Model-integrated mechatronics - toward a new paradigm in the development of manufacturing systems

The traditional approach for the development of manufacturing systems considers the constituent parts of the system, i.e., mechanical, electronic, and software, to be developed independently and then integrated to form the final system. This approach is being criticized as inappropriate for the complexity and the dynamics of today's systems. This paper proposes an architecture that promotes model integration not only for implementation space artifacts but also in artifacts of the early analysis and design phases of the development process. The proposed architecture, which promotes reuse and significantly decreases development and validation time, is at the heart of a new paradigm called model-integrated mechatronics (MIM). MIM applies domain-specific modeling languages for the concurrent engineering of mechanical, electronic and software components of mechatronic systems. It simplifies the integrated development process of manufacturing systems by using as basic construct the mechatronic component. The MIM paradigm was utilized to define "Archimedes," a system platform that supports the engineer through a methodology, a framework, and a set of tools to automate the development process of agile mechatronic manufacturing systems.     

PSM: an object-oriented synthesis approach to multiprocessor systemdesign

Although multiprocessor systems are becoming a trend today, few synthesis tools currently available can actually automate the design of multiprocessor systems. Performance synthesis methodology (PSM) is an object-oriented system-level synthesis approach to multiprocessor system design. Since PSM was designed specifically for the synthesis of multiprocessor systems, it is not only much more efficient when synthesizing parallel systems, but also produces better parallel systems than currently available uniprocessor system-level synthesis tools. Colored Petri nets used in modeling system components and object modeling technique used in the design process have both contributed to the shortening of system development time and to the reduction of design cost. First, user specification consisting of functional models and performance constraints is translated into architecture models. Then, the system is configured by selecting the method of control, the memory organization, the type of processor, and the type of system interconnection. Finally, a heuristic design space exploration algorithm is used to generate several near-optimal design alternatives. The best architecture is chosen by evaluating the design alternatives using a flexible performance estimation formula that mainly considers system level design features, such as system throughput, utilization, reliability, scalability, fault-tolerance, and cost. Several systems were successfully synthesized using this top-down object-oriented PSM, thus showing its feasibility as a design automation tool for parallel systems     

MMV: A Metamodeling Based Microprocessor Validation Environment

With increasing levels of integration of multiple processing cores and new features to support software functionality, recent generations of microprocessors face difficult validation challenges. The systematic validation approach starts with defining the correct behaviors of the hardware and software components and their interactions. This requires new modeling paradigms that support multiple levels of abstraction. Mutual consistency of models at adjacent levels of abstraction is crucial for manual refinement of models from the full chip level to production register transfer level, which is likely to remain the dominant design methodology of complex microprocessors in the near future. In this paper, we present microprocessor modeling and validation environment (MMV), a validation environment based on metamodeling, that can be used to create models at various abstraction levels and to generate most of the important validation collaterals, viz., simulators, checkers, coverage, and test generation tools. We illustrate the functionalities in MMV by modeling a 32-bit reduced instruction set computer processor at the system, instruction set architecture, and microarchitecture levels. We show by examples how consistency across levels is enforced during modeling and also how to generate constraints for automatic test generation.     

基于键合图过程模型的Matlab仿真

研究用一种新型的建模方法——键合图法建立系统的过程模型,提出根据系统键合图模型,完成与方块图模型的转换进而利Matlab强大仿真功能实现键和图仿真。结合实例将该方法应用到碰撞缓冲的火车系统中,验证了该方法的有效性。     

Knowledge-based approach to domain modeling: Application to nasa''s payload operations control centers

Several institutions in industry and academia are pursuing research efforts in domain modeling to address unresolved issues in software reuse. To demonstrate the concepts of domain modeling and software reuse, a prototype software engineering environment is being developed at George Mason University to support the creation of domain models and the generation of target system specifications. This prototype environment, which is application domain independent, consists of an integrated set of commercial off-the-shelf software tools and custom-developed software tools. This paper describes the knowledge-based tool that has been developed as part of the environment to generate target system specifications from a domain model. This knowledge-based approach to domain modeling has been applied to NASA's Payload Operations Control Center (POCC) domain.     

Straightforward and accurate nonlinear device model parameter-estimation method based on vectorial large-signal measurements

To model nonlinear device behavior at microwave frequencies, accurate large-signal models are required. However, the standard procedure to estimate model parameters is often cumbersome, as it involves several measurement systems (DC, vector network analyzer, etc.). Therefore, we propose a new nonlinear modeling technique, which reduces the complexity of the model generation tremendously and only requires full two-port vectorial large-signal measurements. This paper reports on the results obtained with this new modeling technique applied to both empirical and artificial-neural-network device models. Experimental results are given for high electron-mobility transistors and MOSFETs. We also show that realistic signal excitations can easily be included in the optimization process.     

