Radio frequency identification(RFID) is a new type of non-contact automatic identification technology.Due to its low energy consumption,low cost,and its adaptability to harsh environments,it has been applied to many f...Radio frequency identification(RFID) is a new type of non-contact automatic identification technology.Due to its low energy consumption,low cost,and its adaptability to harsh environments,it has been applied to many fields.In the RFID systems,data collision is inevitable when the reader sends a communication request and multiple tags respond with simultaneous data transmission.Data collision is prone to causing problems such as:identification delay,spectrum resource waste,a decreased system throughput rate,etc.Therefore,an efficient,stable anti-collision protocol is crucial for RFID systems.This research analysed the current research into RFID anticollision protocols and summarised means for its improvement through the mechanism of implementation of different types anticollision protocols.Finally,a new direction is proposed for the future development of RFID anti-collision protocol systems.展开更多
As a kind of brand-new technology, radio frequency identification management, data control and acquisition. This paper introduced food safety system construction, analyzed the advantages and problems in dairy modem su...As a kind of brand-new technology, radio frequency identification management, data control and acquisition. This paper introduced food safety system construction, analyzed the advantages and problems in dairy modem suggestions for solution according to the practical situation. （RFID） plays an important role in dairy information tracing and culture function extension of managing breeding technology, and finally put forward some展开更多
A radio frequency identification (RFID) reader will fail to identify tags if a collision occurs. This paper proposes a bi-slotted binary tree algorithm (BSBTA) with stack for RFID tag anti-collision to improve the per...A radio frequency identification (RFID) reader will fail to identify tags if a collision occurs. This paper proposes a bi-slotted binary tree algorithm (BSBTA) with stack for RFID tag anti-collision to improve the performance of binary tree algorithm (BTA). In BSBTA, the reader detects collisions by Manchester code and stores colliding prefixes in a stack. The query is composed of a two-bit prefix and an index value. Following every reader query, there are two timeslots for tags whose pointers and identities (IDs) match the query to respond, one for the tag whose next bit is 0 and the other for the tag with 1 as its next bit. Performance analysis and evaluation are also given. The time complexity and the communication complexity of BTA and BSBTA are derived. The simulation results compare the performance of BSBTA with several related anti-collision algorithms. It is shown that BSBTA outperforms BTA in terms of the average number of responded bits and timeslots for one tag identification.展开更多
A compact antenna formed by three concentric split rings for ultra-high frequency(UHF)radio frequency identification(RFID)tag is proposed in this paper.The antenna is composed of two parts,an outer short-circuited rin...A compact antenna formed by three concentric split rings for ultra-high frequency(UHF)radio frequency identification(RFID)tag is proposed in this paper.The antenna is composed of two parts,an outer short-circuited ring modified from a traditional split-ring resonator(SRR)antenna and an inner SRR load,so the antenna can be regarded as a short-circuited ring loaded with SRR.According to the transmission line theory,to conjugate match with the capacitive input-impedance of a tag chip,the length of the short-circuited ring isλg/4 shorter than that of an open-circuited dipole of a traditional SRR antenna,whereλg is the wavelengh of the operating frequency.Hence,the size of the proposed antenna is more compact than that of the traditional SRR antenna.Thereafter,the proposed antenna is simulated and optimized by ANSYS high-frequency structure simulator(HFSS).The impedance,efficiency,and mutual coupling of the fabricated antenna are tested in a reverberation chamber(RC).The results show that the size of the presented antenna is 83%smaller than that of the traditional SRR antenna and the proposed antenna can cover the whole UHF RFID operating frequency band worldwide(840—960 MHz).The measured read range of the tag exhibits maximum values of 45 cm in free space and 37 cm under dense tag environment.展开更多
A radio frequency identification (RFID) yoking proof scheme can generate proofs of simultaneous presence of two tags in the range of a specified reader so that an off-line verifier can verify the proofs later. This pr...A radio frequency identification (RFID) yoking proof scheme can generate proofs of simultaneous presence of two tags in the range of a specified reader so that an off-line verifier can verify the proofs later. This proof has found several interesting applications. However, many existing RFID yoking schemes are vulnerable to replay attacks. To overcome the weaknesses, Cho et al. proposed a new RFID yoking proof protocol and a new grouping protocol. Unfortunately, Cho et al.'s schemes are still vulnerable to replay attacks. In this paper, in addition to demonstrating weaknesses, we further discuss the rationale behind these weaknesses to provide a guide line for designing secure RFID yoking schemes. Based on the guide line, we propose a new RFID yoking scheme and a new RFID grouping scheme. Performance evaluation shows that our scheme outperforms its counterparts.展开更多
