Here is a programmable robot that can move in all directions easily. The IG52 Mecanum Wheel Robot is an Arduino platform with a CNC cut 4WD base, 8 inch Mecanum wheels, IG52 gear motors, Sabertooth motor controller, and a few other parts.
You can program this robot and try additional sensors to make it autonomous. The robot weighs about 60lbs. You can order yours here.