This paper give an advice that we can realize closed cycle control of feeding shaft by proportional valve and linear grid ruler instead of servo amplifier and servo motor.

V-port trim has a more linear throttling curve than plug or ball discs, but none of these trims are recommended for continuous severe throttling which may require using a control valve.

Currently, the design of shaking table control system is based on two assumptions, i. e. linear servo valve, and rigid table and payloads.