多通道压力传感器综合检测系统设计

主要描述了多通道压力传感器综合检测系统硬件组成及软件功能设计,通过本压力传感器综合检测系统可满足飞机研制试验中压力传感器检测需求,保证飞机型号试验进度及试验压力测量数据的准确可靠。     

油田自动化系统的检测/检定与恢复技术

因油田自动化监控系统的项目验收、日常维护缺少在线、综合检测技术手段,影响了东辛采油厂自动化项目的进展和应用。针对自动化系统的三个环节中的受限问题,开展油田自动化系统的检测/检定与恢复技术研究,设计了一种便携式虚拟综合检定系统。该系统以一台便携式虚拟仪器能完成多种物理参数的传感器/变送器的在线检测/检定,又能完成检测回路的校准和传输回路的诊断分析工作,为油田自动化应用提供了技术保障。该系统可广泛应用于石油、化工、水厂、电厂等行业。     

温湿度在线监测系统研制

以电力线传输为基础,研制了一种温湿度在线监测系统。该系统由温湿度检测单元、系统集成单元和综合控制单元组成;温度和湿度由检测单元的传感器SHT10检测,通过电力线通信传送至系统集成单元;集成单元接收数据后通过RS-232接口发送到综合控制单元,综合控制单元将接收到的数据以图形或报表多种方式显示输出,实验结果证实该系统不仅实现了对环境多点温湿度的监测与管理,以及对历史数据的再现显示,而且大大节省设计成本。     

DYCJ-1型航空电源车性能综合检测系统软件的设计

DYCJ - 1型航空电源车性能综合检测系统实现了对各种电源车供电性能指标的综合检测。本文简要介绍了该系统软件的主要设计思想和实现方法 ,重点论述了软件研制过程中所解决的技术难点。     

一种大型曲面天线装配精度研究

针对双弯曲赋形反射面天线装配,介绍了双电子经纬仪检测系统的测量原理,阐述了光学经纬仪水准仪组建的综合测量平台、对中定位检测系统等检测方案。为提高精度,简化操作过程,改进了测量方法,并用摄影测量系统验证了检测方案的正确性。     

机载火控照相枪综合自动测试系统的设计与实现

介绍了机载火控照相枪综合自动测试系统的功能，硬件和软件的设计思想，提出了为检测火控照相枪各部件及其整体的情况所需信号的产生方法，介绍了为提高综合自动检测系统的可靠性和检测精度所采用的先进技术。     

摄象法热轧圆钢直径在线检测的研究

阐述了摄象法实现热轧圆钢的直径在线检测原理。通过研究热轧圆钢运动时的物距变化摄象法在线检测的影响,提出了建立热轧圆钢运动中的相对监测系统。分析了摄象法热轧圆钢直径在线检测系统的误差,并给出了该系统综合误差的补偿方法以及测量小型棒材的综合测试结果。     

铁路货运装备新型外包保温加热系统综合性能研究

目的 提出一种新型外包保温加热系统,并检测其综合性能。方法 将冷链物流作为切入点,提出一种新型保温加热系统,结合传热学基础理论,从物理性能分析、工艺性能实践、综合性能检测、应用性能验证等不同角度,详细阐述新型保温系统的综合性能。结果 新型外包保温绝热材料达到热动平衡后,漏热率与温差关系曲线相对稳定,无大的波动点;同时与之相搭配的新型加热系统柴油消耗量由19.3 L/h降低至17.2 L/h,平均加热时长减少了1 h。结论 新型外包保温加热系统的加热效率得到了很大的提升,并且进一步减少了热能损失,同时加快了装卸效率。     

机动车检测认证

正主营业务包括机动车安全性能检测、机动车综合性能检测、机动车尾气工况法检测、车管所远程监管查验以及安防弱电工程等系统集成业务,具有国家认监委颁发的《检验检测机构资质认定证书》,可承接相关检测设备的检定、校准及测试业务,是承担各省、市、自治区机动车辆检测和工程认证、鉴定、调修工作的专业企业。我们依靠优秀的科技开发人才和高素质的经营管理队伍,先后开发完成《汽车安全性能检测系统》、《汽车综合性能检测系统》、《汽车出厂质量保证检测系统》、《汽车安全性能检测在线调修系统》、《机动车尾气工况法测控系统》、《机     