On the use of behavioral modeling within the RFIC design flow: Satellite receiver case study

In order to generate a first-time right design, system level modeling and simulation is a major step. Thus, performance evaluation of integrated wireless systems requires the development of RF behavioral models compatible with the microelectronic design tools. Firstly, this paper shows the need of such models within the RFIC Top–Down design flow. Then, behavioral modeling techniques are presented and several classical RF block models are described. Those models are used within an RFIC satellite receiver validation example and finally, several performance evaluation examples allow demonstrating the capabilities of behavioral modeling, compared to other very used modeling techniques as mathematical and baseband approaches.     

Modeling Communication Networks With Hybrid Systems

This paper introduces a general hybrid systems framework to model the flow of traffic in communication networks. The proposed models use averaging to continuously approximate discrete variables such as congestion window and queue size. Because averaging occurs over short time intervals, discrete events such as the occurrences of a drop and the consequent reaction by congestion control can still be captured. This modeling framework, thus, fills a gap between purely packet-level and fluid-based models, faithfully capturing the dynamics of transient phenomena and yet providing significant flexibility in modeling various congestion control mechanisms, different queueing policies, multicast transmission, etc. The modeling framework is validated by comparing simulations of the hybrid models against packet-level simulations. It is shown that the probability density functions produced by the ns-2 network simulator match closely those obtained with hybrid models. Moreover, a complexity analysis supports the observation that in networks with large per-flow bandwidths, simulations using hybrid models require significantly less computational resources than ns-2 simulations. Tools developed to automate the generation and simulation of hybrid systems models are also presented. Their use is showcased in a study, which simulates TCP flows with different roundtrip times over the Abilene backbone.     

Parameterized Scheduling of Topological Patterns in Signal Processing Dataflow Graphs

In recent work, a graphical modeling construct called “topological patterns” has been shown to enable concise representation and direct analysis of repetitive dataflow graph sub-structures in the context of design methods and tools for digital signal processing systems (Sane et al. 2010). In this paper, we present a formal design method for specifying topological patterns and deriving parameterized schedules from such patterns based on a novel schedule model called the scalable schedule tree. The approach represents an important class of parameterized schedule structures in a form that is intuitive for representation and efficient for code generation. Through application case studies involving image processing and wireless communications, we demonstrate our methods for topological pattern representation, scalable schedule tree derivation, and associated dataflow graph code generation.     

Heat dissipation in wearable computers aided by thermal coupling with the user

Wearable computers and PDA's are physically close to, or are in contact with, the user during most of the day. This proximity would seemingly limit the amount of heat such a device may generate, conflicting with user demands for increasing processor speeds and wireless capabilities. However, this paper explores significantly increasing the heat dissipation capability per unit surface area of a mobile computer by thermally coupling it to the user. In particular, a heat dissipation model of a forearmmounted wearable computer is developed, and the model is verified experimentally. In the process, this paper also provides tools and novel suggestions for heat dissipation that may influence the design of a wearable computer.     

基于传播图论的多链路信道仿真及其在TDOA定位系统性能评估中的应用

为了解决在真实环境下到达时间差(time difference of arrival,TDOA)定位性能评估所面临的测量成本高、不可控干扰因素较多等问题,提出了 一种利用传播图论多链路信道仿真来评估TDOA定位系统性能的方法.即采用传播图论的方法生成不同的信道冲激响应,并通过软件无线电装置产生经信道畸变的射频信号,作为...     

基于多模态特征转换嵌入的场景图生成

场景图生成是计算机视觉领域中的热点研究方向，可连接上、下游视觉任务。场景图由形式为<主语-谓语-宾语>的三元组组成，模型需要对整幅图像的全局视觉信息进行编码，从而辅助场景理解。但目前模型在处理一对多、多对一和对称性等特殊的视觉关系时仍存在问题。基于知识图谱与场景图的相似性，我们将知识图谱中的转换嵌入模型迁移至场景图生成领域。为了更好地对此类视觉关系进行编码，本文提出了一种基于多模态特征转换嵌入的场景图生成框架，可对提取的视觉和语言等多模态特征进行重映射，最后使用重映射的特征进行谓语类别预测，从而在不明显增加模型复杂度的前提下构建更好的关系表示。该框架囊括并补充了现存的几乎所有转换嵌入模型的场景图实现，将四种转换嵌入模型（TransE、TransH、TransR、TransD）分别应用于场景图生成任务，同时详细阐述了不同的视觉关系类型适用的模型种类。本文所提框架扩展了传统应用方式，除独立模型之外，本文设计了新的应用方式，即作为即插即用的子模块插入到其他网络模型。本文利用大规模语义理解的视觉基因组数据集进行实验，实验结果充分验证了所提框架的有效性，同时，得到的更丰富的类别预测结...     

UHF RFID tag-antenna matching optimization using VHDL-AMS behavioral modeling

In order to generate a first-time right design, system level modeling and simulation is a major step. Thus, optimization of integrated wireless systems requires the development of behavioral models of the RF link (antenna-medium-antenna) compatible with the microelectronic design tools. Firstly, this paper shows the need of such models within the Top-Down design flow of an UHF RFID system. Then, a behavioral model of a narrow band far field RF link is presented and validated. This model is associated with a new behavioral model of an RFID tag and finally, several examples of tag-antenna matching optimization simulations are presented in order to demonstrate the interest of our approach.     

