Self-diagnostic Function Research Articles

The diagnostics of windings of vehicle alternator units

INTRODUCTION: An alternator unit is a necessary unit in a vehicle, as it provides all the consumers with electricity. Therefore, the operation capability of the whole vehicle depends on the alternator units operational state. The issue of the diagnostics of a vehicle alternator unit by means of determination of alternator phases windings active resistance is addressed.
 AIM: Improvement of diagnostics informativity by means of voltage controllers with a self-diagnostic function.
 METHODS: It is proposed to perform the alternator unit diagnostics without dismantling or disassembly by means of plugging to the diagnostic points.
 RESULTS: The existing and known methods of vehicle alternator unit diagnostics with embedded diagnostic tools and with use of external diagnostic tools were analyzed. The method of diagnostics of phase winding active resistance with use of reference resistance was proposed. The algorithm of implementation of the proposed method was suggested. The recommendations for use of the proposed method were given.
 CONCLUSIONS: The proposed diagnostics method can be used in engine control units or by technicians of maintenance stations during the alternator unit maintenance without dismantling or disassembly.

Development of knitted reinforced structures with self-diagnostic function for composite applications

The research aims the development of knitted reinforcement structures for inducing self-diagnostic properties into knitted reinforced composites for structural health monitoring. Conductive carbon fiber was used in knitted inlaid structures as inlay yarns, and l × 1 Rib knitted base fabric of polyester filament yarn was used for knitting. The reinforcement’s conductive nature induced self-diagnostic properties into composites using correlation of mechanical damages and changes in electrical resistance values. Single and double stimuli layers and inlay patterns of 3 × 1, 6 × 1 and 9 × 1 was used to check their impact on self-diagnostic properties. Mechanical testing and real-time electrical resistance monitoring proved knitted structures as a solution to induce self-diagnostic properties into composite materials. Composites having double stimuli (conductive) layers exhibited better self-diagnostic properties than single stimuli layer composites, and the self-diagnostic properties also improved as the inlay pattern of reinforcement moved from 9 × 1 to 6 × 1 and 3 × 1 inlay. Such knitted reinforced self-diagnostic composites could be practically used in structural health monitoring applications, e.g., complicated structures of large buildings infrastructures and machinery which require record of each minor happening with structures to keep smooth and successful running of the system.

Water Nitrate Remote Monitoring System with Self-Diagnostic Function for Ion-Selective Electrodes.

The detection of nitrate pollutants is a widely used strategy for protecting water sources. Although ion-selective electrodes (ISEs) have been considered for the determination of ion concentrations in water, the accuracy of ISE technology decreases owing to the signal drift and decreasing sensitivity over time. The objectives of the present study were: (1) to develop an online water monitoring system mainly consisting of an Arduino board-based Internet-of-Things (IoT) device and nitrate ISEs; and (2) to propose a self-diagnostic function for monitoring and reporting the condition of the ISEs. The developed system communicates with the cloud server by using the message queuing telemetry transport (MQTT) protocol and provides monitoring information through the developed cloud-based webpage. In addition, the online monitoring system provides information on the electrode status, which is determined based on a self-diagnostic index (SDI, with a range of 0–100) of the electrode drift and sensitivity. The diagnostic method for monitoring and reporting the electrode status was validated in a one-month-long laboratory test followed by a field test in a stream near an agricultural facility. Moreover, a self-diagnostic index (SDI) was applied in the final field experiments with an accuracy of 0.77.

Possibility of creating composite materials with self-diagnosis function based on the effect of mechanoluminescence

The increasing productivity of modern information processing systems opens up new possibilities for various technical devices. The ability to very quickly analyze a large amount of information allows you to constantly improve technical systems, including autonomous ones. Sensors or primary converters are used to obtain information about the surrounding world or external influences in technical systems. However, modern technologies make it possible to create materials with desired properties - composite materials. The programmable properties of materials can be strength, rigidity, resistance to mechanical, chemical and temperature influences, but it is especially worth noting the possibility of obtaining materials with specified informative properties. These materials include composites containing mechanoluminescent substances. Such materials can simultaneously be housings of any devices or enclosing structures, they can be parts of load-bearing structures of buildings and structures and at the same time play the role of shock and destruction sensors. Using such materials, you can create panels with a self-diagnostic function.