机动车检测认证

正主营业务包括机动车安全性能检测、机动车综合性能检测、机动车尾气工况法检测、车管所远程监管查验以及安防弱电工程等系统集成业务,具有国家认监委颁发的《检验检测机构资质认定证书》,可承接相关检测设备的检定、校准及测试业务,是承担各省、市、自治区机动车辆检测和工程认证、鉴定、调修工作的专业企业。我们依靠优秀的科技开发人才和高素质的经营管理队伍,先后开发完成《汽车安全性能检测系统》、《汽车综合性能检测系统》、《汽车出厂质量保证检测系统》、《汽车安全性能检测在线调修系统》、《机动车尾气工况法测控系统》、《机     

Optimal inspection policies with predictive and preventive maintenance

A model is proposed to study the inspection and maintenance policy of systems whose failures can be detected only by periodic tests or inspections. Using predictive techniques, the time of the system failure can be predicted for some failure modes. If the system is found failed in an inspection, a corrective maintenance action is carried out. If the system is in a good condition but the predictive test diagnoses a failure in the period until the next inspection, then the system is replaced. The cost rate function is obtained for general distribution function of the signal time of a future failure and for one specific distribution function recently proposed. An algorithm is presented to find the optimal time between inspections and predictive tests and the optimal system replacement times for an age replacement policy. Numerical experiments illustrate the model.     

On the inspection policy of a two-component parallel system with failure interaction

In this paper we study a two-component standby system which can successfully operate upon a demand if at least one component is not failed. We assume that failures can be detected only by periodic inspections. We consider that the failure of one component can modify the (conditional) failure probability of the component still alive with probability p and do not interact with probability 1−p. For that failure interaction scheme we obtain the system reliability function for the case of staggered inspections. We compare staggered and non-staggered inspections through numerical examples considering constant hazard rates.     

An inspection model for a process with two types of inspections and repairs

This paper considers a problem often met in practice. A production process may be subject to two types of deteriorations. The first is a shift in product quality caused by minor process defects that may be identified and rectified by routine inspections and repairs. The second is a major defect caused by a major mechanical or electrical problem that can be observed only when the defect has led to a breakdown of the process or the defect is revealed by a major inspection followed by an appropriate major repair action at the time of the inspection. We formulated an inspection model for the above problem and aimed at optimising the inspection intervals for both types of inspections. A numerical example is given to demonstrate the applicability and solution procedure of the model.     

The optimal production and quality policy for the vendor in a trade

Arranging an inspection schedule for the production process and taking inspection and burn-in tests to screen out defective items in a production lot before items are shipped to the buyer are widely used by the vendor, such that the defective percentage in an outgoing batch satisfies the quality requirement specified in the contract between them. For an inspection schedule, the number of inspections and the length of time intervals between two inspections are influential to both the precision of detecting the manufacturing process and the inspection cost. As to the inspection test, it is not perfect, so there are two types of errors (Types I and II). Nevertheless, compared with inspection test, burn-in is usually costly. Hence, how to make a suitable trade-off between these three treatments (i.e., inspection schedule, inspection test, and burn-in test) such that the outgoing batch satisfies the purchaser's quality requirement with low cost is an important issue. The main purpose of this paper is to deal with the problem of determining the optimal inspection schedule and the optimal mixed policy of inspection and burn-in, where the average outgoing quality is used as the measure of quality. More specifically, by using the criterion of maximizing the expected profit that the vendor makes in a trade, a nonlinear programming problem is built to determine (a) the number of inspections undertaken in the production process, (b) the times at which the production process is inspected, (c) the total number of items that the vendor should produce (or the production run time), (d) the number of items for inspection, the number of items for burn-in, and the number of items that need neither inspection or burn-in, and (e) the optimal burn-in time for those needing burn-in testing. An example is provided to illustrate the proposed method.     

