Redundant actuator control

Abstract

A control system for operating an actuator in a mechanical system, such as an aircraft turbine engine, employs redundant electronic control channels for increased operational safety in the event of a failure of one of the control channels. In accordance with the reliability or integrity of the various components of the system, a network of triplex redundant electronic control units connects with duplex redundant input driver ports of a servo actuator, the network including a converter of triplex to duplex wherein the converter employs a duplex section of electronic circuits. The control units may include a schedule or memory addressed by a set of input parameters or variables for outputting a desired value of output parameter or variable. The converter includes a fan-in circuit by which signals of the three control units are applied to two power amplifiers for driving the two input sections of the servo actuator. Each input section of the actuator includes a torque motor for converting an electrical signal to a mechanical movement. Electronic sensing of current and voltage of each torque motor is provided for disabling a section of the converter in the event of failure of a torque motor.