检索结果-内蒙古大学图书馆

IEEE International Conference on robotics and Automation (ICRA)

作者： Jing-Xin Shi A. Albu-Schaffer G. Hirzinger Research Establishment DLR Institute for Robotics and System Dynamics German Aerospace Wessling Germany

Compared with industrial robots, the DLR lightweight robot characterizes a new milestone in the field of robot design. The module structure, the highly integrated electrical and mechanical components, the very low own-weight/load ratio, the high motion speed as well as the joint-torque feedback capability are the main features of this new robot generation aiming towards the functionality of a human arm. The paper attempts to integrate the newest results in the field of robotics, nonlinear control theory and electric drive systems to formulate the possible solutions of the dynamic control issues, Some experimental or simulation results are given to confirm the effectiveness of the proposed control approaches.

关键词： Lighting control Robot control Orbital robotics Robot sensing systems Service robots Aerodynamics Humans Torque Feedback Aerospace industry

来源：评论

学校读者我要写书评

暂无评论

Intensity and feature based stereo matching by disparity parameterization

Intensity and feature based stereo matching by disparity par...

引用

International Conference on Computer Vision (ICCV)

作者： Guo-Qing Wei G. Hirzinger Institute of Robotics and System Dynamics German Aerospace Research Establishment (DLR) Oberpfaffenhofen Germany

In this paper, we propose a new solution to the stereo correspondence problem by including features an intensity based matching. The features we use are intensity gradients in both the x and y directions of the left and the deformed right images. Although a uniform smoothness constraint is still used, it is nevertheless applied only to non-feature regions. To avoid local minima in function minimization, we propose to parameterize the disparity function by hierarchical Gaussians. A simple stochastic gradient method is used to estimate the Gaussian weights. Experiments with various real stereo images show robust performances.

关键词： Stochastic processes Gradient methods Robustness Stereo vision Interpolation Cameras Robots Aerodynamics Humans Machine vision

来源：评论

学校读者我要写书评

暂无评论

Computation of minimal realizations of periodic systems

Computation of minimal realizations of periodic systems

引用

IEEE Conference on Decision and Control

作者： A. Varga DLR-Oberpfaffenhofen Institute of Robotics and System Dynamics German Aerospace Center Wessling Germany

We propose balancing related numerically reliable methods to compute minimal realizations of linear periodic systems with time-varying dimensions. The first method belongs to the family of square-root methods with guaranteed enhanced computational accuracy and can be used to compute balanced minimal order realizations. An alternative balancing-free square-root method has the advantage of a potentially better numerical accuracy in case of poorly scaled original systems. The key numerical computation in both methods is the solution of nonnegative periodic Lyapunov equations directly for the Cholesky factors of the solutions. For this purpose, a numerically reliable computational algorithm is proposed to solve nonnegative periodic Lyapunov equations with time-varying dimensions.

关键词： Time varying systems Equations Algorithm design and analysis Observability Eigenvalues and eigenfunctions Robots Aerodynamics Control systems Robustness

来源：评论

学校读者我要写书评

暂无评论

Learning techniques in a dataglove based telemanipulation system for the DLR hand

Learning techniques in a dataglove based telemanipulation sy...

引用

IEEE International Conference on robotics and Automation (ICRA)

作者： M. Fischer P. van der Smagt G. Hirzinger Institute of Robotics and System Dynamics German Aerospace Research Establishment (DLR) Wessling Germany

We present a setup to control a four-finger anthropomorphic robot hand using a dataglove. To be able to accurately use the dataglove we implemented a nonlinear learning calibration using a novel neural network technique. Experiments show that a resulting positioning error not exceeding 1.8 mm, but typically 0.5 mm, per finger can be obtained; this accuracy is sufficiently precise for grasping tasks. Based on the dataglove calibration we present a solution for the mapping of human and artificial hand workspaces that enables an operator to intuitively and easily telemanipulate objects with the artificial hand.

关键词： Data gloves Fingers Calibration Humans Robots Artificial neural networks Switches Aerodynamics Ear Grasping

来源：评论

学校读者我要写书评

暂无评论

LQG/LTR robust flight control design with enforced controller bandwidth restriction

LQG/LTR robust flight control design with enforced controlle...

引用

Guidance, Navigation, and Control Conference and Exhibit, 1998

作者： Kienitz, Karl Heinz Grübel, Georg Instituto Tecnológico de Aeronáutica Department of Systems and Control Alexander-von-Humboldt Foundation CNPq S. José dos Campos Brazil Deutsches Zentrum für Luft- und Raumfahrt Oberpfaffenhofen Institute of Robotics and System Dynamics Germany

This contribution discusses a novel approach to design of robust controllers explicitly taking into account bandwidth restrictions of onboard computer implementation. This is achieved by online modal controller reduction during the synthesis-tuning phase in a multiobjective-optimization design environment. This is different to common approaches where implementability issues of high-order controllers resulting from analytic synthesis procedures are deferred to a separate post-design step. The approach is applied to lateral flight control in the HIRM (High Incidence Research Model) Design Challenge problem defined by GARTEUR (Group for Aeronautical Research and Technology in Europe). For analytical controller synthesis the dual LQG/LTR (Linear Quadratic Gaussian/Loop Transfer Recovery) method is used. © 1998, American institute of Aeronautics and Astronautics, Inc.

关键词： Multiobjective optimization

来源：评论

学校读者我要写书评

暂无评论

Hybrid Automata for Modeling Discrete Transitions in Complex Dynamic systems

引用

IFAC Proceedings Volumes 1998年第29期31卷 43-48页

作者： Pieter J. Mosterman Gautam Biswas Institute of Robotics and System Dynamics DLR Oberpfaffenhofen D-82230 Wessling. Germany. Knowledge Systems Laboratory Stanford University Stanford CA 94305. U.S.A.