Extension of the bond graph causality inversion method for fault detection and isolation

Controlled systems can be subjected to faults that may affect the performance of the system, and unable its objectives to be achieved. Fault detection and isolation algorithms are then used to study these faults. The bond graph tool can be used for modeling purposes and then its structural, and causal properties can be exploited for automatic generation of analytical redundancy relations (ARRs) through a procedure named causality inversion method, which are used for diagnosis applications. These ARRs are mathematical constraints that are used to verify the coherence between the process measurements and the system model. This paper proposes an extension of the causality inversion method by different versions of the same ARR. The goal is to increase the number of isolable faults. Moreover, structural conditions are given in order to avoid the generation of redundant ARRs. To validate the obtained structural procedure, a fault is imposed in a traction of an omnidirectional mobile robot.     

Combining aspects and object-orientation in model-driven engineering for distributed industrial mechatronics systems

Recent advances in technology enable the creation of complex industrial systems comprising mechanical, electrical, and logical – software – components. It is clear that new project techniques are demanded to support the design of such systems. At design phase, it is extremely important to raise abstraction level in earlier stages of product development in order to deal with such a complexity in an efficient way. This paper discusses Model Driven Engineering (MDE) applied to design industrial mechatronics systems. An aspect-oriented MDE approach is presented by means of a real-world case study, comprising requirements engineering up to code generation. An assessment of two well-known high-level paradigms, namely Aspect- and Object-Oriented paradigms, is deeply presented. Their concepts are applied at every design step of an embedded and real-time mechatronics system, specifically for controlling a product assembler industrial cell. The handling of functional and non-functional requirements (at modeling level) using aspects and objects is further emphasized. Both designs are compared using a set of software engineering metrics, which were adapted to be applied at modeling level. Particularly, the achieved results show the suitability of each paradigm for the system specification in terms of reusability quality of model elements. Focused on the generated code for each case study, statistics depicted an improvement in number of lines using aspects.     

Creating compact models of complex electronic systems: an overview and suggested use of existing model reduction and experimental system identification tools

The electronic system packaging community has a great need to reduce the size of its heat transfer simulations so that it can: simulate and analyze more complex systems, include additional physical phenomena, and improve its ability to search the electronic systems packaging design space. Aside from further improvements in machine speed and numerical algorithm efficiency, this is basically a question of model reduction and experimental identification: one would like to know how to dramatically reduce the size of heat transfer simulations when they are available, and one would further like to identify models directly from experiment when accurate, computationally feasible, numerical simulations are not available (as in the case of turbulent flows through complex geometries). Fortunately, the topic of low-order modeling for design has been widely studied and successfully applied in other fields. This paper gives a brief overview of these techniques, it suggests how these tools might be effectively used for electronic systems including cases that involve unsteady fluid dynamics, and it summarizes some of the reduced-order modeling lessons learned in other fields. The paper includes some initial work in model reducing the unsteady heat conduction equation, a result on component model inter-connections, and an outline of a systems level model for an air cooled personal computer.     

基于Power Designer的数据库系统构建

Power Designer是一个运行在Windows平台上的系统建模工具,它可以使软件开发人员和数据库管理员协同工作,快速建立起软件的系统模型,为开发一个稳定可靠的软件打下基础。文中通过实例的建设过程,介绍了Power Designer的分析设计过程及软件代码、数据库的生成过程。     

On modelling mechatronics systems—a geometrical approach

The paper proposes a procedure to apply a geometrical based approach to model mechatronics systems. A brief survey of the geometrical based approach of modelling with illustrative examples is presented here to enable the reader to understand the terminology of the procedure. In this procedure, first, two geometrical based models for both the physical and logical properties of a mechatronics system are established, second, the interconnection between these two models is determined, third, a total model is built up from these two models. The utilization of the procedure is demonstrated for achieving synchronization of multiple independent servo motors in an automated material transfer system which includes two conveyers.     

Knowledge interaction with genetic programming in mechatronic systems design using bond graphs

This paper describes a unified network synthesis approach for the conceptual stage of mechatronic systems design using bond graphs. It facilitates knowledge interaction with evolutionary computation significantly by encoding the structure of a bond graph in a genetic programming tree representation. On the one hand, since bond graphs provide a succinct set of basic design primitives for mechatronic systems modeling, it is possible to extract useful modular design knowledge discovered during the evolutionary process for design creativity and reusability. On the other hand, design knowledge gained from experience can be incorporated into the evolutionary process to improve the topologically open-ended search capability of genetic programming for enhanced search efficiency and design feasibility. This integrated knowledge-based design approach is demonstrated in a quarter-car suspension control system synthesis and a MEMS bandpass filter design application.