The radio frequency identification (RFID) technology progressing is becoming a increasing interest in several application areas. To accommodate diverse and changing requirements from applications,RFID middleware shoul...The radio frequency identification (RFID) technology progressing is becoming a increasing interest in several application areas. To accommodate diverse and changing requirements from applications,RFID middleware should be reconfigurable. However,current RFID middleware is limited in its ability to support reconfiguration. To solve this problem,we adopt the service-oriented component-based approach in building the middleware. Component-based design enables decomposition of middleware functionality and is easier than the current one to manage and modify the structure of the middleware both statically and dynamically. Applying service-oriented architecture (SOA) can further reduce the coupling between components and external software and ease the integration between middleware and applications. We propose a two-layered service component architecture (SCA) open service gateway initiative (OSGi) component model so as to enable reconfigurability. Based on the proposed component model,we build a standard-based RFID middleware-SCA-OSGi based RFID middleware (SORM) which supports flexible deployment topologies and reconfigurability. The design and implementation details of SORM are illustrated.展开更多
In order to construct a resource-saving and environment- friendly society, the advantages of radio frequency identification （RFID） were considered. And it put forward the idea of introducing RFID in the recycling ac...In order to construct a resource-saving and environment- friendly society, the advantages of radio frequency identification （RFID） were considered. And it put forward the idea of introducing RFID in the recycling activities of waste products. Taking into account such elements as the technical level of RFID, cost saving from remanufacturing and the cost of RFID tags, both centralized and decentralized supply chain models with different participants in waste product collection were created, in order to determine the optimal pricing strategy and RFID technical level. In the end, sensitivity analyses were conducted to analyze the impacts of scaling parameter for additional increased recovery rate with RFED on pricing and RFID technology level, and impacts of cost saving on the profits of participants in different remanufacturing closed-loop supply chain models.展开更多
Bridge frequency(BF)identification using the vehicle scanning method has attracted considerable attention during the last two decades.However,most previous studies have adopted unrealistic vehicle models,thus finding ...Bridge frequency(BF)identification using the vehicle scanning method has attracted considerable attention during the last two decades.However,most previous studies have adopted unrealistic vehicle models,thus finding limited practical applications.This study proposes a smartphone-based BF identification method that uses the contact-point acceleration response of a four degree-of-freedom vehicle model.The said response can be inferred from the vehicle body response measured by a smartphone.For realizing practical applications,this method is incorporated into a self-developed smartphone app to obtain data smoothly and identify BFs in a timely manner.Numerical and experimental investigations are performed to verify the effectiveness of the proposed method.In particular,the robustness of this method is investigated numerically against various factors,including the vehicle speed,bridge span,road roughness,and bridge type.Furthermore,laboratory calibration tests are performed to investigate the accuracy of the smartphone gyroscope in measuring the angular velocity,where anomalous data are detected and eliminated.Laboratory experiment results for a simply supported bridge indicate that the proposed method can be used to identify the first two BFs with acceptable accuracy.展开更多
