VAAC Control Strategies

The VAAC program used frequency shaping, gain-scheduling, and iterative design for its flight control systems. It used inverse functions to linearize the significant nonlinearities in the control system. It also used anti-windup techniques as well as control allocation. It used a ‘two-interceptor’ pitch control law. Airspeed-triggered switching between helix rate and pitch rate demand modes was too complicated and introduced poor handling qualities. Instead, airspeed was blended through the modes. Integrator conditioning logic was used for the integral control scheme that involved the thrust vector. The number of control mode blending regions was kept to a minimum. The embedded control laws were autocoded, which allowed for a change to be flown on the same day as a deficiency was discovered.

onlinear Static Inverse]] – used for designing aircraft trim states.
[[Two-Interceptor Pitch Control Law]]
[[VTOL Control Challenges]]

Sources

Backlinks

[[Anti-Windup Scheme]]
[[Code Generation]]
Gain Scheduling
[[Mode-Blending]]
[[Thrust Vectoring]]
[[VAAC Program]]