Hybrid system models combine continuous behavior evolution with discrete mode transitions. These transitions may cause discontinuous changes in the field that defines continuous system behavior and the variable values associated with the continuous state vector. In reality, these discontinuous changes are fast continuous transients. To simplify the analysis of these transients time scale and parameter abstractions are applied to system models with very different impacts on the analysis of system behavior. We have developed a systematic modeling approach based on hybrid automata which combines a priori and a posteriori switching values to formally implement switching semantics associated with the abstraction events.

关键词： hybrid systems compositional modeling modeling abstractions

来源：评论

学校读者我要写书评

暂无评论

Real-time visual servoing for laparoscopic surgery

引用

IEEE ENGINEERING IN MEDICINE AND BIOLOGY MAGAZINE 1997年第1期16卷 40-45页

作者： Wei, GQ ARbter, K Hirzinger, G German AeroSpace Research Establishment Institute of Robotics and System Dynamics DLR Germany

The authors propose a visual tracking method for stereo laparoscopes, which is robust, simple, and operates at a maximum rate of 17 Hz. The use of a stereo laparoscope enables the robot to track the instrument in both lateral and longitudinal motions. Due to the multiplicity of problems with shape analysis, the authors do not check for the presence of any particular shape or structure. Instead, they use color information alone for instrument segmentation. The non-uniqueness of the instrument color inspires the authors to distinguish it by use of an artificial color mark. They analyzed the color distribution of typical laparoscopic images and chose a color that did not appear to mark the instrument. With color image segmentation, the mark can be correctly located in the image and used to control the robot motion. Thus, even if only a very small part of the instrument is visible, reliable data can still be obtained for robot control. The image processing component is implemented on a commercially available image processing system MaxVideo MV200 (Datacube, Inc., Danvers, MA). The robot the authors use is the AESOP 1000 (Automated Endoscope system for Optimal Positioning) (Computer Motion, Inc., Goleta, CA).

关键词： Visual servoing Minimally invasive surgery Motion control Robot control Robot motion Image segmentation Instruments Laparoscopes Image color analysis Tracking

来源：评论

学校读者我要写书评

暂无评论

Parametric shape-from-shading by radial basis functions

引用

IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE 1997年第4期19卷 353-365页

作者： Wei, GQ Hirzinger, G Institute of Robotics and System Dynamics German Aerospace Research Establishment Oberpfaffenhofen Germany

In this paper, we present a new method of shape from shading by using radial basis functions to parameterize the object depth. The radial basis functions are deformed by adjusting their centers, widths, and weights such that the intensity errors are minimized. The initial centers and widths are arranged hierarchically to speed up convergence and to stabilize the solution. Although the smoothness constraint is used, ii can be eventually dropped out without causing instabilities in the solution. An important feature of our parametric shape-from-shading method is that it offers a unified framework for integration of multiple sensory information. We show that knowledge about surface depth and/or surface normals anywhere in the image can be easily incorporated into the shape from shading process. It is further demonstrated that even qualitative knowledge can be used in shape from shading to improve 3D reconstruction. Experimental comparisons of our method with several existing ones are made by using both synthetic and real images. Results show that our solution is more accurate than the others.

关键词： shape from shading radial basis functions hierarchical structure depth constraints normals constraints qualitative knowledge stochastic gradient method

来源：评论

学校读者我要写书评

暂无评论

Automatic tracking of laparoscopic instruments by color coding 1st

Automatic tracking of laparoscopic instruments by color codi...

引用

1st Joint Conference on Computer Vision, Virtual Reality and robotics in Medicine / Medical robotics and Computer-Assisted Surgery (CVRMed-MRCAS 97)

作者： Wei, GQ Arbter, K Hirzinger, G German Aerospace Research Establishment Institute of Robotics and System Dynamics Oberpfaffenhofen 82234 Germany

ISBN: (纸本)3540627340

In this paper we describe an autonomous laparoscopic guidance system for laparoscopic surgery. By analyzing the color histogram of typical laparoscopic images, we propose to code the instrument by a color that does not appear. In terms of image processing, we segment the color mark in the visual image and use the location information to control a robot such that the tip of the color-coded surgical instrument are continuously shown in the central area of the monitor device and a constant distance is held in the case of stereo. The system is implemented by using an image processing hardware and a robot which are all commercially available. Clinical tests show the robustness and efficacy of the system.

关键词： Color

来源：评论

学校读者我要写书评

暂无评论

Periodic Lyapunov equations: Some applications and new algorithms

引用

INTERNATIONAL JOURNAL OF CONTROL 1997年第1期67卷 69-87页

作者： Varga, A DLR–Oberpfaffenhofen German Aerospace Research Establishment Institute for Robotics and System Dynamics Wessling D-82230 P.O.B. 1116 Germany

The discrete-time periodic Lyapunov equation has several important applications in the analysis and design of linear periodic control systems. Specific applications considered are the solution of state- and output-feedback optimal periodic control problems, the stabilization by periodic state feedback and the square-root balancing of discrete-time periodic systems. Efficient and numerically reliable algorithms based on the periodic Schur decomposition are proposed for the solution of periodic Lyapunov equations. The proposed algorithms are extensions of the direct solution methods for standard discrete-time Lyapunov equations for the case of indefinite as well as non-negative definite solution.

关键词： Lyapunov methods

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：