Integral (PI) control in the pitch rate loop and proportional control in the and loops.
The closed-loop system (airframe and autopilot) are modeled in Simulink.
addpath(fullfile(matlabroot,'examples','control','main')) % add example data
open_system('rct_airframeGS')
Autopilot Gain Scheduling
The airframe dynamics are nonlinear and the aerodynamic forces and moments depend
on speed and incidence. To obtain suitable performance throughout the flight
envelope, the autopilot gains must be adjusted as a function of and to compensate for
changes in plant dynamics. This adjustment process is called "gain scheduling" and
are called the scheduling variables. In the Simulink model, gain schedules are
implemented as look-up tables driven by measurements of and.
Gain scheduling is a linear technique for controlling nonlinear or time-varying plants. The
idea is to compute linear approximations of the plant at various operating conditions, tune
the controller gains at each operating condition, and swap gains as a function of
operating condition during operation. Conventional gain scheduling involves three major
steps:
(^1) Trim and linearize the plant at each operating condition
Tuning of Gain-Scheduled Three-Loop Autopilot