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基于PLC高速计数器的重锤落速测量方法研究 被引量:4
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作者 陈静 孔德仁 顾廷炜 《测试技术学报》 2016年第5期438-441,共4页
落锤装置可用于传感器系统的准静态校准、塑性测压器具的准动态标定、材料冲击性能测试以及发射药、炸药等爆炸材料的撞击感度测试等.在实验过程中,重锤由于摩擦阻力等影响可能无法正常下落,因而导致实验结果异常.本文简要介绍了落锤装... 落锤装置可用于传感器系统的准静态校准、塑性测压器具的准动态标定、材料冲击性能测试以及发射药、炸药等爆炸材料的撞击感度测试等.在实验过程中,重锤由于摩擦阻力等影响可能无法正常下落,因而导致实验结果异常.本文简要介绍了落锤装置,基于PLC控制系统,针对重锤下落速度测量的特殊性,采用定距测时法,控制高速计数器发出时间间隔为0.01ms的高速脉冲,将重锤上的凸台经过测速环时产生的上升沿信号作为中断触发信号,通过记录两个凸台经过测速环时发出的高速脉冲个数可得到时间间隔,从而实现落速的测量,证明了该方法可解决因PLC扫描周期引起的测速结果不准确或无法测速等问题. 展开更多
关键词 落锤装置 控制系统 光电测速系统 定距测时法 高速计数器
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Hybrid ToA and IMU indoor localization system by various algorithms 被引量:4
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作者 CHEN Xue-chen CHU Sheng +1 位作者 LI Fan CHU Guang 《Journal of Central South University》 SCIE EI CAS CSCD 2019年第8期2281-2294,共14页
In this paper, we integrate inertial navigation system (INS) with wireless sensor network (WSN) to enhance the accuracy of indoor localization. Inertial measurement unit (IMU), the core of the INS, measures the accele... In this paper, we integrate inertial navigation system (INS) with wireless sensor network (WSN) to enhance the accuracy of indoor localization. Inertial measurement unit (IMU), the core of the INS, measures the accelerated and angular rotated speed of moving objects. Meanwhile, the ranges from the object to beacons, which are sensor nodes with known coordinates, are collected by time of arrival (ToA) approach. These messages are simultaneously collected and transmitted to the terminal. At the terminal, we set up the state transition models and observation models. According to them, several recursive Bayesian algorithms are applied to producing position estimations. As shown in the experiments, all of three algorithms do not require constant moving speed and perform better than standalone ToA system or standalone IMU system. And within them, two algorithms can be applied for the tracking on any path which is not restricted by the requirement that the trajectory between the positions at two consecutive time steps is a straight line. 展开更多
关键词 indoor localization time of arrival (ToA) inertial measurement unit (IMU) Bayesian filter extended Kalman filter MAP algorithm
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Blade Tip Timing Vibration Monitoring Method Based on Fiber Bragg Grating 被引量:1
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作者 Fei WU Lei LIANG Junya XING Lin WANG Lang JIA 《Photonic Sensors》 SCIE EI CAS 2014年第2期188-192,共5页
The ventilators have been vividly called "the lungs of mine". The rotating blades are the core parts of a ventilator, they can influence the safety and reliability of the ventilator. This paper will use the tip-timi... The ventilators have been vividly called "the lungs of mine". The rotating blades are the core parts of a ventilator, they can influence the safety and reliability of the ventilator. This paper will use the tip-timing method based on the fiber Bragg grating magnetically coupling sensor to study and analyze the ventilator blade vibration, in order to realize long-distance and non-contact real-time online safety monitoring of blade vibration. Compared with the electronic sensorand fiber intensity reflective sensor, the fiber grating coupling magnetic sensor has such advantages as explosion-proof, working at harsh environment with humid air, dust and greasy dirt, capable of achieving long-distance signal transmission, and joining easily with other fiber Bragg grating sensors to form a network in order to achieve multi-parameter distributed online monitoring. 展开更多
关键词 Blade vibration fiber Bragg grating magnetic coupling SENSOR
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