1. A robot apparatus comprising: a driving unit: an input unit configured to receive a voice command from a user; a storage unit configured to store information on a number of times the voice command has been received by the input unit from the user; a determination unit configured to determine whether a plurality of different voice commands are received sequentially a predetermined number of times based on the stored information; and a control unit configured to receive, through the input unit, a shortcut command to shorten the plurality of different voice commands if the determination unit determines that the plurality of different voice commands are received sequentially the predetermined number of times, register the shortcut command to the storage unit; and if the registered shortcut command is received through the input unit, control the driving unit to perform different operations corresponding to the plurality of different voice commands; wherein the shortcut command consists of no more than two words.