A Small Diameter Ultrasonic Water Meter With Self-Diagnosis Function and Self-Adaptive Technology

Ultrasonic water meters have current widespread problems of poor site adaptability, low measurement accuracy, and poor stability. A high-precision intelligent ultrasonic water meter with self-diagnosis function and adaptive technology was proposed in this paper, which is focus on improving the measurement accuracy and repeatability of the small pipe diameters. The hardware circuit design of the ultrasonic water meter studied in this paper adopts the low-power STM32L053 microcontroller with Cortex-M0 core architecture and the high-precision 11 ps time resolution timing chip TDC-GP30 to complete the metering function. The software combines pulse width ratio and amplitude voltage measurement technology to make the water meter have self-diagnosis function, avoid measurement errors caused by accidental factors, improve adaptability and measurement accuracy, also the application of adaptive measurement period method is used to improve measurement repeatability. The software adopts the moving average filtering algorithm, which effectively reduces the fluctuation of the time-of-flight(ToF) difference and improve the measurement accuracy of the flow point in the low zone (between the minimum flow and the boundary flow). The experimental verification results show that the accuracy of the small-caliber ultrasonic water meter can reach within ±1.5 %, and the repeatability is less than 0.5 %. In the face of fluid disturbances, adaptive technology is used in this water meter to adjust the measurement period and carry out self-diagnostic function research, and automatically respond to deal with abnormal faults, thereby realizing the demand for intelligence.

Monitoring of cracks near fastener holes using direct-write ultrasonic transducers

Structural health monitoring (SHM) using direct-write transducers is an emerging technology wherein the piezoelectric ultrasonic transducers are directly produced on the structures using scalable in situ processing method. In contrast to implementation of discrete piezoelectric transducers by manual installation as in existing SHM technologies, the direct-write transducer technology is promising for achieving the long-envisioned smart structures with self-diagnostic function, with the advantages of improved reliability, lowered cost, minimized weight and lowered profile. In this work, direct-write piezoelectric ultrasonic transducers were designed and fabricated near fastener holes in aluminum structures for evaluating the feasibility of monitoring the structural integrity around the holes. Notches and fatigue crack were produced from the holes, and the ability of detecting the notches and crack using the direct-write transducers was investigated by comparing the ultrasonic signals and evaluating appropriate damage indexes related to ultrasonic energy. The results and analyses show the potential of applying direct-write ultrasonic transducers for SHM around fastener holes.

Ultrasonic transducers from thermal sprayed lead-free piezoelectric ceramic coatings for in-situ structural monitoring for pipelines

Direct-write ultrasonic transducers comprised of lead-free ceramic coatings were designed and in situ fabricated by thermal spray process onto stainless steel pipe structures. The experimental measurements and simulation analyses showed that both external and internal defects on the pipe structures could be effectively detected with the ultrasonic Lamb waves propagating along the axial direction, which were excited and detected using the direct-write ultrasonic transducers. The results suggested that the implementation of the direct-write ultrasonic transducers made of the lead-free piezoelectric ceramic coating by thermal spray method is promising for realizing structural health monitoring for pipeline structures with improved consistency and reliability. It is also an important step moving toward smart pipelines with real-time self-diagnostic function.

Personalized Mobile Tool AskPCOS Delivering Evidence-Based Quality Information about Polycystic Ovary Syndrome.

Despite polycystic ovary syndrome (PCOS) being the most common endocrine condition affecting reproductive-aged women, studies have shown the information needs of PCOS consumers are not currently met. The expressed need by women with PCOS for accessible, evidence-based personalized PCOS information informed the design and development of the PCOS mobile tool-AskPCOS. The App provides a range of unique features such as: evidence-based PCOS health information, self-diagnostic function, a question prompt list to optimize health practitioner engagement, and a commonly asked questions list. A five-phase App development process involved extensive stakeholder consultation, system architecture design, development of the content repository, system prototyping, and evaluation. AskPCOS is the first evidence-based, consumer-driven mobile App developed by women and for women with PCOS and utilizes innovative technology to empower PCOS consumers and optimize health outcomes. The App content repository is enhanced by the best available evidence and expertise extracted from the International Evidence-Based Guideline in PCOS (2018). The AskPCOS App has extensive data capture capability through the usage of data gathering functions and backend analytics to optimize responsiveness to consumer needs. In addition, the multilingual content and not-for-profit cost model is designed to facilitate worldwide adoption of the tool, and address PCOS information inequities in developing countries.

