face of concurrent gain and phase variations in all three loops. Because the target
margins of 7 dB and 40 degrees are difficult to obtain for extreme orientations (corners of
the (alpha,beta) grid), we use a varying goal to relax the gain and phase margin
requirements at the corners.
% Gain margins vs (alpha,beta)
GM = [...
6 6 6 6 6
6 6 7 6 6
7 7 7 7 7
7 7 7 7 7
7 7 7 7 7
7 7 7 7 7
6 6 7 6 6
6 6 6 6 6];
% Phase margins vs (alpha,beta)
PM = [...
40 40 40 40 40
40 40 45 40 40
45 45 45 45 45
45 45 45 45 45
45 45 45 45 45
45 45 45 45 45
40 40 45 40 40
40 40 40 40 40];
% Create varying goal
FH = @(gm,pm) TuningGoal.Margins('da;de;dr',gm,pm);
R3 = varyingGoal(FH,GM,PM);
Gain Schedule Tuning
To tune the P and I gain schedules for the outer loop, mark the three MATLAB Function
blocks and three lookup table blocks as tunable.
TunedBlocks = {'P phi','P alpha','P beta','I phi','I alpha','I beta'};
ST0.addBlock(TunedBlocks)
Parameterize each tuned gain schedule as a polynomial surface in alpha and beta. Here
we use quadratic surfaces for the proportional gains and multilinear surfaces for the
integral gains.
% Grid of (alpha,beta) design points
alpha_vec = -10:5:25; % Alpha Range
Attitude Control in the HL-20 Autopilot - SISO Design