Advanced Materials Research Vol. 1037

Abstract: According to the function, the technical indexes and the cost control etc, we select the embedded control computer and virtual instrument module based on the PXI, and developed the integrated multipurpose instrument calibrating equipment, it realized the field measurement and calibration of the electrical instrument away from the laboratory. The system is designed based on PXI and LabVIEW, it uses virtual instrument technology, automatic control technology and database technology, by combining these functional modules of NI, we realized the calibration of electrical instruments such as digital multimeter, signal generator, oscilloscope and cymometer etc. The system is used integrated design, and it is very flexible, it can be popularized and applied as working standard to troops, factories or schools etc.

Abstract: Depending on instruments and operator’s experiences, the operation of steel cable grab dredger is influenced by construction environment, weather conditions, monitoring accuracy and human factors. Misjudgment may be made, which will cause safety problems. To achieve data safety monitoring, this paper converted the traditional artificial judgment on potential safety risks caused by crab bucket’s drift into a computational process.

Abstract: This paper proposes a temperature measuring method of low cost and stable precision based on platinum resistance. RC discharge circuit is composed of platinum resistor and fixed capacitor,the discharge time of fixed capacitance in the circuit is used for calculating the platinum resistance temperature resistance. The experimental results show that this is a simple and low cost method .

Abstract: A diagnosis method of aero-engine faults based on Mamdani fuzzy inference is proposed in this paper. Regarding the fault symptoms of aero-engines as input of fuzzy inference, the proposed method establishes rules of inference from experts’ experience and distills the implication relationships. On this basis, the fault symptoms are combined with the implication relationships to obtain the probability of fault causes, so as to achieve the diagnosis of aero-engine faults. The results of experiments showed that the method is feasible and effective.

Abstract: The study mentioned a curing equipment with UV LED array based on pyroelectric sensor and AP3706, which is based on the primary side control circuit so that it can complete the LED array constant voltage constant current output.the light source drive can output the constant voltage and constant current. The sensing signal processing signal integrated circuit BISS0001 as the pyroelectric sensor amplifier circuit as core, with relay making up the protection module of curing device. The experimental results show that, the curing equipment can realize the stable and homogeneous UV output, and when a human body in front of LED, the array will disabled to keep the human body away from damage UV induced.

Abstract: This paper proposes a capacitance resistance measurement method based on time constant. Using the charging and discharging characteristics of the resistance and capacitance measures the value of the resistance and capacitance through a semi potential rise and fall time measurement. Theoretical analysis of the relationship between the value of the resistance and capacitance and the measuring time, designing the fast second charging and discharging method meeting the initial condition of charge and discharge, improving the measurement speed, expanding the measurement range of the resistance and capacitance. Realizing the effective measurement of the resistance and capacitance by the FPGA control logic and timing method.

Abstract: The virtual simulation experiment framework consists of hardware and software function modules, which are both designed in this thesis. The application of virtual experiment framework has changed the traditional teaching method to a large extent, reduced the cost of laboratory construction and management, which is of the first importance to realize the remote experiment teaching. Through virtual experiments, students' interest in knowledge is cultivated and innovation ability is enhanced. With the National Instruments Educational Laboratory Virtual Instrumentation Suite (NI ELVIS) and LabVIEW, we could take advantage of graphical programming and a complete suite of standard test instruments on computer and directly interface these instruments to circuits, which is the base of virtual experiment framework.

Abstract: In accordance with the character sight device of artillery, an examination and adjustment instrument of artillery zero line base on laser technology is designed, and the structure and key technique and design principle of the system are described in detail. The method overcomes some shortcomings of traditional diagnosis system and is available in practice.

Abstract: Gate valve is common equipment in the petrochemical industry. It often brings out internal leakage because of quality, operation, corrosion and other reasons, and has adverse influence on safety production, environment protection and energy conservation. This paper put forward the on-line detection method about the gate valve internal leakage detect problem on the basis of AE signal analysis. Firstly, introduced the structure of gate valve and main reasons of internal leakage, discovered the acoustic emission signal parameters of gate valve internal leakage, and derived the relation model between internal leakage and AE signal theoretically. Then, constructed internal leakage signal acquisition platform based on DN80 gate valve internal leakage simulation system. Finally, put forward gate valve gas internal leakage test, set the different pressure at different points on the conditions of different pressure valve of 0.2MPa, 0.4MPa and 0.6MPa, The experiment showed that gate valve internal leakage status can be displayed by the signal RMS value when the gate valve internal leakage AE signal is between 30kHz and 80kHz. The AE signal next to the gate valve downstream position is the strongest. Internal leakage of the valve exists if downstream signal was significantly greater than the upstream signal or the background noise. The AE signal strengthened while the pressure difference between upstream and downstream is increased.

Abstract: To solve the problem of a type of electronic equipment maintenance, a kind of portable testing instrument is developed. The instrument adopts embedded development, PC104 bus and fault reasoning technology to realize the functions of signal test, fault diagnosis, repair instructions and data query. The instrument is mainly composed of a hand-held chassis, LCD screen, touch screen, Intel main control board, oscilloscope card, multimeter card and power supply module, on the basis of PC104 bus structure. The A/D conversion circuit uses multiple cross parallel high-speed data acquisition architecture to achieve sampling data of higher accuracy and higher speed. The main control board and test function card is designed and the principle of circuit module is described. The signal testing and fault diagnosis software is developed. The instrument has good application effect, with the advantage of practical and portable.