Applied Mechanics and Materials Vols. 347-350

Abstract: This paper sets three fault modes of rotor misalignment, pedestal looseness and rub between rotor and stator by rotor experimental platform and collected corresponding vibratory signals. Part of vibratory signal energy feature was extracted in the time field. As feature parameter of energy, the signal collected was mined using rough set theory, fault diagnosis was established on this basis. Validity of rule was verified by remaining vibratory signal, the result indicates diagnosis are accurate, fault diagnosis rule is meaningful.

Abstract: The technique of optical fiber grating with high tensile strength, small size, and light weight has been widely used for temperature and strain measurement. In this paper, a new flexible fiber Bragg grating sensing beam including its design, calibration, and application is presented for effectively measuring dynamic relative displacement inside the assembled joints in a shaking table test. The two FBG sensors are encapsulated in one flexible arched-beam slice, while FBG sensors are separately located in up-down position of one flexible slice. The arched-beam-based FBG sensor has been fabricated by employing a series of FBG sensors along with design of temperature compensation. Based on this design, the positive and negative strain will make the spectra broaden as the displacement increases, thus by converting strains to relative displacements is derived by calibration data. The relative displacement measured by FBG sensor under dynamic environment are available, subsequently, it can be concluded that the flexible arched-beam-based FBG is capable of measuring dynamic relative displacements with good accuracy mounted in the narrow space of a complex structure.

Abstract: To gain the sensitive fault information, proper sampling point configuration is essential and important. A method based on ensemble empirical mode decomposition and variable precision rough set is proposed to optimize the monitoring points in the gearbox fault diagnosis system. First, the vibration signal was processed by ensemble empirical mode decomposition, the energetic characteristic vector can be got by the intrinsic mode functions. Samples in different conditions constructed the decision table, each monitoring point corresponded to a decision table. Second, the approximate dependence values of condition attributes to decision attributes of every monitoring point were got by variable precision rough set. Finally, the importance of the sampling points was achieved by the approximate dependence value. The experimental results show the method is effective and feasible for the monitoring points configuration, and it can minimize the impact of noise as well as improve the efficiency and accuracy of the fault diagnosis system.

Abstract: For the study of effects of perturbation, such as the change in the resonant frequency and in the other parameters of a rectangular cavity, the resonance condition, the resonant wavelength and the resonant frequency are analyzed in this paper, with the help of perturbation method in a resonance cavity of the reflection type. The relation is deduced in detail under two suppose conditions, which is between the resonant frequency and the dielectric constant or the permeability of the medium filled in the cavity. The accurate relation between the changes in the resonant frequency and in the dielectric constant or the permeability is established. This paper provides the scientific basis for research on the intrinsic characteristic of medium.

Abstract: For days, we are widespread in many parts of the fog haze weather, the gray one everywhere, level of air quality is heavily contaminated, including sources of PM2.5 is complex, both the pollution from motor vehicles, also has the fine particles from the burning of coal, at the same time in the air such as sulfur dioxide, nitrogen oxides and volatile organic compounds, after a series of complex changes, small particles generated the harmful to human body. In change this study, we introduced the PIC control technology; this technology can effectively improve the combustion of coal mine air pollution.

Abstract: With our life becoming increasingly intelligent, The smart home is complies with the development of the era and plays a positive role in the intelligent life.Thus a kind of smart fan, based on PSoC, comes into being. The design, whose main control chip is PSoC, achieves many functions, like the switch between manual control and temperature control, natural wind and other functions with the support of external auxiliary circuit and wireless remote control. The design is much more valuable because of the perfect development prospects of PSoC and smart home.

Abstract: When detecting low-attitude targets, the angular accuracy of the meter-wave radar will descend because of the multipath reflecting from ground. Since the multipath signal can be regarded as a multipath jamming coming from the mainlobe, we propose an angle measurement based on the mainlobe multipath jamming suppression. The weight of the new approach is obtained through certain constraints on the sum-difference beams, which can suppress the jamming and keep the curve of the monopulse ratio unchanged. Then form sum-difference beams and calculate the ratio of the monopulse ratio of the target. Finally, obtain the angle of the target through the determination of the smallest difference between the monopulse ratio of the target and the quiescent monopulse ratio. The method proposed in this paper can preserve good precision of the measurement angle. The result is verified by computer simulation.

Abstract: Electric power automation system can also be called telecontrol system, while video monitoring technology is one of the key of video compression and coding technology. In view of the actual situation of video signal remote transmission, high compression rate and good quality standard should be considered and chosen in priority. This paper analyzes the h.264 standard code rate control method and proposes jump frame judgment criterion based on MAD ratio. Furthermore, it elaborates the contrast test results between the jump frame algorithm and the previous algorithm. Telecontrol video monitoring system should be based on digital video recorder optimization (DVR) design and video monitoring system integrated communication design, which can guarantee the transmission quality of electric power remote data and video data. This paper discusses the main functions of the video management system and the design scheme of the software system.

Abstract: The purpose of this paper is to introduce the important steps of OLP (off-line programming) for robot roller hemming, including acquisition of virtual environment, trajectory generation and optimization and calibration. And an algorithm for calibration was also introduced which is of high accuracy with lower cost. The feasibility of OLP for robot roller hemming was validated by the final experiment.

Abstract: With high volume and flexible automated production line becoming the future trend of automobile welding line, the modular gripper, as the role of the robot tool, is finding increasing application. This article concluded the deformation formula by detecting bending and torsion deformation of aluminum profile in tests and also provided guidance and rationale for designers.