This study can play an important role in addressing the issue of achieving stable controlof launch vehicles when the first-order elastic frequency is near or overlaps with the rigid-body fre-quency,especially without ...This study can play an important role in addressing the issue of achieving stable controlof launch vehicles when the first-order elastic frequency is near or overlaps with the rigid-body fre-quency,especially without prior frequency knowledge.Much of the research up to now,such asthose based on notch-filter or signal-processing techniques,requires a gap of 3 to 5 times betweenthe low-order elastic frequencies and the rigid-body cutoff frequency.Observer-based methods,onthe other hand,require prior knowledge of the frequency data.In this paper,a method is proposed,which takes advantage of the fact that attitude measurements of the rigid-body,obtained by InertialMeasurement Units(IMUs)installed at different locations,are identical,whereas elastic-mode sig-nals differ only in their modal slopes.By differentially processing these IMU measurements,we canextract only the elastic information,thus identifying the frequencies of the elastic modes,and designan observer to distinguish the first-order elastic signal using redundant measurements.Simulationsdemonstrate that this method can autonomously identify low-order elastic frequencies,even whenthey are identical to or less than the rigid-body frequency,thereby enhancing controller perfor-mance.展开更多
This paper presents a design for a self-powered radio frequency identification (RFID) tag with a thin film bulk acoustic reso- nating piezoelectric power supply (PPS), which can be used for portable remote temperature...This paper presents a design for a self-powered radio frequency identification (RFID) tag with a thin film bulk acoustic reso- nating piezoelectric power supply (PPS), which can be used for portable remote temperature monitoring. We call this system a PPS-RFID for short. The RFID systems have been found to have many applications in the internet of things (IOT) in the past decade. But semi-active RFID tags require an onboard battery which limits their applications in many fields. For these reasons, our research focuses on power sources for the RFID tags. This paper emphasizes the circuit design and simulation of PPS. In our tests, 0.283 mW was generated by PPS at 1 Hz vibration by a 650 N impact force. The results showed that the integrated PPS could supply sufficient power for the designed PPS-RFID tag. The PPS-RFID tag can be widely used for temperature monitoring during mobile transport of perishable items such as medicines or food.展开更多
In order to increase the productivity of construction industry, emerging technologies have been constantly introduced and applied in this traditional industry by pilot researchers. This paper provides an integrated mo...In order to increase the productivity of construction industry, emerging technologies have been constantly introduced and applied in this traditional industry by pilot researchers. This paper provides an integrated model of radio-frequency identification (RFID) and four-dimensional Computer-Aided Design (4D CAD) in construction management. RFID involves the use of tags that collect data and transmit data. RFID can collect data by radio waves instead of light waves. RFID technology is surpassing barcode technology where light waves are easily blocked and barcode labels are easy to fall off or become unreadable due to dust, dirt, or other contaminants. 4D CAD which involves 3D construction models and construction schedules presents visualized construction process. Integration of RFID and 4D CAD in this paper built a dynamic construction management and control system which would reduce the time of capturing data on site and control quality of construction materials efficiently. Pilot test result shows that a construction manager can easily understand how and what a complicated construction project will be accomplished. Although further analysis is necessary, RFID and 4D CAD show promises of being a beneficial technology in construction management.展开更多
The noncontact blade tip timing(BTT)measurement has been an attractive technology for blade health monitoring(BHM).However,the severe undersampled BTT signal causes a significant challenge for blade vibration paramete...The noncontact blade tip timing(BTT)measurement has been an attractive technology for blade health monitoring(BHM).However,the severe undersampled BTT signal causes a significant challenge for blade vibration parameter identification and fault feature extraction.This study proposes a novel method based on the minimum variance distortionless response(MVDR)of the direction of arrival(DoA)estimation for blade natural frequency estimation from the non-uniformly undersampled BTT signals.First,based on the similarity between the general data acquisition model for BTT and the antenna array model in DoA estimation,the circumferentially arranged probes on the casing can be regarded as a non-uniform linear array.Thus,BTT signal reconstruction is converted into the DoA estimation problem of the non-uniform linear array signal.Second,MVDR is employed to address the severe undersampling issue and recover the BTT undersampled signal.In particular,spatial smoothing is innovatively utilized to enhance the estimation of covariance matrix of the BTT signal to avoid ill-condition or singularity,while improving efficiency and robustness.Lastly,numerical simulation and experimental testing are employed to verify the validity of the proposed method.Monte Carlo simulation results suggest that the proposed method behaves better than conventional methods,especially under a lower signal-to-noise ratio condition.Experimental results indicate that the proposed method can effectively overcome the severe undersampling problem of BTT signal induced by physical limitations,and has a strong potential in the field of BHM.展开更多
