A cooperative multi-agent robotics system: Design and modelling

This paper presents the development of the robotic multi-agent system SMART. In this system, the agent concept is applied to both hardware and software entities. Hardware agents are robots, with three and four legs, and an IP-camera that takes images of the scene where the cooperative task is carried out. Hardware agents strongly cooperate with software agents. These latter agents can be classified into image processing, communications, task management and decision making, planning and trajectory generation agents. To model, control and evaluate the performance of cooperative tasks among agents, a kind of Petri Net, called Work-Flow Petri Net, is used. Experimental results shows the good performance of the system.     

Bayesian modeling of the risk of non-repeatability for the networked robotic system

This study addresses one of the most important performance criteria, namely the robot’s repeatability, from the e-quality for manufacture (EQM) point of view within the framework of networked robotic system. Real-time monitoring and control of remotely located robots allow the operators to continuously assess the risk of robot’s non-repeatability. The elaborated methodology of predictive modeling on the risk of robot’s non-repeatability consists of three stages: (1) regression analysis on the association between the disturbing factors and the key performance variables that influence the robot repeatability; (2) probabilistic assessment on the admissible deviations of key performance variables that simulate the robot operations as probabilities of job service without failures in the queueing system; and (3) Bayesian assessment on the risk of non-repeatability for the robot operations. The proposed methodology is expected to reduce the risk of robot’s non-repeatability, which is better suited for today’s networked, distributed production environment, where quality standards are stringent and customer expectations are high.     

SMART: Student modeling approach for responsive tutoring

This paper describes a new student modeling paradigm called SMART. The premise is that a single, principled approach to student modeling, involving both theoretical and empirical methods, can render automated instruction more efficacious across a broad array of instructional domains. After defining key terms and discussing limitations to previous student modeling paradigms, I describe the SMART approach, as embedded within a statistics tutor called Stat Lady (Shute and Gluck, 1994). SMART works in conjunction with a tutor design where low-level knowledge and skills (i.e., curricular elements) are identified and separated into three main outcome types. Throughout the tutor, curricular elements with values below a pre-set mastery criterion are instructed, evaluated, and remediated, if necessary. The diagnostic part of the student model is driven by a series of regression equations based on the level of assistance the computer gives each person, per curriculum element. Remediation on a given element occurs when a subject fails to achieve mastery during assessment, which follows instruction. Remediation is precise because each element knows its location within the tutor where it is instructed and assessed. I end with a summary of results from two controlled evaluations of SMART examining the following research issues: (a) diagnostic validity, (b) individual differences in learning from Stat Lady, (c) affective perceptions of the tutorial experience, and (d) contributions of mastery and remediation to learning outcome and efficiency. Comments about related and future research with this paradigm are offered.     

Deadlock avoidance schemes in a distributed robotic system: Petri net modeling and analysis

This article presents a Petri net-based approach to modeling and evaluating four different deadlock avoidance schemes for a distributed robotic system, i.e., a five-robot-five-assembly-line system. Among these four schemes are the conventional, full synchronization, global semaphore, and partial synchronization schemes. To explore such issues as the system performance and control structure complexity, this article conducts detailed Petri net modeling for this system and evaluates performance of the deadlock avoidance schemes using stochastic Petri nets. The interesting results presented include that: (1) any possible system deadlock can seriously degrade the system performance even if effective deadlock resolution techniques are available; (2) conservative use of resources is likely to be the best policy; and (3) higher resource utilization may not necessarily imply higher system production rate in a resource-sharing environment. The related results need to be further explored for the larger resource-sharing discrete event systems. © 1995 John Wiley & Sons, Inc.     

Remote robotic underwater grinding system and modeling for rectification of hydroelectric structures

A submersible grinding robot has been designed to automate the dam gate metallic structure repair process. In order to measure and control the amount of material removed during the process, an empirical approach for modeling the material removal rate (MRR) of the underwater grinding application is proposed and presented in this paper. The objective is to determine the MRR in terms of the process parameters such as cutting speed and grinding power over a range of variable wheel diameters. Experiments show that water causes drag and a significant loss of power occurs during grinding. An air injector encasing the grinding wheel has been prototyped, and it is shown that power loss can be reduced by up to 80%. A model, based on motor characterization and empirical relations among system and process parameters, is developed for predicting MRR which will be used for the robotic grinding control system. A validation is carried out through experiments, and confirms the good accuracy of the model for predicting the depth of cut for underwater grinding. A comparative study for dry and underwater grinding is also conducted through experiments and shows that the MRR is higher for underwater grinding than in dry conditions at low cutting speeds.     

