The problem of searching for hidden or lost objects (called targets) by autonomous smart robots in an unknown environment arises in many applications, e.g., searching for and rescuing lost people during incidents in high-rise buildings, searching for fire sources and hazardous materials, searching for safe paths through the rubble during an emergency evacuation etc. Until the target is found, it may cause loss or damage whose extent depends on the location of the target and the search duration. The problem is to efficiently search for and detect the target as soon as possible with the help of a smart mobile robot. The autonomous mobile robot has no operator on board, as it is guided and controlled by on-board sensors and computer programs. In this paper we construct a mathematical model for the search process in an uncertain environment and provide a new fast algorithm for scheduling the activities of the autonomous robot used during an emergency evacuation.