Design And Implementation Of The Visual Measurement Algorithm Based On The Docking Ring Of Space Objects

The visual measurement based on the optical sensor has been widely used in the space mission such as spatial rendezvous and docking and on-orbit servicing.As the core content of the visual measurement technology,the accuracy and stability of the visual measurement algorithms have direct impact on the quality and effectiveness of the navigation information.As a result,it is the prerequisite for accomplishing the rendezvous and docking and on-orbit servicing mission.This article takes the visual navigation in the process of approaching and grabbing in rendezvous and docking mission as the main research background.Based on measurement algorithm design and ground verification,it carried out deep study on the visual measurement algorithms and simulation system of the visual measurement.The main content of the paper are organized as following:General design of the research scheme,Considering the specific needs of the the approaching and grabbing stage of the spatial rendezvous and docking,A general scheme which applied the monocular and binocular system to the navigation was designed.The monocular system and the binocular system was separately applied in the process of approaching and grabbing stage.The general scheme of the system mainly include the analysis of system composition?design of the system process and design of simulation software system.etcThe visual measurement algorithm,two different posing solutions are proposed for different stages of stage docking.For the approach stage of rendezvous and docking,a binocular pose algorithm based on the circular characteristics of the docking ring are proposed.This method worked out the pose solution by first extracting and recognizing the circular characteristics of the docking ring then applying the monocular spatial circle restoration method and synthesizing the pose result of the binocular system.For the capture stage of rendezvous and docking,a monocular camera calculating method based on local features of the docking ring was proposed.This method extracted the local feature of the docking ring from images and then selected a stable point as the navigation point based on the rotary invariance of a circle.and at last worked out the position of the point using monocular cameras and laser rangefinders.The visual measurement simulation technology,this article designed a ground simulation system,lots of works has been carried out,such as the design of system overall scheme?the design of algorithms?hardware selection?softerware integration and system evaluations.This simulation system is stable and can realize the ground simulation of the navigation target in rendezvous and docking process,at the same time,the measurement accuracy can meet the requirements of actual work and it can provide ground verification environment for the design of real visual measurement system.