US Patent 8428778 Navigational control system for a robotic device

An autonomous cleaning apparatus includes a chassis, a drive system disposed on the chassis and operable to enable movement of the cleaning apparatus, and a controller in communication with the drive system. The controller includes a processor operable to control the drive system to steer movement of the cleaning apparatus. The autonomous cleaning apparatus includes a cleaning head system disposed on the chassis and a sensor system in communication with the controller. The sensor system includes a debris sensor for generating a debris signal, a bump sensor for generating a bump signal, and an obstacle following sensor disposed on a side of the autonomous cleaning apparatus for generating an obstacle signal. The processor executes a prioritized arbitration scheme to identify and implement one or more dominant behavioral modes based upon at least one signal received from the sensor system.