This paper describes the design and implementation of a real-time control system with multiple modes of operation for a mobile redundant dexterous manipulator. The manipulator under study is a seven degree-of-freedom (DOF) arm from Robotics Research Corporation, mounted on a motorized platform. The manipulator-plus-platform system has 2-DOF for the task of hand placement and orientation. The redundancy resolution is achieved by accomplishing two additional tasks using the configuration control technique. The system allows a choice of arm angle control or collision avoidance for the seventh task and platform placement or elbow angle control for the eighth task. In addition, joint limit avoidance task is automatically invoked when any of the joints approach their limits. The system is robust to singularities, and also provides the capability of assigning weighting factors to end-effector and redundancy resolution tasks. The motion control algorithms are executed at 1.1 ms on two MC68040 processors in a VME-bus environment running the VxWorks real-time operating system. The paper describes the hardware and software components of the VME environment. Experimental results are also presented.>

Graphics simulation and real-time implementation of configuration control schemes for a redundant seven-degree-of-freedom (7-DOF) Robotics Research arm are described. The arm kinematics and motion control schemes are described briefly. This is followed by a description of a graphics simulation environment for 7-DOF arm control on the Silicon Graphics IRIS Workstation. Computer simulation results are presented to demonstrate elbow control, collision avoidance, and optimal joint movement as redundancy resolution goals. The laboratory setup for experimental validation of motion control of the 7-DOF Robotics Research arm is then described. The configuration control approach is implemented on a Motorola-68020/VME-bus-based real-time controller, with elbow positioning for redundancy resolution. Experimental results demonstrate the efficacy of configuration control for real-time control.>

Applications of the configuration control approach to motion control of redundant 7 DOF (degree-of-freedom) arms are described. This approach provides a unified framework for resolution of redundancy to accomplish a broad range of objectives. The configuration control approach is briefly described, and a graphics simulation environment for control of 7 DOF Robotics Research arms is discussed. Computer simulation results are presented to demonstrate elbow control, obstacle avoidance, and optimal joint motion as redundancy resolution goals for the 7 DOF arm.>

A description is given of a complete robot control facility built at the CIT Jet Propulsion Laboratory as part of a NASA telerobotic program to develop a state-of-the-art robot control environment for laboratory-based spacelike experiments. This system has the following features: separation of the computing facilities into local and remote sites, autonomous motion generation in joint or Cartesian coordinates, dual-arm force reflecting teleoperation with voice interaction between the operator and the robots, shared control between the autonomously generated motions and operator controlled teleoperation, and dual-arm coordinated trajectory generation. The system has been used to carry out realistic experiments such as the exchange of an orbital replacement unit, bolt turning, and door opening, using a mixture of autonomous actions and teleoperation, with either a single arm or two cooperating arms.>