Optical fiber acceleration seismometer as an important instrument can offer high sensitivity, anti-jamming and non-touched advantage which has an extensive application field. Its signal processing ability will decide ...Optical fiber acceleration seismometer as an important instrument can offer high sensitivity, anti-jamming and non-touched advantage which has an extensive application field. Its signal processing ability will decide whole system’s performance to some extent because it will affect directly the factors such as resolving power, precision and dynamic range. The signal processing is usually realized by analog circuits which was more inferior in stability, flexibility and anti-jamming to digital processing system. A digital processing system of optical fiber acceleration seismometer has been designed based on the embedded system design scheme. Synthetic-heterodyne demodulation has been studied, and signal processing has been realized. The double processors of ARM and DSP are employed to implement respectively the system control and signal processing, and to provide the output interfaces such as LCD, DAC and Ethernet interface. This system can vary with the measured signal in real time and linearly, and its work frequency bandwidth is between 10Hz and 1kHz. The system has better anti-jamming ability and can work normally when the SNR is 40dB.展开更多
In order to realize intelligent control of flower greenhouse＇ s parameters of atmospheric temperature and humidity, lighting intensity, CO2 concentration and soil water content, it carries out design with ZigBee netw...In order to realize intelligent control of flower greenhouse＇ s parameters of atmospheric temperature and humidity, lighting intensity, CO2 concentration and soil water content, it carries out design with ZigBee network, embedded controller and intelligent fuzzy control algorithm as core. With advantages of high precision and stability, the design of sensor circuit mainly employs digital module sensors. In order to save energy, the sensor circuit is controlled by relay switch to work at the proper time. The gateway node is designed by employing high performance 32-digit embedded controller and WinCE6.0 embedded OS is self customized. And embedded SQlite database is realized on WinCE6.0 for effectively managing data. The closed loop control is realized by employing fuzzy control algorithm and the test result shows that the deviation of atmospheric temperature is controlled within ± 0.5° C, the deviation of illumination intensity is controlled within ± 283 LUX, the deviation of CO2 concentration is controlled within ± 24 PPM, the deviation of atmospheric humidity is controlled within ± 13% and that of soil water content is controlled within ± 0.9%, thus all parameters fully meet practical requirements of flower greenhouse.展开更多
The design, manufacture and deployment of embedded systems become increasingly complex and multidisciplinary process. Before the steps of manufacturing and deployment, a simulation and validation phase is necessary. I...The design, manufacture and deployment of embedded systems become increasingly complex and multidisciplinary process. Before the steps of manufacturing and deployment, a simulation and validation phase is necessary. In this paper, a WSN （wireless sensors network） emulator, implemented on a FPGA, is described by： describing some models as examples, how multiple simulations can be done when the device was configured and programmed once, and how results from the behavioral emulator can be extracted. The diversity of applications and the typically scarce node resources set very tight constraints to WSN. It is not possible to fulfill all requirements with a general purpose WSN, for which reason the rapid development of application specific WSNs is preferred. A new emulator for the design, simulation, and evaluation of WSNs, implemented on a very dense FPGA （field programmable gate arrays）, is presented, exploring the parallelism and his resources to do a very rapid simulation ofa WSN for long periods, and without overloading memory by the intermediate data.展开更多
Based on direct absorption spectroscopy(DAS), a portable methane(CH_4) detection device was implemented. The device mainly includes a dual-channel non-dispersive infrared sensor(integrated with an infrared light sourc...Based on direct absorption spectroscopy(DAS), a portable methane(CH_4) detection device was implemented. The device mainly includes a dual-channel non-dispersive infrared sensor(integrated with an infrared light source, light path and pyroelectric detector), a driving circuit of the sensor, an ARM11 embedded Win CE system, and a Lab VIEW-based data-processing platform. Experiments were carried out with prepared CH_4 samples to investigate the sensing performance. The relative detection error is less than 9.14% within the measuring range of 0—7×10^(-2). For a CH_4 sample with concentration of 0(i.e., pure nitrogen), the measured concentration fluctuation range is-1.2×10^(-5)—+2×10^(-5). An Allan deviation analysis on the gas sample with concentration of 0 indicates that the 1σ limit of detection(LoD) of the device is 4.8×10^(-6) with an average time of 1 s. Experiments were performed on three CH_4 samples with different concentrations to test the response time, which is validated to be less than 20 s. Due to the small size of the ARM11 embedded system and the powerful data processing capability of the Lab VIEW platform, the proposed portable and miniaturized CH_4 sensor shows a good application prospect in mining operations and some other industrial fields.展开更多
文摘Optical fiber acceleration seismometer as an important instrument can offer high sensitivity, anti-jamming and non-touched advantage which has an extensive application field. Its signal processing ability will decide whole system’s performance to some extent because it will affect directly the factors such as resolving power, precision and dynamic range. The signal processing is usually realized by analog circuits which was more inferior in stability, flexibility and anti-jamming to digital processing system. A digital processing system of optical fiber acceleration seismometer has been designed based on the embedded system design scheme. Synthetic-heterodyne demodulation has been studied, and signal processing has been realized. The double processors of ARM and DSP are employed to implement respectively the system control and signal processing, and to provide the output interfaces such as LCD, DAC and Ethernet interface. This system can vary with the measured signal in real time and linearly, and its work frequency bandwidth is between 10Hz and 1kHz. The system has better anti-jamming ability and can work normally when the SNR is 40dB.
