Figure10

Figure 10. The comparison of COM trajectories tracking performance with different control strategies. (1) Reference: the reference COM trajectories; (2) Baseline: the human-exoskeleton walks without any assistance of the robotic walker; (3) CMP: the HEW system walks with only the active wheel movements; (4) ESC: the HEW system walks with only the supporting force under the ESC strategy; (5) CEEC: the HEW system walks with the proposed coordinated energy-efficient control approach. CMP: Coordinated Motion Planning; ESC: Extremum Seeking Control; CEEC: Coordinated Energy-Efficient Control; COM: Center of Mass; HEW: human-exoskeleton-walker.