Fraunhofer-Institut für Optronik, Systemtechnik und Bildauswertung IOSB

Filters

16
9 7
Reset filters

Settings
Now showing 1 - 10 of 16
  • Publication
    Workspace monitoring and planning for safe mobile manipulation
    ( 2020)
    Frese, Christian
    ;
    Zube, Angelika
    ;
    Frey, Christian
    In order to enable physical human-robot interaction where humans and (mobile) manipulators share their workspace and work together, robots have to be equipped with important capabilities to guarantee human safety. The robots have to recognize possible collisions with the human co-worker and react anticipatorily by adapting their motion to avert dangerous situations while they are executing their task. Therefore, methods have been developed that allow to monitor the workspace of mobile manipulators using multiple depth sensors to gather information about the robot environment. This encompasses both3D information about obstacles in the close robot surroundings and the prediction of obstacle motions in the entire monitored space. Based on this information, a collision-free robot motion is planned and during the execution the robot continuously reacts to unforeseen dangerous situations by adapting its planned motion, slowing down or stopping. For the demonstration of a manufacturing scenario, the developed methods have been implemented on a prototypical mobile manipulator. The algorithms handle both robot platform and manipulator in a uniform manner so that an overall optimization of the path and of the collision avoidance behavior is possible. By integrating the monitoring, planning, and interaction control components, the task of grasping, placing and delivering objects to humans in a shared workspace is demonstrated.
  • Publication
    A Cooperative HCI Assembly Station with Dynamic Projections
    ( 2020)
    Lengenfelder, Christian
    ;
    Frese, Christian
    ;
    Zube, Angelika
    ;
    Voit, Michael
    ;
    Beyerer, Jürgen
    This paper presents a cooperative human-computer interaction (HCI) assembly station which is assisting a worker during a manual assembly process. The worker's identity, body pose and height is determined to provide individualized assistance like a robot arm which is holding workpieces in a position which is ergonomic for the worker. A second robot arm is equipped with a camera and projector to precisely project information directly on the workpiece. Safe and intuitive human-robot collaboration is achieved by means of workspace monitoring, force detection, compliant control, and hand-guiding. A distinctive feature of this assembly station is that new assembly steps and documentation can be added interactively directly at the workstation during an assembly by interacting with the projected GUI through hand gestures. This paper will detail an assembly station that was developed in a laboratory environment.
  • Publication
    Generic Convoying Functionality for Autonomous Vehicles in Unstructured Outdoor Environments
    ( 2020)
    Albrecht, Alexander
    ;
    Heide, Nina Felicitas
    ;
    Frese, Christian
    ;
    Zube, Angelika
    Autonomously following a leading vehicle is a major step towards fully autonomous vehicles. The contribution of this work consists in the development, implementation, and validation of two following modes: 1) Exact following: accurate compliance with the reference path. 2) Flexible following: tolerate deviation from the reference path in order to avoid obstacles. The proposed method can easily be integrated into existing frameworks for autonomous vehicles. Therefore our approach is flexible enough to be applied to a large variety of different vehicles. To demonstrate the feasibility of our approach an experimental validation is carried out on two autonomous vehicles with major differences in kinematics, weight, and size: A cross-country wheelchair and an off-road truck. Both exact and flexible following have been successfully demonstrated in unstructured outdoor environments.
  • Publication
    Real-time hyperspectral stereo processing for the generation of 3D depth information
    ( 2018)
    Heide, Nina
    ;
    Frese, Christian
    ;
    Emter, Thomas
    ;
    Petereit, Janko
    We present a local stereo matching method for hyperspectral camera data, allowing multiple usage of camera hardware and imaging data such as for object classification or spectral analysis and multichannel input to the correspondence problem. The matching process combines correlation-based similarity measures for pixel windows utilizing all 16 spectral channels followed by a consistency check for disparity selection. We evaluate stereo-processing methods focusing on effectiveness and runtime of the processing on a CPU and analyze parallelization possibilities. Based on the results of the evaluation on the CPU, we implement the optimized stereo matching for images with 16 channels on a graphics processing unit (GPU) utilizing the Compute Unified Device Architecture (CUDA). The parallel processing of the calculation steps to obtain the disparity image on the GPU achieves more than 27× speed up, resulting in calculation and post-processing of hyperspectral images with 8 - 13 Hz, depending on the selection of maximum disparity. The 3D reconstruction achieves a mean square error of 0.0267 m 2 in distance measurements from 5 - 10 m2.
  • Publication
    Algorithmen-Toolbox für autonome mobile Robotersysteme
    ( 2017)
    Emter, Thomas
    ;
    Frese, Christian
    ;
    Zube, Angelika
    ;
    Petereit, Janko
    Schwere Arbeitsmaschinen werden häufig in Umgebungen eingesetzt, die für den Menschen erhebliche Gesundheitsrisiken bergen. Ziel aktueller Forschungsaktivitäten am Fraunhofer IOSB ist es, Baumaschinen mit Autonomiefähigkeiten auszustatten, sodass diese selbstständig in der Gefahrenzone agieren können. Hierfür wurde eine Algorithmen-Toolbox für autonome Robotersysteme entwickelt, die Komponenten beinhaltet, die sich von der Umgebungswahrnehmung über die Aufgaben- und Bewegungsplanung bis hin zur konkreten Nutzfunktionsdurchführung erstrecken. Um die Forschungsergebnisse evaluieren zu können, wurde ein Technologiedemonstrator aufgebaut, der in der Lage ist, selbstständig kontaminierte Erdschichten abzutragen. ...
