| Aim at meaning and trait of the parameters that are required in industry process, the author has studied the data acquisition and processing and real time Ethernet Fieldbus which are used in industrial manufacture process. This study involved the capacitance type pressure measurement, contact thermometry, non-contact thermometry, data fusion, as well as real time Ethernet in the industrial field. These technologies can solve the precise data acquisition and network transport in industrial field effectively.,and can make a great contribution to the automation level of our nation manufacture equipments. The main contribution in this dissertation are as follows:(1) Aim at solving the measurement in the coupling of capacitance and resistance, the author presents a new measurement method that uses the stimulation of square wave which has changeable frequency to disassemble the coupling. This method makes use of the amplitude-frequency characteristic of resistance-capacitance network and the proportion of voltage output from the network which is stimulated by two kinds of square waves at different frequencies. The influence of measure precision is avoided from excitation source. The structure and trait of the circuit of capacitance sensor is developed which is used in oil exploration MEMS. A new method is presented to measure differential mini-capacitance stimulated by square wave. Transformation circuit of differential capacitance, amplifier circuit and filter circuit is designed, and the improved wavelet arithmetic is adopted to reduce the noise in the signal and improve the SNR(signal noise ratio) of the measure circuit greatly.(2) Based on the study of common contact thermometry technique used in industry, the author designs a consecutive nonlinear A/D conversion circuit of measurement used spreading resistance temperature sensor, and adopts the method of using three-wire connection to compensate the lead wire resistance. At last reaches the conclusion that the lead wire resistance has a -4/R effect rate on the measuring precision. The author also studies the technique which used to correct the nonlinearity of sensor and electric bridge in consecutive nonlinear A/D conversion circuit, presents the method of gaining the optimal parameters of correction circuit through the weighted least-squares estimation, and designs the circuit with the optimal parameters. Then, aim at the nonlinearity of thermocouple temperature sensor, the author uses the polynomial fitting method to correct the nonlinearity. In this method, each sensor is divided into five segments, and fits out 4rd-order polynomials of each thermocouple type of K,E,T,J,S,B,N,W and R. This method ensures that the sensor nonlinearity correction precision is better than 0.1℃in the sensor's whole range of temperature. Then the experimental validation is carried out to the actual effect of temperature measurement of each type of thermocouple.(3) Based on the technique of radiate temperature measurement, the author designs a circuit of prismatic decomposition colorimetric radiate temperature measuring. A high resolution A/D converter and measurement range switch technology are adopted to resolve the problem that it has lower radiation power and lower signal sensitivity in the low-temperature stage, while higher signal amplitude and higher need of dynamic range in the high-temperature stage. The technique of the Black Body Furnace demarcates, digital calibration and the quartic curve fitting are applied to correct the sensor and improve its measurement precision. The author studies the method of measuring and identifying high-temperature object based on image color, which acquires color-image at the typical temperature of the Black Body Furnace, establishes the relationship between the HSV special color model and the temperature. The neural network is used to train the identifier and the function of measuring temperature is realized by image color.(4) Based upon the study of data fusion algorithm, the author presents a new grouped variance estimation algorithm to estimate the measurement variance for each group online, which assigns the weight of Weighted Least Squares Fusion algorithm based on the variance.. The author also discusses the grouping method and provides the optimal grouping principle of the grouping fusion algorithm, which is also validated in theory to have the minimal variance characteristic. The heating model is established by taking the heating water process as an object. The detect of boiling state is transformed to that of average speed point in the process of temperature rising, and the CUSUM is adopted to perform change detection. The on-line algorithm is given out to estimate the speed of the temperature rising in heating process and the noise variance, which realizes the quick detection of boiling state.(5) Based on the study of real time Ethernet, the author further studies the EPA (Ethernet for Plant Automation) and the system model, communication model and real time communication technology of the Ethernet fieldbus control system, designs the real time communication scheduling method, and defines the services of network communication and system management. The author presents the technique to realize the function block of EPA system under the model of IEC61131-3 function block, develops the function block configure software using Object Oriented programming technique, and realizes the functions of device management, communication management, configuration link management, variables monitor and so on. The author also studies the test method for Ethernet system's real time characteristic, presents the parameter definition which describes the real time characteristic of EPA and testing method, develops the real time characteristic testing platform, and it is validated by testing the unit devices of "863" program team.Aim at the techniques of parameter checking and real time control network, which are widely used in industry process, this paper gives out various methods of parameter checking, data process and the method of network connecting and harmonizing, and is sponsored by national 863 projects and province projects. At the same time, many relevant hardware and software products are developed which are extended and applied widely, lots of awards are obtained such as the Second-class Science and Technology Advancement of LiaoNing province and the First-class Science and Technology Advancement of DaLian city. This research is hoped to provide a new idea for solving the problems in industrial field data acquisition and system control.
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