Research On Obstacle Information Detection Method Of UAV Based On Visual Structured Light

With the development of technology,unmanned mobile platforms are widely used in various fields of different industries.Environmental awareness and obstacle avoidance techniques are essential for any unmanned mobile platform.Aiming at the obstacle information detection technology of UAV,this paper proposes a spatial obstacle information detection method based on multi-line structured light measurement and octree map expression and constructs a system based on 25-line visual structure light and peripheral vision pointing device to detect obstacle information.The main work is as follows:(1)An obstacle information detection system based on monocular multi-line structured light vision sensor and peripheral vision pointing device was built.The multiangle detection of environmental information by the structured light sensor is realized by controlling the peripheral pointing device,thereby improving the detection range.(2)A calibration method suitable for 25-line structured light vision sensors is proposed.Most of the conventional line-structured calibration methods extract the feature points and transform the coordinates of points to obtain the plane equation.However,a large number of points leads to complicated operation which is not suitable for the application scenarios of multi-line structured light.This calibration method extends the image plane dimension and converts the straight line in the two-dimensional plane into a Plücker line.The calculation is performed in the form of a Plücker line which is suitable for linearity in the calibration process.Based on the properties of the line and plane in the Plücker space,the Plücker matrix of multiple structural light lines can be combined to construct a linear matrix equation and fit the structured light plane.(3)The detection of obstacle information in the environment is realized by using structured light information in the image.In this paper,the information detection of environmental obstacles is divided into two situations: direction detection and depth detection.When the integrity of the structured light information in the image is low,whether the presence of the light stripe in the image determines the direction of the obstacle area relative to the camera,which realizes the initial direction detection of the object information;when the structured light information in the image is relatively complete,the structure of the obstacle in the image is restored according to the principle of multi-line structured light three-dimensional measurement,and the depth information of the obstacle information is realized.(4)The spatial obstacle information obtained by environmental detection is expressed based on the octree map.Because the point cloud obtained according to the principle of multi-line structured light three-dimensional measurement is bulky and complex,it can not directly and efficiently express the spatial structure of obstacles in the environment.This paper uses point cloud filtering and octree map to realize the expression and position of obstacle information in the environment.