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An Area Changeable Capacitive Micro-machined Accelerometer
Li Baoqing,Lu Deren,Wang Weiyuan
Strategic Study of CAE 2000, Volume 2, Issue 2, Pages 36-40
In this paper, a newly developed accelerometer based on the principle of area changeable capacitance is presented at the first time. The movable mass is designed as many bars connected together and suspended by elastic beams. Two comb-shaped fixed electrodes with their fingers side by side are alternately placed under the mass. The mass moves in the direction parallel with the substrate plane under the effect of acceleration. The movable mass and fixed electrodes compose a differential capacitor unit. It is concluded by theoretical analysis that the signal of the acceleration is only proportionally related to the area between movable mass and fixed electrodes but not related to the gap between them. The parasitic capacitance Cp between the mass and fixed electrodes and CB induced by boundary effect both lower the sensitivity of the accelerometer by about 20 % , and lead to a vertical effect on accelerometer that could be ignored if compared with the sensitivity. The quasi-LIGA technology with Ni as structure layer and Cu as sacrificial layer is used to fabricate the sensor chips. The fixed electrodes are fabricated on a glass substrate. A Cu sacrificial layer used to determine the gap between the mass and fixed electrodes is then electroplated with the fixed electrodes layer. Finally, the movable Ni mass is also electroplated with the Cu layer and is released after selective etch of the Cu layer. After packaging in IC ceramic die under atmosphere, the accelerometer is put on avibrator to be tested under a frequency of 25 Hz. The output signal is connected to the interface circuit with electric wires. The experimental results show that the accelerometer has typical sensitivity of 58.1 mV/ (m·s-2) and non-linearity of 4% FS in operating range of 20 m/s2. The obtained non-linearity is not ideal and the reason is discussed based on experimental conditions
Keywords： capacitance accelerometer area changeable
Inverse Analysis and Design of the Rational Acceleration of Mine Winder Rope System
Peng Youduo,Liu Deshun,Zhu Pingyu,Zhang Yongzhong,Guo Yingfu
Strategic Study of CAE 2002, Volume 4, Issue 4, Pages 64-68
The prompting acceleration of hoisting rope system determines the winderssitting comfort and the dynamic load in hoisting rope. The over dynamic load is the main factor which leads slipping or breaking out of hoisting rope. Based on the condition that the hoisting rope. Be regarded as the continuous flexible rod, and the equation of hoisting rope system, by the characteristic lines numerical value analyzing method and taking the ride comfort of hoisting cage and the little dynamic oscillation of hoisting rope as the aim, the rational acceleration curve of rope system is brought out in this paper, and it can provide reference for further study and design of mine winders.
Keywords： hoisting rope system prompting acceleration ride comfort ableness dynamic tensile force inverse design
Tao Xue, Zi-wei Wang, Tao Zhang, Ou Bai, Meng Zhang, Bin Han,taozhang@tsinghua.edu.cn
Frontiers of Information Technology & Electronic Engineering 2020, Volume 21, Issue 5, Pages 649-808 doi: 10.1631/FITEE.1900418
Subway rail transit monitoring by built-in sensor platform of smartphone Research Articles
Jian-li Cong, Ming-yuan Gao, Yuan Wang, Rong Chen, Ping Wang,jlcong2019@my.swjtu.edu.cn,gaomingyuan@swu.edu.cn,wangy39@sustech.edu.cn,chenrong@home.swjtu.edu.cn,wping@home.swjtu.edu.cn
Frontiers of Information Technology & Electronic Engineering 2020, Volume 21, Issue 8, Pages 1119-1266 doi: 10.1631/FITEE.1900242
Keywords： 加速度数据；智能监测；内置传感器；智能手机；地铁
Wireless passive flexible accelerometer fabricated using micro-electro-mechanical system technology for bending structure surfaces Research Article
Chen LI, Mangu JIA, Yingping HONG, Yanan XUE, Jijun XIONG,lichen@nuc.edu.cn
Frontiers of Information Technology & Electronic Engineering 2022, Volume 23, Issue 5, Pages 801-809 doi: 10.1631/FITEE.2100236
Keywords： Bending structure surfaces Flexible accelerometer Micro-electro-mechanical system (MEMS) technology Wireless non-contact measurement
Measurement and characteristics of ground vibration caused by blasting demolition of urban overpass
Hu Jinjun,Yang Yongqiang,Guan Yingjun
Strategic Study of CAE 2014, Volume 16, Issue 11, Pages 90-95
To analyze the ground vibration caused by blasting demolition of urban overpass, in this paper we introduced the measurement method and then studied the characteristics of recorded ground vibrations. Through analysis of peak acceleration, peak frequency and duration, results indicate that, the vertical component of vibration is the most important in the region close to the collapse point; the collapse of bridge segments will lead to superposition of ground vibration, and isolation measures can reduce the peak acceleration but increase the duration of vibration; blasting and collapse vibration cause no damage to the reserved structure which indicates that blasting description is a safe and effective method.
