Application of design parameters space search for belt conveyor design

Belt conveyor design is examined as an application of a proposed Design Parameters Space Search technique. First, the main characteristics of the belt-conveyor design process are presented as they appear in the current literature. Furthermore, a proposed general knowledge-representation platform is described, and its ability to house the relevant conveyor design knowledge is also shown.

Next, the extended search technique of the design space is discussed, and an integrated example of a belt-conveyor design is presented, based on the proposed representation platform and the extended search technique. Finally, it is shown that the design of belt conveyors according to the proposed approach presents the following significant advantages:

• • Due to the knowledge-representation scheme adopted, both qualitative and quantitative knowledge can be used within the same platform.

• • Multiple solutions can be easily produced through user-defined design criteria. These solutions can be further modified and/or evaluated to produce more-specific designs.

• • The required for user-input data is kept to a minimum. Due to the applied extended search method, semiautomatic design can be achieved. As a consequence, the design process is completed in less time than that required by the conventional methods.

     

Theories for graphics processors in TIPS-1

This paper describes the theoretical aspects of graphics processors in CAD/CAM system TIPS-1. As one of the man-machine interfaces in the CAD/CAM field, computer graphics plays an important role. And this field, computer graphics involves not only image processing with shaded pictures produced by raster scan displays but also sectional and/or perspective view drawing picture by line drawing display. By using TIPS-1 graphics processors, we can get both raster scan and line drawing pictures for the same of modeled 3-D geometry. The following items are considered as the necessary conditions for developing graphics processors.

• • To develop geometric modeling theory.

• • To develop generative geometry pattern processing theory.

• • To implement problem-oriented graphics routines based on above conditions.

How to complete these conditions is described with several figures and graphic outputs.     

The BIOPHILE Sample Process Management System - Automated Sample Access at Ultra Low Temperatures

The genomics, proteomics, clinical, and drug discovery laboratories have a growing need to maintain valuable samples at ultra-low (−80°C) temperatures in a validated, secure environment. Automated sample processing systems have until now required manual (off-line) storage of samples at −80°C, reducing system reliability and speed. Both of these important needs are addressed by the Sample Process Management System being introduced by BIOPHILE Inc. Conventional sample management processes, such as storage, retrieval, and cataloging, are increasingly strained by the growing sample populations. There are variable sample types, access requirements and storage requirements. Security and inventory procedures are implemented manually. The evolving technologies present in the laboratory cannot interface with conventional manual storage techniques. Addressing these limitations, the primary benefits of BIOPHILE's solutions are:

• Fully validated sample management process that coordinates the life-cycles of samples and their related data.

• Robotic technology to securely store and retrieve samples, improving their accessibility and stability. Thermal shock is reduced, improving sample longevity and quality. The robotic technology allows integration with larger automation systems.

• A process program to develop a Sample Management Strategy. This strategy is developed by analyzing long-term research goals, current baseline processes, and identification of current sample life cycles. A full validation documentation package can be generated, providing a high level of quality assurance.

• Improved sample visibility and quality assurance - automated sample population cataloging; controlled sample management access and security.

     

ARIANEXPERT: A knowledge based system to analyze ARIANE's mission data

The ARIANE launcher post mission analysis is done at ARIANESPACE. This activity is called the ‘level 0 post flight analysis’ (PFA) and is carried out after each launch by about 60 engineers who are working together under the leadership of ARIANESPACE.

The PFA is one of the most critical of ARIANE operations, for several reasons:

• - The launch rate (8 a year for ARIANE 4) leaves a very short time to carry out all the verification work. Moreover, the PFA is a mandatory step before authorizing the next launch.

• - The complexity of the ARIANE launcher results in a very high demand on the PFA engineers. Moreover, there are problems of availability of people with relevant expert knowledge (characterized by a substantial staff turn-over during the 10 year life duration of ARIANE 4) which could potentially result in errors or omissions.

