Research And Application Of 3D Reconstruction And Measurement Techniques For Astronauts On Orbit

Astronauts on-orbit,due to weight loss and other reasons,their body morphology and movement patterns will change greatly.In order to monitor the astronaut's morphology,movement changes in real-time,design experimental equipment which meet the in-orbit mode of operation,requiring accurate human body Topography and attitude measurement methods to provide detailed data support.With the orbital astronaut anthropometry as the main application background,this article focuses on three-dimensional data acquisition of dynamic human body through the three-dimensional reconstruction technology to restore the three-dimensional topography,and then measure the orbit human body anthropometry parameters.The human body three-dimensional point cloud.Finally,based on the above techniques,the integrated application of these techniques in the industrial practice of three-dimensional shape error detection of moving targets further verifies the feasibility of the technology.This paper mainly includes the following aspects:1.The basic principle of the current mature depth camera is expounded,including binocular stereo camera,structured light camera and TOF camera.The advantages and disadvantages of different strategies are compared.Then,based on the demand for on-orbit astronaut real-time 3D reconstruction,a three-dimensional data acquisition scheme for on-orbit human body is designed?2.The basic method of 3D point cloud registration is introduced,and then the formula derivation of point cloud rigid transformation in point cloud registration is discussed.Also,in this paper,the related concepts of quaternion method and its advantages in implementing point cloud rotation transformation are discussed.The principle and process of the most commonly used ICP algorithm in automatic registration algorithm are described.Finally,aiming at the human point cloud stitching problem,a method combining ICP algorithm with manual registration is proposed to solve the point cloud rigid transformation,realizing the dynamic human body stitching and achieving better results.3.Aiming at high-precision reconstruction of the three-dimensional point cloud of human body,a method for measuring the circumference of a human body based on a three-dimensional point cloud under standard posture is introduced.Firstly,the point cloud rigid transformation is used to correct the orientation of the three-dimensional point cloud with uncertain orientation to the standard position of the reference coordinate system.Then,the feature points and the feature planes of the human body are extracted.The method of calculating the circumference of convex hull based on the Graham scanning method is used,and finally through experimental verification,compared the results of the method of measurement of human body circumference measurements with the manual measurement results,the error is within 3%.4.The real-time three-dimensional reconstruction technology of multiple depth cameras is applied to the actual industrial production,and the key points of the three-dimensional point cloud transformation and point cloud registration are used to analyze and process the reconstructed 3D point cloud.Aiming at the problem of rapid detection of box shape error on conveyor belt,a registration algorithm of shape missing cloud with its standard model is proposed,which can detect the shape error of moving target.