Author name cluster

Norbert Elkmann

Possible papers associated with this exact author name in Arrow. This page groups case-insensitive exact name matches and is not a full identity disambiguation profile.

10 papers

1 author row

ICRA Conference 2019 Conference Paper

Multimodal Bin Picking System with Compliant Tactile Sensor Arrays for Flexible Part Handling

Veit Müller
Norbert Elkmann

This paper presents a robot control architecture comprised of tactile and vision sensors incorporated into an off-the-shelf bin picking system. The proposed architecture facilitates flexible and reliable handling of objects and materials by employing a tactile grasp validation system and in-hand object monitoring. Two industrial grippers, specifically a magnetic gripper and a flexible vacuum gripper, are equipped with a compliant custom tactile sensor array. The algorithms used are for each specific gripper and respective sensor, however are transferrable to other grippers as well. The tactile sensing augments vision-based picking approaches, thus supporting in-hand object recognition [1] that is particularly useful for hard-to-recognize objects such as objects with transparent or shiny surfaces. Algorithms for tactile-based object pose estimation in the gripper and for grasp monitoring, including grasp validation, complete the approach.

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ICRA Conference 2018 Conference Paper

Performance Indicator for Benchmarking Force-Controlled Robots

Roland Behrens
Anton Belov
Maik Poggendorf
Felix Penzlin
Magnus Hanses
Emily Jantz
Norbert Elkmann

Robot-based sensitive assembly is a recent and growing trend in robotics. Force-controlled robots are expected to interact with an unknown environment using solely force feedback information. In general, the exact contact is difficult to predict due to various impact factors, such as the dynamics of the interaction, work-piece stiffness and geometry, the robot's configuration, and the efficiency of the control algorithm. Currently, there is no general indicator for evaluating the performance of a force-controlled robot. This work presents a concept of such a performance indicator. In order to test the proposed concept for comparison, an experimental setup is presented that simulates a contour-following task under force control. This setup is used to test two robots with different force-controllers and control principles, namely direct force and impedance control. The results indicate good applicability of the proposed performance indicator to benchmark force-controlled robots, and this is extensively discussed.

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ICRA Conference 2014 Conference Paper

Study on meaningful and verified Thresholds for minimizing the consequences of human-robot collisions

Roland Behrens
Norbert Elkmann

In order to define meaningful limit values for human-robot collisions, we have come to the conclusion that only comprehensive collision tests with live test subjects will successfully lead to verified limit values. A literature survey about current approaches for limiting the consequences of hazardous contacts between humans and moving machines (including robots) showed that limit values are often specified without an appropriate injury severity or without considering the variety of the human body. In this article, we show why the injury onset is appropriate to limit the consequences of human-robot collisions, and how this onset can be quantified through collision tests with live test subjects. With our work we would like to present a promising method that can remedy the current lack of consensus regarding an appropriate injury severity and verified limit values.

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IROS Conference 2013 Conference Paper

A projection-based sensor system for safe physical human-robot collaboration

Christian Vogel 0003
Christoph Walter
Norbert Elkmann

This paper presents the application of a novel projection-based safety system for ensuring hard safety in human-robot collaboration. We adapted the proposed sensor system to incorporate the joint positions and velocities of a collaborative robot, thus offering the opportunity to establish minimal and well-shaped safety spaces around the robot at any time. In this contribution we explain in detail main challenges and their solutions for generating and monitoring such safety spaces. Furthermore, we build up a future collaborative workplace to demonstrate the practicability of the system under operational conditions.

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ICRA Conference 2011 Conference Paper

Kinematics analysis of a 3-DOF joint for a novel hyper-redundant robot arm

Roland Behrens
Conrad Kuchler
Tilo Forster
Norbert Elkmann

In this paper, the kinematics of a joint with three degrees of freedom for a novel hyper-redundant robot arm is investigated. This joint is able to achieve a superposed rotation about two axes (roll and pitch) and a translational motion along one axis as a common prismatic joint. The forward and inverse kinematics of the so-called Multi-Joint will be determined in a closed-form solution. Next, the reachable and suitable workspace will be worked out to determine the solution space of the inverse kinematics. Finally, the differential kinematics to compute the cartesian velocity and statics will be determined.

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IROS Conference 2011 Conference Paper

Towards safe physical human-robot collaboration: A projection-based safety system

Christian Vogel 0003
Maik Poggendorf
Christoph Walter
Norbert Elkmann

This paper presents a new approach to safety and transparency in physical human-robot collaboration by using conventional projector and camera equipment. Our system is able to establish an arbitrarily shaped light barrier around the workspace of a robot. The barrier can be made dynamic, i. e. it can adapt to the actual movement of the robot. This is a highly desirable property in scenarios requiring human robot collaboration. We will discuss a method for visually detecting violations of the safety barrier including compensation of ambient light. Furthermore, we argue that this method complies with several requirements regarding reliability in safety critical systems.

