Development of a Plus or Minus 7 Bit Parallel Binary Digital Servovalve

摘要

The report describes the development and developmental testing of a digital servovalve designed to provide a flow output proportional to plus or minus 7 bit parallel binary two's complement input signals. The digital servovalve, which acts as an interface between a digital computer and a hydraulic-power-driven analog responder, converts the digital input to the servovalve to an analog flow output used to position the responder. The unit is a standard HR+M Company second-stage mechanical feedback servovalve driven by a digital torquer operating in the area of torque output saturation. The torquer consists of eight solenoidal bits, seven of which are positive torque output devices, while the eighth most significant bit is negative. The mechanical summation of torques is accomplished by applying the array of torques to a common rotor. The rotor receives feedback torque from the second-stage position, which drives the summation of torques to zero. Tests of three experimental digital servovalve units established that the design meets specified requirements, and the valve has been tested in the direct digital control of a missile-launcher hydraulic power drive. (Author)