Research On Vision Measurement Method Of UAV Attitude Angle Based On Laser Projection

In recent years,the technology of civilian UAVs has developed rapidly,and its application in various industries has become more and more extensive.However,China has not yet formed a standardized system for testing the flight performance of civilian UAVs.UAV attitude angle detection is an important method to evaluate the flight performance of UAVs.However,the testing accuracy of existing domestic testing equipment is limited and the practicability needs to be improved.It is impossible to effectively evaluate the changes in UAV flight attitude angles.At the same time,the weight of civilian UAVs is relatively light,and high requirements are also placed on the weight of the measuring equipment carried.Aiming at the high-precision and lightload characteristics of UAV attitude angle measurement,this paper proposes a UAV attitude angle measurement method based on the combination of laser projection and vision.Research has been carried out on the image processing algorithm of feature points,the unification of the measurement coordinate system and the attitude angle calculation algorithm.At the same time,a high-precision UAV attitude angle measurement system based on laser projection and vision was developed,and experimental verification was completed.The paper mainly did the following work:1.Aiming at the requirements of lightweight,high-precision and high real-time measurement of UAV attitude angle,different attitude angle measurement methods are analyzed,and a laser projection-based vision measurement system for UAV attitude angle is designed.The lightweight laser transmitter is rigidly mounted by the drone,and the laser projection displacement is obtained and calculated by the camera to achieve high-precision measurement of the drone’s attitude angle.2.The posture angle calculation model based on Rodriguez’s rotation formula is established,and the real-time calculation of the three-dimensional space coordinates of laser projection is realized.A contour-based circular cross target recognition and a grayscale centroid-based laser point recognition algorithm were designed.According to the attitude angle measurement process,the measurement error of the attitude angle was analyzed and the preliminary verification of the measurement error was completed.3.Built a UAV attitude angle visual measurement hardware system,designed a three-way laser projection device,based on the idea of layered architecture design,developed UAV attitude angle measurement software based on the Qt platform,and realized the real-time display and view of laser point images,UAV flight attitude angle real-time measurement,preliminary analysis of attitude angle data and other functions.4.A comparative experiment on the coordinate conversion accuracy and measurement accuracy of the UAV attitude angle vision measurement system was carried out.The experimental results showed that in the space of 5m×8m×4m,the coordinate solution error of the system is less than 0.5mm,which is the yaw angle to the attitude angle.The measurement error is less than 0.1°,and the measurement error of the roll angle and pitch angle is less than 0.2°,which meets the requirements of the attitude angle measurement system.