RCS-Based RoboCrane Integration

The Intelligent Systems Division (ISD) of the National Institute of Standards and Technology (NIST) has been researching new concepts in robotic cranes for several years. These concepts use the basic idea of the Stewart platform parallel link manipulator. The unique feature of the NIST approach is to use cables as the parallel links and to use winches as the actuators. Based on this idea, a revolutionary new type of robot crane has been developed and aptly named the RoboCrane. The RoboCrane provides six degree-of-freedom load stabilization and maneuverability. This is accomplished through the following control modes: master/slave; joystick input; operator panel input; preprogrammed trajectory following (teach programing, graphical off-line programing, or part programing); and sensor based motion compensation. The current control system includes both the controller and user interface within the same control level, which makes controller enhancements and modifications difficult and error prone. A Real-time Control System (RCS) [1] is currently being developed to include the above control modes, while providing an open systems architecture. This supports hierarchical control modules, along with a separate user interface. A remote telepresence system is also being implemented to provide foveal/peripheral stereo images and other necessary data to enable a remote operator to perform a variety of tasks with the RoboCrane. The objective of this paper is to describe past and future efforts toward integration of an RCS open system architecture controller into the RoboCrane Integration Testbed (RIT). An RCS-based Robo-Crane controller will allow for continuing research into parallel-link manipulator controllers and application oriented controller capabilities. Specifically, this paper introduces the RoboCrane concept, describes the current control system, the envisioned RCSbased RoboCrane control system, and the intended integration procedure.