Design Of Spring-clamped UAV Multi-spectral Camera Pan-tilt System

In recent years,due to the rapid development of small UAV technology,more and more remote sensing technology of UAV is applied in the monitoring and acquisition of agricultural information,in UAV remote sensing system,cradle head plays an important role,it can be equipped with different sensors?visible light,multi-spectrum,thermal infrared,etc.?for information collection,at the same time,through the function of self-stabilization,the visual axis of the sensor is guaranteed to be stable,so that the collected data is not distorted.At present,the connection structure between different sensor cradle head and UAV is not universal,resulting in poor interchangeability of various sensor cradle head,and there is the problem of inconvenient disassembly,as for the problems,in this paper,a clamping connection interface and a triaxial multispectral cradle head system matching the interface structure are designed,the system can realize rapid installation and disassembly of cradle head and UAV,at the same time,the triaxial head can stabilize the multispectral viewing axis and ensure the imaging quality of the camera.The main work and conclusions of this paper are as follows:?1?The structure of cradle head of unmanned aerial vehicles is designed.Creo 3d modeling software was used for structural design of clamping connection interface and triaxial cradle head,the overall structure and size of the cradle head are planned by combining the load of the cradle head with the size and performance of the six-rotor UAV to be carried,so that there is no dimensional interference between the parts of cradle head,At the same time,there is no physical interference in the rotation process of pitch axis,horizontal roller axis and directional axis rotation arm of cradle head in the angle range.?2?Simulation of cradle head of unmanned aerial vehicles's structure.ANSYS workbench simulation software is used to simulate the cradle head structure.Firstly,the design of the cradle head is preliminarily analyzed through static simulation and modal analysis,the results show that the cradle head structure with multi-spectral camera meets the requirements of structural strength and stiffness,meanwhile,the low-order natural frequency?88.91hz?of cradle head structure is greater than the maximum self-excitation frequency?70Hz?of UAV,cradle head does not appear resonance phenomenon when carrying UAV in air operations,Then,through multi-body dynamics analysis and transient dynamics analysis,it is verified that in the rotation process of gimbal pitch axis,transverse roller axis and heading axis,the stability of clamping joint interface and the stiffness of the whole structure of cradle head,the results show that the structural stiffness of the cradle head meets the requirements during the rotation of the cradle head rotating arm,at the same time,in the case that cradle head is not equipped with a multi-spectral camera,the maximum displacement of clamping connection interface during the rotation of the three-axis rotary arm is 5.6843e^-14mm,when equipped with a multispectral camera,the maximum displacement of the clamping connection interface is 0mm,the results show that the clamping interface has a stable clamping effect.Finally,through coupling field analysis and simulation of the actual working environment of the cradle head,the structural stiffness of the cradle head is verified to meet the requirements.Meanwhile,the centroid position of the multi-spectral camera is optimized based on the response surface and multi-objective driving optimization method,so as to minimize the overall equivalent stress and shape variables of the cradle head.?3?Design of cradle head of unmanned aerial vehicles's control system.Combine the structure size of the gimbal and the technical parameters of the drone to select the main control board,drive module,attitude acquisition module and DC step-down module of the PTZ,and complete the overall assembly,and finally control the PTZ according to the motor structure and load weight.The board performs motor power and PID parameter adjustment to achieve stable operation of the gimbal.?4?Cradle head of unmanned aerial vehicles's installation test.The whole platform was loaded onto the six-rotor UAV.The stability of the clamp connection interface and the self-stabilization function of the gimbal were verified by airborne tests.The data collected by the multi-spectral camera was graphically spliced,and the splicing quality report verified the gimbal.The stability of the overall structure.