???????? electro-hydraulic servo valve?????????????????????????????
???????????????flow control electro-hydraulic servo valve????????????????????????????
?? stage????????е?????????????????????????????????????
???????pressure gain??????????????????????????????????仯???
??λ null???????????????????????????????????????λ?á?
??λ????null region????λ????????????????????????????????????
?????threshold??????????????????仯???????С??????????????????????????????
????????resolution??????????????仯???????????????????仯???????С???????????????????????????????????
????????threshold??????????????仯???????????????????仯???????С????????????????????????????????????????????÷???????????????
???null bias??????????????????????仯????????????仯??????????????????
???internal leakage?????????????????????????????????????????????????????????????????仯???仯??