A fast 3-D object recognition algorithm for the vision system of a special-purpose dexterous manipulator

A fast 3-D object recognition algorithm that can be used as a quick-look subsystem to the vision system for the Special-Purpose Dexterous Manipulator (SPDM) is described. Global features that can be easily computed from range data are used to characterize the images of a viewer-centered model of an object. This algorithm will speed up the processing by eliminating the low level processing whenever possible. It may identify the object, reject a set of bad data in the early stage, or create a better environment for a more powerful algorithm to carry the work further

HERMIES-3: A step toward autonomous mobility, manipulation, and perception

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 omni-directional 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

Exploration of Surfaces for Robot Mobility

This paper presents an overview of ongoing research in surface exploration at the GRASP Lab. The objective of the work presented here is to design a system that will explore an environment that is unknown and unconstrained and will enable a robot to adapt to varying surroundings. We are investigating the necessary components/modules that must be embedded into a robot for it to have exploratory capabilities. We have designed and are implementing exploratory procedures (ep\u27s) to recover the mechanical properties from a surface given minimal a priori information so that a robot or a vehicle can decide whether to and how to move on this surface. The laboratory setup involves a compliant wrist with six degrees of freedom, mounted on a robot arm, and a laser range finder, mounted on another robot arm, as the primary sensors to detect the response of surfaces with varying mechanical properties

ROTEX-TRIIFEX: Proposal for a joint FRG-USA telerobotic flight experiment

The concepts and main elements of a RObot Technology EXperiment (ROTEX) proposed to fly with the next German spacelab mission, D2, are presented. It provides a 1 meter size, six axis robot inside a spacelab rack, equipped with a multisensory gripper (force-torque sensors, an array of range finders, and mini stereo cameras). The robot will perform assembly and servicing tasks in a generic way, and will grasp a floating object. The man machine and supervisory control concepts for teleoperation from the spacelab and from ground are discussed. The predictive estimation schemes for an extensive use of time-delay compensating 3D computer graphics are explained

Extraction of Geometrical Features in 3D Environments for Service Robotic Applications

Modeling environments with 3D feature based representations is a challenging issue in current mobile robotics. Fast and robust algorithms are required for applicability to navigation. We present an original and effective segmentation method that uses computer vision techniques and the residuals from plane fitting as measurements to generate a range image from 3D data acquired by a laser scanner. The extracted points of each region are converted into plane patches, spheres and cylinders by means of least-squares fitting

An intelligent robotic inspection system for airframe structures

Robot trajectory control is currently performed in an open loop fashion with the trajectory being specified as either a series of end point positions or as a series of joint angle values which are passed through in sequence. In order to perform any complex tasks in an unstructured or semi-structured environment an 'intelligent' robot is required which can sense its environment and alter its trajectory accordingly. This thesis describes the development of an 'intelligent' robotic inspection system which is capable of automatically deploying test probes for the inspection of the structures commonly found in modern airframes with no prior knowledge of the structure being inspected. It utilises a Puma 560 (articulated arm) industrial robot which is under supervisory control from an IBM ps2 personal computer and a wrist-mounted CCD camera with a low power industrial laser to acquire information about the robot's environment. In order to improve the positional accuracy of the Puma it has been calibrated using a computerised surveying system. Extensive use is made of image processing, pattern recognition and mathematical surface modelling to build up a model of the structure being examined and this is used to define the trajectory of the end point of the Puma

HEAP: A Sensory Driven Distributed Manipulation System

We address the problems of locating, grasping, and removing one or more unknown objects from a given area. In order to accomplish the task we use HEAP, a system of coordinating the motions of the hand and arm. HEAP also includes a laser range finer, mounted at the end of a PUMA 560, allowing the system to obtain multiple views of the workspace. We obtain volumetric information of the objects we locate by fitting superquadric surfaces on the raw range data. The volumetric information is used to ascertain the best hand configuration to enclose and constrain the object stably. The Penn Hand used to grasp the object, is fitted with 14 tactile sensors to determine the contact area and the normal components of the grasping forces. In addition the hand is used as a sensor to avoid any undesired collisions. The objective in grasping the objects is not to impart arbitrary forces on the object, but instead to be able to grasp a variety of objects using a simple grasping scheme assisted with a volumetric description and force and touch sensing