1. A cloud server of a data center, the cloud server in electronic communication with one or more robots, comprising: a storage system; at least one processor; and one or more programs stored in the storage system and being executable by the at least one processor, the one or more programs comprising: a receiving module operable to receive location information of each of the one or more robots from a GPS device of each of one or more robots, and to receive location information of a task location from a client in electronic communication with the cloud server, in response to a determination that the client is permitted to access the cloud server; a search module operable to locate a robot that is closest to the task location according to the location information; and a sending module operable to send a command to the located robot to move to the task location, wherein the command defines a task of the located robot to perform.