It is very important to be able to take into account the experience of the preceding flights and to record the results and the knowledge accumulated for each launch.

• - The quality and the reliability of the PFA mainly depends on the accessibility of data and on the used methodology.

Because the PFA is still largely done manually, and does not benefit from improved methodologies and advanced technologies providing computerized support for data processing and diagnosis, ARIANESPACE has sponsored MATRA ESPACE for the development of a knowledge based system, called ARIANEXPERT, for supporting the PFA activity. This system combines AI techniques and numerical analysis techniques, together with advanced graphical capabilities.

A prototype has been delivered in April 1990 and has been used since 6 months by ARIANESPACE during real PFAs. Several lessons have been drawn from this operational experience and are described in this paper. They concern:

• - The utility and justification of the use of AI techniques mostly coming from the explanation capabilities and the stress put on capturing the expert knowledge.

• - The difficulties associated with the integration of such systems in the exploitation of ARIANE due to the introduction of very new tasks.

• - The user point of view which evolved from reluctant to convinced.

     

An alternative to expert systems for electrical diagnosis

Although the use of an expert system for the detection and location of faults in the power supply subsystem of the TDFI satellite¹ gives good practical results, there are also a certain number of drawbacks:

• - the rules are application-dependent and therefore useless for the diagnosis of other satellites,

• - the amount of knowledge required is quite large and contains a lot of redundant information,

• - testing and updating of the system are tricky,

• - it is far from sure that all possible faults can be taken into account.

The diagnosis theory based on models of correct behavior of the components introduced more recently by de Kleer and Williams seems more suited to this type of problem. Using our program CATS/DIANA, we have been able to validate this approach for analog electronic circuits. We have also tested the method on the diagnosis of satellite power supply subsystems; the results were similar to those obtained using an expert system, but without the drawbacks. This paper describes the two methods and compares the results.     

ATOS — An AI-based space mission operations system

Artificial Intelligence is generally recognised as one of the key technologies for future spaceflight, and a number of ambitious applications for on-board use have been proposed already. Such applications still require a good deal of basic research and development, but on-ground applications could make an impact already in the medium term, and will for some time represent the major part of AI use for space missions.

ESA has started the development of a future integrated and mission-independent spacecraft control data processing system called the Advanced Technology Operations System (ATOS) at the European Space Operations Centre, which will employ artificial intelligence techniques in supporting the operations staff during all mission preparation and implementation phases, in order to cope reliably with complex mission operations and to achieve optimal efficiency in the use of human resources.

ATOS will consist of a number of knowledge based software modules, such as

• Automated mission planning

• Automated operations preparation

• Computer assisted operations

• Advanced operator training,

centred around a Mission Information Base configured for the particular satellite mission, the common data repository for all information required to conduct the mission and operate the spacecraft.

The Mission Information Base will, in addition to numerical data presently found in conventional spacecraft control systems, contain a large amount of ‘knowledge’ about the spacecraft and its mission, which is currently available only in paper documents or embedded in software. It will be implemented as a physically and logically distributed set of databases each representing a particular field of mission information, such that the knowledge can be dynamically shared between different intelligent spacecraft control applications.     

Modeling safety and airworthiness (RTCA DO-178B) information: conceptual model and UML profile

Several safety-related standards exist for developing and certifying safety-critical systems. System safety assessments are common practice and system certification according to a standard requires submitting relevant system safety information to appropriate authorities. The RTCA DO-178B standard is a software quality assurance, safety-related standard for the development of software aspects of aerospace systems. This research introduces an approach to improve communication and collaboration among safety engineers, software engineers, and certification authorities in the context of RTCA DO-178B. This is achieved by utilizing a Unified Modeling Language (UML) profile that allows software engineers to model safety-related concepts and properties in UML, the de facto software modeling standard. A conceptual meta-model is defined based on RTCA DO-178B, and then a corresponding UML profile, which we call SafeUML, is designed to enable its precise modeling. We show how SafeUML improves communication by, for example, allowing monitoring implementation of safety requirements during the development process, and supporting system certification per RTCA DO-178B. This is enabled through automatic generation of safety and certification-related information from UML models. We validate this approach through a case study on developing an aircraft’s navigation controller subsystem.     

