annotate toolboxes/FullBNT-1.0.7/bnt/examples/dynamic/SLAM/Old/paskin1.m @ 0:e9a9cd732c1e tip

first hg version after svn
author wolffd
date Tue, 10 Feb 2015 15:05:51 +0000
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children
rev   line source
wolffd@0 1 % This is like robot1, except we only use a Kalman filter.
wolffd@0 2 % The goal is to study how the precision matrix changes.
wolffd@0 3
wolffd@0 4 seed = 1;
wolffd@0 5 rand('state', seed);
wolffd@0 6 randn('state', seed);
wolffd@0 7
wolffd@0 8 if 0
wolffd@0 9 T = 20;
wolffd@0 10 ctrl_signal = [repmat([1 0]', 1, T/4) repmat([0 1]', 1, T/4) ...
wolffd@0 11 repmat([-1 0]', 1, T/4) repmat([0 -1]', 1, T/4)];
wolffd@0 12 else
wolffd@0 13 T = 60;
wolffd@0 14 ctrl_signal = repmat([1 0]', 1, T);
wolffd@0 15 end
wolffd@0 16
wolffd@0 17 nlandmarks = 6;
wolffd@0 18 if 0
wolffd@0 19 true_landmark_pos = [1 1;
wolffd@0 20 4 1;
wolffd@0 21 4 4;
wolffd@0 22 1 4]';
wolffd@0 23 else
wolffd@0 24 true_landmark_pos = 10*rand(2,nlandmarks);
wolffd@0 25 end
wolffd@0 26 if 0
wolffd@0 27 figure(1); clf
wolffd@0 28 hold on
wolffd@0 29 for i=1:nlandmarks
wolffd@0 30 %text(true_landmark_pos(1,i), true_landmark_pos(2,i), sprintf('L%d',i));
wolffd@0 31 plot(true_landmark_pos(1,i), true_landmark_pos(2,i), '*')
wolffd@0 32 end
wolffd@0 33 hold off
wolffd@0 34 end
wolffd@0 35
wolffd@0 36 init_robot_pos = [0 0]';
wolffd@0 37
wolffd@0 38 true_robot_pos = zeros(2, T);
wolffd@0 39 true_data_assoc = zeros(1, T);
wolffd@0 40 true_rel_dist = zeros(2, T);
wolffd@0 41 for t=1:T
wolffd@0 42 if t>1
wolffd@0 43 true_robot_pos(:,t) = true_robot_pos(:,t-1) + ctrl_signal(:,t);
wolffd@0 44 else
wolffd@0 45 true_robot_pos(:,t) = init_robot_pos + ctrl_signal(:,t);
wolffd@0 46 end
wolffd@0 47 nn = argmin(dist2(true_robot_pos(:,t)', true_landmark_pos'));
wolffd@0 48 %true_data_assoc(t) = nn;
wolffd@0 49 %true_data_assoc = wrap(t, nlandmarks); % observe 1, 2, 3, 4, 1, 2, ...
wolffd@0 50 true_data_assoc = sample_discrete(normalise(ones(1,nlandmarks)),1,T);
wolffd@0 51 true_rel_dist(:,t) = true_landmark_pos(:, nn) - true_robot_pos(:,t);
wolffd@0 52 end
wolffd@0 53
wolffd@0 54 R = 1e-3*eye(2); % noise added to observation
wolffd@0 55 Q = 1e-3*eye(2); % noise added to robot motion
wolffd@0 56
wolffd@0 57 % Create data set
wolffd@0 58 obs_noise_seq = sample_gaussian([0 0]', R, T)';
wolffd@0 59 obs_rel_pos = true_rel_dist + obs_noise_seq;
wolffd@0 60 %obs_rel_pos = true_rel_dist;
wolffd@0 61
wolffd@0 62
wolffd@0 63 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
wolffd@0 64 % Create params for inference
wolffd@0 65
wolffd@0 66 % X(t) = A X(t-1) + B U(t) + noise(Q)
wolffd@0 67
wolffd@0 68 % [L1] = [1 ] * [L1] + [0] * Ut + [0 ]
wolffd@0 69 % [L2] [ 1 ] [L2] [0] [ 0 ]
wolffd@0 70 % [R ]t [ 1] [R ]t-1 [1] [ Q]
wolffd@0 71
wolffd@0 72 % Y(t)|S(t)=s = C(s) X(t) + noise(R)
wolffd@0 73 % Yt|St=1 = [1 0 -1] * [L1] + R
wolffd@0 74 % [L2]
