机器人手臂弹性动力学分析的高效算法

本文提出一种用于机器人手臂弹性动力学分析的新方法,该方法采用了动力学方程缩减技术,使计算时间大为减少。在此基础上针对关节型机器人结构特点,提出了考虑手臂关节之间的弹性连接的数学模型,使计算精度得到提高,最后给出了一个实例。

一种新的机器人自适应控制方式

本文提出了一种新的、有效的机器人自适应控制方式,克服了其他方法由于模型不准或计算量大等所带来的一系列问题。本文首先将 Lagrange 运动方程转化为 ARMA 模型,并用虚拟噪声补偿模型误差(即由于线性化、解耦、观测不准和干扰等误差).然后利用改进的 Kalman 自适应滤波算法在线进行参数辨识和状态估计,将获得的参数用于机器人控制系统自适应控制器的设计.最后给出了该算法的仿真结果并对此进行了讨论。

基于视觉的机器人激光焊接质量检测技术研究

视觉检测技术是随着计算机视觉技术和光电技术的飞速发展，而出现的一种新的检测技术。检测被测目标时，把图像当作检测和传递信息的手段或载体，从图像中提取有用的信号，它是以现代光学为基础，融光电子学、计算机图像学、信息处理、计算机视觉等科学技术为一体的现代检测技术。现代激光自动化焊接技术是由激光、计算机、机器人、数控和精密机床等相结合的综合高新技术,此项技术已成为工业生产自动化的关键技术，拥有普通加工技术所不能比拟的优势。为了克服机器人焊接过程中各种不确定因素对焊接质量的影响，提高机器人作业的智能化水平和工作可靠性，要求焊接机器人系统不仅能实现空间焊缝的实时跟踪，而且还能实现焊接参数的在线调整和焊缝质量的实时控制，即焊接机器人焊接过程的自主化和智能化。本文的研究依托于中国科学院知识创新工程方向性项目“全自动激光拼焊成套装备生产线”，旨在探索立体视觉检测系统的实现及其在激光拼焊工程中的应用的问题。从理论和实践两个方面，对其中的若干关键技术，如视觉检测系统创新设计、数学模型、量化误差、摄像机标定、结构光条纹中心线提取、焊前特征检测、溶池边缘提取、焊后缺陷图像匹配算法、三维重建和表面孔的视觉定位等进行了研究。主要研究成果如下： 1．提出了一种可以用于焊前跟踪，焊后检测，以及焊接过程中对激光溶池进行监测的多功能激光视觉检测装置。推导了检测系统在不考虑像平面安装倾斜角度时和考虑像平面安装倾斜角度时检测点坐标的计算公式以及量化误差公式，分别针对由于数模转换量化误差、安装角度倾斜误差、安装高度误差三个方面引起的量化误差，分析其关于行，列，以及不同倾斜角度的影响分布规律。并对于各种情况进行了仿真，对于各种误差分布特征进行了分析，提出了检测奇异点的情况和数学模型的局限性。以上工作为实现焊缝三维信息的高精度提取奠定了基础。 2．对于摄像机的标定技术进行了研究，结合工程实际，利用zhang的标定法和matlab标定工具包，对于摄像机进行了标定；针对检测相机视场较小，标定采集范围不易调整和相机的畸变主要发生在视场边缘等特征，在保证要求的精度范围之内，提出一种基于标定靶的标定方法，实验证明该方法的标定与测量精度能够满足工程需要。 3．研究了现有的条纹中心提取算法过程，提出了基于OTSU阈值的多次高斯拟合平均法和基于OTSU阈值的质心平均法计算激光条纹中心坐标。该法对条纹的噪声，散斑和被测工件表面漫反射有很强的抵制作用，因此具有很强的鲁棒性。实验表明，与传统方法相比，具有更高的提取精度。同时为了适应激光条纹被工件表面调制后发生的角度变化，以及硬件安装带来的激光线型条纹倾斜，提出了一种自适应方向模板法，可以解决特殊倾斜角度时的激光条纹中心线提取问题。三个仿真试验验证了方法的可行性。 4．提出了一套在线实时进行焊前检测的图形处理算法，可以实现焊缝宽度，焊前错配和焊缝中心位置检测。通过工程实验提取了各指标的检测结果，并验证了算法的正确性。 5．提出了一种基于数学形态学的激光拼焊溶池边缘检测算法，对于激光拼焊中的溶池图像进行边缘提取，基于真实图像进行了实验研究表明，提取边缘效果可以达到单像素。 6．对焊后表面形貌检测的图像实时处理算法进行了研究。提出了一套在线实时进行焊后焊缝表面缺陷检测的图形处理算法,可以进行焊缝宽度，错配，凹度，凸度，咬边，焊接倾角，过高七种表面焊接缺陷的匹配识别；对于整个焊缝的表面形貌进行三维重建。通过等厚板焊接和不等厚板焊接两种试验，验证了算法的合理性和鲁棒性。提出了一种基于randon变换的错配和兴趣区域快速检测算法。对于表面孔的检测算法进行了探讨，主要针对孔的检测中的噪声和表面反射，研究了腐蚀膨胀对于表面孔定位和大小的检测影响。 7．研究了以普通6R机器人进行焊缝视觉检测的工作视野，即焊缝视觉检测空间，提出了一种生成焊缝视觉检测空间的解算法；以此检测视野为依托，探索了在视觉检测视野中进行焊缝视觉检测的初始位置规划问题，提出了一种初始位置规划算法；仿真结果证明了算法的正确性。

