【正文】 Signal processing module is the most important module of the test system and its submodules include digital filtering, curve fitting , the difference, frequency response calculation and error pensation. Algorithms can be used by digital filtering conclude median filtering , correlation filtering , limited convergence filtering and so on . We can choose the appropriate filtering method according to field interfere circumstance . Leastsquares principle is usually used in curve fitting to make error sum squares of curve points the minimum . Frequency response calculation includes the calculation of autocorrelation and crosscorrelation calculation . The relevant calculation uses the fast Fourier transform and inverse transform to achieve fast correlation algorithm . Functions of munication module include read and write input/output data buffer, modules of municate with each other of digital signal generator. Before the test , operator put needed pressure , channel of flow signal and waveform parameters of signal generator into the system .The system will call the buffer zone to establish the function and municating functions to establish data buffering area of each channel and send parameters to the signal generator and start the D / A and A / D data conversion at the same time . Each channel using interrupt mode to write data into the buffer zone . CPU reads the data of each buffer zone at intervals 11 of 1s and call interface processing management module to refresh the output interface after date diaposition . Interface management module is mainly responsible for the drawing of static and dynamic characteristic process is pleted by esch submodule through calling Plot（） function . Auxiliary function modules includes test data formatted output to a file, and test documents and data printing . The entire test system was developed under Microsoft , and its overall operation process is shown in Figure 3. 12 P re pa ra ti onM a i n In te rf a c e S ta ti cD yn a m icS ta ti c or d yn a m ict e s t ?C ho os e st a t ic i temC ho os e te st onp re ss ur e / fl ow /c urr e ntS e t p a r a m a t e r o r pr e s sureo f si gn a l g e n e r a torI np ut w ro ng ?S ta rt D /AB ui ld b uf fe r z oneD e l a y f or 2sS ta rt A /DR e a d da teD a t e fi lt e ringC ur ve f it ti nga nd d if fe re nc eO ve r ?S to p da te c ol le c t , dr a w c ur veS a v e da teO ve rC ho os e c u rr e n t a nds pe e d i np ut c ha nne lS e t s c a ni ng s ig na l pa ra m a terI np ut w ro ng ?S ta rt D /AB ui ld b uf fe r z oneD e l a y f or 2sS ta rt A /DR e a d da teD a t e fi lt e ring C a l c u latea uto c o rr e lat ionC a l c u la te c rossc or re la ti onC a l c u la te f re que nc yr e s po ns e fu nc ti onC ur ve f it ti nga nd d if fe re nc eO ve r ?NoS a v e da te ?NoY e sNoY e sY e sY e sF i g .3 t e s ti n g s o ft w a re f low chat 13 6. Examples for the test Table 1 is a experimental report generated by D072386 servo valve produced by MOOG after repair . The main pilot project results and standard specifies were list in the report . Relate curves of the testing results are not enumerate here . Produc t60L/m in(m A)GB20 233 882020/ 05/ 13MOD D0 72 386S/N2 1321MP aA+ ， B add 18mA bi as in g ：C+ ， Dsi gna l（ 2020 ） Ser vo c he ck wo rd No . （ 0001 ）177。 △ PL) i = Cont. Test method of pressure characteristics Before the test, closed switch valve 17,18 and 7 and open the valve 9, make sure the output flow of the valve to be tested is adjust the pressure relief valve 3 so that the pressure of the system equals to the rated pressure and return oil pressure (measured by pressure sensor 13) . Then input the valve coil to be tested with a triangular wave current signal of puter reads the value of pressure transducer 14 and 15,so we can detect the pressure difference of the two out port of the servo the input current signal amplitude,and we can measure pressure value under different current curves can be sketched out,according to the value of current and pressure difference 177。 dynamic characteristics are mainly the test on frequency characteristics of serv