initial test - totally unfeasible calculation times

EmaMaker 2024-08-05 21:17:17 +02:00
parent b9a9ed9395
commit cc70c4717b
3 changed files with 183 additions and 71 deletions

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@ -18,21 +18,29 @@ function [u_corr, U_corr_history, q_pred] = ucorr(t, q, sim_data)
tc = sim_data.tc;
u_corr = zeros(2,1);
U_corr_history = zeros(2,1,sim_data.PREDICTION_HORIZON);
U_corr_history = zeros(2,1);
q_act = q;
u_track_pred=zeros(2,1, pred_hor);
T_inv_pred=zeros(2,2, pred_hor);
q_pred = [];
if eq(pred_hor, 0)
return
end
U_corr_history = optimvar('ucorr', 2, pred_hor); %zeros(2,1,sim_data.PREDICTION_HORIZON);
if pred_hor > 1
% move the horizon over 1 step and add trailing zeroes
U_corr_history = cat(3, sim_data.U_corr_history(:,:, 2:end), zeros(2,1));
% prepare objective function. Sum of squared norms
obj = 0
for k = 1:pred_hor
% squared norm
obj = obj + ones(1, 2) * (U_corr_history(:, k).^2);
end
prob = optimproblem('Objective', obj);
cons = []
%if pred_hor > 1
% % move the horizon over 1 step and add trailing zeroes
% U_corr_history = cat(3, sim_data.U_corr_history(:,:, 2:end), zeros(2,1));
%end
%disp('start of simulation')
% for each step in the prediction horizon, integrate the system to
@ -44,7 +52,7 @@ function [u_corr, U_corr_history, q_pred] = ucorr(t, q, sim_data)
% compute the inputs, based on the old state
% u_corr is the prediction done at some time in the past, as found in U_corr_history
u_corr_ = U_corr_history(:, :, k);
u_corr_ = U_corr_history(:, k);
% u_track can be computed from q
t_ = t + tc * (k-1);
u_track_ = utrack(t_, q_act, sim_data);
@ -67,77 +75,34 @@ function [u_corr, U_corr_history, q_pred] = ucorr(t, q, sim_data)
q_new = [x_new; y_new; theta_new];
% save history
q_pred = [q_pred; q_new'];
u_track_pred(:,:,k) = u_track_;
T_inv_pred(:,:,k) = T_inv;
% this thing is not allowed with optimization variables, so build
% the problem while predicting the behaviour
%q_pred = [q_pred; q_new'];
%u_track_pred(:,:,k) = u_track_;
%T_inv_pred(:,:,k) = T_inv;
% Prepare old state for next iteration
q_act = q_new;
end
%{
Now setup the qp problem
It needs:
- Unknowns, u_corr at each timestep. Will be encoded as a vector of
vectors, in which every two elements is a u_j
i.e. (u_1; u_2; u_3; ...; u_C) = (v_1; w_1; v_2, w_2; v_3, w_3; ...
; v_C, w_C)
It is essential that the vector stays a column, so that u'u is the
sum of the squared norms of each u_j
% since saving history is not possible, create box constraints
% while simulating
- Box constraints: a constraint for each timestep in the horizon.
