基于Skinner操作条件反射的两轮机器人自平衡控制

针对两轮自平衡机器人的运动平衡控制问题,采用了基于Skinner操作条件反射理论的自回归神经网络学习算法作为机器人的学习机制,利用自回归神经网络对评价函数进行逼近,以实现对行为决策的优化,从而使机器人能够在无需外部环境模型的情况下,通过学习和训练,获得像人或动物一样的自主学习技能,解决了两轮机器人的运动平衡控制问题.最后分别在无扰动和有扰动的两种状态下设计了仿真实验并进行了比较.结果表明,该操作条件反射学习机制具有较快的自主平衡控制技能和较好的鲁棒性能,体现了较高的理论研究意义和工程应用价值.     

两轮自平衡机器人动力学建模及其平衡控制*

针对高阶次、不稳定、多变量、非线性、强耦合的两轮自平衡移动机器人系统,采用Lagrange方程推导出动力学模型,对其进行稳定性和可控性判断,并利用LQR和龙伯格极点配置的方法在此模型的基础上对两轮自平衡机器人的姿态和速度进行控制,可获得较为稳定的动态平衡过程。给出了数学模型推导的具体步骤,分别采用以上两种方法进行了仿真研究和比较。仿真实验结果表明,这两种控制方法对机器人的稳定性控制都是有效的。其中龙伯格极点配置控制方法使系统的跟踪速度更快、稳定性更高,具有较高的实际应用价值。     

基于强化学习规则的两轮机器人自平衡控制

两轮机器人是一个典型的不稳定,非线性,强耦合的自平衡系统,在两轮机器人系统模型未知和没有先验经验的条件下,将强化学习算法和模糊神经网络有效结合,保证了函数逼近的快速性和收敛性,成功地实现两轮机器人的自学习平衡控制,并解决了两轮机器人连续状态空间和动作空间的强化学习问题;仿真和实验表明:该方法不仅在很短的时间内成功地完成对两轮机器人的平衡控制,而且在两轮机器人参数变化较大时,仍能维持两轮机器人的平衡。     

Skinner 操作条件反射的一种仿生学习算法与机器人控制

针对两轮自平衡机器人的运动平衡控制问题,提出了基于Skinner 操作条件反射理论的BP 神经网络 与资格迹相结合的仿生自主学习算法作为两轮机器人的学习机制．该算法利用资格迹能解决延迟影响、加快学习速 度和提高可靠性的特点,将其与BP 神经网络相结合构成复合学习算法,能够预测机器人将要获得的行为评价函数, 并依据概率取向机制以一定的概率选择最大评价值对应的最优行为,从而使机器人能够在未知环境下通过与环境的 交互、学习和训练,获得像人或动物一样的自主学习技能,实现对两轮机器人的运动平衡控制．最后,分别用基于 Skinner 操作条件反射理论的BP 算法和BP 资格迹复合算法对两轮机器人做了仿真实验并进行了比较．结果表明, 基于Skinner 操作条件反射理论的BP 资格迹复合仿生自主学习算法的学习机制能够使机器人获得良好的动态性能 和较快的学习速度,体现了机器人较强的自主学习技能和平衡控制能力．     

基于内在动机的智能机器人自主发育算法

针对两轮自平衡机器人在学习过程中主动性差的问题,受心理学内在动机理论启发,提出一种基于内在动机的智能机器人自主发育算法。该算法在强化学习的理论框架中,引入模拟人类好奇心的内在动机理论作为内部驱动力,与外部奖赏信号一起作用于整个学习过程。采用双层内部回归神经网络存储知识的学习与积累,使机器人逐步学会自主平衡技能。最后针对测量噪声污染对机器人平衡控制中两轮角速度的影响,进一步采用卡尔曼滤波方法进行补偿,以提高算法收敛速度,降低系统误差。仿真实验表明,该算法能够使两轮机器人通过与环境的交互获得认知,成功地学会运动平衡控制技能。     

模糊操作条件概率自动机仿生自主学习系统和机器人自平衡控制

为了实现两轮机器人的自平衡控制, 利用Skinner操作条件反射机理, 以概率自动机为平台, 融入模糊推理, 构造了模糊操作条件概率自动机(OCPA)仿生自主学习系统. 该学习系统是一个从状态集合到操作行为集合的随机映射, 采用操作条件反射学习机制, 从操作行为集合中随机学习作为控制系统控制信号的最优行为, 并利用学习到的操作行为取向值信息, 调整操作条件反射学习算法. 此外, 学习系统还引入行为熵, 以验证其自学习和自组织能力. 应用于两轮机器人自平衡控制的仿真结果, 验证了模糊OCPA学习系统的可行性.     