A new comb shaped antenna for radio frequency identification is proposed. The kind of antenna can replace some antenna array. So it is very convenient for omnidirectional identification. The test result proves this a...A new comb shaped antenna for radio frequency identification is proposed. The kind of antenna can replace some antenna array. So it is very convenient for omnidirectional identification. The test result proves this antenna is viable.展开更多
CIFER software is used to identify steering and roll dynamics of a container ship. In this software, advanced features such as the Chirp-Z transform(CZT) and composite window optimization are applied to the time histo...CIFER software is used to identify steering and roll dynamics of a container ship. In this software, advanced features such as the Chirp-Z transform(CZT) and composite window optimization are applied to the time history of steering and roll dynamics to extract high quality frequency responses. From the extracted frequency responses, two linear transfer functions of Nomoto model are fitted for yaw and roll dynamics of the vessel. Based on the identified Nomoto model, a PID heading controller and a Kalman filter observer are constructed. The simulation results of heading controller for line of sight(LOS) waypoint guidance show excellent tracking of pilot inputs in the presence of wave induced motions and forces.展开更多
A new kind of fuzzy control scheme, based on the identification of the signal' s main frequency and the behavior of the ER damper, is proposed to control the semi-active suspension system. This method ad-justs ...A new kind of fuzzy control scheme, based on the identification of the signal' s main frequency and the behavior of the ER damper, is proposed to control the semi-active suspension system. This method ad-justs the fuzzy controller to achieve the best isolation effect by analyzing the main frequency' s characters and inspecting the change of system parameters. The input of the fuzzy controller is the main frequency and the op-timal damping ratio is the output. Simulation results indicated that the proposed control method is very effec-tive in isolating the vibration.展开更多
It is a challenge for passive RFID tags to be mounted on the surface of metal because the parameters of tag antennas,such as the impedance matching,the radiation efficiency and the radiation pattern,are seriously affe...It is a challenge for passive RFID tags to be mounted on the surface of metal because the parameters of tag antennas,such as the impedance matching,the radiation efficiency and the radiation pattern,are seriously affected by the metallic surface.This paper presents the characteristics of the dipole-like antennas of ultra high frequency(UHF) radio frequency identification(RFID) tags that are placed close to metallic surfaces.The finite element method(FEM) and method of moment(MoM) were used to simulate the changes of the antenna parameters near the metallic surface.Two typical dipole-like antennas close to the metallic surface,a closed loop antenna and a loaded meander antenna,were modeled,and the performance was evaluated.Experiment was carried out and the results were in good agreement with the simulation,showing that a distance of 0.05λ～0.1λ(λ is the free space wavelength) from the metallic surface could make the dipole-like UHF RFID tag performance be acceptable.展开更多
In a passive ultra-high frequency(UHF)radio frequency identification(RFID)system,the recovery of collided tag signals on a physical layer can enhance identification efficiency.However,frequency drift is very common in...In a passive ultra-high frequency(UHF)radio frequency identification(RFID)system,the recovery of collided tag signals on a physical layer can enhance identification efficiency.However,frequency drift is very common in UHF RFID systems,and will have an influence on the recovery on the physical layer.To address the problem of recovery with the frequency drift,this paper adopts a radial basis function(RBF)network to separate the collision signals,and decode the signals via FM0 to recovery collided RFID tags.Numerical results show that the method in this paper has better performance of symbol error rate(SER)and separation efficiency compared to conventional methods when frequency drift occurs.展开更多
Dynamic framed slotted Aloha algorithm is one of popular passive radio frequency identification(RFID) tag anticollision algorithms. In the algorithm, a frame length requires dynamical adjustment to achieve higher iden...Dynamic framed slotted Aloha algorithm is one of popular passive radio frequency identification(RFID) tag anticollision algorithms. In the algorithm, a frame length requires dynamical adjustment to achieve higher identification efficiency.Generally, the adjustment of the frame length is not only related to the number of tags, but also to the occurrence probability of capture effect. Existing algorithms could estimate both the number of tags and the probability of capture effect. Under large-scale RFID tag identification, however, the number of tags would be much larger than an initial frame length. In this scenario, the existing algorithm's estimation errors would substantially increase. In this paper, we propose a novel algorithm called capture-aware Bayesian estimate, which adopts Bayesian rules to accurately estimate the number and the probability simultaneously. From numerical results, the proposed algorithm adapts well to the large-scale RFID tag identification. It has lower estimation errors than the existing algorithms. Further,the identification efficiency from the proposed estimate is also higher than the existing algorithms.展开更多
