检索结果-内蒙古大学图书馆

American Control Conference (ACC)

作者： E. Hallberg I. Kaminer A. Pascoal Department of Aeronautical and Astronautical Engineering Naval Postgraduate School Monterrey CA USA Department of Electrical Engineering and Institute for Systems and Robotics (ISR) Instituto Superior Technico Lisboa Portugal

This paper describes the development of a rapid prototyping system for flight testing of guidance, navigation, and control algorithms for unmanned air vehicles. The system affords a small team the ability to take a new concept in guidance, navigation, and control from initial conception to flight test. In order to do this, a number of engineering problems had to be overcome addressing a gamut of issues including weight, power, portability, risk, electronic interference, vibration, manpower, etc. The main contribution of the paper is the proof of concept flight test demonstration of a new integrated guidance and control algorithm.

关键词： System testing Prototypes Navigation Control systems Unmanned aerial vehicles Aerospace engineering Automotive engineering Design engineering Power engineering and energy Aerospace electronics

来源：评论

学校读者我要写书评

暂无评论

Map building using fuzzy ART, and learning to navigate a mobile robot on an unknown world

Map building using fuzzy ART, and learning to navigate a mob...

引用

IEEE International Conference on robotics and Automation (ICRA)

作者： R. Araujo A.T. de Almeida Dept. of Electr. Eng. Coimbra Univ. Portugal Institute for Systems and Robotics (ISR) and Electrical Engineering Department University of Coimbra Portugal

This paper introduces a new approach, based on the application of the fuzzy ART neural architecture, for online map building from actual sensor data collected with a mobile robot. This method is then integrated as a complement, on the parti-game learning approach, allowing the system to make a more efficient use of collected sensor information. Also, a predictive online trajectory filtering method is introduced on the learning approach. Instead of having a mechanical device (robot) moving to search the world the idea is to have the system analysing trajectories in a predictive mode, by taking advantage of the improved world model. The real robot will only move to try trajectories that have been predicted to be successful, allowing lower exploration costs. This results on an overall new and powerful method for simultaneous and cooperative construction of a world model, and learning to navigate from an initial position to a goal region on an unknown world. It is assumed that the robot knows its own current world location. It is additionally assumed that the mobile robot is able to perform sensor-based obstacle detection (not avoidance), and straight-line motions. Results of experiments with a real Nomad 200 mobile robot will be presented, demonstrating the effectiveness of the proposed methods.

关键词： Subspace constraints Navigation Mobile robots Trajectory Robot sensing systems Buildings Mechanical sensors Sensor systems Filtering Predictive models

来源：评论

学校读者我要写书评

暂无评论

Fuzzy ART based approach for real-time map building

Fuzzy ART based approach for real-time map building

引用

International Workshop on Advanced Motion Control (AMC)

作者： R. Araujo A.T. de Almeida Dept. of Electr. Eng. Coimbra Univ. Portugal Institute for Systems and Robotics (ISR) and Electrical Engineering Department University of Coimbra Coimbra Portugal

In order to perform complicated tasks in previously unknown indoor environments, autonomous mobile robots must be able to acquire models of their environments. The model or map, is often used for planning robot motions which perform a task while avoiding obstacles in the environment. Applications where there is no previously available world model usually rely on sensor systems, such as laser range finders, and infrared and sonar range sensors, to collect thousands of range points which are difficult to handle and interpret. The paper introduces an approach, based on the fuzzy ART neural architecture, for online map building. The map is incrementally constructed in real-time by fitting rectangular geometrical primitives to actual sensor data collected with a mobile robot. This results in a compact world model that is easy to integrate into planning approaches. A sensor data filtering approach is proposed to reject noisy range points. It is assumed that the robot knows its own current world location. Results of experiments with a real Nomad 200 mobile robot are presented, demonstrating the operation of the proposed map building method.