基于机器学习实现双轮机器人平衡控制的应用研究

为了有效地解决双轮机器人平衡控制问题,改善学习时间过长的问题,使双轮机器人具有自学习能力;将机器学习中强化学习算法应用于双轮机器人上,利用内部回归神经网络构造性能评价函数,设计了一种新型控制算法;该算法是一种不需要预测和辨识模型,在模型未知及没有先验经验的条件下,通过自身神经网络的在线学习,以实现对双轮机器人的自学习平衡控制; Matlab仿真以及物理实验表明:该方法能在短时间内成功实现对双轮机器人的自学习平衡控制,且在性能上优于其它学习算法.     

一种两轮自平衡机器人比例-积分-微分控制方法

两轮自平衡机器人以其机械结构简单,灵活高效的运动特性,具有广阔的应用前景。本文应用理论力学原理,分析并建立了两轮自平衡机器人的动力学模型。在此基础上,分别针对机器人系统的自平衡控制、速度控制设计了比例-积分-微分(PID)控制器。通过复频域和时域分析的方法,提出了一种简便的PID控制参数的整定方法。根据系统PID控制模型,给出了计算机器人马达输出转矩的理论公式。应用实验表明,该控制方法的平衡和速度控制动态和稳态性能良好,且具有占用机器人系统资源少,PID控制参数整定效率高的特点。     

自平衡两轮机器人的参数自整定模糊控制

为解决具有强耦合、非线性和不确定性等特点的自平衡两轮机器人的平衡控制问题,提出一种参数自整定模糊控制器.该控制器通过比较系统响应与给定的差别来对控制参数进行自整定,降低了控制器设计过程中对设计者经验的要求.该控制器采用零阶Takagi Sugeno模型,易于在嵌入式系统中实现.搭建了自平衡两轮机器人硬件本体,建立了相应的数学模型,并给出仿真与实验结果,验证了该控制器的有效性.     

非同轴两轮机器人自平衡与转向闭环控制

针对车速、车身侧倾角和前轮转角变化较大工况下的非同轴两轮机器人在基于前轮转角的自平衡控制中,因动力学模型准确性对自平衡控制带来的影响,设计了基于RBF神经网络模糊滑模控制的自平衡控制器,利用RBF神经网络的逼近特性,对动力学模型中非线性时变的不确定部分进行自适应逼近,从而提高动力学模型的准确性,并借助模糊规则削弱滑模控制中产生的系统抖振;以及因前轮转角用于自平衡控制中难以实现转向闭环控制,建立了基于纯跟踪法的轨迹跟踪控制器,并设计利用车身平衡时车身侧倾角与前轮转角的耦合关系,将转向闭环控制中的目标前轮转角替换为目标车身侧倾角,从而将自平衡控制器与轨迹跟踪控制器相结合,在保证车身平衡行驶的前提下,实现带有轨迹跟踪的转向闭环控制。实验结果表明,凭借动力学模型的较高准确性,RBF神经网络模糊滑模自平衡控制器具有鲁棒性好、超调量低和响应迅速的优点,并且利用车身平衡后车身侧倾角与前轮转角耦合关系,实现转向闭环控制是可行的,具有良好的轨迹跟踪效果。     

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。     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

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.     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.     

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.     

The Distributed Time-Triggered Simulation Scheme: Core Principles and Supporting Execution Engine

Distributed real-time simulation is a young technology field but its practice is under increasing demands. In recent years the author and his collaborators have been establishing a new approach called the distributed time-triggered simulation (DTS) scheme which is conceptually simple and easy to use but widely applicable. The concept was initiated in the course of developing a new-generation object-oriented real-time programming scheme called the time-triggered message-triggered object (TMO) programming scheme. Some fundamental issues inherent in distributed real-time simulation that were learned during recent experimental studies are discussed along with some approaches for resolving the issues. An execution engine developed to support both the TMOs engaged in control computation and the TMOs engaged in DTS is also discussed along with its possible extensions that will enable significantly larger-scale DTSs.     

Software-Konfigurationsmanagement in großen Softwareprojekten

Zusammenfassung Mit zunehmender Größe der Softwaresysteme verschärfen sich die für die Software-Herstellung typischen Probleme: Beherrschen großer Objektmengen, Erhalten der Systemkonsistenz, Kontrolle der ständigen Änderungseinflüsse und Gewährleisten einer langen Lebensdauer. Die Disziplin Konfigurationsmanagement bildet den methodischen Ansatz, diese Probleme besser zu beherrschen. Software-Konfigurationsmanagement faßt die Herstellung von Softwaresystemen als eine Abfolge von kontrollierten Änderungen an gesicherten Zwischen- und Endergebnissen auf. Dargestellt werden die Objekte und Funktionen des Software-Konfigurationsmanagements sowie die hierfür in großen Software-Projekten benötigten Methoden, Instanzen und Hilfsmittel.     

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。