Automatic Landing Of Unmanned Aerial Vehicle Research Articles

Autonomous battery-changing system for UAV’s lifelong flight

Unmanned aerial vehicles (UAVs) lifelong flight is essential to accomplish various tasks, e.g., aerial patrol, aerial rescue, etc. However, traditional UAVs have limited power to sustain their flight and need skilled operators manually control their charging process. Manufacturers and users are eagerly seeking a reliable autonomous battery-changing solution. To address this need, we propose and design an autonomous battery-changing system for UAVs using the theory of inventive problem solving (TRIZ) and user-centered design (UCD) methods. For practical application, we employ UCD to thoroughly analyze user requirements, identify multiple pairs of technical contradictions, and solve these inconsistencies using TRIZ theory. Furthermore, we design an autonomous battery-changing hardware system that meets user requirements and realizes the battery change process after the automatic landing of UAVs. Finally, we conduct experiments to validate our system’s effectiveness. The experimental results show that our battery-changing system can implement the autonomous battery-changing task, and our system has high efficiency and robustness in the real environment.

Control of Autonomous Landing of UAV of Airplane-Type on the Static and Dynamic Sites with Using of "Flexible" Kinematic Trajectories

The final and one of the most important stages of the aircraft-type unmanned aerial vehicles (UAV) flight is landing. In this regard the problem of automating the control by UAV landing in difficult meteorological conditions is becoming increasingly urgent. In some cases for refueling and recharging UAVs it is advisable to use the dynamic mobile landing site (MLS) instead of the traditional stationary landing site (SLS). In the present paper we consider the setting of and solution of the control problem by the terminal landing maneuver of a UAV. It provides its transfer from the current initial state to the target final state along " flexible" kinematic trajectories both on the SLS and on the MLS. To solve the problem of automatic landing of UAV on SLS or MLS the mathematical model of the dynamics of its movement was developed. It’s based on the concept of " flexible" kinematic trajectories with spatial synchronization of controlled movements. The control algorithm by the terminal vertical landing maneuver of UAV on SLS by the method of dynamics inverse problem using the principle of " flexible" kinematic trajectories is developed. And also the control algorithm by the terminal landing maneuver of UAV on MLS by the method of dynamics inverse problems using the principles of " flexible" kinematic trajectories and aiming into the target point was also developed. Computer approbation of the synthesized control algorithms for the landing maneuver of UAV "Aerosonde" under conditions of various wind disturbances was carried out using digital modeling in the Matlab environment.

A camera calibration method for large field optical measurement

A camera calibration method is presented for large field optical measurement, where the camera is close to the ground and the control points can only be located close to the ground, too. In such conditions, the camera's optical center and the control points are approximately coplanar. Only a single image of these control points captured by the camera in measurement state is used in the method. Neither to distribute the control points in space rationally nor to calibrate the camera's intrinsic parameters in laboratory in advance is needed. By the presented method, the camera's principal point position, focal length, radial and transverse tangency lens distortion coefficients, and the camera's position and attitude parameters can be estimated precisely. Then the calibration results can be used for precise large field optical measurement in the conditions that the camera's longitudinal tangency lens distortion can be neglected or the objects’ movement field is close to the ground, which is usually factual in practical applications. The presented camera calibration method has been successfully used in applications, such as automatic landing of UAV (Unmanned Aerial Vehicle) based on optical measurement guidance, to calibrate the cameras precisely.