Evolving Robocode Tank Fighters

In this paper, I describe the application of genetic programming to evolve a controller for a robotic tank in a simulated environment. The purpose is to explore how genetic techniques can best be applied to produce controllers based on subsumption and behavior oriented languages such as REX. As part of my implementation, I developed TableRex, a modification of REX that can be expressed on a fixed-length genome. Using a fixed subsumption architecture of TableRex modules, I evolved robots that beat some of the most competitive hand-coded adversaries.

The Effect of Transmission Design on Force-Controlled Manipulator Performance

Previous research in force control has focused on the choice of appropriate servo implementation without corresponding regard to the choice of mechanical hardware. This report analyzes the effect of mechanical properties such as contact compliance, actuator-to-joint compliance, torque ripple, and highly nonlinear dry friction in the transmission mechanisms of a manipulator. A set of requisites for high performance then guides the development of mechanical-design and servo strategies for improved performance. A single-degree-of-freedom transmission testbed was constructed that confirms the predicted effect of Coulomb friction on robustness; design and construction of a cable-driven, four-degree-of- freedom, "whole-arm" manipulator illustrates the recommended design strategies.

Residual Vibration Reduction in Computer Controlled Machines

Control of machines that exhibit flexibility becomes important when designers attempt to push the state of the art with faster, lighter machines. Three steps are necessary for the control of a flexible planet. First, a good model of the plant must exist. Second, a good controller must be designed. Third, inputs to the controller must be constructed using knowledge of the system dynamic response. There is a great deal of literature pertaining to modeling and control but little dealing with the shaping of system inputs. Chapter 2 examines two input shaping techniques based on frequency domain analysis. The first involves the use of the first deriviate of a gaussian exponential as a driving function template. The second, acasual filtering, involves removal of energy from the driving functions at the resonant frequencies of the system. Chapter 3 presents a linear programming technique for generating vibration-reducing driving functions for systems. Chapter 4 extends the results of the previous chapter by developing a direct solution to the new class of driving functions. A detailed analysis of the new technique is presented from five different perspectives and several extensions are presented. Chapter 5 verifies the theories of the previous two chapters with hardware experiments. Because the new technique resembles common signal filtering, chapter 6 compares the new approach to eleven standard filters. The new technique will be shown to result in less residual vibrations, have better robustness to system parameter uncertainty, and require less computation than other currently used shaping techniques.