Si_3N_4陶瓷球轴承的检验方法

通过分析国内外陶瓷球检测状况 ,结合国内研制和生产工艺 ,确定了能表征陶瓷球质量特征的检验项目 ,即化学分析、密度、断裂韧性、表面缺陷、硬度、压碎强度、孔隙度、显微组织等。提出了陶瓷毛坯球的材质性能、制造质量和显微组织等检验方法。对陶瓷球的研制和生产起到质量控制作用 ,为陶瓷球的质量检验标准的制定提供了依据。     

Layer modelling for the inspection allocation problem in re-entrant production systems

In the past two decades, re-entrant production systems have received a great deal of attention. One of the most important characteristics of re-entrant production systems is that the work units are manufactured layer-by-layer, so that some defects are more difficult to inspect after they are covered by the next layer. In this research, a mathematical model considering layered fabrication is developed to find the optimal solution for allocating inspections in re-entrant production systems. Workstations of variables data and inspections of quality characteristics measurement are modelled. In addition, this study considers three possibilities for the treatment of detected non-conforming units, namely repair, rework and scrap. Moreover, a heuristic algorithm is proposed in order to improve the optimization method based on complete enumeration, which suffers from a large amount of computation time, especially as the number of workstations increases. The model is highly extensible and applicable, so it can serve as a production-planning tool to solve the inspection allocation problem in re-entrant production systems.     

Cost and reliability based strategies for fatigue maintenance planning of floating structures

Floating structures are designed in such way that the appearance of fatigue failures cannot be avoided, implying the need for inspections during their life. Their maintenance has to be planned from an economic point of view so as to minimize maintenance costs but satisfying a minimum reliability level. A method is proposed to quantify the repair costs resulting of different reliability-based maintenance strategies. As an application of this approach a side shell structure typical of a floating production unit is analysed and the influence of different parameter with respect to the repair cost is also studied here.     

Minimum Cost 100% Inspection Systems with Inspection Error

A field failure in certain products has the potential to cause human suffering and/or loss of life. To the manufacturer, these failures will result in a significant external failure cost. In this paper, cost minimization models are developed to determine an optimal inspection system for multiple 100% attribute inspections with inspection error. An example involving the visual inspection of a braze joint in a cardiac biopsy device is presented to illustrate the use of the models. A key result is that a system requiring an item to pass every inspection in order to be shipped to a customer is not always the best alternative. Examples illustrating the sensitivity of the model results to key cost and operational parameters are shown.     

Optimal age-based inspection scheme for condition-based maintenance using A* search algorithm

In condition-based maintenance (CBM) with periodic inspection, the system is preventively replaced if failure risk, which is calculated based on the information obtained from inspection, exceeds a pre-determined threshold. The determination of optimal replacement threshold is often based on the minimisation of average maintenance costs per unit time due to preventive and failure replacements over a long time horizon. It is often assumed that inspections are performed at equal time intervals with no cost. However, in practice, inspections require labour, specific test devices, and sometimes suspension of operations and, thus, it is reasonable to inspect less frequently during the time the system is in its early age and/or in a healthier state and to perform inspections more frequently as time passes and/or as the system degrades. In other words, an age-based inspection scheme.

This paper proposes a novel two-phase approach for the determination of an optimal replacement threshold and an optimal age-based inspection scheme for CBM such that the total long-run average costs of replacements and inspections are minimised. First, it takes into account failure and preventive replacement costs to determine the optimal replacement threshold assuming that inspections are performed at equal time intervals with no cost. This assumption is, subsequently, relaxed and its consequences on total average cost are evaluated using a proposed iterative procedure based on A* search algorithm to obtain the optimal age-based inspection scheme. The proposed approach is illustrated through a numerical example.     

Availability and cost functions for periodically inspected preventively maintained units

Unavailability and cost rate functions are developed for components whose failures can occur randomly but they are detected only by periodic testing or inspections. If a failure occurs between consecutive inspections, the unit remains failed until the next inspection. Components are renewed by preventive maintenance periodically, or by repair or replacement after a failure, whichever occurs first (age-replacement). The model takes into account finite repair and maintenance durations as well as costs due to testing, repair, maintenance and lost production or accidents. For normally operating units the time-related penalty is loss of production. For standby safety equipment it is the expected cost of an accident that can happen when the component is down due to a dormant failure, repair or maintenance. The objective of maintenance optimization is to minimize the total cost rate by proper selection of two intervals, one for inspections and one for replacements. General conditions and techniques are developed for solving optimal test and maintenance intervals, with and without constraints on the production loss or accident rate. Insights are gained into how the optimal intervals depend on various cost parameters and reliability characteristics.