US Patent 7491112 Mobile robotic device capable of collision detection

A mobile robotic device capable of collision detection includes a base frame, two connecting rods pivotably mounted to the base frame for contact with the switches, two gearboxes slidably mounted at bilateral sides of the base frame respectively, two driving mechanisms connected with the gearboxes, two switches mounted to the base frame for generating signals, two springy members connected with the base frame and the connecting rods for keeping the gearboxes rebounding backward, two wheels mounted to the two gearboxes respectively, and a control system mounted to the base frame for receiving the signals from the switches and driving the driving mechanisms and thus driving clockwise or counterclockwise rotation of the wheels.