Machine Learning has evolved with a variety of algorithms to enable state-of-the-art computer vision applications.In particular the need for automating the process of real-time food item identification,there is a huge...Machine Learning has evolved with a variety of algorithms to enable state-of-the-art computer vision applications.In particular the need for automating the process of real-time food item identification,there is a huge surge of research so as to make smarter refrigerators.According to a survey by the Food and Agriculture Organization of the United Nations(FAO),it has been found that 1.3 billion tons of food is wasted by consumers around the world due to either food spoilage or expiry and a large amount of food is wasted from homes and restaurants itself.Smart refrigerators have been very successful in playing a pivotal role in mitigating this problem of food wastage.But a major issue is the high cost of available smart refrigerators and the lack of accurate design algorithms which can help achieve computer vision in any ordinary refrigerator.To address these issues,this work proposes an automated identification algorithm for computer vision in smart refrigerators using InceptionV3 and MobileNet Convolutional Neural Network(CNN)architectures.The designed module and algorithm have been elaborated in detail and are considerably evaluated for its accuracy using test images on standard fruits and vegetable datasets.A total of eight test cases are considered with accuracy and training time as the performance metric.In the end,real-time testing results are also presented which validates the system’s performance.展开更多
基金The authors would like to thank the reviewers for their detailed reviews and constructive comments, which have helped improve the quality of this paper. This paper is supported by the National Natural Science Founda- tion of China （No. 61371092）, the Doctoral Fund of Ministry of Education of China （No.20130061120062）, and the China Postdoc- toral Science Foundation （No. 2014M551184）.
文摘Radio frequency identification(RFID) is a new type of non-contact automatic identification technology.Due to its low energy consumption,low cost,and its adaptability to harsh environments,it has been applied to many fields.In the RFID systems,data collision is inevitable when the reader sends a communication request and multiple tags respond with simultaneous data transmission.Data collision is prone to causing problems such as:identification delay,spectrum resource waste,a decreased system throughput rate,etc.Therefore,an efficient,stable anti-collision protocol is crucial for RFID systems.This research analysed the current research into RFID anticollision protocols and summarised means for its improvement through the mechanism of implementation of different types anticollision protocols.Finally,a new direction is proposed for the future development of RFID anti-collision protocol systems.
基金Supported by the Project of the National "948" (2006-Z12)
文摘As a kind of brand-new technology, radio frequency identification management, data control and acquisition. This paper introduced food safety system construction, analyzed the advantages and problems in dairy modem suggestions for solution according to the practical situation. （RFID） plays an important role in dairy information tracing and culture function extension of managing breeding technology, and finally put forward some
基金the National Natural Science Foundation of China (No. 61071078)
文摘A radio frequency identification (RFID) reader will fail to identify tags if a collision occurs. This paper proposes a bi-slotted binary tree algorithm (BSBTA) with stack for RFID tag anti-collision to improve the performance of binary tree algorithm (BTA). In BSBTA, the reader detects collisions by Manchester code and stores colliding prefixes in a stack. The query is composed of a two-bit prefix and an index value. Following every reader query, there are two timeslots for tags whose pointers and identities (IDs) match the query to respond, one for the tag whose next bit is 0 and the other for the tag with 1 as its next bit. Performance analysis and evaluation are also given. The time complexity and the communication complexity of BTA and BSBTA are derived. The simulation results compare the performance of BSBTA with several related anti-collision algorithms. It is shown that BSBTA outperforms BTA in terms of the average number of responded bits and timeslots for one tag identification.
