Abstract: A redundant, dual-fail/operate fly-by-wire control system actuates a redundant tandem piston actuator (10) to provide a single composite output evidenced by movement of a piston rod (12). The basic fault-tolerate actuation system consists of dual hydraulic primary actuators, quadruplex electrical control loops (14-17), and control servo valves (22-25). A failure management system connects to the actuation system by means of lines (18-21) to control the servo valves (22-25). The four control loops (14-17) connect to a pilot controller that provides a pilot individual input signals to amplifiers (26-29) for each of the control loops. A tracking loop (450) includes switches (480, 482, 484) for connecting the four control loops (14-17) and providing isolation therebetween.

Abstract: A redundant, dual-fail/operate fly-by-wire control system actuates a redundant tandem piston actuator (10) to provide a single composite output evidenced by movement of a piston rod (12). The basic fault-tolerate actuation system consists of dual hydraulic primary actuators, quadruplex electrical control loops (14-17), and control servo valves (22-25). A failure management system connects to the actuation system by means of lines (18-21) to control the servo valves (22-25). The four control loops (14-17) connect to a pilot controller that provides pilot individual input signals to amplifiers (26-29) for each of the control loops.