检索结果-内蒙古大学图书馆

IEEE Conference on Control Technology and Applications (CCTA)

作者： D. Hughes J.T. Wen Control Laboratory for Mechanical Structures (CLaMS) Center for Advanced Technology in Automation Robotics & Manufacturing Department of Electrical Computer and Systems Engineering Rensselaer Polytechnic Institute Troy NY USA

Smart materials such as piezoceramics and shape memory alloys (SMAs) exhibit significant hysteresis and in order to estimate the effect on open and closed loop control a suitable model is needed. One promising candidate is the Preisach independent domain hysteresis model that is characterized by the congruent minor loop and wiping out properties. Comparable minor loop and decaying oscillation test data for a multi-sheet piezoceramic actuator (made of lead zirconate titanate) attached to a flexible beam are presented and are seen to be very consistent with the two Preisach model properties. The commanded parameter is the sheet transverse electric field while the measured parameter is an approximately colocated strain induced in the beam. Equivalent data for a Nitinol SMA wire muscle, attached to the same beam, are also presented. The input and output parameters are the SMA current and a beam strain respectfully. The minor loop and wiping out evidence is less strong than that of the piezoceramic case, but encouraging. In all experiments the quasi-steady state responses were generated in order to avoid exciting beam flexible modes which would complicate the analysis.

关键词： Piezoelectric materials Shape memory alloys Hysteresis Strain measurement Shape control Open loop systems Testing Actuators Titanium compounds Electric variables measurement

来源：评论

学校读者我要写书评

暂无评论

A novel method to calculate looming cue for threat of collision

A novel method to calculate looming cue for threat of collis...

引用

International Symposium on Computer Vision (ISCV)

作者： K. Joarder D. Raviv The Electrical Engineering Department and The Robotics Center Florida Atlantic University Boca Raton FL USA Intelligent Systems Division National Institute for Standards and Technology Gaithersburg MD USA

Visual looming is related to an increased projected size of an object on a viewer's retina as the relative distance between the viewer and the object decreases. Psychologists have reported about subjects avoiding collision using this information by reacting defensively. In this paper we present a quantitative approach to visual looming and describe a novel method to measure this visual cue using visual fixation and studying the relative change in irradiance in the image. This visual cue can be used in the sense of a threat of collision for autonomous obstacle avoidance.

关键词： Retina Intelligent robots Psychology Intelligent systems Timing Acceleration Animals Nervous system Robot sensing systems Measurement units

来源：评论

学校读者我要写书评

暂无评论

Synthesized passive feedback control of sensor-rich smart structures-experimental results

Synthesized passive feedback control of sensor-rich smart st...

引用

IEEE Conference on Control Technology and Applications (CCTA)

作者： P. Akella J.T. Wen Control Laboratory for Mechanical Structures Department of Electrical Computer and Systems EngineeringCenter for Advanced Technology in Automation Robotics & Manufacturing Rensselaer Polytechnic Institute RPI Troy NY USA

Passivity based controllers are used in structural control due to their inherent robustness properties. These controllers require sensor/actuator collocation. In this paper, we consider the design of a "squaring down" matrix which renders a system passive by using a linear combination of all collocated and non-collocated sensor/actuator pairs. The design uses experimental transfer functions and does not require the knowledge of the system model. The problem of finding the squaring down matrix is cast as a solution to a set of linear matrix inequalities (LMIs) subject to some additional performance considerations. The design procedure of the squaring down matrix assumes that velocity information is available from the sensors which is not generally the case. We show that the squaring down matrix can be implemented without the use of such velocity information. We provide experimental results gathered from the single link flexible beam setup in the C/sub La/MS laboratory at RPI to show that implementation of passive loops without velocity measurements provides very good results.

关键词： Feedback control Linear matrix inequalities Intelligent sensors Control system synthesis Robust control Sensor systems Hydraulic actuators Transfer functions Laboratories Economic indicators

来源：评论

学校读者我要写书评

暂无评论

Complete algorithms for reorienting polyhedral parts using a pivoting gripper

Complete algorithms for reorienting polyhedral parts using a...

