基于深度强化学习的固体放射性废物抓取方法研究

针对固体放射性废物分拣作业中,放射性废物杂乱无序、远程遥操作抓取效率低、人工分拣危险性大等典型问题,提出一种基于深度强化学习的放射性固体废物抓取方法。该方法使用改进深度Q网络算法,通过获取的图像信息,使机器人与环境不断进行交互并获得回报奖励,回报奖励由机械臂动作执行结果和放射性区域内放射性活度的高低构成,根据◢Q◣值的大小得到机械臂的最佳抓取位置。用V-REP软件对UR5机械臂建立仿真模型,在仿真环境中完成不同类型固体放射性废物抓取的训练与测试。仿真结果表明,固体废物在松散放置时该方法可使机械臂抓取成功率大于90%,在紧密放置时抓取成功率大于65%,机械臂不会受到废物堆叠的影响,并且会优先抓取放射性区域内具有高放射性活度的物体。     

一种基于深度学习的机械臂抓取方法

提出了一种基于深度神经网络的机械臂最优抓取位置检测方法.相比传统手工设定的特征,基于深度神经网络的方法学习得到的特征具有较强的鲁棒性和稳定性,能够适应训练集中未曾出现的新物体.本方法首先使用基于深度学习的目标检测算法对图像中的目标物体进行检测,记录目标的类别和位置.然后根据分类检测结果,使用基于深度学习的机械臂抓取方法进行抓取位置学习.仿真实验表明所提方法能对图像中的目标物体进行较为准确的分类,在Universal Robot 5机械臂上得到的抓取实验结果证明了所提方法的有效性.     

基于机器视觉的目标定位与机器人规划系统研究

为完成机械臂在非特定复杂背景环境下的自主抓取,通过设计RGB-D相机对场景内的物体进行实时检测,采用基于深度学习的目标检测定位方法,并对相机-机械臂-目标物体的三维标定模型进行研究。将物体的三维坐标信息通过ROS话题机制发送给机械臂,并通过moveIT编程规划抓取规划。 通过设计一套基于ROS的视觉检测和机械臂抓取系统,将计算机视觉检测技术以及机械臂运动规划抓取应用在机器人操作系统ROS平台上。实验结果表明,该系统可以实时高效地操作机器人来完成指定的控制作业,提高了系统对环境的适应能力,该系统具有抓取准确、物体识别准确率高的特点,解决了传统机械臂操控中的不足。     

基于GPR和KRR组合模型的机械臂抓取研究

为了避免机械臂自主抓取方法中普遍存在的运动学求逆耗时和视觉系统标定计算复杂度高的问题,提出一种基于高斯过程回归(GPR)和核岭回归(KRR)组合模型的机械臂抓取方法.在学习阶段,训练基于Mask-RCNN的目标检测和实例分割算法及GPR和KRR的机械臂抓取策略;在抓取阶段,首先使用目标检测和实例分割算法获取目标物体的位...     

基于多约束条件的机器人抓取策略学习方法

针对机器人在多类别物体不同任务下的抓取决策问题,提出基于多约束条件的抓取策略学习方法.该方法以抓取对象特征和抓取任务属性为机器人抓取策略约束,通过映射人类抓取习惯规划抓取模式,并采用物体方向包围盒(OBB)建立机器人抓取规则,建立多约束条件的抓取模型.利用深度径向基(DRBF)网络模型结合减聚类算法(SCM)实现抓取策略的学习,两种算法的结合旨在提高学习鲁棒性与精确性.搭建以Refiex 1型灵巧手和AUBO六自由度机械臂组成的实验平台,对多类别物体进行抓取实验.实验结果表明,所提出方法使机器人有效学习到对多物体不同任务的最优抓取策略,具有良好的抓取决策能力.     

基于深度强化学习与旋量法的机械臂路径规划EI北大核心CSCD

深度强化学习在机械臂路径规划的应用中仍面临样本需求量大和获取成本高的问题.针对这些问题,本文基于数据增强的思路,提出了深度强化学习与旋量法的融合算法.本算法通过旋量法将与环境交互所得的自然轨迹进行有效复制,使深度强化学习样本利用率和算法训练效率得到提高;复制轨迹的同时对被控物体、障碍物等环境元素进行同步复制,以此提高机械臂在非结构环境中的泛化性能.最后,在具备物理模拟引擎的Mujoco仿真平台中,通过Fetch机械臂和UR5机械臂在非结构化环境下进行实验对比分析,结果表明了本文算法对于提升深度强化学习样本利用率和机械臂模型泛化性能的可行性及有效性.     