An integrated processing energy modeling and optimization of automated robotic polishing system

The automated robotic polishing system (ARPS) consisting of several robotic polishing cells (RPCs) is widely adopted in polishing industry to replace manual labor. Recently, energy-saving becomes a hotspot issue in manufacturing industry because of the increase in energy costs and requirement of environmental protection. Traditionally, robot motion planning and task scheduling are carried out separately and sequentially, which constrain the potential for energy-saving. In this paper, a task energy characteristic model is proposed as a polynomial function of the feedrate override to forecast the energy consumption of the polishing process of RPC, in which the designed parameters of the RPC and the polishing process parameters are encapsulated into the polynomial coefficients based on experimental data. Furthermore, an optimization model is proposed for an ARPS with mass tasks to minimize the energy consumption, in which the robot motion planning and the task scheduling are considered integratedly. An adaptive genetic algorithm with elite retention strategy is adopted to solve the optimization model. A case study is introduced to verify the proposed approach, which demonstrates the forecast error of task energy is less than 7%, and the proposed optimization approach can reduce the energy consumption of ARPS by more than 18% compared with the original processing scheme.     

Design a personalised product service system utilising a multi-agent system

To help achieve sustainability, reduce the risk of uncertainty, and fulfil a variety of customer needs, the concept of a Product Service System has evolved for use as a business model. While previous studies have addressed PSS development, there is yet no dynamic methodology enabling a PSS to adjust quickly to external changes and customer response. With that gap in mind, this paper presents a Multi-Agent-based Personalised Product Service System (MAPPSS) system. MAPPSS provides a reliable method for analysis which is applicable in various pervasive environments. With this proposed system, users are able to select expected service characteristics, after which service composition is conducted by selecting related products and services from a database. In a comparison of existing systems using different scenarios, we show that customer acceptance, energy utilization, and product utilization generate a two-digit improvement with the proposed system, while profit and costs may increase slightly. When using the proposed method, the competence of an enterprise can be enhanced as a result of these user-oriented features. The performance monitoring and iterating elements of the system allow an almost immediate improvement in the generated PSS.     

Design fundamentals of a reconfigurable robotic gripper system

Discusses the design and modeling fundamentals of a multi-degree-of-freedom reconfigurable robotic gripper system (RGS), designed to automate the process of limp material handling, reliably and without distortion, deformation, and/or folding. The reconfigurable gripper design draws upon a previously reported flat surfaced, fixed-dimensions gripper system (Kolluru et al., 1998). The design consists of four arms in a cross-bar configuration, with a flat surfaced, fixed dimensions, suction-based gripper unit mounted on each of the arms. The kinematic and dynamic performance of the reconfigurable RGS is analyzed theoretically and then validated using Integrated Design Engineering Analysis Software (I-DEAS) simulation software     

Discrete-time modeling and control of robotic manipulators

A general approach is presented to derive discrete-time models of robotic manipulators. Such models are obtained by applying numerical discretization techniques directly to the problem of the minimization of the Lagrange action functional. Although these models are in implicit form, they own a dynamic structure that allows us to design discrete-time feedback linearizing control laws. The proposed models and control algorithms are validated by simulation with reference to a three link robot.     

Multimedia Indexing with the SMART system

The storage and retrieval of multimedia data is a crucial problem in multimedia information systems due to the huge storage requirements. It is necessary to provide an efficient methodology for the indexing of multimedia data for rapid retrieval. The aim of this paper is to introduce a methodology to represent, simplify, store, retrieve and reconstruct an image from a repository. An algebraic representation of the spatio-temporal relations present in a document is constructed from an equivalent graph representation and used to index the document. We use this representation to simplify and later reconstruct the complete index. This methodology has been tested by implementation of a prototype system called Simplified Modeling to Access and ReTrieve multimedia information (SMART). Experimental results show that the complexity of an index of a 2D document is O (n^*(n−1)/k) with k≥2 as opposed to the O (n^*(n−1)/2) known so far. Since k depends on the number of objects in an image more complex documents have lower overall complexity.     