wolffd@0 75 % [R ]
wolffd@0 76
wolffd@0 77 % Create indices into block structure
wolffd@0 78 bs = 2*ones(1, nlandmarks+1); % sizes of blocks in state space
wolffd@0 79 robot_block = block(nlandmarks+1, bs);
wolffd@0 80 for i=1:nlandmarks
wolffd@0 81 landmark_block(:,i) = block(i, bs)';
wolffd@0 82 end
wolffd@0 83 Xsz = 2*(nlandmarks+1); % 2 values for each landmark plus robot
wolffd@0 84 Ysz = 2; % observe relative location
wolffd@0 85 Usz = 2; % input is (dx, dy)
wolffd@0 86
wolffd@0 87
wolffd@0 88 % create block-diagonal trans matrix for each switch
wolffd@0 89 A = zeros(Xsz, Xsz);
wolffd@0 90 for i=1:nlandmarks
wolffd@0 91 bi = landmark_block(:,i);
wolffd@0 92 A(bi, bi) = eye(2);
wolffd@0 93 end
wolffd@0 94 bi = robot_block;
wolffd@0 95 A(bi, bi) = eye(2);
wolffd@0 96 A = repmat(A, [1 1 nlandmarks]); % same for all switch values
wolffd@0 97
wolffd@0 98 % create block-diagonal system cov
wolffd@0 99
wolffd@0 100
wolffd@0 101 Qbig = zeros(Xsz, Xsz);
wolffd@0 102 bi = robot_block;
wolffd@0 103 Qbig(bi,bi) = Q; % only add noise to robot motion
wolffd@0 104 Qbig = repmat(Qbig, [1 1 nlandmarks]);
wolffd@0 105
wolffd@0 106 % create input matrix
wolffd@0 107 B = zeros(Xsz, Usz);
wolffd@0 108 B(robot_block,:) = eye(2); % only add input to robot position
wolffd@0 109 B = repmat(B, [1 1 nlandmarks]);
wolffd@0 110
wolffd@0 111 % create observation matrix for each value of the switch node
wolffd@0 112 % C(:,:,i) = (0 ... I ... -I) where the I is in the i'th posn.
wolffd@0 113 % This computes L(i) - R
wolffd@0 114 C = zeros(Ysz, Xsz, nlandmarks);
wolffd@0 115 for i=1:nlandmarks
wolffd@0 116 C(:, landmark_block(:,i), i) = eye(2);
wolffd@0 117 C(:, robot_block, i) = -eye(2);
wolffd@0 118 end
wolffd@0 119
wolffd@0 120 % create observation cov for each value of the switch node
wolffd@0 121 Rbig = repmat(R, [1 1 nlandmarks]);
wolffd@0 122
wolffd@0 123 % initial conditions
wolffd@0 124 init_x = zeros(Xsz, 1);
wolffd@0 125 init_v = zeros(Xsz, Xsz);
wolffd@0 126 bi = robot_block;
wolffd@0 127 init_x(bi) = init_robot_pos;
wolffd@0 128 %init_V(bi, bi) = 1e-5*eye(2); % very sure of robot posn
wolffd@0 129 init_V(bi, bi) = Q; % simualate uncertainty due to 1 motion step
wolffd@0 130 for i=1:nlandmarks
wolffd@0 131 bi = landmark_block(:,i);
wolffd@0 132 init_V(bi,bi)= 1e5*eye(2); % very uncertain of landmark psosns
wolffd@0 133 %init_x(bi) = true_landmark_pos(:,i);
wolffd@0 134 %init_V(bi,bi)= 1e-5*eye(2); % very sure of landmark psosns
wolffd@0 135 end
wolffd@0 136
wolffd@0 137 %k = nlandmarks-1; % exact
wolffd@0 138 k = 3;
wolffd@0 139 ndx = {};
wolffd@0 140 for t=1:T
wolffd@0 141 landmarks = unique(true_data_assoc(t:-1:max(t-k,1)));
wolffd@0 142 tmp = [landmark_block(:, landmarks) robot_block'];
wolffd@0 143 ndx{t} = tmp(:);
wolffd@0 144 end
wolffd@0 145
wolffd@0 146 [xa, Va] = kalman_filter(obs_rel_pos, A, C, Qbig, Rbig, init_x, init_V, ...