关键词： Subspace constraints Mobile robots Infrared sensors Indoor environments Motion planning Robot motion Sensor systems Laser modes Sonar applications Sensor systems and applications

来源：评论

学校读者我要写书评

暂无评论

Exploring spherical image properties for robot navigation

Exploring spherical image properties for robot navigation

引用

IEEE International Workshop on Intelligent Robots and systems (IROS)

作者： I. Fonseca J. Dias Dept. of Electr. Eng. Coimbra Univ. Portugal Institute of Systems and Robotics Electrical Engineering Department Polo II University of Coimbra Coimbra Portugal

Addresses the problem of performing navigation with a mobile robot using active vision exploring the image sphere properties in a stereo divergent configuration. The navigational process is supported by the control of the robot's steering and forward movements just using visual information as feedback. The steering control solution is based on the difference between signals of visual motion flow computed in images on different positions of a virtual image sphere. The majority of solutions based on motion flow and proposed until now, were usually very unstable because they normally compute other parameters from the motion flow. In our case the control is based directly on the different between motion flow signals on different images. Those multiple images are obtained by small mirrors, that simulate cameras positioned in different positions on the image sphere. The control algorithm described in this work is based on a discrete-event approach to generate a control feedback signal for navigation of an autonomous robot with an active vision system.

关键词： Navigation Feedback Motion control Robot vision systems Control systems Mobile robots Robot control Mirrors Computational modeling Cameras

来源：评论

学校读者我要写书评

暂无评论

Subtly different facial expression recognition and expression intensity estimation

Subtly different facial expression recognition and expressio...

引用

Conference on Computer Vision and Pattern Recognition (CVPR)

作者： J.J.-J. Lien T. Kanade J.F. Cohn Ching-Chung Li Vision and Autonomous Systems Center The Robotics Institute Carnegie Mellon University Pittsburgh PA USA Department of Electrical Engineering University of Pittsburgh Pittsburgh PA USA Department of Psychology University of Pittsburgh USA Department of Electrical Engineering University of Pittsburgh USA

We have developed a computer vision system, including both facial feature extraction and recognition, that automatically discriminates among subtly different facial expressions. Expression classification is based on Facial Action Coding System (FACS) action units (AUs), and discrimination is performed using Hidden Markov Models (HMMs). Three methods are developed to extract facial expression information for automatic recognition. The first method is facial feature point tracking using a coarse-to-fine pyramid method. This method is sensitive to subtle feature motion and is capable of handling large displacements with sub-pixel accuracy. The second method is dense flow tracking together with principal component analysis (PCA) where the entire facial motion information per frame is compressed to a low-dimensional weight vector. The third method is high gradient component (i.e., furrow) analysis in the spatio-temporal domain, which exploits the transient variation associated with the facial expression. Upon extraction of the facial information, non-rigid facial expression is separated from the rigid head motion component, and the face images are automatically aligned and normalized using an affine transformation. This system also provides expression intensity estimation, which has significant effect on the actual meaning of the expression.

关键词： Face recognition Data mining Facial features Hidden Markov models Principal component analysis Computer vision Tracking Motion analysis Image coding Transient analysis

来源：评论

学校读者我要写书评

暂无评论

Automated facial expression recognition based on FACS action units

Automated facial expression recognition based on FACS action...

引用

International Conference on Automatic Face and Gesture Recognition

作者： J.J. Lien T. Kanade J.F. Cohn Ching-Chung Li Vision and Autonomous Systems Center The Robotics Institute Carnegie Mellon University Pittsburgh PA USA Department of Electrical Engineering University of Pittsburgh Pittsburgh PA USA Department of Psychology University of Pittsburgh

Automated recognition of facial expression is an important addition to computer vision research because of its relevance to the study of psychological phenomena and the development of human-computer interaction (HCI). We developed a computer vision system that automatically recognizes individual action units or action unit combinations in the upper face using hidden Markov models (HMMs). Our approach to facial expression recognition is based an the Facial Action Coding System (FACS), which separates expressions into upper and lower face action. We use three approaches to extract facial expression information: (1) facial feature point tracking; (2) dense flow tracking with principal component analysis (PCA); and (3) high gradient component detection (i.e. furrow detection). The recognition results of the upper face expressions using feature point tracking, dense flow tracking, and high gradient component detection are 85%, 93% and 85%, respectively.

关键词： Face recognition Face detection Computational Intelligence Society Computer vision Neutron spin echo Principal component analysis Humans Image recognition Image motion analysis Psychology

来源：评论

学校读者我要写书评

暂无评论

Guidance and control of the SIRENE underwater vehicle: from system design to tests at sea

Guidance and control of the SIRENE underwater vehicle: from ...

引用

OCEANS

作者： P. Oliverira C. Silvestre P. Aguiar A. Pascoal Dept. of Electr. Eng. Inst. Superior Tecnico Lisbon Portugal Department of Electrical Engineering Institute of Systems and Robotics and Instituto Superior Técnico Lisboa Portugal

The paper describes the implementation and testing at sea of the control and guidance systems of SIRENE, an autonomous underwater shuttle for the automatic deployment of benthic stations down to depths of 4000 meters.