文摘A compact antenna formed by three concentric split rings for ultra-high frequency(UHF)radio frequency identification(RFID)tag is proposed in this paper.The antenna is composed of two parts,an outer short-circuited ring modified from a traditional split-ring resonator(SRR)antenna and an inner SRR load,so the antenna can be regarded as a short-circuited ring loaded with SRR.According to the transmission line theory,to conjugate match with the capacitive input-impedance of a tag chip,the length of the short-circuited ring isλg/4 shorter than that of an open-circuited dipole of a traditional SRR antenna,whereλg is the wavelengh of the operating frequency.Hence,the size of the proposed antenna is more compact than that of the traditional SRR antenna.Thereafter,the proposed antenna is simulated and optimized by ANSYS high-frequency structure simulator(HFSS).The impedance,efficiency,and mutual coupling of the fabricated antenna are tested in a reverberation chamber(RC).The results show that the size of the presented antenna is 83%smaller than that of the traditional SRR antenna and the proposed antenna can cover the whole UHF RFID operating frequency band worldwide(840—960 MHz).The measured read range of the tag exhibits maximum values of 45 cm in free space and 37 cm under dense tag environment.
基金the National Science Council(No. NSC99-2218-E-260-002)
文摘A radio frequency identification (RFID) yoking proof scheme can generate proofs of simultaneous presence of two tags in the range of a specified reader so that an off-line verifier can verify the proofs later. This proof has found several interesting applications. However, many existing RFID yoking schemes are vulnerable to replay attacks. To overcome the weaknesses, Cho et al. proposed a new RFID yoking proof protocol and a new grouping protocol. Unfortunately, Cho et al.'s schemes are still vulnerable to replay attacks. In this paper, in addition to demonstrating weaknesses, we further discuss the rationale behind these weaknesses to provide a guide line for designing secure RFID yoking schemes. Based on the guide line, we propose a new RFID yoking scheme and a new RFID grouping scheme. Performance evaluation shows that our scheme outperforms its counterparts.
基金the National High Technology Research and Development Program (863) of China(No. 2006AA04A114)
文摘The radio frequency identification (RFID) technology progressing is becoming a increasing interest in several application areas. To accommodate diverse and changing requirements from applications,RFID middleware should be reconfigurable. However,current RFID middleware is limited in its ability to support reconfiguration. To solve this problem,we adopt the service-oriented component-based approach in building the middleware. Component-based design enables decomposition of middleware functionality and is easier than the current one to manage and modify the structure of the middleware both statically and dynamically. Applying service-oriented architecture (SOA) can further reduce the coupling between components and external software and ease the integration between middleware and applications. We propose a two-layered service component architecture (SCA) open service gateway initiative (OSGi) component model so as to enable reconfigurability. Based on the proposed component model,we build a standard-based RFID middleware-SCA-OSGi based RFID middleware (SORM) which supports flexible deployment topologies and reconfigurability. The design and implementation details of SORM are illustrated.
基金National Natural Science Foundation of China(No.71301038)
文摘In order to construct a resource-saving and environment- friendly society, the advantages of radio frequency identification （RFID） were considered. And it put forward the idea of introducing RFID in the recycling activities of waste products. Taking into account such elements as the technical level of RFID, cost saving from remanufacturing and the cost of RFID tags, both centralized and decentralized supply chain models with different participants in waste product collection were created, in order to determine the optimal pricing strategy and RFID technical level. In the end, sensitivity analyses were conducted to analyze the impacts of scaling parameter for additional increased recovery rate with RFED on pricing and RFID technology level, and impacts of cost saving on the profits of participants in different remanufacturing closed-loop supply chain models.
