Fly by wire servos with internal loop closure
Embodiments are directed to obtaining a first analog signal corresponding to a position error between a commanded gang output of a plurality of electro-mechanical actuators configured to be run in parallel with one another and a measured gang output of the plurality of electro-mechanical actuators, obtaining a second analog signal corresponding to an output torque, and processing, by a circuit, the first analog signal and the second analog signal to generate and output a discrete that indicates a status of the torque in terms of direction and magnitude.
1. A servo assembly comprising:
a hydraulic primary servo;
a plurality of electro-mechanical actuators coupled to the primary servo and configured to drive the primary servo;
at least one device configured to perform loop closure; and
a summation bar coupled to a plurality of output arms associated with the plurality of electro-mechanical actuators and configured to perform a mechanical averaging of differences in outputs of the electro-mechanical actuators.
2. The servo assembly of claim 1 , wherein the loop closure comprises obtaining a difference between a desired ram position and an actual ram position driving a spool valve.
3. The servo assembly of claim 1 , wherein the plurality of electro-mechanical actuators are configured to be run in parallel with one another.
4. The servo assembly of claim 1 , wherein the servo assembly is configured to communicate with at least one flight control computer of an aircraft via a communication bus.
5. The servo assembly of claim 1 , wherein the communication bus is configured to adhere to at least one of RS485, RS232, ARINC 629, and AFDX.
6. The servo assembly of claim 1 , wherein each of the electro-mechanical actuators is controlled via a separate fly by wire channel.
7. The servo assembly of claim 1 , wherein a stiffness and damping are selected for the summation bar relative to the electro-mechanical actuators.
8. The servo assembly of claim 1 , wherein the at least one device comprises at least one sensor, and wherein the at least one sensor comprises at least one of: a rotary variable differential transformer and a linear variable differential transducer.
9. The servo assembly of claim 1 , wherein the servo assembly is configured to calculate a torque associated with the plurality of electro-mechanical actuators.
10. The servo assembly of claim 9 , further comprising:
a circuit configured to generate and output a discrete that indicates a status of the torque in terms of direction and magnitude.
11. A system comprising:
at least one flight control computer; and
at least one servo assembly coupled to the at least one flight control computer comprising:
a hydraulic primary servo;
a plurality of electro-mechanical actuators coupled to the primary servo and configured to drive the primary servo; and
at least one device configured to perform loop closure;
wherein the at least one servo assembly comprises a summation bar coupled to a plurality of output arms associated with the plurality of electro-mechanical actuators and configured to perform a mechanical averaging of differences in outputs of the electro-mechanical actuators.
12. The system of claim 11 , wherein the at least one servo assembly is coupled to the at least one flight control computer via a serial communications bus, and wherein the at least one flight control computer is configured to issue commands to the at least one servo assembly via the serial communications bus, and wherein the at least one servo assembly is configured to provide feedback to the at least one flight control computer via the serial communications bus.
13. The system of claim 11 , wherein the at least one device comprises at least one sensor configured to support obtaining difference between a desired ram position and an actual ram position driving a spool valve.
14. The system of claim 11 , wherein the plurality of electro-mechanical actuators are configured to be run in parallel with one another.
15. A method comprising:
obtaining a first analog signal corresponding to a position error between a commanded gang output of a plurality of electro-mechanical actuators configured to be run in parallel with one another and a measured gang output of the plurality of electro-mechanical actuators;
obtaining a second analog signal corresponding to an output torque; and
processing, by a circuit, the first analog signal and the second analog signal to generate and output a discrete that indicates a status of the torque in terms of direction and magnitude;
wherein the second analog signal corresponds to a difference between a position of one of the electro-mechanical actuators and the measured gang output.
16. The method of claim 15 , further comprising:
turning off one of the electro-mechanical actuators based on determining that the one of the electro-mechanical actuators is subject to a fault mode.
17. The method of claim 16 , wherein the one of the electro-mechanical actuators is turned off by at least one of: a first discrete input associated with a first flight control computer and a master disable input control by a second flight control computer, wherein the first and second flight control computers are dissimilar computers.