Implementation procedure of an advanced supervisory and control strategy in the pharmaceutical industry

This paper describes the different steps followed in implementing a temperature controller and a supervisory controller in a Supervisory Control And Data Acquisition (SCADA) system to control a 60 and 160 l reactor in a pharmaceutical factory. These reactors are used to produce the initial quantities of drugs needed to perform clinical tests. The chemical reactions involved are often changed (several times a week). The different steps of the project will be presented:

• design of a new heating–cooling system,

• design of the predictive and Supervisory Control Algorithm (SCA),

• connection of the SCA to the SCADA system,

• experimental validation according to Good Manufacturing Practice (GMP).

This SCA has been in daily use as the standard control system for more than 2 years.     

航电软件开发标准与过程研究

随着综合模块化航空电子系统研究的深入,其软件开发标准的重要地位日益突出,ARP4754 和DO-178C共同构成了综合模块化航空电子系统软件开发的新标准。从标准内容与信息流程两方面论述了标准之间的关系,同时讨论了航电软件计划过程、开发过程和综合过程的子过程、目标及活动内容,提出了过程自动化和过程省略的基本概念与方法。     

机载软件适航认证标准新进展及展望

为了满足机载软件适航认证的迫切需求,对机载软件适航认证标准进行分析研究.阐述了DO-178B的发展动因及过程,总结了随着软件开发技术的快速更新DO-178B所表现的不足.说明了对DO-178B进行更新的必要性,并将即将发布的新版本DO-178C与DO-178B进行了对比.根据对比结果重点分析了DO-178C的4个新增特性.对DO-178C所带来的影响以及未来应用进行了展望.     

面向适航标准的机载软件测试验证方法综述

机载软件测试是指机载系统中嵌入式软件执行的测试验证过程,目的是为了挖掘出软件缺陷从而提高机载系统的可靠性。随着机载嵌入式系统功能的多样化需求,软件的规模和复杂程度不断增加,同时因为其实时性、嵌入性、高可靠性等特殊性,因此对机载软件进行充分测试成为当前的一个挑战。为了满足要求,机载系统的测试需要遵循最新的适航标准DO-178C,针对机载软件生命周期过程提出了一系列目标要求和设计考虑。为此,简介了机载软件适航认证标准的发展及其测试环境;根据DO-178C对机载软件测试的各个过程从基于需求、基于模型、基于安全性分析以及软件验证的测试研究机载软件的测试验证方法,并进行小结;对相关领域的发展进行总结和展望。     

民用机载软件集成过程的技术研究

民用机载软件的研制以DO-178B标准为指导.与传统的软件工程相比,DO-178B标准更面向目标和过程.该标准为各个等级的软件提出了相对应的目标,申请者需要向局方提供证据以表明研制的软件满足适航目标.软件的编码和集成过程,该标准要求集成过程的输出是正确和完整的.但该标准中并没有提出如何满足这个目标.本文通过无线电调谐软件对软件编码和集成过程以及对软件编译和链接过程的研究,提出一种方式来满足DO-178B标准的这一目标.     

