Cost effective control of a large manipulator for industrial construction was investigated. This research was based on physical testing of the Dupont/Grove Pipe Manipulator, which featured a 750 kg capacity, 20 m radius, eight axis hydraulic arm with load gripping jaws on a mobile chassis. This machine was built in 1980 for the erection of pipe spools during petrochemical plant construction. It fell into disuse due to poor performance as compared to a conventional crane with rigging crew.; Alternatives to the cumbersome lever-box operator interface were explored. Interfaces for other large scale machines were found to be expensive in terms of development cost and installed controls. These were justifiable in the U.S. only where unmanned operation was demanded, as in munitions recovery. The feasibility of a simple interface, with economics and ruggedness suitable for general industrial construction, was unknown.; A plan for an arm control system with incremental upgrade steps was created. The first step of this plan was physically implemented as the Ergosticks teleoperator. This replica rate controller was used to validate the hypothesis: that the Pipe Manipulator will compete with a conventional crane in pipe spool erection, by use of a simple teleoperator interface for arm control.; This hypothesis was disproved when testing the Ergosticks with open loop driving of Manipulator hydraulic actuators. Erratic Manipulator response overwhelmed potential improvement offered by the intuitive Ergosticks interface. Wrist orientation at pick and place positions remained particularly troublesome. Test data proved the hypothesis with the Ergosticks and automatic Manipulator wrist control. This allowed computer operation of the tedious orientation, and retained the operator for high level task planning and collision free translations about the job site.; Fourteen other areas for Pipe Manipulator improvement are described for near term usefulness of the teleoperated machine, or for speculative study of a CAD database driven machine.
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