Applied Mechanics and Materials Vols. 668-669

Abstract: Energy-saving lamp will still be a favorite product on the lighting market in the long run. One of the drawbacks of common energy saving lamp is that it cannot be dimmed. Energy is wasted when bright light is not necessary. To promote the idea of energy saving and environmental protection, a plan for the applicability of dimming of energy saving lamp is in urgent need. In this study, we put forward two plans for the dimming of energy saving lamp. Our effort is to make the energy saving lamp adapted to the variety of power frequency and to maximize its smooth dimming as close to that of an incandescent lamp.

Abstract: In the study of excavator automation, the conventional contact-type sensors can be easily damaged because of the collision or vibration when measuring the posture of excavator’s manipulator. For this case, a novel vision-based approach for measuring the posture of excavator’s manipulator is proposed. In this approach, an industrial camera with an infrared filter is used to grab the perspective images of the manipulator under the irradiation of a LED infrared light source; and saddle point detection is adopted to detect the man-made targets which fixed on every arm of the manipulator. Then the selection algorithm based on the fixed geometric dimensioning between two targets is optimized to select the saddle point in targets, and the posture angle of the corresponding arm can be derived from the saddle point coordinates. Furthermore, the detection regions are tracked by anticipating the three group targets’ movement separately. Experiments show that with the infrared device, the vision-based posture measurement system of the excavator’s manipulator can better adapt to different illumination intensity conditions; and the optimization of target selection algorithm reduces the false detection rate from 4 times in every 30s to 1 time in every 30s; also, the average processing time for every manipulator movement frame is reduced from about 70 ms to 50ms by tracking the detection regions separately.

Abstract: In order to help teachers to identify plagiarism in student assignment submissions among students’ Source code quickly and accurately, this paper discusses a measurement method of Source code similarity. In the proposed algorithm, firstly, both of token oriented edit distance (TD) and token oriented length of longest common subsequence (TLCSLen) is calculated; secondly, considering the TD and TLCSLen, a similarity calculation formula is given to measure similarity of Source code; Thirdly, a dynamic and variable similarity threshold is set to determine whether there is plagiarism between Source codes, which ensure a relatively reasonable judgment of plagiarism. This method has been applied to the university's programming course work online submission system and online examination system. Practical application results show that this method can identify similar Source code timely, effectively and accurately.

Abstract: This paper introduced principle and function of construction machinery intelligent monitor. The STM32 microcontroller-centered, through to installation in construction machinery such as bulldozers, tractors, loader various sensor output signals on real-time acquisition, data processing and records to achieve work condition monitoring of construction machinery. Also monitor implementation methods are described in detail.

Abstract: In the modern society, with the rapid development of industrial technology and information industry, electrical loads become more and more complex. As a result, the harmonics and reactive power problems have become increasingly serious. In the non-sinusoidal conditions, conventional power definitions don’t work well any more. Power theory is one of the foundations of financial accounts for energy, evaluation of the efficiency of power transmission and control of current compensation. Among them, the instantaneous reactive power theory is regarded as one of the most promising power theories. What’s more, it has been improved. Based on the three-phase three-wire system and four kinds of different supply voltage conditions, this paper compares the instantaneous reactive power theory (pq theory) with the extension pq theory. At last, the simulation results are presented. As a conclusion, the extension pq theory is the improvement of the pq theory and has a wider applicability.

Abstract: Digital piezoelectric constant testing system was designed in this paper, which was based on hydrostatic test method. The system is composed of hydrostatic device, charge amplifier circuit, peak holding circuit, A/D calibration circuit, data processing by DSP. Pressure-release value is obtained by digital pressure transmitter on the hydrostatic device. Combining with mean filtering and A/D calibration, DSP can sample accurate voltage signal. Considering the difference between the equivalent circuit of charge amplifier and its practical circuit, the calculated hydrostatic piezoelectric constant is in better agreement with the theoretical value. The experiment results show that the accuracy of testing system is less than 4%.

Abstract: A failure analytical tool, Failure Anticipation Analysis (FAA) of modern TRIZ, is briefly described in this paper. FAA algorithm is put forward, and employed to solve a failure problem of E-bike lighting system in the Case study. The practice shows the power and efficiency of FAA.

Abstract: Fiber Bragg Grating (FBG) sensing technology is widely used in detection of temperature, strain and etc. Now the application of FBG sensor is limited below 200°C. Application over 200°C is still an engineering challenge since no suitable FBG strain gauge. In this paper, FBG strain gauge structure which consists of three FBGs is designed and fabricated based on the theoretical strain and stress analysis. This strain gauge can be used for the real-time high temperature strain monitoring situation. The elastic high-temperature alloy (10MoWVNb) is chosen as the substrate. The three FBGs with a similar performance are fabricated on the substrate by high-temperature glue. Among the three FBGs, FBG1 is used for the horizontal strain monitoring, FBG2 is used for the longitudinal strain monitoring, and FGB3 is used for high temperature cross-sensitive compensation. The fabricated high temperature FBG gauge is demonstrated suitable for high temperature strain monitoring by experiment.

Abstract: Boron-containing plastic scintillator detectors have a high detection efficiency for low-intensity thermal neutrons and fast neutrons which is currently the preferred types of neutron detector. This article is based on Monte Carlo method, studied boron-containing plastic scintillator for neutron detection performance, and analysis the energy deposition flux characteristics and detection efficiency when low intensity fission neutron incident to the boron plastic scintillator. We obtain the low-flux neutron detector performance in a variety of neutron source energy, boron-containing plastic scintillator diameter and length. Results showed that, when the boron-containing plastic scintillator lengths increase, the energy deposition flux will increase. When the length and diameter is constant, increasing source strength can increase the energy deposition flux brought by the recoil proton to a certain extent. When the source intensity over after thermal neutrons, due to the decrease of the cross section, the energy deposition fluxes brought by the react of neutrons and will decrease. The results provide help for low intensity fission neutron radiation detection technology with high sensitivity.

Abstract: Based on the measurement sensitivity matrices, a new Kalman filter is proposed to obtain the optimal state estimates by mitigating the influence of the measurement bias, when the observations have the measurement bias. Its effectiveness is verified by the Monte Carlo simulation.