Hierarchical system for autonomous sensing-healing of delamination in large-scale composite structures

This study combines our hierarchical fiber-optic-based delamination detection system with a microvascular self-healing material to develop the first autonomous sensing-healing system applicable to large-scale composite structures. In this combined system, embedded vascular modules are connected through check valves to a surface-mounted supply tube of a pressurized healing agent while fiber-optic-based sensors monitor the internal pressure of these vascular modules. When delamination occurs, the healing agent flows into the vascular modules breached by the delamination and infiltrates the damage for healing. At the same time, the pressure sensors identify the damaged modules by detecting internal pressure changes. This paper begins by describing the basic concept of the combined system and by discussing the advantages that arise from its hierarchical nature. The feasibility of the system is then confirmed through delamination infiltration tests. Finally, the hierarchical system is validated in a plate specimen by focusing on the detection and infiltration of the damage. Its self-diagnostic function is also demonstrated.

The Research of Fault Diagnosis Method for ECU Controllers in Electric Vehicles Based on CAN Bus

With the increasing degree of automotive electronics, automotive electronic control systems continue to increase and a large amount of these complex systems using electronic chips to perform their own function, making them very difficult to repair. For ease of maintenance, automotive electronic control systems are generally designed with self-diagnostic function, which is usually referred to OBD diagnostic feature that can automatically diagnose faults of systems, store the Diagnostic Trouble Code (DTC) in memory and can be read through the communication port. This article mainly focuses on fault diagnostic method for ECU in electric vehicle based on CAN bus, for electric vehicles are developed very fast in order to solve the energy crisis and environmental pollution. This diagnostic system described in the article has designed a host computer and a lower machine. The development of software in host computer is based on LabVIEW virtual instrument technology and NEC micro-processing chip is used to develop the lower machine, achieving the automatic and controlled ECU test.

Design of Current Selective Protection in Intelligent Molded Case Circuit Breaker

Synthetically applied the technology of Full Current Selective Protection and Zone-Selective interlocking mainly, this paper comes up with a new Intelligent Molded Case Circuit Breaker system. Use the accurate calculation method, to achieve a good function of three kinds of current protection. By means of coordinate communication, the system implements selective trip and protection function, and improve the reliability and safety of the distribution system. Self-diagnostic function works when the system goes wrong, which extend the service life of this circuit breaker system.

The Effect of the Fault Tolerant Capability due to Degradation of the Self-diagnostics Function in the Safety Critical System for Nuclear Power Plants

The safety critical systems in nuclear power plants should be designed to have a high level of fault tolerant capability because those systems are used for protection or mitigation of the postulated accidents of nuclear reactor. Due to increasing of the system complexity of the digital based system in nuclear fields, the reliability of the digital based systems without an auto-test or a self-diagnostic feature is generally lower than those of analog system. To overcome this problem, additional redundant architectures in each redundant channel and self-diagnostic features are commonly integrated into the digital safety systems. The self diagnostic function is a key factor for increasing fault tolerant capabilities in the digital based safety system. This paper presents an availability and safety evaluation model to analyze the effect to the system's fault tolerant capabilities depending on self-diagnostic features when the loss or erroneous behaviors of self-diagnostic function are expected to occur. The analysis result of the proposed model on the several modules of a safety platform shows that the improvement effect on unavailability of each module has generally become smaller than the result of usage of conventional models and the unavailability itself has changed significantly depending on the characteristics of failures or errors of self-diagnostic function.

健全性診断機能を付与した機械的継手部の革新設計

The primary objective of this study is to address a key research challenge for improving tradi-tional joint design, which develop functions and structures that can monitor their own structural integrity. A self-sensing technique using the bolt itself to monitor the bearing damage in bolted composite or metallic joints is proposed. The basic concept is based on making Bolt Gauge (BG) measurements. That is, have only to bond a strain gauge onto the surface of bolt head to reflect changes in the bolt strain, which would identify the state of bearing damage. Novel system can maintain not only the peculiar structures and functions of the mechanical fastener, but more importantly, also can provide the self-diagnostic function for component damage. And, it can be contributed directly to technology development for structural health monitoring (SHM) to address these issues, and to meet demanding goals in increasing aerospace vehicle safety and reliability while reducing operating costs. Extensive tests using double lap bolted joint specimen are performed to verify this technique in the various joint cases. The investigations include the effects of the bolt clamp-up, material response, joint geometry and loading history on the detection sensitivities for the bearing damage. The onset and progress of the bearing damage monitored by BG measurements are also compared with acoustic emission (AE) measurements that used in traditional NDE method. A further consideration of the detection mechanisms by BG including an axial loading test and a three-dimensional finite element analysis is performed. The behavior of bolt deformation and stiffness degradation due to the bearing damage initiation and progression are estimated using damage mechanics approach.

