Extended Data Fig. 3: Performance evaluation of the controller of the toolbox MAV.
From: Proximal cooperative aerial manipulation with vertically stacked drones
a. Experimental setup. The toolbox MAV remains stationary while the manipulator MAV gradually approaches from above until the bottom of the robotic arm is 6 cm above the toolbox. This creates three phases of influence on the toolbox MAV: approach, above, and leave. Here, “above” refers to the phase when at least one of the manipulator MAV’s rotors enters the vertical projection area determined by the rotors of the toolbox MAV. b. Ablation study of force compensation. The proposed controller is compared to two baseline controllers, a PX4 open-source flight controller (baseline 1) and the proposed controller without force compensation (baseline 2). As can be seen, the proposed controller outperforms the baselines in terms of both control accuracy and settling time. The settling time is defined as the time at which the toolbox MAV’s height first enters the ± 1 cm error band. The statistical results were based on 5, 8, and 13 trials of experiments using baseline 1, baseline 2, and the proposed controller, respectively. c. Ablation study of torque compensation. As can be seen, torque compensation can improve control accuracy especially when the downwash of the manipulator MAV starts or ends impacting the toolbox MAV. For instance, the maximum error in the y-direction can be reduced from 11.9 cm to 4.8 cm with torque compensation.
