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Title: Control of flexible robots with prismatic joints and hydraulic drives

Conference ·
OSTI ID:459424
 [1]; ;  [2]
  1. Oak Ridge Inst. for Science and Education, TN (United States)
  2. Oak Ridge National Lab., TN (United States). Robotics and Process Systems Div.

The design and control of long-reach, flexible manipulators has been an active research topic for over 20 years. Most of the research to date has focused on single link, fixed length, single plane of vibration test beds. In addition, actuation has been predominantly based upon electromagnetic motors. Ironically, these elements are rarely found in the existing industrial long-reach systems. One example is the Modified Light Duty Utility Arm (MLDUA) designed and built by Spar Aerospace for Oak Ridge National Laboratory (ORNL). This arm operates in larger, underground waste storage tanks located at ORNL. The size and nature of the tanks require that the robot have a reach of approximately 15 ft and a payload capacity of 250 lb. In order to achieve these criteria, each joint is hydraulically actuated. Furthermore, the robot has a prismatic degree-of-freedom to ease deployment. When fully extended, the robot`s first natural frequency is 1.76 Hz. Many of the projected tasks, coupled with the robot`s flexibility, present an interesting problem. How will many of the existing flexure control algorithms perform on a hydraulic, long-reach manipulator with prismatic links? To minimize cost and risk of testing these algorithms on the MLDUA, the authors have designed a new test bed that contains many of the same elements. This manuscript described a new hydraulically actuated, long-reach manipulator with a flexible prismatic link at ORNL. Focus is directed toward both modeling and control of hydraulic actuators as well as flexible links that have variable natural frequencies.

Research Organization:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
USDOE Office of Environmental Restoration and Waste Management, Washington, DC (United States)
DOE Contract Number:
AC05-96OR22464
OSTI ID:
459424
Report Number(s):
CONF-970464-6; ON: DE97002980; TRN: 97:007650
Resource Relation:
Conference: 7. American Nuclear Society topical meeting on robotics and remote systems, Augusta, GA (United States), 27 Apr - 1 May 1997; Other Information: PBD: [1997]
Country of Publication:
United States
Language:
English