文摘In order to realize intelligent control of flower greenhouse＇ s parameters of atmospheric temperature and humidity, lighting intensity, CO2 concentration and soil water content, it carries out design with ZigBee network, embedded controller and intelligent fuzzy control algorithm as core. With advantages of high precision and stability, the design of sensor circuit mainly employs digital module sensors. In order to save energy, the sensor circuit is controlled by relay switch to work at the proper time. The gateway node is designed by employing high performance 32-digit embedded controller and WinCE6.0 embedded OS is self customized. And embedded SQlite database is realized on WinCE6.0 for effectively managing data. The closed loop control is realized by employing fuzzy control algorithm and the test result shows that the deviation of atmospheric temperature is controlled within ± 0.5° C, the deviation of illumination intensity is controlled within ± 283 LUX, the deviation of CO2 concentration is controlled within ± 24 PPM, the deviation of atmospheric humidity is controlled within ± 13% and that of soil water content is controlled within ± 0.9%, thus all parameters fully meet practical requirements of flower greenhouse.
文摘The design, manufacture and deployment of embedded systems become increasingly complex and multidisciplinary process. Before the steps of manufacturing and deployment, a simulation and validation phase is necessary. In this paper, a WSN （wireless sensors network） emulator, implemented on a FPGA, is described by： describing some models as examples, how multiple simulations can be done when the device was configured and programmed once, and how results from the behavioral emulator can be extracted. The diversity of applications and the typically scarce node resources set very tight constraints to WSN. It is not possible to fulfill all requirements with a general purpose WSN, for which reason the rapid development of application specific WSNs is preferred. A new emulator for the design, simulation, and evaluation of WSNs, implemented on a very dense FPGA （field programmable gate arrays）, is presented, exploring the parallelism and his resources to do a very rapid simulation ofa WSN for long periods, and without overloading memory by the intermediate data.
基金supported by the National Natural Science Foundation of China(Nos.61627823,61307124 and 11404129)the Science and Technology Department of Jilin Province of China(Nos.20120707 and 20140307014SF)+1 种基金the Changchun Municipal Science and Technology Bureau(No.14KG022)the State Key Laboratory of Integrated Optoelectronics of Jilin University(No.IOSKL2012ZZ12)
文摘Based on direct absorption spectroscopy(DAS), a portable methane(CH_4) detection device was implemented. The device mainly includes a dual-channel non-dispersive infrared sensor(integrated with an infrared light source, light path and pyroelectric detector), a driving circuit of the sensor, an ARM11 embedded Win CE system, and a Lab VIEW-based data-processing platform. Experiments were carried out with prepared CH_4 samples to investigate the sensing performance. The relative detection error is less than 9.14% within the measuring range of 0—7×10^(-2). For a CH_4 sample with concentration of 0(i.e., pure nitrogen), the measured concentration fluctuation range is-1.2×10^(-5)—+2×10^(-5). An Allan deviation analysis on the gas sample with concentration of 0 indicates that the 1σ limit of detection(LoD) of the device is 4.8×10^(-6) with an average time of 1 s. Experiments were performed on three CH_4 samples with different concentrations to test the response time, which is validated to be less than 20 s. Due to the small size of the ARM11 embedded system and the powerful data processing capability of the Lab VIEW platform, the proposed portable and miniaturized CH_4 sensor shows a good application prospect in mining operations and some other industrial fields.
