The technical report presents the design and implementation of PACO-PLUS robot platforms (humanoi... more The technical report presents the design and implementation of PACO-PLUS robot platforms (humanoid head for active vision and audio perception and a haptic sensor concept for a five-finger anthropomorphic hand) as well as the specification of the hardware and software interfaces that allows for efficient exchange of hardware and software modules in order to minimize the overhead in the overall
Autonomous grasping of household objects is one of the major skills that an intelligent service r... more Autonomous grasping of household objects is one of the major skills that an intelligent service robot necessarily has to provide in order to interact with the environment. In this paper, we propose a grasping strategy for known objects, comprising an off-line, box-based grasp generation technique on 3D shape representations. The complete system is able to robustly detect an object and
2011 IEEE International Conference on Robotics and Biomimetics, 2011
Reconstruction of surface models from camera images has many applications in robotics such as sur... more Reconstruction of surface models from camera images has many applications in robotics such as surface registration or object recognition. In this paper, we describe a workflow in which we extract depth information from stereo image sequences to generate a surface model. We present our solutions to correspondence analysis, disparity correction and refinement, as well as 3D reconstruction, point cloud smoothing and meshing. One important feature of the correspondence analysis that we evaluate in detail is the use of temporal information. Another emphasis is on correcting and smoothing the disparity images as well as the reconstructed point cloud without losing too much detail. We, hence, introduce our application of the Bilateral filter on disparity images and our usage of least squares smoothing. The components of the workflow were evaluated using three image sources: Endoscopic images from the daVinci® telemanipulator; images from a stereo camera integrated in the ARMAR III humanoid robot; synthetic data. Depending on the image resolution and the application, the workflow reconstructs surface models in real-time. We show that by using temporal information we obtain more accurate and robust correspondences. Additionally, the Bilateral filter was especially useful in refining the correspondences extracted from endoscopic images as well as the synthetic data sets, whereas the least squares method showed good results in smoothing the point cloud of ARMAR III images. Overall, the presented approach achieves good results for different camera settings and image types, especially with respect to the real-time requirement.
ó This paper describes ongoing effort in developing an anthropomorphic arm/hand manipulation syst... more ó This paper describes ongoing effort in developing an anthropomorphic arm/hand manipulation system as part of the German Humanoid Research Project SFB588. This project aims at building a humanoid robot that assists humans in everyday service tasks. The manipulation part of this project has to deal with a service environment and to cope with the wide variety of objects and
In this paper, we present a new humanoid robot currently being developed for applications in huma... more In this paper, we present a new humanoid robot currently being developed for applications in human-centered environ- ments. In order for humanoid robots to enter human-centered environments, it is indispensable to equip them with mani- pulative, perceptive and communicative skills necessary for real-time interaction with the environment and humans. The goal of our work is to provide reliable and highly
2013 IEEE/RSJ International Conference on Intelligent Robots and Systems, 2013
ABSTRACT Generating robot motion trajectories instantaneously in the moment unforeseen sensor eve... more ABSTRACT Generating robot motion trajectories instantaneously in the moment unforeseen sensor events happen is very essential for many real-world robot applications. Using a previous work on online trajectory generation as a basis, this paper proposes an alternative approach that also considers dynamic models. The former class of algorithms does not take into account dynamically changing acceleration capabilities based on maximum actuator forces/torques. This paper extends target velocity-based algorithms of the previous approach by taking into consideration the entire system dynamics when generating trajectories online within one control cycle (typically 1 ms or less). The extension includes the acceleration capabilities of a robot at every discrete time step assuming constant values for the maximum actuator forces/torques, thus allowing the generation of adaptive trajectory profiles during the motion of the robot. Several real-world experimental results using a seven-degree-of-freedom lightweight robot arm underline the relevance of this extension.
ABSTRACT The term "Visual Servoing" subsumes all control approaches, that use f... more ABSTRACT The term "Visual Servoing" subsumes all control approaches, that use feedback information extracted from vision sensors. Therefore corrective actions are being generated on the continuous analysis of camera images, e. g. for controlling a robot arm. In this article we present the Visual-Servoing system for the humanoid robot ARMAR-III which enables safe execution of single and dual-handed grasping and manipulation actions. Inaccuracy of actuators and sensor systems can be compensated by the closed-loop approach.