Keywords： blasting demolition urban overpass collapse ground vibration acceleration
The Pendulum Characteristic of Natural Convection Gas and the Application for Sensor
Zhang Fuxue
Strategic Study of CAE 2002, Volume 4, Issue 8, Pages 50-53
It is discovered that the natural convection gas has the pendulum characteristic, so the new concept of gas pendulum is presented. In this paper, the buoyancy lift of natural convection gas is analyzed in a hermetic chamber, and given the formula between the buoyancy lift and the change of temperature. The results of experiment have shown that gas pendulum can be utilized to measure the acceleration and tilt angle as same as solid pendulum and liquid pendulum.
Keywords： gas pendulum characteristic tilt sensor accelerometer
Thermal Stability Evaluation of Non-explosive and Irrestorable Fertilizer-grade Ammonium Nitrate
Wang Xuguang,Shen Lijin
Strategic Study of CAE 2004, Volume 6, Issue 11, Pages 53-57
A new method using accelerating rate calorimeter (ARC) was introduced in this paper to evaluate the thermal stability of energetic materials. By the method, the adiabatic decompositions of ammonium nitrate (AN) and non-explosive and irrestorable fertilizer-grade ammonium nitrate (NEIFAN) were investigated. The curves of thermal decomposition temperature and pressure versus time, self-heating rate and pressure versus temperature were obtained. The kinetic parameters such as apparent activation energy and pre-exponential factor were calculated. The effects of thermal inertia factor on the results of measurement of the adiabatic ARC are discussed. It was indicated that NEIFAN has better thermal stability and safety. At the same time, it can be shown that the elimination of NEIFAN explosive characteristic is due to the improvement on its thermal stability.
Keywords： fertilizer-grade ammonium nitrate non-explosivity irrestorability accelerating rate calorimeter thermal stability
Hualin Wang, Pengbo Fu, Jianping Li, Yuan Huang, Ying Zhao, Lai Jiang, Xiangchen Fang, Tao Yang, Zhaohui Huang, Cheng Huang
Engineering 2018, Volume 4, Issue 3, Pages 406-415 doi: 10.1016/j.eng.2018.05.014
The environmentally friendly and resourceful utilization of organic waste liquid is one of the frontiers of environmental engineering. With the increasing demand for chemicals, the problem of organic waste liquid with a high concentration of inorganic pollutants in the processing of petroleum, coal, and natural gas is becoming more serious. In this study, the high-speed self-rotation and flipping of particles in a threedimensional cyclonic turbulent field was examined using a synchronous high-speed camera technique; the self-rotation speed was found to reach 2000–6000 rad·s−1. Based on these findings, a cyclonic gasstripping method for the removal of organic matter from the pores of particles was invented. A technological process was developed to recover organic matter from waste liquid by cyclonic gas stripping and classifying inorganic particles by means of airflow acceleration classification. A demonstration device was built in Sinopec’s first ebullated-bed hydro-treatment unit for residual oil. Compared with the T-STAR fixed-bed gas-stripping technology designed in the United States, the maximum liquid-removal efficiency of the catalyst particles in this new process is 44.9% greater at the same temperature, and the time required to realize 95% liquid-removal efficiency is decreased from 1956.5 to 8.4 s. In addition, we achieved the classification and reuse of the catalyst particles contained in waste liquid according to their activity. A proposal to use this new technology was put forward regarding the control of organic waste liquid and the classification recovery of inorganic particles in an ebullated-bed hydro-treatment process for residual oil with a processing capacity of 2 × 106 t·a−1. It is estimated that the use of this new technology will lead to the recovery of 3100 ta−1 of diesel fuel and 647 t·a−1 of high-activity catalyst; in addition, it will reduce the consumption of fresh catalyst by 518 t·a−1. The direct economic benefits of this process will be as high as 37.28 million CNY per year.
