Patent ID: 7352153

Claim:
A battery charging method for a mobile robotic system that includes a mobile robot and a charging device, the charging device having one side provided with a light emitter and a set of first charging contacts for supplying a charging signal, the mobile robot having a first side provided with a first light sensor facing in a first direction, a second side provided with a second light sensor facing in a second direction generally transverse to said first direction, a set of second charging contacts disposed on said second side and corresponding to the first charging contacts, and a rechargeable battery unit, said battery charging method comprising the steps of: a) when charging of the rechargeable battery unit is intended, moving the mobile robot until the first light sensor detects light emitted by the light emitter, stopping the mobile robot, and subsequently rotating the mobile robot until the second light sensor detects the light emitted by the light emitter; and b) while the second light sensor detects the light emitted by the light emitter, driving the mobile robot to move toward the charging device until the second charging contacts come into contact with the first charging contacts, thereby permitting charging of the rechargeable battery unit via the charging signal.