面向DO-178C的襟缝翼控制系统需求的形式化描述

DO-178C是对机载软件适航认证标准DO-178B的改进和补充,用于对民用飞机机载系统和设备软件质量控制提供指导。SCR(Software Cost Reduction)方法作为一种形式化方法,基于四变量模型,可以对复杂和大型的嵌入式系统进行需求描述。文中基于DO-178C,使用SCR方法对原飞机系统中的襟缝翼控制系统的需求文档进行形式化的需求描述,针对襟缝翼控制系统中的襟翼电机转速控制模块进行详细的案例分析,判断其是否满足DO-178C的相关验证指标。通过分析和验证,提出了SCR方法中的一些应用技巧。该工作可为SCR方法在机载软件系统中的应用提供依据。     

Software and hardware certification of safety-critical avionic systems: A comparison study

To ensure the safety of avionic systems, civil avionic software and hardware regulated by certification authorities must be certified based on applicable standards (e.g., DO-178B and DO-254). The overall safety integrity of an avionic system, comprising software and hardware, should be considered at the system level. Thus, software and hardware components should be planned, developed and certified in a unified, harmonized manner to ensure the integral safety of the entire avionic system. One of the reasons for the high development costs of avionic systems complying with standards may be a lack of sufficient understanding of how to employ these standards efficiently. Therefore, it is important to understand the similarities and differences between DO-178B and DO-254 to effectively manage the processes required by these standards, to minimize cost, and to ultimately ensure the safety of the entire avionic system. Thus, the goal of this paper is to compare various aspects of DO-178B and DO-254 comprehensively. The paper may serve as a useful supplementary material for the practitioner to understand the rationales behind and the differences between two main standards used in avionic industries.     

A use of case-based reasoning technique in building expert systems

Matra Marconi Space France and Aramiihs (Action de Recherche et Application Matra Irit en Interaction Homme Système) laboratory have used and evaluated Case Based Reasoning (CBR) techniques in two projects:

• - The first project is about the development of a system dedicated to help satellites AIT/AIV (Assembly Integration and Test/Validation) test engineers to cope with incidents occurring during test activities. The project is funded by the EGSE System Section of ESTEC (European Space Research and Technology Centre.).

• - The second project is related to the building of a knowledge-based system for diagnosis assistance in AIT/AIV activities of Ariane4 Vehicle Equipment Bay (VEB). The project is financed by internal funding of MMS-F.

In the two projects, CBR technique is neither used the same way nor with the same purpose.

In the first project, CBR technique is used to find out or suggest the cause of an anomaly when an incident appears. Confronted with the occurrence of an incident, the system will refer to its characteristics (test context, symptoms…) that are considered as relevant to retrieve previous similar incidents.

In the second project, CBR technique is combined with Rule Based Reasoning and Model Based Reasoning ones to form the reasoning core of a Hybrid Knowledge Based System. When an incident occurs, the system proposes to test engineers a diagnosis approach based on the combination of different knowledge (coded into rule, cases and models).

Aramiihs is a research unit where engineers from MMS and researchers from the IRIT (Institut de Recherche en Informatique de Toulouse) CNRS (Centre National de la Recherche Scientifique) collaborate on problems concerning new types of man-system interaction.     

Certification of software for real-time safety-critical systems: state of the art

This paper presents an overview and discusses the role of certification in safety-critical computer systems focusing on software, and partially hardware, used in the civil aviation domain. It discusses certification activities according to RTCA DO-178B “Software Considerations in Airborne Systems and Equipment Certification” and touches on tool qualification according to RTCA DO-254 “Design Assurance Guidance for Airborne Electronic Hardware.” Specifically, certification issues as related to real-time operating systems and programming languages are reviewed, as well as software development tools and complex electronic hardware tool qualification processes are discussed. Results of an independent industry survey done by the authors are also presented.     

Applications of power series in computational geometry

A number of algorithms are presented for obtaining power series expansions of curves and surfaces at a point. Some results on the radius of convergence are given. Two applications of series are given:

1. • for curve tracing algorithms, where a truncated series is used to approximate the curve of intersection of two surfaces

2. • to define nth degree geometric continuity, for arbitrary

Aviation software guidelines

Regulatory authorities in the US and Europe have received two documents crucial to aviation software developers. The first one, DO-248B, clarifies existing software guidelines for airborne systems and equipment certification, and the other, CNS/ATM (a counterpart to DO-178B) provides new guidance for non-airborne communication and navigation systems.