2010 IEEE International Conference on Robotics and Automation, 2010
The autonomous acquisition of object representations which allow recognition, localization and gr... more The autonomous acquisition of object representations which allow recognition, localization and grasping of objects in the environment is a challenging task, which has shown to be difficult. In this paper, we present a systems for autonomous acquisition of visual object representations, which endows a humanoid robot with the ability to enrich its internal object representation and allows the realization of
The technical report presents the design and implementation of PACO-PLUS robot platforms (humanoi... more The technical report presents the design and implementation of PACO-PLUS robot platforms (humanoid head for active vision and audio perception and a haptic sensor concept for a five-finger anthropomorphic hand) as well as the specification of the hardware and software interfaces that allows for efficient exchange of hardware and software modules in order to minimize the overhead in the overall
Autonomous grasping of household objects is one of the major skills that an intelligent service r... more Autonomous grasping of household objects is one of the major skills that an intelligent service robot necessarily has to provide in order to interact with the environment. In this paper, we propose a grasping strategy for known objects, comprising an off-line, box-based grasp generation technique on 3D shape representations. The complete system is able to robustly detect an object and
2011 IEEE International Conference on Robotics and Biomimetics, 2011
Reconstruction of surface models from camera images has many applications in robotics such as sur... more Reconstruction of surface models from camera images has many applications in robotics such as surface registration or object recognition. In this paper, we describe a workflow in which we extract depth information from stereo image sequences to generate a surface model. We present our solutions to correspondence analysis, disparity correction and refinement, as well as 3D reconstruction, point cloud smoothing and meshing. One important feature of the correspondence analysis that we evaluate in detail is the use of temporal information. Another emphasis is on correcting and smoothing the disparity images as well as the reconstructed point cloud without losing too much detail. We, hence, introduce our application of the Bilateral filter on disparity images and our usage of least squares smoothing. The components of the workflow were evaluated using three image sources: Endoscopic images from the daVinci® telemanipulator; images from a stereo camera integrated in the ARMAR III humanoid robot; synthetic data. Depending on the image resolution and the application, the workflow reconstructs surface models in real-time. We show that by using temporal information we obtain more accurate and robust correspondences. Additionally, the Bilateral filter was especially useful in refining the correspondences extracted from endoscopic images as well as the synthetic data sets, whereas the least squares method showed good results in smoothing the point cloud of ARMAR III images. Overall, the presented approach achieves good results for different camera settings and image types, especially with respect to the real-time requirement.
ó This paper describes ongoing effort in developing an anthropomorphic arm/hand manipulation syst... more ó This paper describes ongoing effort in developing an anthropomorphic arm/hand manipulation system as part of the German Humanoid Research Project SFB588. This project aims at building a humanoid robot that assists humans in everyday service tasks. The manipulation part of this project has to deal with a service environment and to cope with the wide variety of objects and
In this paper, we present a new humanoid robot currently being developed for applications in huma... more In this paper, we present a new humanoid robot currently being developed for applications in human-centered environ- ments. In order for humanoid robots to enter human-centered environments, it is indispensable to equip them with mani- pulative, perceptive and communicative skills necessary for real-time interaction with the environment and humans. The goal of our work is to provide reliable and highly
2013 IEEE/RSJ International Conference on Intelligent Robots and Systems, 2013
ABSTRACT Generating robot motion trajectories instantaneously in the moment unforeseen sensor eve... more ABSTRACT Generating robot motion trajectories instantaneously in the moment unforeseen sensor events happen is very essential for many real-world robot applications. Using a previous work on online trajectory generation as a basis, this paper proposes an alternative approach that also considers dynamic models. The former class of algorithms does not take into account dynamically changing acceleration capabilities based on maximum actuator forces/torques. This paper extends target velocity-based algorithms of the previous approach by taking into consideration the entire system dynamics when generating trajectories online within one control cycle (typically 1 ms or less). The extension includes the acceleration capabilities of a robot at every discrete time step assuming constant values for the maximum actuator forces/torques, thus allowing the generation of adaptive trajectory profiles during the motion of the robot. Several real-world experimental results using a seven-degree-of-freedom lightweight robot arm underline the relevance of this extension.
ABSTRACT The term "Visual Servoing" subsumes all control approaches, that use f... more ABSTRACT The term "Visual Servoing" subsumes all control approaches, that use feedback information extracted from vision sensors. Therefore corrective actions are being generated on the continuous analysis of camera images, e. g. for controlling a robot arm. In this article we present the Visual-Servoing system for the humanoid robot ARMAR-III which enables safe execution of single and dual-handed grasping and manipulation actions. Inaccuracy of actuators and sensor systems can be compensated by the closed-loop approach.
2010 IEEE International Conference on Robotics and Automation, 2010
The autonomous acquisition of object representations which allow recognition, localization and gr... more The autonomous acquisition of object representations which allow recognition, localization and grasping of objects in the environment is a challenging task, which has shown to be difficult. In this paper, we present a systems for autonomous acquisition of visual object representations, which endows a humanoid robot with the ability to enrich its internal object representation and allows the realization of
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Papers by Tamim Asfour