  • Publication
    A non-invasive cyberrisk in cooperative driving
    ( 2017)
    Bapp, F.
    ;
    Becker, J.
    ;
    Beyerer, Jürgen
    ;
    Doll, J.
    ;
    Filsinger, Max
    ;
    Frese, Christian
    ;
    Hubschneider, C.
    ;
    Lauber, A.
    ;
    Müller-Quade, J.
    ;
    Pauli, M.
    ;
    Roschani, Masoud
    ;
    Salscheider, O.
    ;
    Rosenhahn, B.
    ;
    Ruf, Miriam
    ;
    Stiller, C.
    ;
    Willersinn, Dieter
    ;
    Ziehn, J.
    This paper presents a hacking risk arising in fully automated cooperative driving. As opposed to common cyber risk scenarios, this scenario does not require internal access to an automated car at all, and is therefore largely independent of current on-board malware protection. A hacker uses a wireless mobile device, for example a hacked smartphone, to send vehicle to- vehicle (V2V) signals from a human-driven car, masquerading it as a fully-automated, cooperating vehicle. It deliberately engages only in high-risk cooperative maneuvers with other cars, in which the unwitting human driver is expected to perform a specific maneuver to avoid collisions with other vehicles. As the human driver is unaware of the planned maneuver, he fails to react as expected by the other vehicles; depending on the situation, a severe collision risk can ensue. We propose a vision-based countermeasure that only requires state-of-the-art equipment for fully-automated vehicles, and assures that such an attack without internal access to an automated car is impossible.
  • Publication
    Machine vision. Automated visual inspection: Theory, practice and applications
    (Springer, 2016)
    Beyerer, Jürgen
    ;
    Puente Leon, Fernando
    ;
    Frese, Christian
    The book offers a thorough introduction to machine vision. It is organized in two parts. The first part covers the image acquisition, which is the crucial component of most automated visual inspection systems. All important methods are described in great detail and are presented with a reasoned structure.The second part deals with the modeling and processing of image signals and pays particular regard to methods, which are relevant for automated visual inspection.
  • Publication
    Sampling-based path planning to cartesian goal positions for a mobile manipulator exploiting kinematic redundancy
    ( 2016)
    Seyboldt, Ruben
    ;
    Frese, Christian
    ;
    Zube, Angelika
    A robot path planner is presented which integrates both collision-free path planning and finding an inverse kinematics solution in a single search stage. Thereby the degrees of freedom resulting from redundant robot kinematics with regard to goal positions specified in the Cartesian workspace are used to optimize the path length, whereas the usual two-stage approach of decoupled inverse kinematics computation and path planning in the configuration space fails to exploit this potential. In addition to sampling-based exploration of the configuration space, the proposed algorithm uses a computationally efficient gradient descent method for approaching the Cartesian goal pose. Furthermore, the planner is extended by the possibility to respect end-effector path orientation constraints. A detailed evaluation of the planning performance in comparison with a two-stage planner is presented.
  • Publication
    Automatische Sichtprüfung: Grundlagen, Methoden und Praxis der Bildgewinnung und Bildauswertung. 2., erweiterte und verbesserte Auflage
    (Springer Vieweg, 2016)
    Beyerer, Jürgen
    ;
    Puente Leon, Fernando
    ;
    Frese, Christian
    Das Lehrbuch behandelt systematisch die Bildgewinnung für die automatische Sichtprüfung. Die Autoren leiten die wesentlichen Methoden detailliert ab und stellen alle gängigen Bildgewinnungsverfahren in einem strukturierten Zusammenhang dar. Der zweite Teil des Buches ist der Bildsignalbeschreibung und der Bildauswertung gewidmet, wobei insbesondere Methoden behandelt werden, die für die automatische Sichtprüfung relevant sind. Die Autoren skizzieren die Herleitung der beschriebenen Methoden, ohne sich in mathematischen Details zu verlieren. Ihr Ziel ist, dass der Leser die Zusammenhänge wirklich versteht und das "große Bild" des Fachgebietes erkennt. Das Buch ist in sich geschlossen und bedarf zum Verständnis keiner ergänzenden Literatur. Die 2. Auflage wurde gründlich überarbeitet, inhaltlich ergänzt und aktualisiert. Neue Beispiele verdeutlichen den Bezug zur Praxis.
  • Publication
    AgriApps: an App-based Solution for Field-Robot-Based Agriculture
    ( 2015)
    Frese, Christian
    ;
    Frey, Christian
    ;
    Meßmer, F.
    ;
    Pfeiffer, K.
    ;
    Sander, S.
    ;
    Marco, Daniel di
    ;
    Wenger, M.
    ;
    Albert, A.
    ;
    Wopfner, M.
    ;
    Burkhardt, A.
    ;
    Hochdorfer, S.
    ;
    Bittner, M.
    ;
    Bosch, J.
    ;
    Strobel, M.
    · Today agriculture has to deal with an increasing cost pressure. Innovative Field-Robot-Based solutions can help to handle this challenge. Until now, such systems are not profitable and technically mature for commercial use. In the project AgriApps these issues are addressed. An application based system is developed where a carrier platform can be equipped with different apps. This allows the usage of the system throughout the year to handle different tasks. Thus such a system is profitable for end users. To evaluate the developed concepts. an app for mechanical weed control in special cultures was developed. It consists of a multi-sensor setup for plants and weed detection and a manipulator for digging the soil around the plants. This not only removes the weed but also provides better water absorption for the plants. The app is finally tested on the BoniRob platform, which is the reference platform in this project. A novelty and major contribution of the project is the general definition and specification of the interface between robot and the apps, which covers mechanical and electrical issues as well as the information flow, static and dynamic working area descriptions and energy demand management. The general approach of the interface specification is not limited on robotics, especially it can be transferred to working implements on mobile machinery.