Applied Mechanics and Materials Vols. 494-495

Abstract: Oil temperature plays a key role in state monitoring and fault diagnosis of hydraulic systems. Traditional methods for measuring oil temperature are neither convenient nor safe. In this paper, a non-invasive test technique together with its calculation model for obtaining fluid temperature is proposed by measuring the pipe surface temperature and the ambient temperature. A series of experiments had been carried out on different pressure values, and the oil temperature calculation model proposed was optimized accordingly. Experimental results show that this measurement technique together with the model can provide a fast and accurate way of oil temperature testing non-invasively under different pressure conditions, so it can be introduced to the hydraulic system application.

Abstract: The surface coating of insulation resistance is one of the key technical indexes of electrical steel sheet, and one of the important parameters of the products of electrical steel sheet. Nowadays the surface coating of insulation resistance device is relatively heavy, measurement error is relatively large, and measurement repeatability is not good. To solve these problems, we design an insulation resistance measurement system based on Infineon XE166 microcontroller. This article analyzes the measuring principle of silicon steel coating surface insulation resistance and includes the three aspects of mechanical, circuit and software. The experimental results validate the feasibility of this system. The measurement system is stable and reliable, high repetition rate, and has a good application prospect.

Abstract: In order to study the typical fault types of Field (Factory) Special Motor Vehicle in the inspection process, we visited many warehouses and wharves in Huangpu District for inspection research, then summarizedthe typical failure modesand took its failure causes and treatment measures for key research. First, wemade statistics and summarized the failure law according to the typical fault types among the old vehicles of annual test. Then we analyzed the concrete manifestation and summarized the failure causes from the braking performance, knuckle mechanic, tire wear, fork loose and other failures of forklift. Then we aimed at the new vehicles of test and acceptance of fault type for statistical analysis. Finally, weformulate corresponding measures according to different fault types. As the result of Inspection and investigation showed, the failure rate of electric forkliftreaches to 1.3% as the failure rate of diesel forklift is to 10.7%; the market share of electric forklift of test and acceptance rose from 41.6% to 78.3% compared with electric forklift of annual test. Braking deviation oflinear acceleration is the most typical fault type of forklift; electric forklift make more excellent performance than diesel forklift on key parameterssuch as braking; forward forklift easily has rollover accidents.

Abstract: By analyzing the design process configuration design for order in much discipline, high coupling, many iterations, and the basic characteristics such as systemic, based on the characteristics of table things ETO enterprise operation critical process research method. The study in the process of enterprise operation several key technology, puts forward the design process and process data of integrated model; Analysis of process management and process quotation system integration method. Through the and process management of integration, to design and the changing design as the main means, to realize the rapid design ETO process. Finally, taking the electric power company risk management system for an example to verify the feasibility of the theory.

Abstract: In the paper, firstly establishes the pipeline system model based on the principles of correlation analysis, and determines the correlation characteristics of pipeline flow and pressure. Secondly multi-scale analysis is introduced into dynamic system processing. A leak detection method is shown with the multiscale correlation analysis, and is compared to the residual correlation analysis; it overcomes two the mistakes with different nature, such as too much interference or loss of leakage signal details. Finally through the actual data verification, the methods suitable for mutation signal, but slowly changing signals need to find another method.

Abstract: A nonlinear dynamic compensation for probability analysis in fault diagnosis of electric equipment was reported. Because of the limitations of Threshold temperature diagnosis method and the traditional Bayesian theory fault diagnosis method of electric equipment, a nonlinear SGompertz model and quadratic power model were used to compensate the diagnosis results for the influence of equipment aging and running temperature, then the maximum probability principle was adapted to judge whether the equipment is in malfunctioning state. The 3-D simulation results indicates that: (1) there is a strong relationship between the status and equipment aging and running temperature; (2) an obviously difference exists between linear and nonlinear compensational results of the characteristic temperature region. This proposed methodology is testified having important significance in improving the reliability and the information level of power transformers operation.

Abstract: In this paper, one ground freezing monitoring system based on Zigbee is designed. System is divided into four parts: sensor cable based on 1-wire technology, monitoring terminal with a drive circuit based on Zigbee, Zigbee coordinator and monitoring host with the function of network. This paper mainly introduces the network communication system. The system is suitable for the construction site of the engineering test; anti-interference and robustness of system are strong. It implements the project managers and experts operation of real-time control without time and space limits for freezing monitoring system. It provides technical support for the application of freezing engineering.

Abstract: Established the gearbox fault model and simulated it at different load conditions view of the problem with gearbox experimental technique research under the variable speed and load conditions. The law between the changes of rotational speed and load with the system vibration signals was investigated and the corresponding optimal test fault condition was given. Based on this, validated the feasibility on fault diagnosis by increasing (decreasing) speed signal and found that the different load will have a different influence on the different fault signal. The different diagnostic purpose should be considered to design load conditions.

Abstract: By means of inductive analysis the health diagnosis weighting methods in engineering, this paper discusses the basic principle, advantages, disadvantages and applicable scope of weighting methods. On the basis, combining with multi-level, multi-standard and multi-factor characteristic of hydraulic metal structures health diagnosis, the methods of AHP, information gain, information diffusion and improved entropy are studied, which are applicable to hydraulic metal structures health diagnosis weighting. Based on fuzzy theory, the fuzzy multi-level comprehensive weighting method is put forward and studied, which combined both subjective and objective method advantages and its complementary. In addition, it provides the necessary theory foundation and new ideas for the development of hydraulic metal structure health diagnosis technology.

Abstract: According to the common problem that radiation emission exceeds (one domain of electromagnetic compatibility) of DK-N-MS surgical power device, we use the EMC standard as a guide, understand radiation emission testing mechanism, analyze its radiation exceeding cause, and then take effective rectification measures. Testing experiments show that it meets the EMC requirement, improves devices stability and reliability. Moreover, it provides a guiding design for subsequent devices.