Fly-by-wire flight control system and method
A multi-axis serially redundant, single channel, multi-path fly-by-wire control system comprising: serially redundant flight control computers in a single channel where only one “primary” flight control computer is active and controlling at any given time; a matrix of parallel flight control surface controllers including stabilizer motor control units (SMCU) and actuator electronics control modules (AECM) define multiple control paths within the single channel, each implemented with dissimilar hardware and which each control the movement of a distributed set of flight control surfaces on the aircraft in response to flight control surface commands of the primary flight control computer; and a set of (pilot and co-pilot) controls and aircraft surface/reference/navigation sensors and systems which provide input to a primary flight control computer and are used to generate the flight control surface commands to control the aircraft in flight in accordance with the control law algorithms implemented in the flight control computers.
1. A fly-by-wire flight control system of an aircraft, the system comprising:
a plurality of input controls, each one of the plurality of input controls being capable of generating a signal indicative of a commanded position of at least one flight control surface;
a plurality of flight control computers, each one of the plurality of flight control computers being capable of generating flight surface control commands according to predetermined flight control algorithms in part as a function of the signal, wherein at least one of the plurality of flight control computers comprises a command lane and a monitor lane capable of comparing against one another, the at least one of the plurality of flight control computers being capable of determining that it is invalid based on a self-testing regime; and
a plurality of flight control surface controllers, each one of the plurality of flight control surface controllers being capable of controlling the at least one flight control surface based on at least one of (i) the flight surface control commands generated by at least one of the plurality of flight control computers and (ii) the signal.
2. The fly-by-wire flight control system of claim 1 , wherein at least another one of the plurality of flight control computers is capable of becoming an active primary flight control computer upon determination by the at least one of the plurality of flight control computers that it is invalid.
3. The fly-by-wire flight control system of claim 2 , wherein the at least another one of the plurality of flight control computers is capable of becoming the active primary flight control computer based on (i) a determination by the at least one of the plurality of flight control computers that it is invalid and (ii) a priority logic.
4. The fly-by-wire flight control system of claim 1 , wherein at least one of the plurality of flight control surface controllers, upon determining that none of the plurality of flight control computers is capable of becoming an active primary flight control computer, is capable of being commanded according to predetermined flight control algorithms for direct mode operation in response to the signal.
5. The fly-by-wire flight control system of claim 1 , wherein the self-testing is configured so that a discrepancy outside a predetermined tolerance between the command lane and the monitor lane results in the at least one of the plurality of flight control computers setting its status as invalid.
6. The fly-by-wire flight control system of claim 5 , wherein at least one of the plurality of flight control surface controllers is being indicated that the status of the at least one of the plurality of flight control computers is invalid.
7. The fly-by-wire flight control system of claim 1 , wherein the self-testing is configured so that a discrepancy outside a predetermined tolerance between the command lane and the monitor lane results in the at least one of the plurality of flight control computers taking itself offline.
8. The fly-by-wire flight control system of claim 1 , wherein the command lane and the monitor lane have dissimilar processors.
9. The fly-by-wire flight control system of claim 1 , further comprising a validity block configured to detect whether no valid flight control computer amongst the plurality of flight control computers is available and further configured to instruct a switching block to disconnect flight surface control commands and to connect direct mode control.