Applied Mechanics and Materials Vols. 536-537

Abstract: Based on the model and feature of combination testing, a novel technique of fault analysis based on combination testing is proposed. The faults of software can be triggered by system parameters and their interaction. The result of combination testing is analyzed, and discovered the possible reasons, and then generates an additional test cased which involved from the test case causing the fault, and analysis and verify the result. This method can locate the faults in a relative small area, and can simplify the process of software debugging and testing.

Abstract: Based on sound intensity and acoustic array methods, noise source identification of an engine is measured at idle condition. The main noise source of intake surface and exhaust surface are determined, also their frequency spectrum analysis. This two kinds of method testing results fundamentally agreed very well, and verify acoustic array method is more simple and easier than sound intensity method.

Abstract: In this paper, To the energy efficiency of power adapter as the research target, we analyzed the demand for automated testing, establish safety regulations automated test system based on LabVIEW. We will use open, modular design and flexible hardware framework, increase the hardware configuration according to customer product testing requirements, and has a good price and versatility. The test process will be automated, the test results will be displayed in real time, and realize the test data storage, analysis and print. By establishing automates of the entire testing process, greatly saving time and reducing test engineers labor costs, and improve the testing laboratory automation and testing reliability.

Abstract: Paper defects mean that there are some defects in the paper such as hole, emboss, and fold during the paper production, which mainly results from the limitation of technological level. In the past time, artificial visual inspection and off-line checking were often used to detect the paper defects. However, its shortcoming was highlighted along with the improvement of industrial technology level and increasing demand for paper. In order to realize the online detection and markers for paper defects, the project designs the on-line detection system based on line-scan digital camera. Firstly, the principle and detection scheme of the system for the paper defects was presented. Then the overall structure of the system was designed. After that, the hardware circuit of the system was designed using TMS320F2812 as main control chip. It mainly consists of the function of each module and the working process of the system. Finally, the software of the image acquisition system was presented. With the experimental verification, the system has advantages of low cost, high efficiency and strong resistance to interference. The functions and indexes achieved the design requirements.

Abstract: Scanning Acoustic Microscopy (SAM) has been a powerful non-destructive testing tool used in electronic packaging and material characterization. With the development of 3D electronic packaging, internal dimensions of electronic packaging are getting more and more smaller, and the detection accuracy of existing non-destructive testing technology is far behind the requirements of manufacturing technology. In this study, a set of practical SAM system was developed independently by our Lab. And its detection resolution was analyzed using high frequency focused transducers with center frequency ranging from 20 MHz to 100MHz. The experimental results show that the lateral resolution of the ultrasonic transducer with 100MHz central frequency can reach about 40 microns, which is consistent with calculated resolution. Comparing with Sparrow criteria, Rayleigh criteria is more coherent with the experimental results.

Abstract: Dynamic precision measurement of transmission error involves many subjects such as optical, mechanical and electrical and computer at the forefront of technology has very important significance in the production. In order to achieve the accurate testing of motion error automobile gear, convenient and quick to obtain the gear tooth form error parameters, this paper research and design of the automobile gear error motion detection based on virtual instrument technology system, can accurately test automation, including visual inspection process, real-time detection information, read the data measured parameters, the analysis of characteristic curve, and other functions.

Abstract: Aiming at the bumps in distributed instrumentation which is applied to performance test and evaluation of fixed facilities in coal mine, this paper proposed a new idea of establishing a virtual instrument with intelligence and integration. Complex and numerous testing parameters were classified according to their common features, the hardware and software resources were shared fully. The hardware platform was developed based on USB interface, met the requirements of convenient movement in coal mine site. The design idea of modularization and design manner of LCOD component-oriented were adopted to develop the software, which made the instrument more universal, extensible and integrated. The performance evaluation and practical application shown that, this instrument can meet all the requirements of performance test and evaluation for fixed equipments in coal mine in terms of function, measurement accuracy, dynamic characteristics, etc.

Abstract: This paper first discusses the basic principles of binocular stereo vision inspection, followed by discussion of the three-dimensional mathematical model of binocular vision sensor measurements, non-contact measurement accuracy binocular stereo vision again spring geometric parameters were analyzed, and then double-structure stereo vision sensor configurations were analyzed for binocular stereo vision to do a simple discussion of the basis for discussion.

Abstract: Aiming at the problem of low accuracy of indoor positioning by singular wireless access point, this paper proposes a method which is based on the result of weighted calculation using the positioning of two wireless access points. In the experiment, the method use two wireless access point to acquire the signal samples respectively in an office, using the signal propagation model and manifold regularization model to study the surroundings. At the positioning phase, the final position can be obtained by weighted calculating the results of the two wireless access point and the nature of triangular midline. The experimental results show that using the proposed method, the average error value is 20% lower than the corresponding version, using singular wireless access point.

Abstract: As a typical reciprocating engine power machinery, complex structure determines its failure brings about the complexity and diversity, it shows the uncertainties of operating environment, system noise and sensor accuracy, and engine fault diagnosis accuracy rate is reduced, taking into account the limitations of traditional BP neural networks, improved BP algorithms include statistical algorithms, additional momentum method, variable learning rate method and conjugate gradient method are studied. Finally, the engine is as an example, engine fault diagnosis experimental system is set, the vibration signals are measured in the normal state, left one and right six cylinders off the oil and air filter blockage in the load of 2565Nm, and the speed of 1500r/min, 1800r/min and 2200r/min. The test and analysis by comparing above mentioned methods indicate it is verified the superiority improved BP neural network with the conjugate gradient method.