The problem of dismounted operation support with Unmanned Ground Vehicles (UGV) often called robots is widely discussed and many solutions were tested to verify theory and find technological gaps and limitation for such application. In this paper the initial demand and requirements and their evolution is described on an example of US Army. Described changes concerns demanded level of autonomy, fire support possibility, possibility of performing combat engineer tasks, using UGV for reconnaissance, surveillance, and target acquisition, longitudinal and lateral stability, obstacle negotiation and overall terrain mobility and efficiency of make use of the “mule”.