加速度データを用いたエレベーター診断手法(J19 製品ライフサイクルとメンテナンス)

In order to reduce the rate of a down time of an elevator, it is effective to detect abnormalities at early stage by strengthening the self-diagnostic function of the elevator by addition of sensors. For this reason, we are developing the distinction technique between normal and abnormal state by the data of an acceleration sensor. This time, we collected the acceleration data of the elevator which simulated abnormalities, and tried application of the examined distinction technique. In conclusion, distinction of abnormalities from normal is possible, and a possibility that the kind of abnormalities could be distinguished was shown.

Development of Acceleration Sensor and Acceleration Evaluation System for Super-Low-Range Frequencies

This paper describes the development process for acceleration sensors used on automobiles and an acceleration evaluation system designed specifically for acceleration at super-low-range frequencies. The features of the newly developed sensor are as follows. 1) Original piezo-bimorph design based on a disc-center-fixed structure achieves pyroeffect cancelling and stabilization of sensor characteristics and enables the detection of the acceleration of 0.0009 G at the super-low-range-frequency of 0.03 Hz. 2) The addition of a self-diagnostic function utilizing the characteristics of piezoceramics enables constant monitoring of sensor failure. The frequency range of acceleration for accurate vehicle motion control is considered to be from DC to about 50 Hz. However, the measurement of acceleration in the super-low-range frequency near DC has been difficult because of mechanical and electrical noise interruption. This has delayed the development of the acceleration sensor for automotive use. We have succeeded in the development of an acceleration evaluation system for super-low-range frequencies from 0.015 Hz to 2 Hz with detection of the acceleration range from 0.0002 G (0.2 gal) to 1 G, as well as the development of a piezoelectric-type acceleration sensor for automotive use.

An intelligent power IC with reverse battery protection for fast-switching high-side solenoid drive

A highly reliable and fast-switching intelligent power IC (IPIC) for a high-side solenoid drive is described. There are two main features in this IPIC. The first feature is a built-in reverse battery protection method that can be used in both 12-V battery systems and 24-V battery systems in large vehicles. This protection is accomplished by using a high-voltage MOSFET to suppress a forward current of a parasitic diode in the reverse battery condition. The other notable feature is a device isolation structure and driving method using two sets of pull-down circuits to reduce the turn-off time for the inductive load current. The turn-off time for the inductive load is reduced to two-thirds that of a conventional IPIC. This is achieved by increasing the absolute value of the sustained negative output voltage from -18 to -34 V. This IPIC also has over-current protection, over-heating protection, over-voltage protection, and a self-diagnostic function as well as the conventional IPIC function. It is useful for high-side solenoid drivers frequently used in automotive electronics.

Detection of Damage by Measurement of Electrical Resistance in CFGFRP Composites.

CFGFRP (carbon fiber-glass fiber-reinforced plastics) composites are materials with a self-diagnostic function for detecting latent damage. Three type of carbon fiber bundles with different ultimate elongations and one type of glass fiber bundle with a large ultimate elongation were tested as conductive fibers and insulating fibers, respectively. Electrical resistance increased with increasing strain, and a tremendous change was seen at the transition point where the carbon fiber bundles fractured. Data obtained by the acoustic emission method were measured simultaneously, and these changes showed results similar to changes in the electrical resistance. Permanent, residual strain and residual electrical resistance were observed even after the removal of load, and these changes were dependent on the maximum strain applied in the past. Latent damage of CFGFRP composites can be detected by a method based on the measurement of their changes in residual electrical resistance after unloading. The method based on measuring changes in the electrical resistance of the CFGFRP composites during and after loading is simple in terms of technique and manageable in terms of cost for detecting latent damage and preventing fatal fracture.

HVDC Transmission Control Equipment with High Reliability

A triplicated digital control equipment has been developed to improve reliability and performance of HVDC transmission. For improved reliability, DDC is used which is best suited to triplicated systems. The triplicated control equipment made up of three digital control equipments utilizes the self-diagnostic function of microcomputer to the maximum extent. It also employs an intermediate value selection as a signal selection method. The computation in the three control systems is performed in synchronism with the ac system to minimize signal transfer among the three systems and thereby facilitate maintenance. A new PLL circuit for synchronism detection is used to protect the HVDC transmission against ac system disturbances. An Operating System (OS) specially programed for HVDC transmission control is incorporated in the microcomputer to perform ac system control. The developed digital control equipment was tested in the simulated transmission facility. The simulation test showed that the control system has improved performance and reliability.