function M = adaptive_methods()
%ADAPTIVE_METHODS Declarative specs for the adaptive-PID strategies under test.
% Each is driven by the SAME asymmetric law (margin_law) on a normalized knob; they
% differ only in how the knob maps to the controller, and whether they use M9.1's
% reported BINDING FREQUENCY to gate/route/place their action. simulate_adaptive_case
% turns 'kind' into the actual time-varying gains and the analytic loop.
%
% Fields:
%   id, name, kind, knob_max, params (cell of plotted-parameter labels), note.
%
% The 5 methods, by design intent (see the analytic knob<->mechanism sweep):
%   1 authority   uniform PID gain a (the user's idea): universal, monotone, sign-safe.
%   2 integral    detune the integral branch g_I: best for LOW-frequency / integral-
%                 driven mechanisms; self-gated OFF when M9.1 binds high (wrong sign there).
%   3 lowpass     adaptive roll-off cutoff f_c: best for HIGH-frequency gain damage;
%                 self-gated OFF when M9.1 binds low (adds lag there).
%   4 schedule    use M9.1's binding freq to pick the cheap targeted knob (integral for
%                 an observable mid-low resonance, else authority); if that knob saturates
%                 without moving the indicator (the pure-delay case, where M9.1 mis-reports
%                 the binding freq), FALL BACK to the always-observable authority knob.
%                 Universal + minimal intervention, with no need to know the mechanism.
%   5 auth_notch  authority + an adaptive notch placed at M9.1's binding freq. Notch-first
%                 ladder (knob 0..1 deepens the notch, 1..2 then lowers authority): claws
%                 back resonant margin so less uniform gain is sacrificed. Universal.

M = struct( ...
 'id',   {'baseline','M1','M2','M3','M4','M5'}, ...
 'name', {'No adaptation (baseline)', ...
          'Authority gain reduction', ...
          'Integral-branch detuning', ...
          'Adaptive low-pass roll-off', ...
          'Frequency-scheduled detuning', ...
          'Authority + adaptive notch'}, ...
 'kind', {'baseline','authority','integral','lowpass','schedule','auth_notch'}, ...
 'knob_max', {0, 1, 1, 1, 2, 2}, ...
 'params', {{}, {'a'}, {'g_I'}, {'f_c [Hz]'}, {'a / g_I (active)'}, {'a','notch depth'}}, ...
 'note', {'controller frozen at nominal', ...
          'a: scale P,I,D uniformly (dc = a*C*e)', ...
          'g_I: scale the integral branch only', ...
          'f_c: one-pole roll-off on the PID output', ...
          'route by M9.1 binding freq vs f_split', ...
          'notch at M9.1 binding freq, then authority'});
end