Keywords： Organic waste liquid Inorganic particles Cyclonic gas stripping Particle self-rotation Airflow acceleration classification
The measurement and analysis of ice induced vibration of JZ9-3WHPB oil platform in Bohai Sea
lan Zhigang,Zhao Yinnina,Guo Jianfeng,Zhou Zhentao,Xing Jian,Bai Gang,Lu Hongge,Li Huihui
Strategic Study of CAE 2011, Volume 13, Issue 5, Pages 79-87
Based on the structure and layout of the untended JZ9-3WHPB platform, remote controllable ice induced vibration monitoring system was designed and installed on JZ9-3WHPB platform to record the vibration of the structure so as to learn its dynamic characteristics. Short time Fourier transform was employed to study the temporal variations and mode frequencies of the vibration. Vibration mode was analyzed by comparison of the phase difference between the vibrations of the upper and lower deck and applying bandpass filtering to the signal. Based on the count and analysis of the maximum amplitude and duration of the vibrations, tide and current of the water, and the structure of the platform, the defects of anti-ice induced vibration structure were analyzed, and ice resistant proposals were presented.
Keywords： ffshore platform sea ice of Bohai Sea ice induced vibration vibration acceleration short time Fourier transform
Zero-failure accelerated reliability demonstration test method based on degradation model
Zhang Huirui
Strategic Study of CAE 2015, Volume 17, Issue 5, Pages 31-37
Traditional life demonstration test is conducted under normal conditions and fails to use degradation observations，thus requires large amount of time and money. We can employ degradation data to predict whether a unit will pass the test by the end of test，and the test can be terminated early when this prediction does not cost unacceptable risk. Also higher stress can accelerate the degradation of the unit to cut down the test time. Thus it is necessary to propose a method that take advantage of both degradation data and accelerated test to reduce the test time and cost，which is done by this article. In particular，the article propose an approach to analyses and calculate the additional risks caused by early termination of the test and applying higher stress based on degradation model，then the minimum sample size of different test time can be picked. The article also use optimal plan to give expected test time and give deciding rules of terminating the test for each unit. At last，the method is illustrated by an example， showing that the method is efficient in reducing test time.
Keywords： degradation model；accelerated testing；life demonstration；risk analysis；optimum plan
Xin Chen,Youdun Bai,Zhijun Yang,Jian Gao,Gongfa Chen
Engineering 2015, Volume 1, Issue 3, Pages 391-398 doi: 10.15302/J-ENG-2015063
High-speed and precision positioning are fundamental requirements for high-acceleration low-load mechanisms in integrated circuit (IC) packaging equipment. In this paper, we derive the transient nonlinear dynamicresponse equations of high-acceleration mechanisms, which reveal that stiffness, frequency, damping, and driving frequency are the primary factors. Therefore, we propose a new structural optimization and velocity-planning method for the precision positioning of a high-acceleration mechanism based on optimal spatial and temporal distribution of inertial energy. For structural optimization, we first reviewed the commonly flexible multibody dynamic optimization using equivalent static loads method (ESLM), and then we selected the modified ESLM for optimal spatial distribution of inertial energy; hence, not only the stiffness but also the inertia and frequency of the real modal shapes are considered. For velocity planning, we developed a new velocity-planning method based on nonlinear dynamic-response optimization with varying motion conditions. Our method was verified on a high-acceleration die bonder. The amplitude of residual vibration could be decreased by more than 20% via structural optimization and the positioning time could be reduced by more than 40% via asymmetric variable velocity planning. This method provides an effective theoretical support for the precision positioning of high-acceleration low-load mechanisms.
Keywords： high-acceleration low-load mechanism precision positioning spatial and temporal distribution inertial energy equivalent static loads method (ESLM) velocity planning
Application of Satellite Gravity Gradiometry Data to the Refinement of the Earth’s Gravity Field
Ning Jinsheng,Luo Zhicai,Chen Yongqi
Strategic Study of CAE 2002, Volume 4, Issue 7, Pages 23-28
In recent times, one of the primary scientific objectives of physical geodesy is to determine the geoid with centimeter level and to develop the ultra high global earth’s gravity field model，and for this purpose satellite gravity gradiometry is one of the most promising techniques. This paper first comments on the main progress of satellite gravity gradiometry, and then discusses some theories and methods for refining the earth´s gravity field using satellite gravity gradiometry data.
