60 * IEEE ROBOTICS & AUTOMATION MAGAZINE * DECEMBER 2022 1.5 2 Ground Truth Start End (a) 0.5 1 0 0.5 1 1.5 2 2.5 3 X (m) 1.5 2 (b) 0.5 1 0 0.5 1 1.5 2 2.5 3 X (m) 1.5 2 (c) 0.5 1 0 0.5 1 1.5 2 2.5 3 X (m) 100 150 200 50 05 10 15 Time (s) 100 150 200 50 05 10 15 Time (s) 20 25 30 20 40 −40 −20 05 10 15 Time (s) 20 25 30 20 25 30 100 150 200 50 05 10 15 Time (s) 20 40 −40 −20 05 10 15 Time (s) 20 25 30 20 25 30 No. 1 No. 2 No. 3 20 40 −40 −20 05 10 15 Time (s) 20 25 30 Figure 8. Experiment 2: Localization of a robot under towing under the " electric sense + IMU " method. From top to bottom: (a) Architecture 1, (b) Architecture 2, (c) Architecture 3. (Left column) The robot's trajectories of ground truth (black dotted lines), emitter 1 (blue circles), and emitter 2 (red circles). (Middle column) The position errors compared to the ground truth. The different lines represent repeated experiments. (Right column) The orientation errors compared to the ground truth. Y (m) Y (m) Y (m) Position Error (cm) Position Error (cm) Position Error (cm) Orientation Error (°) Orientation Error (°) Orientation Error (°)