This paper is concerned with the design of intelligent subsystems that interface actuators and sensors to intelligent supervisors for robot work-cells. Benefits of our approach include removal of low level computation and stringent real-time constraints from the superviser, potential for combining and interpreting information from sensor combinations, and provision of a uniform information interface for disparate devices. Our approach to the design and organisation of these subsystems is based on the concept of virtual devices. We demonstrate the applicability of the concept by describing the design and implementation of an intelligent controller for a sensory gripper.

This paper describes the robotics facilities and associated research program of the Jet Propulsion Laboratory, lead center in telerobotics for the United States National Aeronautics and Space Administration. Emphasis is placed on evolution from teleoperation to remote System automation. Research is described in manipulator modelling and control, real-time planning and monitoring, navigation in outdoor terrain, real-time sensing and perception, human-machine interface, and overall System architectures. Applications to NASA missions emphasize robotic spacecraft for solar System exploration, satellite servicing and retrieval, assembly of structures, and surveillance. Applications to military missions include battlefield navigation, surveillance, logistics, command and control.

This paper presents research work which crosses the divide between “Path Planning” and “Trajectory Generation & Tracking”. These subjects have tended to develop along two parallel lines, in isolation from each other. The work uses the Lagrange formulation for the three major joints of an industrial manipulator. Simple planning rules are developed from this formulation. The rules are used to select new paths for a manipulator rather than to improve preplanned trajectories. The method has been applied to pick and place tasks requiring gross motions of the manipulator and the results are presented. It is shown that using this method, pre-planned manipulator paths can be modified to improve the gross motions associated with the pick and place task.

This paper describes a new approach to the automatic generation of assembly precedence constraints for robotic assembly, using a part contact level graph. Since inference of precedence constraints is a prerequisite to generate assembly sequences of a product, much work has been done in this field. However, most of it has some limitations in that they use a cumbersome user query or time-consuming geometric reasoning. To cope with these problems, this paper utilizes three directional part contact level graphs which, in three orthogonal directions, contain the information on directional connections for each pair of mating parts. By using these graphs, an assembly precedence constraint is inferred in two steps: The first step infers a precedence constraint for each directional connection by applying the path-finding algorithm. Utilizing the precedence constraints thus obtained, the next step infers the precedence constraint for each part to be assembled with its base assembly. Examples are given to illustrate the concepts and procedure of the proposed scheme.

For ease of manufacture, axisymmetric components produced by processes such as forging, casting and moulding are often designed with a taper angle. This paper presents a family of devices for handling such components by their tapered portion. The devices are essentially finger tips, or jaws, to be fitted to standard scissor-type robot grippers. The jaws possess a three-dimensional profile constructed as a stack of v-shaped planar curves. The special jaw profile enables components of different diameters and taper angles to be gripped concentrically without calling for complex movements to reposition the gripper. The equations describing two categories of profile are derived and the optimum selection of profile parameters to yield compact jaws to grip components of a wide range of dimensions is discussed in the paper.

HERMIES-III is an autonomous robot comprised of a seven degree-of-freedom (DOF) manipulator designed for human scale tasks, a laser range finder, a sonar array, an omnidirectional wheel-driven chassis, multiple cameras, and a dual computer system containing a 16-node hypercube expandable to 128 nodes. The current experimental program involves performance of human-scale tasks (e.g., valve manipulation, use of tools), integration of a dexterous manipulator and platform motion in geometrically complex environments, and effective use of multiple cooperating robots (HERMIES-IIB and HERMIES-III). The environment in which the robots operate has been designed to include multiple valves, pipes, meters, obstacles on the floor, valves occluded from view, and multiple paths of differing navigation complexity. The ongoing research program supports the development of autonomous capability for HERMIES-IIB and III to perform complex navigation and manipulation under time constraints, while dealing with imprecise sensory information.

The concept of tension is introduced and applied to a robot's trajectories, then new joint interpolation strategies are implemented. A joint interpolation strategy is proposed which uses joint variable reference data calculated from inverse kinematics, along with a polynomial equation or quintic equation as the parametric equation of the joint variables. This method can use any polynomial equation which has the C2 continuity property and has intermediate points which pass through the reference data. For the time variable, first order linear equations can be used where the number of equations is n – 1, n being the number of points in the reference data. Due to large reductions in computational burden resulting from this form, this method may be suited for real time applications.