Advanced Materials Research Vols. 317-319

Abstract: This paper introduces the design of front circuit in cleaning grain loss monitoring and control system for a new electric combine harvester. This front circuit mainly includes signal conditioning circuits which are amplification circuit, anti-jamming circuit and filter circuit for transforming sensor output signal. 8031 single-chip is used as its core and implemented automatic monitoring of the cleaning grain loss. Owing to adopt the modular design method and mature technology, the circuit is powerful in function and easy to realize and has extensive value in use. The simulation results show that the effect is excellent and performance is stable.

Abstract: For transient electromagnetic meter home-made, there are some disadvantages, for example early signal detection is difficulty, and speed and accuracy of signal acquisition is no high. Therefore a high-performance TEM based on embedded PC is designed to overcome these disadvantages. And its main part is measurement and control system, which design is mainly introduced. The system consists of a transmitter and receiver modules, which hardware block diagram and schematic design are introduced in detail. Laboratory tests for the system developed show that the electromagnetic transmitter module has advantages of short off-time and high transmitting current detection accuracy; the electromagnetic receiver has advantage of high sampling speed, big dynamic range and achieving accurate measurement of early signal. Laboratory test results are satisfactory.

Abstract: LonWorks technology is a complete development platform used in monitoring network system. In order to improve the real-time of LonWorks node, its master processor AT89C2051 and slave processor MC143150 will realize data exchange each other in Slave A parallel mode. Data transfer mechanism using virtual token passing can solve the issue of master and slave processor seizing the data bus. PLT-22 transceiver featuring a dual carrier and narrow band frequency can complete data communication on LonWorks power line network, the transceiver can overcome the drawbacks of noise sources, attenuation, distortion. Experiments show that LonWorks node achieving power communication based on Slave A parallel mode has good communication and high real-time performance.

Abstract: The LabVIEW virtural instrument platform was established to measure the temperature by the thermocouple with a temperature compensating.The LabVIEW virtual instrument technology is efficiently used to implement a number of significant measurements, which was designed by the PC computer connected with a data acquisition device. Compared with the traditional temperature measurement device, this system has the advantages of simple structure, low cost，easy operation and high stability.

Abstract: In electrolytic aluminum production processing, the measurement and control of alumina concentration is one of the three most important control aims. However, due to alumina concentration can not be measured directly and continuously online, and electrolytic aluminum production process is nonlinear, time-varying and large delay, which can not be described through the mathematical analysis model. Therefore, efficient and reliable development of alumina concentration control method is very important. In view of the above problems, alumina concentration is controlled by intelligent characteristic model and single neural adaptive PID controller, which achieve a good control effect.

Abstract: It make a detailed description and instruction with the control condition of the Active Power Filter, at the same time , it also make a comparison with the advantage and the shortcoming one by one , at the end, make a prospection with the developing tendency and research keys.

Abstract: For the requirement of online ultrasonic inspection for welding belt on pipeline, and the influence of its surface contour error (roundness) on stabilization of the clearance between the probe and the work pieces, a novel self-adaptive contacting ultrasonic scanner is advanced, which makes the ultrasonic wave transmit into the rotational part along with the normal direction of the detecting surface so as to realize online ultrasonic flaw-detection on pipelines. Based on those works, a software system is also developed, which realizes the requirement of online ultrasonic flaw detection process. The practical application proves the developed system can promote both the inspection quality and the efficiency of .welding belt on pipeline.

Abstract: In order to resolve the problem of not taking into account color, texture and shape features in crop disease intelligent recognition systems, feature extraction method based on three feature types was proposed. Two types of color spaces such as RGB and HIS were considered, and the transformation formula of the two color spaces was improved. Then ten color features were defined and extracted. Meanwhile sixteen texture features were defined and extracted based on gray level co-occurrence matrix. And thirteen shape features were defined and extracted based on invariant moment theory. Finally the feature dataset was received which was suitable for identifying four types of wheat leaf diseases. The results show that the system recognition rate is relatively high, and can meet the practical application requirements.

Abstract: A metal coating corrosion monitoring system (CMS) based on corrosion potential was introduced. It’s working principle, especially the design and selection of soft and hardware and the main technical specifications. The system has the characters of real-time monitoring of changes in corrosion potential status of coatings, automatically storing corrosion information and alarming according to corrosion degree in monitoring sites.

Abstract: Leakage is one of big security risks in the explosive gas atmosphere. In view of the weak current and detection difficulty of leakage signal, a novel method of leakage detection is proposed. According to leakage transient characteristics, this method takes zero-sequence voltage as the fault threshold value triggering measurement device. Auto-correlation function is used to analyze leakage signal energy and cross-correlation function is used to calculated leakage signal phase relationship in order to identify leakage line further. Theoretical analysis and simulation show that the proposed method can greatly improve the sensitivity of weak leakage signal detection.