In this study,the design and development of a sensor made of low-cost parts to monitor inclination and acceleration are presented.Αmicro electro-mechanical systems,micro electro mechanical systems,sensor was housed i...In this study,the design and development of a sensor made of low-cost parts to monitor inclination and acceleration are presented.Αmicro electro-mechanical systems,micro electro mechanical systems,sensor was housed in a robust enclosure and interfaced with a Raspberry Pi microcomputer with Internet connectivity into a proposed tilt and acceleration monitoring node.Online capabilities accessible by mobile phone such as real-time graph,early warning notification,and database logging were implemented using Python programming.The sensor response was calibrated for inherent bias and errors,and then tested thoroughly in the laboratory under static and dynamic loading conditions beside high-quality transducers.Satisfactory accuracy was achieved in real time using the Complementary Filter method,and it was further improved in LabVIEW using Kalman Filters with parameter tuning.A sensor interface with LabVIEW and a 600 MHz CPU microcontroller allowed real-time implementation of highspeed embedded filters,further optimizing sensor results.Kalman and embedded filtering results show agreement for the sensor,followed closely by the lowcomplexity complementary filter applied in real time.The sensor's dynamic response was also verified by shaking table tests,simulating past recorded seismic excitations or artificial vibrations,indicating negligible effect of external acceleration on measured tilt;sensor measurements were benchmarked using highquality tilt and acceleration measuring transducers.A preliminary field evaluation shows robustness of the sensor to harsh weather conditions.展开更多
The virtual machine of code mechanism （VMCM） as a new concept for code mechanical solidification and verification is proposed and can be applied in MEMS （micro-electromechanical systems） security device for high c...The virtual machine of code mechanism （VMCM） as a new concept for code mechanical solidification and verification is proposed and can be applied in MEMS （micro-electromechanical systems） security device for high consequence systems. Based on a study of the running condition of physical code mechanism, VMCM＇s configuration, ternary encoding method, running action and logic are derived. The cases of multi-level code mechanism are designed and verified with the VMCM method, showing that the presented method is effective.展开更多
A novel and efficient absorption line recovery technique is presented.A micro-electromechanical systems(MEMS) mirror driven by an electrothermal actuator is used to generate laser intensity modulation through the mirr...A novel and efficient absorption line recovery technique is presented.A micro-electromechanical systems(MEMS) mirror driven by an electrothermal actuator is used to generate laser intensity modulation through the mirror reflection.Tunable diode laser spectroscopy(TDLS) and photoacoustic spectroscopy(PAS) are used to recover the target absorption line profile which is compared with the theoretical Voigt profile.The target gas is 0.01% acetylene(C2H2) in a nitrogen host gas.The laser diode wavelength is swept across the P17 absorption line of acetylene at 1 535.4 nm by a current ramp,and an erbium-doped fibre amplifier(EDFA) is used to enhance the optical intensity and increase the signal-to-noise ratio(SNR).A SNR of about 35 is obtained with 100 mW laser power from the EDFA.Good agreement is achieved between the experimental results and the theoretical simulation for the P17 absorption line profile.展开更多
基金Research Committee,National Technical University of Athens。
文摘In this study,the design and development of a sensor made of low-cost parts to monitor inclination and acceleration are presented.Αmicro electro-mechanical systems,micro electro mechanical systems,sensor was housed in a robust enclosure and interfaced with a Raspberry Pi microcomputer with Internet connectivity into a proposed tilt and acceleration monitoring node.Online capabilities accessible by mobile phone such as real-time graph,early warning notification,and database logging were implemented using Python programming.The sensor response was calibrated for inherent bias and errors,and then tested thoroughly in the laboratory under static and dynamic loading conditions beside high-quality transducers.Satisfactory accuracy was achieved in real time using the Complementary Filter method,and it was further improved in LabVIEW using Kalman Filters with parameter tuning.A sensor interface with LabVIEW and a 600 MHz CPU microcontroller allowed real-time implementation of highspeed embedded filters,further optimizing sensor results.Kalman and embedded filtering results show agreement for the sensor,followed closely by the lowcomplexity complementary filter applied in real time.The sensor's dynamic response was also verified by shaking table tests,simulating past recorded seismic excitations or artificial vibrations,indicating negligible effect of external acceleration on measured tilt;sensor measurements were benchmarked using highquality tilt and acceleration measuring transducers.A preliminary field evaluation shows robustness of the sensor to harsh weather conditions.
基金Project supported by High-Technology Research and Develop-ment Program of China (Grant No .863 -2003AA404210)
文摘The virtual machine of code mechanism （VMCM） as a new concept for code mechanical solidification and verification is proposed and can be applied in MEMS （micro-electromechanical systems） security device for high consequence systems. Based on a study of the running condition of physical code mechanism, VMCM＇s configuration, ternary encoding method, running action and logic are derived. The cases of multi-level code mechanism are designed and verified with the VMCM method, showing that the presented method is effective.
基金Financial support from National High Technology Research and Development Programof China(Grant No.:2007A A06Z1122007AA03Z446)
文摘A novel and efficient absorption line recovery technique is presented.A micro-electromechanical systems(MEMS) mirror driven by an electrothermal actuator is used to generate laser intensity modulation through the mirror reflection.Tunable diode laser spectroscopy(TDLS) and photoacoustic spectroscopy(PAS) are used to recover the target absorption line profile which is compared with the theoretical Voigt profile.The target gas is 0.01% acetylene(C2H2) in a nitrogen host gas.The laser diode wavelength is swept across the P17 absorption line of acetylene at 1 535.4 nm by a current ramp,and an erbium-doped fibre amplifier(EDFA) is used to enhance the optical intensity and increase the signal-to-noise ratio(SNR).A SNR of about 35 is obtained with 100 mW laser power from the EDFA.Good agreement is achieved between the experimental results and the theoretical simulation for the P17 absorption line profile.
