POSITION AND ORIENTATION TRACKING SYSTEM

摘要

The Position and Orientation Tracking System (POTS) is a triangulating laser-based pose tracking measurement system. POTS provides real-time tracking of multiple target vehicles from the chase vehicle (25 - 100 samples/second) with a wide field of view (45 degrees vertical and horizontal). In addition, POTS is composed mainly of off-the-shelf commercially available equipment. As the measurement does not use a camera, no image processing and analysis routines will be needed to determine the position of the target vehicle, all position solutions are derived in closed form automatically (no iterations). POTS uses triangulation to determine the position of the target position sensors that are acquired every sample. POTS measurements are absolute; allowing the target to be momentarily occluded without the need to incrementally reference a fixed coordinate frame (as is the case with interferometry). POTS works over a 4 π steradians work space and can be extended from the current range of 13.7 m (45 ft) to thousands of feet with new higher power semiconductor or solid state lasers. The POTS system was designed to track the Department of Energy's (DOE) Light Duty Utility Arm as well as the Houdini Remotely Operated Vehicle (ROV) during nuclear waste tank cleanup operations. The POTS system could be directly applicable to task that require precision tracking of the pose parameters of the space shuttle manipulator as well as all of its joints. In addition, by extending the range of the lasers, POTS could provide very accurate pose information on a target vehicle during a docking operation. The POTS system is the result of a 4-year effort under the Robotics Development and Technology Program to develop a tracking system for long reach manipulators and ROVs. The optical metrology expertise developed under the program is an extension of expertise gained while performing research and development in the area of long-range surface mapping. Topographical maps were needed for robotic tasks in underground storage tank characterization and remediation as well as during robotic decontamination and decommissioning work at DOE complexes throughout the nation. These systems were designed to operate in 200-500 rads/hr gamma fields with total accumulated doses in the le6 rads range. Oak Ridge National Laboratory (ORNL) designed and developed topographical mapping systems that have been used to map underground storage tanks at Fernald, Ohio and Oak Ridge, TN.3 The ranging systems in these designs were based on structured-light triangulation range determination technology. In addition, ORNL has participated in the design of a Frequency Modulation Laser Range Finder for inspection of plasma facing components in an experimental fusion reactor. The optical metrology system requirements included surviving in a le8 rad/hr neutron and gamma field.