The application of ultrasonic sensor in the obstacle avoidance of quad-rotor UAV

In order to solve the collision problem of quad-rotor UAV with low flight altitude the method to calculate the distance between the obstacles and UAV by using the ultrasonic sensors is proposed. And an effective method is devised to avoid the obstacles. Firstly, the structure of quad-rotor UAV is introduced. Then the induced velocity standard strip analysis and the working principle of the ultrasonic sensor are described. The distance calculation method when the obstacle appears in the positive direction and the side direction is given. Finally the way to control the quad-rotor UAV motor output and correct the speed of the flight by using distance information is devised. The simulation results verify the method proposed in this paper.