Fraunhofer-Institut für Produktionsanlagen und Konstruktionstechnik IPK

Filters
Reset filters

Settings
Now showing 1 - 10 of 15
  • Publication
    Concept of an offline correction method based on historical data for milling operations using industrial robots
    ( 2016)
    Krüger, J.
    ;
    Zhao, H.
    ;
    Reis de Ascencao, G.
    ;
    Jacobi, P.
    ;
    Surdilovic, D.
    ;
    Schöll, S.
    ;
    Polley, W.
    Industrial robots for machining applications have been researched to achieve an alternative, flexible and less expensive machining technology against conventional machine tools. The previous work on industrial robots indicates that industrial robots are only applicable without requirement of high accuracy. The low accuracy and instability under various configurations of industry robot are still major barriers for deploying robots for machining in industries. In this paper, a new method, namely historical data based correction (HDC), is presented to improve the accuracy of industrial robots for milling operations. First, the HDC method is able to calculate the corrected values to compensate the systematical errors during milling operations. Consequently, new tool paths of robots with corrected values are generated. In addition, the HDC method is able to fulfill the requirement of large-scale production. With the proposed method, the surface quality of the machined parts can be improved by more than 60 % without using any additional measuring systems.
  • Publication
    Intuitive dual arm robot programming for assembly operations
    ( 2014)
    Makris, S.
    ;
    Tsarouchi, P.
    ;
    Surdilovic, D.
    ;
    Krüger, J.
    This study has to do with a method for the intuitive programming of dual arm robots. A task oriented programming procedure is described for this reason, including the proposed dual arm robotics library and the human language. The robotics library aspires after human like capabilities and implements bi-manual operations. This intuitive programming framework is based on a service oriented architecture and is developed in ROS. The user can easily interact with a dual arm robot platform through depth sensors, noise canceling microphones and GUIs. The methods have been implemented in a dual arm robot platform for an assembly case from the automotive industry.
  • Publication
    The industrial robot as intelligent tool carrier for human-robot interactive artwork
    ( 2014)
    Vick, A.
    ;
    Surdilovic, D.
    ;
    Dräger, A.K.
    ;
    Krüger, J.
    This paper gives an introduction to the process of an experimental project in pertaining to the planning and integrating of a human-robot interactive stone carving system. The process includes an analysis of manual stone carving by a professional sculptor, a risk assessment of the projected robotic assistant system resulting in the safety concepts, a design of a tool carrier with force sensors and the human-machine interface. A standard industrial robot was selected and enhanced with extensive periphery to build up the intelligent tool carrier. Besides scientific results regarding work space and contact force suitable for human-robot collaboration, this paper presents the sculptural aspects within the experiment project. The professional scluptor evaluated the results as beyond manual processing.
  • Publication
    HEPHESTOS: Hard material small-batch industrial machining robot
    ( 2014)
    Schreck, G.
    ;
    Surdilovic, D.
    ;
    Krüger, J.
    In September 2012 a European collaborative project was launched entitled "Hard Material Small-Batch Industrial Machining Robot (HEPHESTOS)". HEPHESTOS' main objective is to develop novel technologies for the robotic hard material removal that will provide standard industrial robots with advanced techniques in machining planning, programming and real-time control. Hard materials machining has recently attracted great attentions from the advanced industries, in particular, the European automotive, the aerospace and the biomedical industries. However, the existing technology failed to provide these industries with a cost efficient solution to cope with small-batch production of large and complex-shaped products. The project HEPHESTOS, with its focus on developing sophisticated methods in robotic manufacturing, shall give rise to a cost-efficient solution in hard materials machining for this small-batch production of highly customized products through the application of industrial robots.
  • Publication
    Geometric stiffness analysis of wire robots: A mechanical approach
    ( 2013)
    Krüger, J.
    ;
    Surdilovic, D.
    ;
    Radojicic, J.
