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作者： Elibol, Armagan Gracias, Nuno Garcia, Rafael Kim, Jinwhan Division of Ocean Systems Engineering Korea Advanced Institute of Science and Technology Yuseong Daejeon 305-701 Korea Republic of Computer Vision and Robotics Group University of Girona Campus Montilivi Edifici P4 17071 Girona Spain

One of the crucial steps in image mosaicing is global alignment, which requires finding the best image registration parameters by employing nonlinear minimization methods over correspondences between overlapping image pairs for a dataset. Based on graph theory, we propose a simple but efficient method to reduce the number of overlapping image pairs without any noticeable effect on the final mosaic quality. This reduction significantly lowers the computational cost of the image mosaicing process. The proposed method can be applied in a topology estimation process to reduce the number of image matching attempts. The method has been validated through experiments on challenging underwater image sequences obtained during sea trials with different unmanned underwater vehicles. © 2014 Optical Society of America.

关键词： Graph theory

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Auto-adjusting Camera Exposure for Outdoor robotics using Gradient Information

Auto-adjusting Camera Exposure for Outdoor Robotics using Gr...

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IEEE/RSJ International Conference on Intelligent Robots and Systems

作者： Inwook Shim Joon-Young Lee In So Kweon Robotics and Computer Vision Laboratory Division of Future Vehicle KAIST Daejeon 305-701 Korea Robotics and Computer Vision Laboratory Department of Electrical Engineering KAIST Daejeon 305-701 Korea Department of Electrical Engineering KAIST Daejeon 307-701 Korea

ISBN: (纸本)9781479969357

We present a new method to auto-adjust camera exposure for outdoor robotics. In outdoor environments, scene dynamic range may be wider than the dynamic range of the cameras due to sunlight and skylight. This can results in failures of vision-based algorithms because important image features are missing due to under-/over-saturation. To solve the problem, we adjust camera exposure to maximize image features in the gradient domain. By exploiting the gradient domain, our method naturally determines the proper exposure needed to capture important image features in a manner that is robust against illumination conditions. The proposed method is implemented using an off-the-shelf machine vision camera and is evaluated using outdoor robotics applications. Experimental results demonstrate the effectiveness of our method, which improves the performance of robot vision algorithms.

关键词： Cameras Lighting Robot vision systems Manuals Dynamic range Heuristic algorithms

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RGBD sensor and mirrors: A practical setup for 3D reconstruction of dynamic objects

RGBD sensor and mirrors: A practical setup for 3D reconstruc...

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International Conference on Ubiquitous Robots and Ambient Intelligence (URAI)

作者： Min-Hyun Kim Jaesik Park In So Kweon Robotics and Computer Vision Laboratory KAIST Daejeon Korea Korea Advanced Institute of Science and Technology Daejeon Daejeon KR

ISBN: (纸本)9781479953349

In order to get full 3D model from consumer depth cameras, previous approaches used set of synchronized depth cameras or moved the depth sensor around the target object. This on-going work introduces a cost effective and convenient framework for filming dynamic 3D object. This set is comprised of a consumer depth camera, or RGBD sensor and a pair of mirrors. Because of the images reflected from two mirrors in the system, it can capture a depth-map of the target object in an extended view. The practicality and effectiveness of this framework is demonstrated.

关键词： Three-dimensional displays Mirrors Robot sensing systems Cameras Mathematical model Equations Joints

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Online discovery of AUV control policies to overcome thruster failures

Online discovery of AUV control policies to overcome thruste...

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IEEE International Conference on robotics and Automation (ICRA)

作者： Seyed Reza Ahmadzadeh Matteo Leonetti Arnau Carrera Marc Carreras Petar Kormushev Darwin G. Caldwell Department of Advanced Robotics Istituto Italiano di Tecnologia Genova Italy Department of Computer Science The University of Texas at Austin Austin TX Computer Vision and Robotics Group (VICOROB) University of Girona Girona Spain

We investigate methods to improve fault-tolerance of Autonomous Underwater Vehicles (AUVs) to increase their reliability and persistent autonomy. We propose a learning-based approach that is able to discover new control policies to overcome thruster failures as they happen. The proposed approach is a model-based direct policy search that learns on an on-board simulated model of the AUV. The model is adapted to a new condition when a fault is detected and isolated. Since the approach generates an optimal trajectory, the learned fault-tolerant policy is able to navigate the AUV towards a specified target with minimum cost. Finally, the learned policy is executed on the real robot in a closed-loop using the state feedback of the AUV. Unlike most existing methods which rely on the redundancy of thrusters, our approach is also applicable when the AUV becomes under-actuated in the presence of a fault. To validate the feasibility and efficiency of the presented approach, we evaluate it with three learning algorithms and three policy representations with increasing complexity. The proposed method is tested on a real AUV, Girona500.

