Applied Mechanics and Materials Vols. 385-386

Abstract: Daqing Wuzhan gas field is a deformable low permeability gas filed. Based on the lab study of changing law of porosity and permeability with confining pressure, a numerical simulation model of deformable low permeability gas reservoir is established and is solved by using IMPES method. Comparing with the result of eclipse shows the method is valid. Field example shows the dynamic geological reserves of Wuzhan gas field is low and the new wells should be drilled at the area where there is production potential and larger effective thickness. Comparison of results obtained from different models with field data shows the result considering medium deformation is more reasonable.

Abstract: In order to study grasss rotary compression characteristics during round bundle process, measurement and control system for silage cylindrical baler was developed in this paper based on virtual instrument technology. The system was constituted of KM520-B silage cylindrical baler, three-phase asynchronous motor, frequency converter, sensors, data acquisition card, the LabVIEW software platform, and so on. This system can be used to acquire information such as forming chambers rotary compression pressure, motors input torque and motors power consumption. By controlling the motors input rotate speed, this paper studied the motor speed, the grass moisture content and the grass bale densitys influence on compression power consumption, grass bale forming quality and forming chambers rotary compression pressure. At the same time, this paper established simulation equipment using MAX of NI Corporation to check the built measurement and control system. The results proved that the system can well complete the set of functions.

Abstract: Aiming at improving and optimizing the ventilators performance and by reviewing the whole procession for design and research of a modern medical mechanical ventilator, many things about its ventilation control are taken into being considered toward the perspective of machine system in this paper. They are included those building the respiratory system model, getting its parameters and the technique of ventilation control, etc. Their essential mechanism, related key technologies and the working principle of each sub-system are described in detail. And a control-experimentation for realizing the ventilation in a test plat is also given out. And a continuous positive airway pressure (CPAP) control mode realized in this experiment shown the technologies of airflow control are considered well in our design.

Abstract: This design is based on the theory of ultrasonic attenuation,design of pulp concentration is C8051F021 microcontroller as the core of the meter, And contains the ultrasonic transmitting circuit, receiving circuit, the power amplification circuit, detection shaping circuit, LCD display circuit, 485 communication circuit. In addition to the data processing by appropriate filtering software, shield the noise and clutter signal, the rich information of real-time display, and the measurement of data transmission in serial port to a PC through the analysis and comparison.

Abstract: Virtual instrument is a result of the computer combined with some instrument hardware, working for the instrumentation applications, it is one trend of the instrumentation development .This paper presents a design of a high-power and high-precision constant current source, studied three different electrical testing technologies based on constant current source and propose the principle of integrated the three electrical test technologies on a virtual instrument platform. A multi-function virtual instrument system based on LabView language, USB data acquisition card and a constant current source has been developed. This system has a high accuracy, high integration and a thecapability of further development etc..

Abstract: Position detection method is applied in industrial production. Some of these methods can ensure positioning accuracy but poor ability to resist pollution, some lower cost but positioning is not accurate. In this paper, we study the Gray bus location system can be used in linear or circular displacement detection. Gray bus location system has a precise location. Its ability to resist pollution is strong, waterproof. Gray bus location system detecting the unloading cars real time location, then, let the signal of real-time location transmitted to MCU.MCU converts the signal into switch signal to control the discharging car running. Through Gray bus position detection device and control system to work together, can realize the unloading car walk smoothly, the stop position accurately.

Abstract: In order to solve the existing problems of artificial monitoring transfusion treatment and enhance the automation level of the hospital care and management, a hospital infusion monitoring system is designed. Hospital infusion monitoring system adopts the structure of distributed computer control system, adopts RS485 bus to realize the communication between the upper computer and the lower computer. The lower computer uses MSP430F149 MCU as the core, implements the dripping speed detection, the drug liquid remaining amount detection, at the same time to adjust dripping speed by controlling the stepper motor. PC microcomputer as the monitoring center, accepts data that transmits from the lower computer, and displays, storages, analysises and statistics, at the same time controls the lower computer.

Abstract: Measurement and control system plays a gatekeeper and director role in industrial production. It obtains various parameters from the production site, in order to meet the needs of production, improve quality, ensure safety in production. Distributed measurement and control systems scalability, inexpensive cost and other factors have been widely used. This paper mainly discusses a distributed measurement and control system which based on STC89C52 MCU, RS485 bus, 18B20 temperature components and ADS7822 voltage acquisition components with a main control terminal and three nodes, through RS485 communications. The main control terminal has keyboard and LCD1602 displayer, which can read each node state. Each node refers to one of the measurement and control items below (temperature measurement, current or voltage measurement, switch input measurement and switch output control).

Abstract: The measuring principle of SO₂, which is the main gaseous contaminants in flue gas, is given based on the differential optical absorption spectroscopy (DOAS). And the structure and composition of the measurement system are introduced. In the aspect of obtaining the absorption feature of measured gas, an information extraction method using statistics is presented for measuring the concentration of SO₂. The nonlinear calibration and the temperature compensation for the system were executed. In the lab, the full scale error of the retrieving concentration is less than 0.5%FS. And the measuring result is-9.47mg/m³ during the concentration of SO₂ is zero.

Abstract: In shallow water the acoustic wave from ambient noise sources carries a large number of environment information based on the complicated reflection both on the surface and seabed interface. The sound speed profile is one of the influencing factors of sound propagation characteristic, while for a long distance the sound absorption coefficient of water medium has an important significance to propagation range. The simulation results show that in shallow water sound absorption of seabed, sound speed profile and sound absorption of water were taken into account, then range prediction of active sonar can be exactly obtained using normal-mode propagation.