引用

IEEE International Conference on robotics and Automation (ICRA)

作者： A. Rao D. Kriegman K. Goldberg Department of Computer Science Utrecht University Postbus Utrecht Netherlands Center for Systems Science Department of Electrical Engineering Yale University New Heaven CT USA University of Utrecht Netherlands Institute for Robotics and Intelligent Systems Department of Computer Science University of Southern California Los Angeles CA USA

To rapidly feed industrial parts on an assembly line, Carlisle et. al. (1994) proposed a flexible part feeding system that drops parts on a flat conveyor belt, determines the pose of parts with a vision system and manipulates them into a desired pose. A robot arm with 4-DOF is capable of moving parts through 6-DOF when equipped with a passive pivoting axis between the parallel jaws of its gripper. We refer to these actions as pivot grasps. This paper considers the planning problem. Given a polyhedral part shape, coefficient of friction and a pair of stable configurations as input, find pairs of grasp points that will cause the part to pivot from one stable configuration to the other. For some transitions, pivot grasps may not exist. For a part with n faces and m stable configurations, we give an O(m/sup 2/n log n) algorithm to generate the m/spl times/m matrix of pivot grasps. When the part is star shaped, this reduces to O(m/sup 2/n). We also study a generalization that considers "capture regions" around stable configurations. Both algorithms are complete in that they are guaranteed to find pivot grasps when they exist.

关键词： Grippers robotics and automation Service robots Feeds Belts Machine vision Computer science Intelligent robots Manipulators Robotic assembly

来源：评论

学校读者我要写书评

暂无评论

PLACING REGISTRATION MARKS

引用

IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS 1994年第1期41卷 51-59页

作者： RAO, AS GOLDBERG, KY Department of Computer Science University of Utrecht Utrecht Netherlands Departments of Computer Science and Electrical Engineering-Systems Institute of Robotics and Intelligent Systems University of Southern California Los Angeles CA USA

In industrial assembly, a registration mark can be placed on parts to aid a computer vision system in determining the position and orientation (pose) of parts. However, when sensor noise and limits on resolution introduce errors in the measured location of the registration mark, these errors can propagate into the measurement of part pose. In this paper, we define the registration mark problem: given an n-sided rigid planar polygonal part-and a set of k poses for the part, locate a point on the surface of the part that maximizes the minimum distance between transformed points. A registration mark at this point will be maximally robust to sensor imperfections. We give an 0(n log n + k4 log k log* k) time algorithm to solve this planar problem using a result from Schwartz and Sharir [21], and demonstrate the algorithm using a commercial vision system. Our results extend to classes of curved planar parts and polyhedral parts.

关键词： Computer vision Computer errors Noise measurement Manufacturing automation robotics and automation Computer science Intelligent robots Computer industry Assembly systems Robustness

来源：评论

学校读者我要写书评

暂无评论

Parallel texture analysis using high-order statistics and neural networks

Parallel texture analysis using high-order statistics and ne...

引用

1994 International Symposium on Speech, Image Processing and Neural Networks, ISSIPNN 1994

作者： Araujo, H. Dias, J. Almeida, A.T. Institute of Systems and Robotics Department of Electrical Engineering University of Coimbra Coimbra3000 Portugal

ISBN: (纸本)078031865X

In this paper we present a texture analysis and classification method based on the computation of high-order statistics of gray-levels or selected features. The computation of these high-order statistics can be performed in parallel in non-overlapping windows that cover the full image. Classification is performed by neural networks. In this extended summary results are presented for backpropagation networks only, but several other types of neural nets were also tested. © 1994 IEEE.