基于MAS的政府采购平台设计与分析

在研究政府采购和电子商务的基础上,建立了多Agent技术在G to B中的应用模型,阐述了相应的商务流程,讨论了多Agent之间的协作、通信和安全等问题,给出了评标和投标的策略以及安全认证方案。     

基于多Agent的聚合级装备保障CGF系统设计

聚合级装备保障CGF系统提高了基于分布式战场环境的装备保障仿真训练的复杂度和逼真度,是装备保障仿真训练系统的重要组成部分。在简要分析聚合级CGF系统基本概念和结构的基础上,提出了基于多Agent的聚合级装备保障CGF系统的体系结构,在理论上初步探讨了系统的运行机制和通信机制。     

Automated modeling of modular robotic configurations

This research presents an automated method to build kinematic and dynamic models for assembling modular components of modular robotic systems. By comparison with other approaches, the proposed method is applicable to any robotic configuration with serial, parallel, or hybrid structures. In addition, it is object oriented so that each modular component is an element with a submodel and the overall model can be assembled from submodels subject to the connection constraints.     

基于K64机械臂控制系统的设计与实现

机械臂被广泛应用,其结合不同末端工具来完成特定功能。机械臂的合理使用能大大解放人力,代替人们完成一些重复枯燥或危险的工作。针对自行设计的三自由度机械臂,提出一种专用的嵌入式控制系统。该控制系统以K64为核心控制板,MQX_Lite为操作系统,通过与上位机的通信解析相关命令,计算相应关节旋转角度,多任务并发执行。通过实验验证,该系统运行平稳高效,具有很强的应用价值。     

Design and evaluation of an ambient assisted living system based on an argumentative multi-agent system

This paper focuses on ambient assisted living systems employed to monitor the ongoing situations of elderly people living independently. Such situations are represented here as contexts inferred by multiple software agents out of the data gathered from sensors within a home. Sensors can give an incomplete, sometimes ambiguous, picture of the world; hence, they often lead to inconsistent contexts and unreliability on the system as a whole. We report on a solution to this problem based on a multi-agent system where each agent is able to support its understanding of the context through arguments. These arguments can then be compared against each other to determine which agent provides the most reliable interpretation of the reality under observation.     

MAPS: a system for multi-agent coordination

MAPS (Multi-Agent Planning System) is a system for multi-agent coordination that has been developed in the robot soccer domain. It uses potential fields to model the environment and provide directives for the robots. The key feature that enables successful coordination is the use of a shared world model. This paper describes MAPS and demonstrates it as a viable coordination system for use in multiple robot domains.     

Modular dynamic virtual-reality modeling of robotic systems

This article presents the results of research into the field of dynamic simulation of mechanical and robotic systems. The main goal of the whole project is to achieve an efficient modular approach to modeling, in order to make the modeling process easier, ensure its traceability and inspectability, and support model reuse. This is achieved through the declarative definition of models, the standardization of model interfaces, and the object-oriented approach to model development and model data management. The article presents the specific features ofa general-purpose simulation environment, including an overview of the 3D solid modeling software interfaces. The modeling and simulation of a 3-DOF gripper designed for Space robotics applications is also discussed to show the performance of the whole simulation environment in terms of complexity management, efficiency, and accuracy     

Behavioral modeling and verification of multi-agent systems for manufacturing control

Simulation is the primary approach to the performance analysis of multi-agent manufacturing systems. In a typical simulation experiment, varying the agent negotiation protocol’s timing parameters can yield incomparable results in performance terms due to behavioral problems such as deadlocks and livelocks. Formal verification can help resolve such problems and therefore plays an important role in the design of agent negotiation protocols. We describe an efficient and scalable approach to formal verification based on an industrial-strength model checking tool and illustrate it with an example.     

Flapping flight for biomimetic robotic insects: part I-system modeling

This paper presents the mathematical modeling of flapping flight inch-size micro aerial vehicles (MAVs), namely micromechanical flying insects (MFIs). The target robotic insects are electromechanical devices propelled by a pair of independent flapping wings to achieve sustained autonomous flight, thereby mimicking real insects. In this paper, we describe the system dynamic models which include several elements that are substantially different from those present in fixed or rotary wing MAVs. These models include the wing-thorax dynamics, the flapping flight aerodynamics at a low Reynolds number regime, the body dynamics, and the biomimetic sensory system consisting of ocelli, halteres, magnetic compass, and optical flow sensors. The mathematical models are developed based on biological principles, analytical models, and experimental data. They are presented in the Virtual Insect Flight Simulator (VIFS) and are integrated together to give a realistic simulation for MFI and insect flight. VIFS is a software tool intended for modeling flapping flight mechanisms and for testing and evaluating the performance of different flight control algorithms.