This research paper address a novel auxiliary power drive design problem with planetary gear system. The proposed configuration can produce dynamic obstacle avoidance and robot safe evacuation during power failure. The proposed system uses two stage planetary gear systems. First stage acts as a speed reduction phase connected to constant power source such as engine. Since dynamic controls and system output are applied to the second stage, system dependency at first stage is reduced. In this proposed configuration, the second stage can be used to alter the output of first stage by increasing or decreasing speed. Further in case of first stage power failure for any reason, the second stage alone can produce the necessary output to evacuate the robot safely. This article covers the basic mechanical design.