Sponsored by China Instrument and Control Society
ISSN 0254-3087 CN 11-2179/TH
12 issues per year
Discipline(s): Engineering Technology
Current Issue: Issue 04, 2019
Chinese Journal of Scientific Instrument is 2nd in Mechanical Engineering, Top10. Supervised by China Association for Science and Technology. Sponsored by China Instrument and Control Society. Chinese Journal of Scientific Instrument publishes papers with the highest academic level in the field of Chinese instrument and automation, aims to report scientific frontier, research hotspot and research direction, and also supports the creative scientific thought, values the verification of science experiment. Collected by Ei, CA, SA, JST and CSCD.Impact factor is 2.67.
Wang Weiqi, Xu Yunzhong, Wang Xue
Vol 40,No. 04
The traditional rotary electro-mechanical converter has the problems of low linearity and small work range of static characteristics. To improve its performance, we have designed a novel rotating proportional electro-mechanical converter. The static characteristics of the rotating proportional electro-mechanical converter are studied by means of magnetic circuit analysis, Maxwell 3D static magnetic field finite element analysis and experimental tests. Meanwhile, a prototype is developed and a series of experiments are conducted. Experimental results indicate that the proportional electro-mechanical converter has a working range from −5° to 5°, and the maximum torque is about ±252 mN·m. In addition, it has a positive magnetic stiffness. The experiment and simulation of torque values are concentrated within the 9.6 mN·m. The relative error is less than 6%, which means that electro-mechanical converter has good repeatability. Furthermore, the nonlinear error of the angle-torque curve is less than 1.5% with a hysteresis of less than 3.5%, which demonstrates that the current–torque curve has good linearity and low hysteresis. It proves that the test results are basically consistent with the simulation results.
Vol 40,No. 04
The piezoelectric film sensor is affected by temperature and the piezoelectric quartz sensor is expensive. Therefore, a fusion design method is achieved by embedding two piezoelectric quartz sensors into four-row piezoelectric film sensors. The equivalent installation model and temperature compensation algorithm of piezoelectric film sensor are established. The piezoelectric quartz sensors are used to perform accurate and real-time temperature compensation for all piezoelectric film sensors. Under the excitation of sinusoidal wave pavement, a quarter vehicle model is selected to conduct weigh-in-motion simulation experiment in MATLAB. In the experiments, the vehicle speed is ranged from 10 km/h to 120 km/h and the environment temperature shifts from 0 to 40 °C. The results show that weighing error mean value of fusion design is less than 0.97%, and accuracy is over 23 times than four-row piezoelectric film sensors, and price is three times lower than four-row piezoelectric quartz sensors. This design can realize high-precision and low-cost detection for vehicle weigh-inmotion, which shows good prospects for engineering applications.
Vol 40,No. 04
In system reliability analysis, the correct expression of the uncertain parameters is a prerequisite for stability evaluation. However, the parameter distribution that affects system reliability often lacks strict regularity in engineering. Even the parameters generally obey a certain distribution, they always drift. Information loss is another concern when traditional methods are used to deal with such uncertainties. Therefore, a new method to conduct system reliability analysis under uncertain information is proposed by introducing the probability-box theory. Firstly, the probability-box is used to model uncertain parameters. Secondly, the probability-box model of system reliability is obtained by discretizing each parameter into equal belief values and calculating Cartesian product with the system reliability equation. Finally, the risk zone and the stable zone are divided with zero as boundary, and the system reliability is quantitatively analyzed by integral calculating the area of probability-box. The cantilever beam system is analyzed in the experiments. Experimental results demonstrate that the proposed method is effective and can also improve the accuracy compared with other related approaches.