关键词： Optimization Trajectory Vectors Vehicles Robots Fault tolerance Fault tolerant systems

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Autonomous I-AUV Docking for Fixed-base Manipulation

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IFAC Proceedings Volumes 2014年第3期47卷 12160-12165页

作者： Narcís Palomeras Pere Ridao David Ribas Guillem Vallicrosa Computer Vision and Robotics Research Institute Scientific and Technological Park of the University of Girona CIRS Building C/ Pic de Peguera CO 17071 Girona Catalonia - Spain

While commercially available autonomous underwater vehicles (AUVs) are routinely used in survey missions, a new set of applications exist demanding intervention capabilities. This is the case, for instance, of the maintenance of permanent underwater observatories or submerged oil wells. These tasks, currently undertaken by remotely operated vehicles (ROVs), can be automated using intervention AUVs (I-AUVs) reducing their complexity and costs. The TRITON spanish funded project proposes the use of light I-AUV for autonomous intervention tasks, such as valve turning or connector pluging/unpluging, in adapted sub-sea infrastructures. To this aim, this paper presents the design and implementation of an I-AUV-friendly sub-sea docking panel, as well as the vision-based autonomous docking procedure for the Girona 500 lightweight I-AUV. The panel implements a funnel-based docking method for passive accommodation. It also includes a T valve and a custom designed hot stab connector. Once docked, the I-AUV and the panel become rigid and basic fixed-base manipulation strategies can be used for manipulation.

关键词： Autonomous vehicles Marine systems Robot navigation Robot vision Robot control Robotic manipulators

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Optimal Production Planning for the Virgin Olive Oil Elaboration Process

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IFAC Proceedings Volumes 2014年第3期47卷 8921-8926页

作者： P. Cano Marchal D. Martínez Gila J. Gámez García J. Gómez Ortega Group of Robotics Automation and Computer Vision University of Jaén. Agrifood Campus of International Excellence (ceiA3) ES–23071 Jaén Spain

The quality and obtained quantity of Virgin Olive Oil is bounded by the characteristics of the olives to be processed, and further determined by the influence of the process variables during the actual elaboration. Since the quality of the olives evolves during the harvesting season, it is relevant to consider when to harvest the olives in order to maximize the profit over the whole season. This work proposes a method to determine an optimal production plan for the whole harvesting season and presents the results obtained in its application to four different scenarios.

关键词： Production planning and control Intelligent decision support systems in manufacturing

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Computed torque control with variable gains through Gaussian process regression

Computed torque control with variable gains through Gaussian...

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IEEE-RAS International Conference on Humanoid Robots

作者： Nicolas Torres Alberto Michael Mistry Freek Stulp Robotics and Computer Vision ENSTA-Paris Tech Paris France School of Computer Science University of Birmingham UK FLOWERS Team INRIA Bordeaux Sud-Ouest Talence France

In computed torque control, robot dynamics are predicted by dynamic models. This enables more compliant control, as the gains of the feedback term can be lowered, because the task of compensating for robot dynamics is delegated from the feedback to the feedforward term. Previous work has shown that Gaussian process regression is an effective method for learning computed torque control, by setting the feedforward torques to the mean of the Gaussian process. We extend this work by also exploiting the variance predicted by the Gaussian process, by lowering the gains if the variance is low. This enables an automatic adaptation of the gains to the uncertainty in the computed torque model, and leads to more compliant low-gain control as the robot learns more accurate models over time. On a simulated 7-DOF robot manipulator, we demonstrate how accurate tracking is achieved, despite the gains being lowered over time.