Calculated using the predicted state and inputs. They need to be
put in matrix (Ax <= b) form
%}
s_ = SATURATION - ones(2,1)*PREDICTION_SATURATION_TOLERANCE;
d = T_inv*u_track_;
% box constrains
% A becomes sort of block-diagonal
% A will be at most PREDICTION_HORIZON * 2 * 2 (2: size of T_inv; 2:
% accounting for T_inv and -T_inv) by PREDICTION_HORIZON (number of
% vectors in u_corr times the number of elements [2] in each vector)
A_max_elems = pred_hor * 2 * 2;
A_deq = [];
b_deq = [];
c1 = T_inv * u_corr_ <= s_-d;
c2 = -T_inv * u_corr_ <= s_ + d;
s_ = SATURATION - ones(2,1)*PREDICTION_SATURATION_TOLERANCE;
for k=1:pred_hor
T_inv = T_inv_pred(:,:,k);
u_track = u_track_pred(:,:,k);
% [T_inv; -T_inv] is a 4x2 matrix
n_zeros_before = (k-1) * 4;
n_zeros_after = A_max_elems - n_zeros_before - 4;
zeros_before = zeros(n_zeros_before, 2);
zeros_after = zeros(n_zeros_after, 2);
column = [zeros_before; T_inv; -T_inv; zeros_after];
A_deq = [A_deq, column];
d = T_inv*u_track;
b_deq = [b_deq; s_ - d; s_ + d];
cons = [cons; c1; c2];
end
%A_deq
%b_deq
% unknowns
% squared norm of u_corr. H must be identity,
% PREDICTION_HORIZON*size(u_corr)
H = eye(pred_hor*2);
% no linear terms
f = zeros(pred_hor*2, 1);
% solve qp problem
options = optimoptions('quadprog', 'Display', 'off');
U_corr = quadprog(H, f, A_deq, b_deq, [],[],[],[],[],options);
%U_corr = lsqnonlin(@(pred_hor) ones(pred_hor, 1), U_corr_history(:,:,1), [], [], A_deq, b_deq, [], []);
% reshape the vector of vectors to be an array, each element being
% u_corr_j as a 2x1 vector
% and add the prediction at t_k+C
U_corr_history = reshape(U_corr, [2,1,pred_hor]);
% first result is what to do now
u_corr=U_corr_history(:,:, 1);
prob.Constraints.cons = cons;
x0.ucorr = zeros(2,1,pred_hor);
show(prob)
[sol,fval,exitflag,output] = solve(prob,x0)
U_corr_history=reshape(sol.ucorr, [2,1,pred_hor]);
u_corr=U_corr_history(:,:,1);
end
function u_track = utrack(t, q, sim_data)

8
tesi.m
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@ -20,7 +20,8 @@ for i = 1:s_(1)
for fn = fieldnames(test_data)'
sim_data.(fn{1}) = test_data.(fn{1});
end
sim_data.tfin = 1;
sim_data.q0 = set_initial_conditions(sim_data.INITIAL_CONDITIONS);
[ref dref] = set_trajectory(sim_data.TRAJECTORY, sim_data);
sim_data.ref = ref;
@ -34,6 +35,9 @@ for i = 1:s_(1)
sim_data.(fn{1}) = data.(fn{1});
end
if sim_data.PREDICTION_HORIZON > 1
sim_data.PREDICTION_HORIZON = 3;
end
sim_data.U_corr_history = zeros(2,1,sim_data.PREDICTION_HORIZON);
sim_data
@ -105,7 +109,7 @@ function [t, q, ref_t, U, U_track, U_corr, U_corr_pred_history, Q_pred] = simula
U_track = [U_track; ones(length(v), 1)*u_track'];
Q_pred(:, :, 1+n) = q_pred;
U_corr_pred_history(:,:,n) = permute(U_corr_history, [3, 1, 2]);
U_corr_pred_history(:,:,n) = permute(U_corr_history, [3, 1, 2]);
end
ref_t = double(subs(sim_data.ref, t'))';

143
untitled.m Normal file
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@ -0,0 +1,143 @@
clear all
sim_data.b = 0.2
sim_data.PREDICTION_HORIZON=5
sim_data.SATURATION=[2.5; 2.5]
sim_data.PREDICTION_SATURATION_TOLERANCE=0
sim_data.tc=0.1
sim_data.U_corr_history=zeros(2,1,sim_data.PREDICTION_HORIZON)
sim_data.r=0.08;
sim_data.d=0.15;
sim_data.K=eye(2)
sim_data.q0=[0;0;0]
[ref dref] = set_trajectory(1);
sim_data.ref=ref;
sim_data.dref=dref;