Motion Planning with Six Degrees of Freedom

The motion planning problem is of central importance to the fields of robotics, spatial planning, and automated design. In robotics we are interested in the automatic synthesis of robot motions, given high-level specifications of tasks and geometric models of the robot and obstacles. The Mover's problem is to find a continuous, collision-free path for a moving object through an environment containing obstacles. We present an implemented algorithm for the classical formulation of the three-dimensional Mover's problem: given an arbitrary rigid polyhedral moving object P with three translational and three rotational degrees of freedom, find a continuous, collision-free path taking P from some initial configuration to a desired goal configuration. This thesis describes the first known implementation of a complete algorithm (at a given resolution) for the full six degree of freedom Movers' problem. The algorithm transforms the six degree of freedom planning problem into a point navigation problem in a six-dimensional configuration space (called C-Space). The C-Space obstacles, which characterize the physically unachievable configurations, are directly represented by six-dimensional manifolds whose boundaries are five dimensional C-surfaces. By characterizing these surfaces and their intersections, collision-free paths may be found by the closure of three operators which (i) slide along 5-dimensional intersections of level C-Space obstacles; (ii) slide along 1- to 4-dimensional intersections of level C-surfaces; and (iii) jump between 6 dimensional obstacles. Implementing the point navigation operators requires solving fundamental representational and algorithmic questions: we will derive new structural properties of the C-Space constraints and shoe how to construct and represent C-Surfaces and their intersection manifolds. A definition and new theoretical results are presented for a six-dimensional C-Space extension of the generalized Voronoi diagram, called the C-Voronoi diagram, whose structure we relate to the C-surface intersection manifolds. The representations and algorithms we develop impact many geometric planning problems, and extend to Cartesian manipulators with six degrees of freedom.

Performance evaluation of the RPL Protocol in fixed and mobile sinks low-power and lossy networks.

Low-Power and Lossy-Network (LLN) are usually composed of static nodes, but the increase demand for mobility in mobile robotic and dynamic environment raises the question how a routing protocol for low-power and lossy-networks such as (RPL) would perform if a mobile sink is deployed. In this paper we investigate and evaluate the behaviour of the RPL protocol in fixed and mobile sink environments with respect to different network metrics such as latency, packet delivery ratio (PDR) and energy consumption. Extensive simulation using instant Contiki simulator show significant performance differences between fixed and mobile sink environments. Fixed sink LLNs performed better in terms of average power consumption, latency and packet delivery ratio. The results demonstrated also that RPL protocol is sensitive to mobility and it increases the number of isolated nodes.

JUBA-II. La enseñanza experiencial en un concurso de robótica

La enseñanza utilizando proyectos es una metodología activa de aprendizaje de gran eficiencia. En este trabajo se expone la experiencia de los alumnos que han participado en un proyecto muy especial, la construcción de un robot para el concurso internacional, “Laureate Award for Excellence in Robotic Engineering”. Los alumnos expondrán el bagaje competencial que llevaron al proyecto, de dónde provenía (formal o informal, reglado o no reglado, teórico o experiencial) y cómo ha contribuido este proyecto al refuerzo y adquisición de nuevas competencias y talentos, que contribuyen a una formación integral, poliédrica; tanto desde el punto de vista profesional, como personal.

Teaching from Examples in Assembly and Manipulation of Snack Food Ingredients by Robot

T. G. Williams, J.J. Rowland, and Lee M.H., Teaching from Examples in Assembly and Manipulation of Snack Food Ingredients by Robot, Proc. IEEE/RSJ Int. Conf. on Robots and Systems (IROS 2001), Nov., 2001, pp2300-2305.

Functional genomic hypothesis generation and experimentation by a robot scientist

King R. D., Whelan, K. E., Jones, F. M., Reiser, P. G. K., Bryant, C. H., Muggleton, S., Kell, D. B. and Oliver, S. G. (2004) Functional genomic hypothesis generation and experimentation by a robot scientist. Nature 427 (6971) p247-252

Diminishing Returns of Engineering Effort in Telerobotic Systems

Wilson, M.S. and Neal, M.J., 'Diminishing Returns of Engineering Effort in Telerobotic Systems', IEEE Transactions on Systems, Man and Cybernetics - Part A:Systems and Humans, 2001, September, volume 31, number 5, pp 459-465, IEEE Robotics and Automation Society, ed. Dautenhahn,K., Special Issue on Socially Intelligent Agents - The Human in the Loop

An ontology for a Robot Scientist

Soldatova, L., Clare, A., Sparkes, A. and King, R. D. (2006) An ontology for a robot scientist. Bioinformatics 2006 22: 464-471

Developmental Learning for Autonomous Robots

M.H. Lee, Q. Meng and F. Chao, 'Developmental Learning for Autonomous Robots', Robotics and Autonomous Systems, 55(9), pp 750-759, 2007.

Staged Competence Learning in Developmental Robotics

M.H. Lee, Q. Meng and F. Chao, 'Staged Competence Learning in Developmental Robotics', Adaptive Behavior, 15(3), pp 241-255, 2007. the full text will be available in September 2008