The robots using docking stations for battery recharging
mentioned above need to stay in fixed positions during the
battery charging process. Therefore the robot cannot work
continuously. Many researchers begin to develop robot
systems with the capabilities of battery swapping and charging.
When the battery voltage is lower than a preset threshold, the
robot can exchange it with a charged one. The authors [18]
design a novel robot docking station for automatic battery
exchanging and charging. The battery can be exchanged
automatically within 45s. K. A. Swieringa et al. [19] design an
autonomous battery swapping system for small-scale
helicopters. The authors [20] design and analyze an automatic
battery replacement system for Unmanned Aerial Vehicles. Y.
Saito et al. [21] develop a battery support system using
support robots to deliver fresh battery to working robots. This
method can decrease the interruption time of the working
robots.