关键词：

来源：评论

学校读者我要写书评

暂无评论

3D laser-based sensor for robotics

3D laser-based sensor for robotics

引用

Mediterranean Electrotechnical Conference (MELECON)

作者： L. Marques F. Moita U. Nunes A.T. de Almeida ISR-Institute of Systems and Robotics Electrical Engineering Department University of Coimbra Coimbra Portugal

The paper presents the analysis and design of a distance and orientation sensor based on the triangulation principle, using three laser diodes and a position sensitive detector (PSD). A 16-bit microcontroller controls the acquisition and the lasers, processes the data and integrates the sensor in a distributed sensor network (DSN). A DSP based processing system gathers the multisensor data, for real-time control of a PUMA 560 robot manipulator through the DSN network. A sensor model based on theoretical and experimental results is emphasized.< >

关键词： Robot sensing systems Optical design Diode lasers Position sensitive particle detectors Microcontrollers Optical control Laser modes Laser theory Digital signal processing Real time systems

来源：评论

学校读者我要写书评

暂无评论

Integral Force Control with Robustness Enhancement

引用

IEEE Control systems 1994年第1期14卷 31-40页

作者： Wilfinger, L.S. Wen, J.T. Murphy, S.H. The Department of Electrical Computer and Systems Engineering Rensselaer Polytechnic Institute Troy 12180 United States ABB Robotics 72168 Vasteras Sweden

For robotic tasks involving contact between the robot end effector and the environment, force feedback is frequently used to maintain the required force of interaction. Among the many force control strategies proposed in the literature, integral force feedback has been found to be the most desirable algorithm due to its robustness with respect to the measurement time delay and its removal of steady state force error. However, there has not been any serious investigation of the controller performance under large force disturbances. We have experimentally observed that large force disturbances can cause bouncing instability of a nominally stable force control system. Motivated by this observation, we augment the standard integral force controller with three robustness enhancements: integral error scaling, force set-point scheduling, and integral windup saturation. Extensive experimentation on surfaces with different stiffness has shown the dramatic improvement of the modified controller.< >

关键词： Force control Robust control Force feedback Robots Force measurement Error correction End effectors Time measurement Delay effects Steady-state

来源：评论

学校读者我要写书评

暂无评论

Design of a mission management system for the autonomous underwater vehicle MARIUS

Design of a mission management system for the autonomous und...

引用

Symposium on Autonomous Underwater Vehicle Technology (AUV)

作者： C. Bizingre P. Oliveira A. Pascoal F.L. Pereira J.-P. Pignon E. Silva C. Silvestre J.B. de Sousa Thomson Sintra Activités-Sous-Mariiies Arcueil France Department of Electrical Engineering and Institute for Systems and Robotics (ISR) Instituto Superior Técnico Lisboa Portugal Department of Electrical Engineering Institute for Systems and Robotic Porto Portugal

This paper describes the initial design phase of the software control architecture for the AUV MARIUS. This research effort is part of a long term project that aims to enable the prototype vehicle to carry out environmental surveying missions in coastal waters, in a completely autonomous mode. Throughout the project, MARIUS will be used as an advanced testbed to test developments in the areas of mission planning and real-time mission execution systems for AUVs.

关键词： Underwater vehicles Computer architecture Remotely operated vehicles Mobile robots Control systems Marine vehicles Sea measurements System testing Artificial intelligence Contracts

来源：评论

学校读者我要写书评

暂无评论

Robot 3D force-based surface-tracking

Robot 3D force-based surface-tracking

引用

International Conference on Industrial Electronics, Control and Instrumentation

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

The problem of control of a robot manipulator performing compliant tasks is addressed. The force and position control is based on the Smith predictor design. For the overall control we are pursuing a behaviour-based architecture approach. The paper describes a 3D surface tracking behaviour controller. The tracking operation is performed in real-time using contact force feedback. Surface tracking is an important operation for self-teaching and exploratory tasks in unknown environments. It can be seen as a first step to the more general and important problem of surface following in contact. A method for tool tip contact frame calibration is presented. Results of simulations and real-time implementation are presented and discussed.< >

关键词： Force control Control systems Force feedback Force sensors Manipulator dynamics Robot control Position control Calibration Force measurement Geometry

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：