ELSEVIER Robotics and Autonomous Systems 28 (1999) 249-258 Robotics and Autonomous Systems www.elsevier.com/locate/robot Automated model verification of the International Space Station for path planning W.EW. Haak a'*, EC.A. Groen a, E. Holweg b a University of Amsterdam, Kruislaan 403, 1098 SJ Amsterdam, Netherlands b Fokker Space, P.O. Box 32070, 2303 DB Leiden, Netherlands Received 1 December 1998 Abstract The goal of this project is an automated model verification tool for the International Space Station. The 3D model of the ISS is used as a basis for path-planning the European Robotic Arm. The ISS contains several different types of video cameras. The images from these cameras are used to verify the model. Each camera image is compared with an artificially generated image by a graphics engine. An iterative approach optimizes the artificial image generation by calculating the exact camera orientation. The 2D match can be traced back to a position in 3D space. The system was tested with the use of a mock-up of the ISS. Test results show that the model verification system detects object changes as small as 2% of the field of vision. © 1999 Elsevier Science B.V. All rights reserved. Keywords: Autonomous systems; Computer vision; Model verification 1. Introduction Autonomous systems often rely on a 3D model of the real world. Real-world objects are not static but prone to change. Most systems that interact with the real world should be able to detect these dynamic changes and update the model. The 3D model verification system that has been studied in this paper is that of the International Space Station (ISS). On the ISS the European Robotic Arm (ERA) will be operating. The path planning of the ERA will be based on a 3D computer model of the ISS. The aim of this project is to build a model verification system that safeguards against discrepancies between the computer model and the real word. Many systems have a-priori knowledge of the real world and it is the purpose of this project to use this knowledge to build a robust model verification tool that is based on a-priori information. The ISS has a variety of on-board cameras. These will be employed to generate visual data. The verification of the 3D model can of course be accomplished by human analysis of the image data. The shear amount of data and * Corresponding author. E-mail: haak@xs4all.nl 0921-8890/99/$ - see fi'ont matter © 1999 Elsevier Science B.V. All fights reserved. PII: S0921-8890(99)00021-4