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IROS Conference 2008 Conference Paper

Application of visual odometry for sewer inspection robots

José F. Saenz
Christoph Walter
Erik Schulenburg
Norbert Elkmann
Heiko Althoff

Large waste water pipes are a hazardous working environment for humans. Nevertheless such pipes must be inspected on a regular basis. Many of today’s inspection systems for underground sewer pipes consist of a single TV-camera and are designed for pipes smaller than one meter in diameter. The most recent automatic inspection systems [1] are equipped with advanced sensors that make it possible for an operator to perform this task from an outside position for larger pipes (diameter between 1. 4 to 2. 8 meters). The cable-guided damage surveying system, SEK, (see Fig. 1) was developed by the Fraunhofer IFF on behalf of the Emschergenossenschaft to be a versatile and easy-to-use tool to detect various kinds of damages above and below the water-line with high accuracy.

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ICRA Conference 2007 Conference Paper

Development of Fully Automatic Inspection Systems for Large Underground Concrete Pipes Partially Filled with Wastewater

Norbert Elkmann
Heiko Althoff
Sven Kutzner
Thomas Stürze
José F. Saenz
Bert Reimann

The Emschergenossenschaft based in Germany is currently planning the Emscher sewer system, arguably the largest residential water management project in Europe in years to come. The Emschergenossenschaft engaged the Fraunhofer Institute for Factory Operation and Automation (IFF) in Magdeburg, Germany, as the general contractor to develop automatic inspection and cleaning systems to meet the requirements imposed by legal guidelines. The systems must operate continuously in a sewer line that has diameters ranging from 1400 to 2800 mm and is partially filled, 25% at minimum, all the time. To construct the Emscher sewer system, the Emschergenossenschaft favors a one-pipe line in long sections. A walk-through or inspection by personnel would be impossible in these sections. The Fraunhofer Institute IFF has developed prototypes of all systems for motion through the sewer and all sensor systems, thus achieving a new quality of inspection above and below the water line under these difficult conditions. This article describes significant project results and important components of inspection such as the inspection systems, pipe axis measurement, system positioning, and sensor systems for damage detection. Fundamental for the development of the inspection systems is the detail of the inspection, which goes far beyond the video inspection common today, and the ability to take comparative measurements throughout the sewer system's period of operation in order to track the development of damage.

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IROS Conference 2006 Conference Paper

Fully Automatic Inspection Systems for Large Underground Concrete Pipes Partially Filled with Wastewater

Norbert Elkmann
Sven Kutzner
José F. Saenz
Bert Reimann
Falko Schultke
Heiko Althoff

The Emschergenossenschaft based in Germany is currently planning the Emscher sewer system, arguably the largest residential water management project in Europe in years to come. In 2002, the Emschergenossenschaft engaged the Fraunhofer Institute for Factory Operation and Automation (IFF) in Magdeburg, Germany, as the general contractor to develop automatic inspection and cleaning systems to meet the requirements imposed by legal guidelines. The systems must operate continuously in a sewer line that has diameters ranging from 1400 to 2800 mm and is partially filled, 25% at minimum, all the time. To construct the Emscher sewer system, the Emschergenossenschaft favors a one-pipe line in long sections. A walk-through or inspection by personnel would be impossible in these sections. The Fraunhofer Institute IFF has developed prototypes of all systems for motion through the sewer and all sensor systems, thus achieving a new quality of inspection under these difficult conditions. This article describes significant project results and important components of inspection such as the inspection systems, pipe axis measurement, system positioning and sensor systems for damage detection. Fundamental for the development of the inspection systems are the detail of the inspection that far surpasses the video inspection common today and the capability to take comparative measurements throughout the sewer system's period of operation in order to track the development of damage

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IROS Conference 2002 Conference Paper

Innovative service robot systems for facade cleaning of difficult-to-access areas

Norbert Elkmann
Torsten Felsch
Mario Sack
José F. Saenz
Justus Hortig

The Fraunhofer Institute for Factory Operation and Automation (IFF) is intensively exploring possibilities for robots to engage in various service tasks, especially fully-automatic systems for facade cleaning. We have already designed and built a variety of different facade cleaning robots and concepts. These robots and concepts are based on various motion systems (i. e. walking mechanisms, wheeled vehicles, balloon-based systems, etc.) that are specially-suited for motion along different building types. This paper gives an overview about different facade cleaning robots developed by the Fraunhofer IFF The facade cleaning robot, SIRIUSc, for use on skyscrapers, the robot to clean the 25, 000 m/sup 2/ vaulted glass hall of the Leipzig Trade Fair in Germany, as well as the completed concept for a balloon-based robot for cleaning the inner side of atriums and glass roofs are discussed here. The unique aspects of the main components of these robots will be addressed in particular.

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