结合增量学习的物体抓取检测框架

为了解决未知类别物体的抓取问题，提出了一种结合增量学习的物体抓取检测框架，该框架分为抓取学习和增量学习两个阶段.在第1阶段，对已知的物体使用密集注意力网络进行训练，该网络利用注意力机制对特征通道和密集残差连接之间的关系进行建模.在第2阶段，引入了聚类优先样本选择策略，该策略会挑选出那些与其聚类质心距离相近的样本，用这些新样本替换掉示例集中的部分旧样本进行训练.此外在未知类别物体上训练网络时，还引入了蒸馏损失，以保留之前在已知类中学到的知识.通过在Jacquard数据集和UR10e机器人上进行的实验，表明了该方法在抓取未知类别物体方面有一定的可行性和有效性，克服了机器人在抓取未知类别物体上的缺陷.     

基于LSTM与非对称网络的改进DDPG算法研究

针对深度强化学习算法在复杂动态环境中训练时,由于环境的部分可观测性原因导致智能体难以获得有用信息而不能学习到良好策略且算法收敛速度慢等典型问题,提出一种基于LSTM和非对称actor-critic网络的改进DDPG算法。该算法在actor-critic网络结构中引入LSTM结构,通过记忆推理来学习部分可观测马尔可夫状态中的隐藏状态,同时在actor网络只使用RGB图像作为部分可观测输入的情况下,critic网络利用仿真环境的完全状态进行训练构成非对称网络,加快了训练收敛速度。通过在ROS中进行机械臂抓取仿真实验,结果显示该算法相比于DDPG、PPO和LSTM-DDPG算法获得了更高的成功率,同时具有较快的收敛速度。     

基于机器视觉的非特定物体的智能抓取系统的研究

针对传统机械臂局限于按既定流程对固定位姿的特定物体进行机械化抓取,设计了一种基于机器视觉的非特定物体的智能抓取系统;系统通过特定的卷积神经网络对深度相机采集到的图像进行目标定位,并在图像上预测出一个该目标的可靠抓取位置,系统进一步将抓取位置信息反馈给机械臂,机械臂根据该信息完成对目标物体的抓取操作;系统基于机器人操作系统,硬件之间通过机器人操作系统的话题机制传递必要信息;最终经多次实验结果表明,通过改进的快速搜索随机树运动规划算法,桌面型机械臂能够根据神经网络模型反馈的的标记位置对不同位姿的非特定物体进行实时有效的抓取,在一定程度上提高了机械臂的自主能力,弥补了传统机械臂的不足.     

基于深度强化学习的二连杆机械臂运动控制方法

针对二连杆机械臂的运动控制问题,提出了一种基于深度强化学习的控制方法。首先,搭建机械臂仿真环境,包括二连杆机械臂、目标物与障碍物;然后,根据环境模型的目标设置、状态变量和奖罚机制来建立三种深度强化学习模型进行训练,最后实现二连杆机械臂的运动控制。对比分析所提出的三种模型后,选择深度确定性策略梯度（DDPG）算法进行进一步研究来改进其适用性,从而缩短机械臂模型的调试时间,顺利避开障碍物到达目标。实验结果表明,所提深度强化学习方法能够有效控制二连杆机械臂的运动,改进后的DDPG算法控制模型的收敛速度提升了两倍并且收敛后的稳定性增强。相较于传统控制方法,所提深度强化学习控制方法效率更高,适用性更强。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于QTE的蒙古文显示机制研究与实现

蒙古语言是中国蒙古族使用的通用语言,由于蒙古文区别于其他文字的书写方式和其自身变形机制等特点,在很多通用的文字处理引擎中都不被支持。在嵌入式产品开发与应用领域中Linux加QTE已经成为流行方式。该文给出了一种在QTE环境上实现基于标准Unicode的蒙古文点阵显示和变形算法, 并自定义了支持蒙古文的QTE组件,扩展了QTE功能,为在Linux加QTE方式的嵌入式体系结构中处理蒙古文提供了一种解决方法。     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。