Vision Based Autonomous Tracking and Landing on an Arbitrary Object of Quadrotor

This paper addresses the problem of tracking and landing on an arbitrary object of a quadrotor. It is assumed that the vertical and lateral velocity controllers of a quadrotor can be designed independently. We have developed an image based visual servoing method that uses only a downward looking camera for tracking and landing from a quadrotor. Our visual detection algorithm allows the user to specify an arbitrary object to detect its movements in the image plane. In the horizontal plane, we use the lateral velocity controller to keep tracking with the object in the center of the camera image. In the vertical profile, we adopted a log polynomial velocity to guarantee zero closing velocity and acceleration at touchdown. During the tracking phase, the quadrotor tracks the object continuously while maintaining a fixed altitude from the object and keeps it in the center. Once the quadrotor satisfies the landing condition, it moves on to the landing phase at the planned vertical velocity until touchdown. Here, we use the ultrasound sensor running kalman filter to detect the landing condition. Our experiments show that the system is able to track an arbitrary object and land on it successfully.