This paper describes the development of a system for dexterous telemanipu-lation and presents the results of tests involving simple manipulation tasks. The user wears an instrumen-ted glove augmented with an arm-grounded haptic feedback apparatus. A linkage attached to the user’s wrist measures gross motions of the arm. The movements of the user are transferred to a two fingered dexterous robot hand mounted on the end of a 4-DOF industrial robot arm. Forces measured at the robot fingers can be transmitted back to the user via the haptic feedback apparatus. The results obtained in blockstacking and object-rolling experiments indicate that the addition of force feedback to the user did not improve the speed of task execution. In fact, in some cases the presence of incomplete force information is detrimen-tal to performance speed compared to no force information. There are indications that the presence of force feedback did aid in task learning.

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This report presents human engineering design guidelines for the development of exoskeletons, which can help the Army do its job faster, safer, with fewer people, and at lower cost by augmenting and enhancing the capabilities of individual soldiers. Descriptions of exoskeletons, which have been developed or attempted, are included to provide background information about previous work in this are& Because many of the tasks that soldiers perform require walking and carrying a load of some kind, the guidelines presented in this report are intended for exoskeletons that are capable of bipedal motion, able to augment the user’s strength, and able to enhance the user’s endurance. Aspects of anatomy, biomechanics, human performance, and physiology relevant to the design of an exoskeleton are presented. These fundamental human characteristics must be considered in the design of a machine that must work so closely with its user. In addition to the human engineering design guidelines, potential problems associated with exoskeletons are discussed. Finally, areas of the unique interface between the user and the exoskeleton that need further research are listed.

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A human’s ability to perform physical tasks is limited by physical strength, not by intelligence. We coined the word «extenders» as a class of robot manipulators worn by humans to augment human mechanical strength, while the wearer’s intellect remains the central control system for manipulating the extender. Our research objective is to determine the ground rules for the control of robotic systems worn by humans through the design, construction, and control of several prototype experimental direct-drive/non-direct-drive multi-degree-of-freedom hydraulic/electric extenders. The design of extenders is different from the design of conventional robots because the extender interfaces with the human on a physical level. The work discussed in this article involves the dynamics and control of a prototype hydraulic six-degree-of-freedom extender. This extender’s architecture is a direct drive system with all revalue joints. Its linkage consists of two identical subsystems, the arm and the hand, each having three degrees of freedom. Two sets of force sensors measure the forces imposed on the extender by the human and by the environment. The extender’s compliances in response to such contact forces were designed by selecting appropriate force compensators. The stability of the system of human, extender, and object being manipulated was analyzed. A mathematical expression for the extender performance was determined to quantify the force augmentation. Experimental studies on the control and performance of the experimental extender were conducted to verify the theoretical predictions.

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This report describes the MBAssociates Exoskeleton/Merlin Robot Interface used in th Human Sensory Feedback Lab Testbed for studies of human performance in coarse positioning tasks. The dual-armed, seven-degree-of-freedom (DOF) exoskeleton, worn by an operator, serves as a master device to control the end-effector position/orientation of a six-DOF Merlin slave robot. Kinematic position transformation matrices are detailed for both master and slave devices, as is the approach used for operator control of a six-DOF robot using a seven- DOF exoskeleton. The use of a desktop 386-33MHz type personal computer as a central system controller, user interface, and software development platform is described.

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This paper describes a systems approach to improving the performance of a telerobotic testbed. The testbed is the Force-Reflecting Interfaces to Telemanipulators Testing Systems (FITTS), at the Harry G. Armstrong Aerospace Medical Research Laboratory. First, the testbed hardware is described, along with an overview of the system’s communications paths. Next, the previously-determined forward kinematics for the MBA exoskeleton are outlined. Then the optimization of these kinematic equations is given. The paper also details efficient forward and inverse kinematic solutions for the Merlin industrial robots, using the method of wrist partitioning. The utility of these solutions in toto is that the interfacing of the two systems, given sufficient communications bandwidth between the MBA exoskeleton and the control computer, can now achieve the 4 ms compute time attainable by the Merlin hardware. This optimization puts the FITTS hardware at a milestone stage of completion, as the system is now capable of operating at its peak as a unilateral telerobotic testbed. Finally, future steps to extend FITTS for force reflection research are specified. Teleoperation, Robotics, Remote Control, Human Factors, Force Reflection.

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