A floor cleaning robot includes a housing having an underside, a substantially semi-circular front portion, and a substantially semi-circular rear portion. A displaceable bumper of a substantially semi-circular leading edge is located along a front portion of the housing. A leading wheel is mounted on the underside of the housing located adjacent to a mid-point of the semi-circular leading edge, and a battery pack cover is positioned rearwardly of the leading wheel and covers a battery pack that supplies power to the robot. At least two drive wheels are positioned rearwardly of the leading wheel, and at least one main brush is positioned rearwardly of the at least two drive wheels and is configured to rotate about an axis substantially parallel to the underside. The floor cleaning robot also includes at least one side brush having at least two arms extending outwardly from a central hub located in a recess in the underside of the housing, the at least one side brush being attached to the hub such that rotation of the hub causes the brush to direct debris from a floor surface beyond the semi-circular leading edge of the robot housing for collection by the robot. An ejectable dust bin is provided that has a surface forming at least a portion of a semi-circular trailing edge of the housing.