In the absence of GPS signal, visual servoing can make use of visual information to control quadrotor autonomous flight, so it has been widely used in the field of autonomous flight control in recent years. This article reviews the achievements of small quadrotor autonomous flight control based on visual servoing. Depending on the difference of image information, visual servoing can be divided into position-based visual servoing and image-based visual servoing. Compared with image-based visual servoing, pose estimation of positionbased visual servoing is stabile, and position-based visual servoing can define the robot movement in the rectangular coordinate space, and the controller design of position-based visual servoing is simple. But the control precision of position-based visual servoing is affected by camera and robot calibration precision, and calculation is large. It is pointed out that for further application of small quadrotor UAV autonomous flight control, the real-time accuracy and robustness of visual servoing need to be improved, and the intelligence of small quadrotor UAV requires upgrading. Also the research should be strengthened in aspects such as indoor/outdoor mode conversion and indoor coordinate control.

visual servoing  /  autonomous flight control  /  small quadrotor UAV