基金National Natural Science Foundation of China under Grant Nos.51978215 and 52378295National Key R&D Program of China under Grant No.2019YFC1511100+1 种基金Guangdong Basic and Applied Basic Research Foundation under Grant No.2022A1515110587Shenzhen S&T Project under Grant Nos.JCYJ20200109112816582 and KQTD20210811090112003。
文摘Bridge frequency(BF)identification using the vehicle scanning method has attracted considerable attention during the last two decades.However,most previous studies have adopted unrealistic vehicle models,thus finding limited practical applications.This study proposes a smartphone-based BF identification method that uses the contact-point acceleration response of a four degree-of-freedom vehicle model.The said response can be inferred from the vehicle body response measured by a smartphone.For realizing practical applications,this method is incorporated into a self-developed smartphone app to obtain data smoothly and identify BFs in a timely manner.Numerical and experimental investigations are performed to verify the effectiveness of the proposed method.In particular,the robustness of this method is investigated numerically against various factors,including the vehicle speed,bridge span,road roughness,and bridge type.Furthermore,laboratory calibration tests are performed to investigate the accuracy of the smartphone gyroscope in measuring the angular velocity,where anomalous data are detected and eliminated.Laboratory experiment results for a simply supported bridge indicate that the proposed method can be used to identify the first two BFs with acceptable accuracy.
文摘This study can play an important role in addressing the issue of achieving stable controlof launch vehicles when the first-order elastic frequency is near or overlaps with the rigid-body fre-quency,especially without prior frequency knowledge.Much of the research up to now,such asthose based on notch-filter or signal-processing techniques,requires a gap of 3 to 5 times betweenthe low-order elastic frequencies and the rigid-body cutoff frequency.Observer-based methods,onthe other hand,require prior knowledge of the frequency data.In this paper,a method is proposed,which takes advantage of the fact that attitude measurements of the rigid-body,obtained by InertialMeasurement Units(IMUs)installed at different locations,are identical,whereas elastic-mode sig-nals differ only in their modal slopes.By differentially processing these IMU measurements,we canextract only the elastic information,thus identifying the frequencies of the elastic modes,and designan observer to distinguish the first-order elastic signal using redundant measurements.Simulationsdemonstrate that this method can autonomously identify low-order elastic frequencies,even whenthey are identical to or less than the rigid-body frequency,thereby enhancing controller perfor-mance.
基金supported by the MEMS subject construction fund of the Kunming University of Science and Technology (Grant No. 14078024)
文摘This paper presents a design for a self-powered radio frequency identification (RFID) tag with a thin film bulk acoustic reso- nating piezoelectric power supply (PPS), which can be used for portable remote temperature monitoring. We call this system a PPS-RFID for short. The RFID systems have been found to have many applications in the internet of things (IOT) in the past decade. But semi-active RFID tags require an onboard battery which limits their applications in many fields. For these reasons, our research focuses on power sources for the RFID tags. This paper emphasizes the circuit design and simulation of PPS. In our tests, 0.283 mW was generated by PPS at 1 Hz vibration by a 650 N impact force. The results showed that the integrated PPS could supply sufficient power for the designed PPS-RFID tag. The PPS-RFID tag can be widely used for temperature monitoring during mobile transport of perishable items such as medicines or food.
文摘In order to increase the productivity of construction industry, emerging technologies have been constantly introduced and applied in this traditional industry by pilot researchers. This paper provides an integrated model of radio-frequency identification (RFID) and four-dimensional Computer-Aided Design (4D CAD) in construction management. RFID involves the use of tags that collect data and transmit data. RFID can collect data by radio waves instead of light waves. RFID technology is surpassing barcode technology where light waves are easily blocked and barcode labels are easy to fall off or become unreadable due to dust, dirt, or other contaminants. 4D CAD which involves 3D construction models and construction schedules presents visualized construction process. Integration of RFID and 4D CAD in this paper built a dynamic construction management and control system which would reduce the time of capturing data on site and control quality of construction materials efficiently. Pilot test result shows that a construction manager can easily understand how and what a complicated construction project will be accomplished. Although further analysis is necessary, RFID and 4D CAD show promises of being a beneficial technology in construction management.