关键词： Navigation Control systems Underwater vehicles System testing Laboratories Automatic testing Automatic control Marine vehicles Computer architecture Motion control

来源：评论

学校读者我要写书评

暂无评论

Plant/controller optimization with applications to integrated surface sizing and feedback controller design for autonomous underwater vehicles (AUVs)

Plant/controller optimization with applications to integrate...

引用

American Control Conference (ACC)

作者： C. Silvestre A. Pascoal I. Kaminer A. Healey Institute for Systems and Robotics and Department of Electrical Engineering Instituto Superior Technico Lisboa Portugal Department of Aeronautics and Astronautics Naval Postgraduate School Monterrey CA USA Autonomous Underwater Vehicles Laboratory and Department of Mechanical Engineering Naval Postgraduate School Monterrey CA USA

This paper describes a solution to the following plant-controller optimization (PCO) problem: given an autonomous underwater vehicle (AUV)-with a fixed baseline body configuration-that is required to operate over a finite number of representative trimming conditions in the vertical plane, determine the optimal size of the bow and stern control surfaces so that a weighted average J of the power required at trimming is minimized, subject to the conditions that: (i) a given set of open loop requirements are met, and (ii) stabilizing feedback controllers can be designed to meet desired time and frequency closed loop performance requirements about each trimming point. The solution proposed is rooted in the theory of linear matrix inequalities (LMIs) and leads to efficient PCO algorithms that build on a recently released LMI Toolbox.

关键词： Adaptive control Size control Open loop systems Underwater vehicles Optimal control Control systems Linear matrix inequalities Optimization methods Constraint optimization Robots

来源：评论

学校读者我要写书评

暂无评论

Intelligent Navigation on a Autonomous Vehicle

引用

IFAC Proceedings Volumes 1998年第3期31卷 247-252页

作者： Nelson Costa Manuel Crisóstomo Paulo Coimbra Aníbal T. de Almeida † Assistant at the Polytechnic Institute ofLeiria Morro do Lena Alto Vieiro - 2400 Leiria - PORTUGAL Tel. +351.44.820349 Fax. +351.39.7006247 Researcher at the Institute for Systems and Robotics - University of Coimbra Pinhal de Marrocos - 3030 Coimbra - PORTUGAL. Professor at the Electrical Engineering Department - University of Coimbra Tel. +351.39.7006286 Fax. +351.39.7006247

The work presented in this paper describes a low cost implementation of mobile vehicles, capable of moving in semi-structured environments, using an ultrasonic sensor based approach for navigation. The first robot developed knows a working map which contains permanent obstacles. The use of external sensing mechanisms allows the vehicle to interact with its environment in a flexible manner, in order to move autonomously in the test area, detecting unknown obstacles and avoid them. The movement is ensured by two stepping motors without feedback. A radio communication system was also developed allowing the transfer of live video pictures and data between the robot and a remote station. The user interface is performed by a portable computer placed onto the robot. In this way it is possible to endow the robot with new capacities, increasing its flexibility. In order to give a greater degree of intelligence, reliability, usability, and safety a second prototype is being developed. To ensure this a more efficient and robust navigation, composed by map acquisition, planning and steering algorithms together with the use of additional sensors such as electronic compass and infrared proximity sensors is being developed.

关键词： Vehicle sensors navigation path planning control

来源：评论

学校读者我要写书评

暂无评论

Visual behaviors for real-time control of a binocular active vision system

引用

CONTROL engineering PRACTICE 1997年第10期5卷 1451-1461页

作者： Batista, J Peixoto, P Araujo, H Department of Electrical Engineering Institute of Systems and Robotics University of Coimbra Coimbra Portugal

An active vision system has to enable the implementation of reactive visual processes and of elementary visual behaviors in real time. Therefore the control architecture is extremely important. This paper discusses a number of issues related to the implementation of a real-time control architecture, and describes an architecture being used with camera heads. Even though in most applications a fully calibrated system is not required, a methodology for calibrating the camera head is also described, taking advantage of its degrees of freedom. Several visual processes are implemented, computing relevant measures for the control process. At higher levels the architecture is modelled as a state transition system. Finally, the paper shows how this architecture can be used to implement a pursuit behavior using optical flow. Copyright (C) 1997 Elsevier Science Ltd.

关键词： active vision real-time tracking smooth pursuit

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：