An omnidirectional mobile robot is able, kinematically, to move in any direction regardless of currentpose. To date, nearly all designs and analyses ofomnidirectional robots have considered the case of motion onflat, smooth terrain. This paper presents a kinematic analysisand control method for an omnidirectional mobile robot drivenby active split offset casters operating on rough, uneventerrain. Robot average isotropy is analyzed as a function ofwheel module geometry on both flat and rough terrain. Asimple kinematic control scheme that considers the effects ofterrain unevenness is presented. The performance of thealgorithm in rough terrain is studied in simulation. It is shownthat with knowledge of terrain conditions, nearomnidirectionalmobility is achievable in rough terrain.