Applied Mechanics and Materials Vols. 635-637

Abstract: Taking solar photovoltaic panels as the research object, infrared diagnosis technology is used to inspect the quality of crystalline silicon solar panels, and using infrared detecting principle of infrared thermal imager to design a set of device, which can detect the internal and surface defects of the solar panels. Common defects such as black piece, broken gate, crack and fragment can be detected and classified according to the infrared image characteristics of the four kinds of defects, also it can quickly locate the defects. Experiments show that, after image processing of the images captured by the infrared imager, it can be easily and visually to determine whether a photovoltaic panels is flawed. Last but not least, to classify the defects.

Abstract: Eddy current sensor with online non-contact measurement, no coupling medium and high sensitivity etc, is widely used in engineering. In this paper, based on the eddy current testing principle, the eddy current sensor is modeled in ANSYS software to complete the optimization design. The article research on the method of flaw recognition after extracting the detection signal features and analysis the impact of the flaw size on the detection signal, so as to provide a theoretical method of qualitative detection in the practical application.

Abstract: Distance measurement technology of binocular stereo vision has the advantages of wide-range detection, simplicity and reliability. The method is widely applied to robot obstacle avoidance and path planning. Binocular stereo vision can only measure the distance of images feature points generally. However, more information about distance of non-feature points is also needed to acquire in practical applications. This paper proposes a stereo distance measurement method, which can measure distance of points whether it is a feature point or not based on a dense matching method. A dense parallax map is obtained by the graph-cuts algorithm. On the basis of the calibration parameters of binocular camera and the left and right image dense parallax map, the three-dimensional coordinates of the any points and their distance will be gotten. The true image experiment has proved the feasibility of this algorithm with high accuracy and maneuverability.

Abstract: Aiming at the problems of travel time tomography with sparse rays, this paper improves the inversion stability by optimizing experiment design. This paper analyzes the influence factors of inversion stability and proposes the evaluating function on optimizing experiment design. The numerical simulations show that the optimization method is feasible and the optimum design make inversion more stable.

Abstract: Inspection on chips from oil system is an important method for modern aeroengine condition monitoring. Energy spectrum analysis technique is the most widely used and effective method in inspection on metal chips. In this method, size and quantity of chips are observed by scanning electronic microscope and qualitative and quantitative analysis of element contents are finished by energy dispersive spectrometer. Through above experiments, material type of metal chips can be analyzed and material mark can be determined by comparison with the materials list used in the aeroengine. In this article, characteristics and advantages of energy spectrum analysis technology are systematically introduced and typical appearance feature and energy spectrum curve of common l chips are summarized in engineering practice. In addition, problems and prospects of energy spectrum analysis technique are proposed.

Abstract: Microbial density is an important biochemical parameters of the training process. This article adopts the method of online measuring optical density of the reactor to obtain information on the growth of microorganisms, and flow photoelectric colorimetric instrument was developed based on this principles. Through MCU STM32F107VC output PWM to control peristaltic pump, to achieve the culture of continuous flow through the optical flow cuvette, using photocell to detect culture absorbed light intensity. The instrument can display detected parameters independently and adjust the control parameters, also can communicate with the PC by RS485. The instrument can achieve real-time monitoring of the growth of microorganisms in the reactor.

Abstract: Gas valves are very important parts in compressors. If a valve fault in a compressor takes place, the expulsion of the compressor will decrease. In some critical cases, abnormal gas transmission will lead to a serious accident. This article proposes a method of fixed time basis in multi-resolution analysis and wavelet transform. This method can thoroughly resolve the problems occurred in present valve fault diagnosis caused by the fact that the wavelet transform does not have time shift invariance. By the analysis of experimental data, it shows that the valve fault can be preferably and accurately detected by using the method.

Abstract: The DOA estimation by the model of four elements in the square array has studied based on the theory of compressed sensing. Using matching pursuit algorithm and orthogonality matching pursuit algorithm, the computer simulation was presented. The results show the method of DOA estimation by compressed sensing theory is simple, practical and low computational complexity.

Abstract: Obstacle identification is one of the critical technologies of unmanned vehicle, edge detection is the basic step of obstacle identification based on video sensor and the magnitude guarantee of identification effect. In order to meet the demand of accuracy, real-time and stability of obstacle identification, a new multiple order morphology edge detection algorithm is proposed. We adopt two-dimensional histogram oblique segmentation to locate edge, then detected edge by improving the existing mathematical morphology edge detection operators and using appropriate structuring elements and percentile. Experimental results showed the edge detected is exquisite, continuous and intact. The algorithm possesses good robustness for different noised images, cuts operation time by nearly half compared with algorithm without edge location, then makes a good foundation for subsequent processing of obstacle identification.

Abstract: Because of the influence of complex image background, illumination changes, facial rotation and some other factors, makes face detection in complex background is much more difficult, lower accuracy and slower speed. Adaboost algorithm was used for face detection, and implemented the test process in OpenCV. Face detection experiments were performed on images with facial rotation and complex background, the detection accuracy rate was 85% and 99% respectively, the average detection time of each picture was 16.67ms and 76ms.Experimental results show that the face detection algorithm can accurately and quickly realize face detection in complex background, and can satisfy the requirements of real-time face recognition system.