wolffd@0 147 'model', true_data_assoc, 'u', ctrl_signal, 'B', B, ...
wolffd@0 148 'ndx', ndx);
wolffd@0 149
wolffd@0 150 [xe, Ve] = kalman_filter(obs_rel_pos, A, C, Qbig, Rbig, init_x, init_V, ...
wolffd@0 151 'model', true_data_assoc, 'u', ctrl_signal, 'B', B);
wolffd@0 152
wolffd@0 153
wolffd@0 154 if 0
wolffd@0 155 est_robot_pos = x(robot_block, :);
wolffd@0 156 est_robot_pos_cov = V(robot_block, robot_block, :);
wolffd@0 157
wolffd@0 158 for i=1:nlandmarks
wolffd@0 159 bi = landmark_block(:,i);
wolffd@0 160 est_landmark_pos(:,i) = x(bi, T);
wolffd@0 161 est_landmark_pos_cov(:,:,i) = V(bi, bi, T);
wolffd@0 162 end
wolffd@0 163 end
wolffd@0 164
wolffd@0 165
wolffd@0 166
wolffd@0 167 nrows = 10;
wolffd@0 168 stepsize = T/(2*nrows);
wolffd@0 169 ts = 1:stepsize:T;
wolffd@0 170
wolffd@0 171 if 1 % plot
wolffd@0 172
wolffd@0 173 clim = [0 max(max(Va(:,:,end)))];
wolffd@0 174
wolffd@0 175 figure(2)
wolffd@0 176 if 0
wolffd@0 177 imagesc(Ve(1:2:end,1:2:end, T))
wolffd@0 178 clim = get(gca,'clim');
wolffd@0 179 else
wolffd@0 180 i = 1;
wolffd@0 181 for t=ts(:)'
wolffd@0 182 subplot(nrows,2,i)
wolffd@0 183 i = i + 1;
wolffd@0 184 imagesc(Ve(1:2:end,1:2:end, t))
wolffd@0 185 set(gca, 'clim', clim)
wolffd@0 186 colorbar
wolffd@0 187 end
wolffd@0 188 end
wolffd@0 189 suptitle('exact')
wolffd@0 190
wolffd@0 191
wolffd@0 192 figure(3)
wolffd@0 193 if 0
wolffd@0 194 imagesc(Va(1:2:end,1:2:end, T))
wolffd@0 195 set(gca,'clim', clim)
wolffd@0 196 else
wolffd@0 197 i = 1;
wolffd@0 198 for t=ts(:)'
wolffd@0 199 subplot(nrows,2,i)
wolffd@0 200 i = i+1;
wolffd@0 201 imagesc(Va(1:2:end,1:2:end, t))
wolffd@0 202 set(gca, 'clim', clim)
wolffd@0 203 colorbar
wolffd@0 204 end
wolffd@0 205 end
wolffd@0 206 suptitle('approx')
wolffd@0 207
wolffd@0 208
wolffd@0 209 figure(4)
wolffd@0 210 i = 1;
wolffd@0 211 for t=ts(:)'
wolffd@0 212 subplot(nrows,2,i)
wolffd@0 213 i = i+1;
wolffd@0 214 Vd = Va(1:2:end,1:2:end, t) - Ve(1:2:end,1:2:end,t);
wolffd@0 215 imagesc(Vd)
wolffd@0 216 set(gca, 'clim', clim)
wolffd@0 217 colorbar
wolffd@0 218 end
wolffd@0 219 suptitle('diff')
wolffd@0 220
wolffd@0 221 end % all plot
wolffd@0 222
wolffd@0 223
wolffd@0 224 for t=1:T
wolffd@0 225 i = 1:2*nlandmarks;
wolffd@0 226 denom = Ve(i,i,t) + (Ve(i,i,t)==0);
wolffd@0 227 Vd =(Va(i,i,t)-Ve(i,i,t)) ./ denom;
wolffd@0 228 Verr(t) = max(Vd(:));
wolffd@0 229 end
wolffd@0 230 figure(6); plot(Verr)
wolffd@0 231 title('max relative Verr')
wolffd@0 232
wolffd@0 233 for t=1:T
wolffd@0 234 %err(t)=rms(xa(:,t), xe(:,t));
wolffd@0 235 err(t)=rms(xa(1:end-2,t), xe(1:end-2,t)); % exclude robot
wolffd@0 236 end
wolffd@0 237 figure(5);plot(err)
wolffd@0 238 title('rms mean pos')