US Patent 10149589 Sensing climb of obstacle of a robotic cleaning device

A robotic cleaning device having a main body and a propulsion system to move the robotic cleaning device, an obstacle detecting device, a controller to control the propulsion system to move the robotic cleaning device, and an angle-measuring device to measure tilt angles of the robotic cleaning device. The controller controls the angle-measuring device to measure a first tilt angle of the robotic cleaning device before the obstacle is traversed, and to measure a second tilt angle of the robotic cleaning device while the robotic cleaning device traverses the obstacle. The controller compares the second tilt angle with the first tilt angle, and controls the operation of the robotic cleaning device based on a difference between the second tilt angle and the first tilt angle.