Keywords： satellite gravity gradiometry satellite gravity gradiometry boundary value problem earth's gravity field model geoid
Dai Juchuan,Wu Xinkai,Wen Li
Strategic Study of CAE 2009, Volume 11, Issue 4, Pages 91-95
In direct torque control system, the PID controller is often adopted to be the speed adjuster. When disturbances are thrown to the motor, a long time is taken to renew the motor to steady state. In this paper, new auto-disturbance-rejection controller (ADRC) is introduced into direct torque control system. Instead of PID speed adjuster, ADRC speed adjuster is designed. The speed observer is designed based on model reference adaptive system (MRAS), too. The performance difference is analyzed between PID controller and ADRC in speed sensorless direct torque control system. The simulation results show that the AC speed adjustable system has speedier response performance, stronger disturbance-rejection performance when ADRC is adopted. Moreover, according to simulation results, there is smaller warp between motor command speed and actual speed when motor parameters perturb.
Keywords： direct torque control active disturbances rejection control speed observer speed sensorless induction motor
Calculation Method of Explosively Formed Projectile Velocity
Zhao Huiying,Shen Zhaowu
Strategic Study of CAE 2007, Volume 9, Issue 8, Pages 62-65
From the theory of instantaneous expansion of detonation product and momentum conservation, this paper obtains velocity calculation model of explosively formed projectile (EFP) and the model is revised due to the influence of the ratio of charge altitude to charge diameter. This paper calculates the velocities of EFPs formed by large apex angle liner and sphere liner through the velocity calculation model and the results are consistent with the numerical simulation and experiment results. This velocity calculation model is applicable in engineering.
Keywords： explosively formed projectile (EFP) instantaneous expansion of detonation product momentum conservation EFP velocity
Title Author Date Type Operation
An Area Changeable Capacitive Micro-machined Accelerometer
Li Baoqing,Lu Deren,Wang Weiyuan
Journal Article
Inverse Analysis and Design of the Rational Acceleration of Mine Winder Rope System
Peng Youduo,Liu Deshun,Zhu Pingyu,Zhang Yongzhong,Guo Yingfu
Journal Article
Fixed-time constrained acceleration reconstruction scheme for robotic exoskeleton via neural networks
Tao Xue, Zi-wei Wang, Tao Zhang, Ou Bai, Meng Zhang, Bin Han,taozhang@tsinghua.edu.cn
Journal Article
Subway rail transit monitoring by built-in sensor platform of smartphone
Jian-li Cong, Ming-yuan Gao, Yuan Wang, Rong Chen, Ping Wang,jlcong2019@my.swjtu.edu.cn,gaomingyuan@swu.edu.cn,wangy39@sustech.edu.cn,chenrong@home.swjtu.edu.cn,wping@home.swjtu.edu.cn
Journal Article
Wireless passive flexible accelerometer fabricated using micro-electro-mechanical system technology for bending structure surfaces
Chen LI, Mangu JIA, Yingping HONG, Yanan XUE, Jijun XIONG,lichen@nuc.edu.cn
Journal Article
Measurement and characteristics of ground vibration caused by blasting demolition of urban overpass
Hu Jinjun,Yang Yongqiang,Guan Yingjun
Journal Article
The Pendulum Characteristic of Natural Convection Gas and the Application for Sensor
Zhang Fuxue
Journal Article
Thermal Stability Evaluation of Non-explosive and Irrestorable Fertilizer-grade Ammonium Nitrate
Wang Xuguang,Shen Lijin
Journal Article
Separation-and-Recovery Technology for Organic Waste Liquid with a High Concentration of Inorganic Particles
Hualin Wang, Pengbo Fu, Jianping Li, Yuan Huang, Ying Zhao, Lai Jiang, Xiangchen Fang, Tao Yang, Zhaohui Huang, Cheng Huang
Journal Article
The measurement and analysis of ice induced vibration of JZ9-3WHPB oil platform in Bohai Sea
lan Zhigang,Zhao Yinnina,Guo Jianfeng,Zhou Zhentao,Xing Jian,Bai Gang,Lu Hongge,Li Huihui
Journal Article
Zero-failure accelerated reliability demonstration test method based on degradation model
Zhang Huirui
Journal Article
A Precision-Positioning Method for a High-Acceleration Low-Load Mechanism Based on Optimal Spatial and Temporal Distribution of Inertial Energy
Xin Chen,Youdun Bai,Zhijun Yang,Jian Gao,Gongfa Chen
Journal Article
Application of Satellite Gravity Gradiometry Data to the Refinement of the Earth’s Gravity Field
Ning Jinsheng,Luo Zhicai,Chen Yongqi
Journal Article
Study on auto-disturbances-rejection AC adjustable speed based on speed sensorless direct torque control
Dai Juchuan,Wu Xinkai,Wen Li
Journal Article
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