The flight control system of the X-29 used a triple-redundant fly-by-wire system with a triple redundant backup analog system. Each control channel used 2 CPUs with a cycle loop time of 25ms. The full-state feedback system was initially designed with simplified aircraft and actuator models. Lead and lag filters were used to augment this design to account for sensor dynamics, zero-order hold effects, and actuator time delays. The pitch rate and pitch acceleration feedback controlled the short-period stability. The forward loop used PI control law. Neal-Smith analysis was used for predicting handling qualities. The compensator in the Neal-Smith analysis was meant to represent the transfer function of a pilot controlling the aircraft. The compensator needed a large amount of lead for proper tracking. The flight controls used a linear variable differential transducer for the pilot inputs. The multivariable control theory was developed by Brian Porter. The longitudinal and lateral systems were designed from decoupled equations. For some simulations the engine was modeled as.a first-order transfer function
$$f(s)=\frac{20}{s+20}$$
The rate-saturation of the ailerons led to an unstable wing-rock above 35 degrees AOA. The second aircraft had a flow control system of jets that helped to control the forebody vortices at high AOA.[^4]
[[Actuator Time Constant Reduction]] – first- order lag filter can be used for actuator.
[[Fin Control]] – second order lag filter can be used for modeling entire control surface.
[[X-29 Automatic Camber Controls]]
[[X-29 longitudinal control system]]
X-29 Lateral Directional Control System
[[X-29 flight control handling quality process]]
[[Neal-Smith Analysis]]
[[Honeywell Multi-Application Control (MACH)]] – used for FCS design
[[State Feedback]] – X-29 used state feedback
X-29 Air Data Sensors
[[Brian Porter]]
[[MULTI]] – computer program for control loops
[[Direct Lift]]
[[Pitch Pointing]] – AOA can change without changing flight path
[[Vertical Translation]] – advanced control maneuver.
[[X-29 Neal-Smith Results]]
[[X-29 Gyroscope Response]]
- clarkeX29FlightControl
- OperationalViewpointX29AFCS