bore’s Cylindricity Based On Error Compensation

Electro-hydraulic servo system is a servo controlling system usingelectro-hydraulic servo valve as its core, electro-hydraulic servo system hascharacteristics like highly controlling precision, fast responding speed and highlypower output, which has a irreplaceable place in aerospace. The quality ofelectro-hydraulic servo valve has a crucial effect to the system, as theelectro-hydraulic servo valve is the key parts of electro-hydraulic servo system.Servo valve sleeve is the main power amplification element of the electro-hydraulicservo valve, which is important to the servo valve’s controlling precision andresponding frequency, thus the sleeve’s processing technology is important to servovalve production. The sleeve bore is produced by repeated processing and repeatedmeasuring for the moment, this kind of production method is hard to satisfy therequirement to servo valve’s precision and number for our country’s spaceengineering, to face the space engineering’s demand, the production process ofservo valve must be improved, and the improvement of the servo valve sleeve bore’scylindricity’s measuring efficiency and measuring precision is a key link. Therefore,it is important for our country’s servo valve production level enhancement byresearching servo valve sleeve bore’s cylindricity measuring method, and it has anincidence influence to our country’s space engineering career.This paper uses cylindrical least square method(CLSM) to calculate the sleevebore’s cylindricity first, and then proposals the rotary pneumatic scanningmeasurement method, which based on nozzle flapper principle, as the data collectionmethod for pneumatic measuring, this paper also makes error analysis for thepneumatic measurement method, and finds out the biggest error term, thennominates the error collection measuring method, finally, this paper builds up theerror compensation model in math.Then, this paper designs the hardware of the mearsuring system, the designs arebased on the CLSM and the error compensation model, the hardware consists ofmechanical parts for measuring, electronic parts for signal processing, the gas partsfor providing gas sources and the computer interface parts for controlling, this alsocompiles the software according to the hardware, the software is used to control themeasuring process, dispose the measuring data and error compensation, andcalculates the servo valve sleeve bore’s cylindricity.Last, this paper takes some experiments by using the measuring system tocalibrates the measuring system and gets the system’s working parameters, withthese experiments, this paper testifies the precision of the system, and the contrast experiment in the last of this paper verifies the compensation effect by theproposal error compensation model. These experiments verified the errorcompensation model is useful to the servo valve sleeve bore’s cylindricitymeasuring.