[uc, U_corr_history, q_pred] = ucorr(0, [0;0;0], sim_data)
function [u_corr, U_corr_history, q_pred] = ucorr(t, q, sim_data)
pred_hor = sim_data.PREDICTION_HORIZON;
SATURATION = sim_data.SATURATION;
PREDICTION_SATURATION_TOLERANCE = sim_data.PREDICTION_SATURATION_TOLERANCE;
tc = sim_data.tc;
u_corr = zeros(2,1);
U_corr_history = zeros(2,1);
q_act = q;
q_pred = [];
if eq(pred_hor, 0)
return
end
U_corr_history = optimvar('ucorr', 2, pred_hor); %zeros(2,1,sim_data.PREDICTION_HORIZON);
% prepare objective function. Sum of squared norms
obj = 0
for k = 1:pred_hor
% squared norm
obj = obj + ones(1, 2) * (U_corr_history(:, k).^2);
end
prob = optimproblem('Objective', obj);
cons = []
%if pred_hor > 1
% % move the horizon over 1 step and add trailing zeroes
% U_corr_history = cat(3, sim_data.U_corr_history(:,:, 2:end), zeros(2,1));
%end
%disp('start of simulation')
% for each step in the prediction horizon, integrate the system to
% predict its future state
for k = 1:pred_hor
% start from the old (known) state
% compute the inputs, based on the old state
% u_corr is the prediction done at some time in the past, as found in U_corr_history
u_corr_ = U_corr_history(:, k);
% u_track can be computed from q
t_ = t + tc * (k-1);
u_track_ = utrack(t_, q_act, sim_data);
T_inv = decouple_matrix(q_act, sim_data);
% compute inputs (wr, wl)
u_ = T_inv * (u_corr_ + u_track_);
% map (wr, wl) to (v, w) for unicicle
u_ = diffdrive_to_uni(u_, sim_data);
% integrate unicycle
theta_new = q_act(3) + tc*u_(2);
% compute the state integrating with euler
%x_new = q_act(1) + tc*u_(1) * cos(q_act(3));
%y_new = q_act(2) + tc*u_(1) * sin(q_act(3));
% compute the state integrating via runge-kutta
x_new = q_act(1) + tc*u_(1) * cos(q_act(3) + 0.5*tc*u_(2));
y_new = q_act(2) + tc*u_(1) * sin(q_act(3) + 0.5*tc*u_(2));
q_new = [x_new; y_new; theta_new];
% save history
% this thing is not allowed with optimization variables, so build
% the problem while predicting the behaviour
%q_pred = [q_pred; q_new'];
%u_track_pred(:,:,k) = u_track_;
%T_inv_pred(:,:,k) = T_inv;
% Prepare old state for next iteration
q_act = q_new;
% since saving history is not possible, create box constraints
% while simulating
s_ = SATURATION - ones(2,1)*PREDICTION_SATURATION_TOLERANCE;
d = T_inv*u_track_;
c1 = T_inv * u_corr_ <= s_-d;
c2 = -T_inv * u_corr_ <= s_ + d;
cons = [cons; c1; c2];
end
prob.Constraints.cons = cons;
x0.ucorr = zeros(2,1,pred_hor);
show(prob)
[sol,fval,exitflag,output] = solve(prob,x0)
U_corr_history=reshape(sol.ucorr, [2,1,pred_hor]);
u_corr=U_corr_history(:,:,1);
end
function u_track = utrack(t, q, sim_data)
ref_s = double(subs(sim_data.ref, t));
dref_s = double(subs(sim_data.dref, t));
f = feedback(q, sim_data.b);
err = ref_s - f;
u_track = dref_s + sim_data.K*err;
end
function q_track = feedback(q, b)
q_track = [q(1) + b*cos(q(3)); q(2) + b*sin(q(3)) ];
end
function T_inv = decouple_matrix(q, sim_data)
theta = q(3);
st = sin(theta);
ct = cos(theta);
b = sim_data.b;
r = sim_data.r;
d = sim_data.d;
%a1 = sim_data.r*0.5;
%a2 = sim_data.b*sim_data.r/sim_data.d;
%det_inv = -sim_data.d/(sim_data.b*sim_data.r*sim_data.r);0
%T_inv = det_inv * [ a1*st - a2*ct, -a1*ct - a2*st;-a1*st-a2*ct , a1*ct - a2*st];
T_inv = [2*b*ct - d*st, d*ct + 2*b*st ; 2*b*ct + d*st, -d*ct+2*b*st] / (2*b*r);
end