    This paper presents a mechanical approach for the modelling of wire robots dynamics considering the effects of structural elasticity. The mechanical wires represent critical flexible elements of a wire robot that are responsible for elastic deformations and vibrations of the entire structure. A comprehensive elastodynamic analysis plays a crucial role in wire-robot synthesis and control. Especially in the large-span systems, the elastic deformations and vibrations may be characterized by relatively low frequencies and high amplitudes causing undesirable behaviour. The paper considers coupled 6D deformations of the common wire-robot platform in both over- and under-constrained wire robot structures. Special emphasis is on the geometric stiffness matrix that is dependent on wire tension and which has been derived following a rigorous mechanical approach analysing the motion of the entire system and specific components. The geometric stiffness matrix in wire robots plays a crucial role in stabilization of the wire robot, such as in active stiffening and damping of unacceptable vibration effects. The decomposition of both spatial elastic wire and geometric stiffness matrices on virtual elemental springs has been applied to provide a physical insight and better understanding of the wire robot elastic behaviour. Several examples illustrate the theoretical analysis.
  • Publication
    Safe physical human-robot interaction with industrial dual-arm robots
    ( 2013)
    Vick, A.
    ;
    Surdilovic, D.
    ;
    Krüger, J.
    This paper presents methodologies and tests for the safe physical human-robot interaction in conventional position controlled and non-back driveable industrial robotic systems. The developed algorithms are based on a simplified sensor-less estimation of external forces and saturation of joint control torques to keep the effective external forces under safety level. To cope with non-linear saturation phenomena, position control compensators and path error governor have been implemented and designed to ensure smooth behaviour and preserved control performance. Being able to stop the robot arm motion when applying risky forces, as recommended by ISO 10218, the human feels subjective safe in the robot vicinity. Experiments with the PISA Workerbot dual-arm robot system illustrate feasibility and robustness of the developed algorithms.
  • Publication
    Application challenges of large-scale wire robots in agricultural plants
    ( 2013)
    Radojicic, J.
    ;
    Surdilovic, D.
    ;
    Krüger, J.
    The paper presents an efficient approach for the modelling of wire robots kinematic and dynamics considering the effects of structural elasticity. Using the simulation and animation system several potential applications in agriculture have been simulated and analysed. The paper discusses possible robot configurations, system dynamic constraints and limits, as well as reachable performance for typical large-span wire robot applications in agriculture.
  • Publication
    Advanced methods for small batch robotic machining of hard material
    ( 2012)
    Krüger, J.
    ;
    Schreck, G.
    ;
    Surdilovic, D.
    ;
    Zhao, H.
  • Publication
    Dual arm robot for flexible and cooperative assembly
    ( 2011)
    Krüger, J.
    ;
    Schreck, G.
    ;
    Surdilovic, D.
    Dual-arm robots provide efficient approach for automated execution of complex assembly operations. With bimanual-manipulation, a dual-arm robot can simultaneously control relative motion and interaction of assembly counterparts in a dexterous human-like manner. This requires, however, sophisticated programming and control algorithms for arms cooperation. This paper addresses the development of an advanced industrial dual-arm robot system with novel capabilities, such as easy and rapid commissioning, compliance control of bimanual interaction in all assembly process phases, as well as intuitive planning and programming. The robot can be leased and easily integrated in assembly environment sharing the same workspace with human workers.
  • Publication
    PISA: Next generation of flexible assembly systems - from initial ideas to industrial prototypes
    ( 2010)
    Krüger, J.
    ;
    Katschinski, V.
    ;
    Surdilovic, D.
    ;
    Schreck, G.
    In September 2006 an integrated European project (IP) was launched entitled "Flexible Assembly Systems through Workplace-Sharing and Time-Sharing Human-Machine Cooperation (PISA)". The general aim of the project is to develop intelligent assist systems (IAS) in order to support the human worker instead of replace him. The idea is to combine human flexibility, intelligence and skills with the advantages of sophisticated technical systems. Further developments within the project are focused on reconfigurability and reusability of assembly equipment, and required planning tools for end-users. The paper presents the initial project objectives, and the resulting prototype systems developed by the partners of the PISA consortium.