关键词： Ground penetrating radar Computational modeling Robots Torque Joints Trajectory Gaussian processes

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Iterative Learning Control for Machining with Industrial Robots

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IFAC Proceedings Volumes 2014年第3期47卷 9327-9333页

作者： Pablo Cano Marchal Olof Sörnmo Björn Olofsson Anders Robertsson Juan Gómez Ortega Rolf Johansson Group of Robotics Automation and Computer Vision University of Jaén ES–23071 Jaén Spain Department of Automatic Control LTH Lund University SE–221 00 Lund Sweden

We consider an iterative learning control (ILC) approach to machining with industrial robots. The robot and the milling process are modeled using system identification methods with a data-driven approach. Two different model-based ILC algorithms are proposed and subsequently experimentally verified in a milling scenario. The difference between the two approaches is the required sensors for acquiring relevant input data for the algorithms. The results from the experiments indicate that the proposed methods have the potential of significantly decreasing the position errors in robotic machining, up to 85% in the considered milling scenario.

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Intervention AUVs: The next challenge 19

Intervention AUVs: The next challenge

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19th IFAC World Congress on International Federation of Automatic Control, IFAC 2014

作者： Ridao, Pere Carreras, Marc Ribas, David Sanz, Pedro J. Oliver, Gabriel Computer Vision and Robotics Research Institute Scientific and Technological Park University of Girona CIRS Building C/Pic de Peguera Girona CataloniaCO 17071 Spain Av. Vicent Sos Banyat S/N Castelln12006 Spain Cra. Valldemossa Palma07122 Spain

ISBN: (纸本)9783902823625

While commercially available AUVs are routinely used in survey missions, a new set of applications exists which clearly demand intervention capabilities. The maintenance of: permanent observatories underwater;submerged oil wells;cabled sensor networks;pipes;and the deployment and recovery of benthic stations are but a few of them. These tasks are addressed nowadays using manned submersibles or work-class ROVs, equipped with teleoperated arms under human supervision. Although researchers have recently opened the door to future I-AUVs, a long path is still necessary to pave the way to underwater intervention applications performed in an autonomous way. This paper reviews the evolution timeline in autonomous underwater intervention systems. Milestone projects in the state of the art are reviewed, highlighting their principal contributions to the field. To the best of the authors knowledge only three vehicles have demonstrated some autonomous intervention capabilities so far: ALIVE, SAUVIM and GIRONA 500 I-AUV. Next, GIRONA 500 I-AUV is presented and its software architecture discussed. Recent results in different scenarios are reported: 1) Valve turning and connector plugging/unplugging while docked to a sub-sea panel, 2) Free floating valve turning using learning by demonstration, and 3) Free floating multipurpose multisensory based object recovery. The paper ends discussing the lessons learned so far and presenting the authors view of the future. © IFAC.

关键词： Autonomous underwater vehicles

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Control Strategies for a Humanoid Robot to Drive and then Egress a Utility Vehicle for Remote Approach

Control Strategies for a Humanoid Robot to Drive and then Eg...

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IEEE-RAS International Conference on Humanoid Robots

作者： Hyobin Jeong Jaesung Oh Mingeuk Kim Kyungdon Joo In So Kweon Jun-Ho Oh Humanoid Research Center School of Mechanical Aerospace & Systems Engineering Department of Mechanical Engineering Korea Advanced Institute of Science and Technology Robotics and Computer Vision Laboratory School of Mechanical Aerospace & Systems Engineering Department of Electrical Engineering Korea Advanced Institute of Science and Technology Department of Electrical Engineering KAIST

ISBN: (纸本)9781479968862

This paper proposes strategies for the driving and egress of a vehicle with a humanoid robot. To drive the vehicle, the RANSAC method was used to detect obstacles, and the Wagon model was used to control the steering and velocity of the vehicle with only a limited number of sensors which were installed on the humanoid robot. Additionally, a manual teleoperating method was used with the lane projection technique. For the egress motion, gain override and the Cartesian position/force control technique were used to interact with the vehicle structure. To overcome the disadvantages of a highly geared manipulator, a special technique was used that included modelled friction compensation and a non-complementary switching mode. DRC-HUBO+ used the proposed method to perform a vehicle driving and egress task in the DRC finals 2015.

关键词： Humanoid robots EGRESS vehicle Vehicle driving Automobile driving UTILITY VEHICLES control strategy friction compensation DRIVES Steering

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