基金the National Natural Science Foundation of China(Grant Nos.52105117 and 51875433)the Funds for Distinguished Young Talent of Shaanxi Province,China(Grant No.2019JC-04).
文摘The noncontact blade tip timing(BTT)measurement has been an attractive technology for blade health monitoring(BHM).However,the severe undersampled BTT signal causes a significant challenge for blade vibration parameter identification and fault feature extraction.This study proposes a novel method based on the minimum variance distortionless response(MVDR)of the direction of arrival(DoA)estimation for blade natural frequency estimation from the non-uniformly undersampled BTT signals.First,based on the similarity between the general data acquisition model for BTT and the antenna array model in DoA estimation,the circumferentially arranged probes on the casing can be regarded as a non-uniform linear array.Thus,BTT signal reconstruction is converted into the DoA estimation problem of the non-uniform linear array signal.Second,MVDR is employed to address the severe undersampling issue and recover the BTT undersampled signal.In particular,spatial smoothing is innovatively utilized to enhance the estimation of covariance matrix of the BTT signal to avoid ill-condition or singularity,while improving efficiency and robustness.Lastly,numerical simulation and experimental testing are employed to verify the validity of the proposed method.Monte Carlo simulation results suggest that the proposed method behaves better than conventional methods,especially under a lower signal-to-noise ratio condition.Experimental results indicate that the proposed method can effectively overcome the severe undersampling problem of BTT signal induced by physical limitations,and has a strong potential in the field of BHM.
文摘A new comb shaped antenna for radio frequency identification is proposed. The kind of antenna can replace some antenna array. So it is very convenient for omnidirectional identification. The test result proves this antenna is viable.
文摘CIFER software is used to identify steering and roll dynamics of a container ship. In this software, advanced features such as the Chirp-Z transform(CZT) and composite window optimization are applied to the time history of steering and roll dynamics to extract high quality frequency responses. From the extracted frequency responses, two linear transfer functions of Nomoto model are fitted for yaw and roll dynamics of the vessel. Based on the identified Nomoto model, a PID heading controller and a Kalman filter observer are constructed. The simulation results of heading controller for line of sight(LOS) waypoint guidance show excellent tracking of pilot inputs in the presence of wave induced motions and forces.
文摘A new kind of fuzzy control scheme, based on the identification of the signal' s main frequency and the behavior of the ER damper, is proposed to control the semi-active suspension system. This method ad-justs the fuzzy controller to achieve the best isolation effect by analyzing the main frequency' s characters and inspecting the change of system parameters. The input of the fuzzy controller is the main frequency and the op-timal damping ratio is the output. Simulation results indicated that the proposed control method is very effec-tive in isolating the vibration.
基金Project (No.2006C12051) supported by the Science and Technology Plan of Zhejiang Province,China
文摘It is a challenge for passive RFID tags to be mounted on the surface of metal because the parameters of tag antennas,such as the impedance matching,the radiation efficiency and the radiation pattern,are seriously affected by the metallic surface.This paper presents the characteristics of the dipole-like antennas of ultra high frequency(UHF) radio frequency identification(RFID) tags that are placed close to metallic surfaces.The finite element method(FEM) and method of moment(MoM) were used to simulate the changes of the antenna parameters near the metallic surface.Two typical dipole-like antennas close to the metallic surface,a closed loop antenna and a loaded meander antenna,were modeled,and the performance was evaluated.Experiment was carried out and the results were in good agreement with the simulation,showing that a distance of 0.05λ～0.1λ(λ is the free space wavelength) from the metallic surface could make the dipole-like UHF RFID tag performance be acceptable.
基金supported by the National Natural Science Foundation of China(61762093)the 17th Batches of Young and Middle-aged Leaders in Academic and Technical Reserved Talents Project of Yunnan Province(2014HB019)+1 种基金the Key Applied and Basic Research Foundation of Yunnan Province(2018FA036)the Program for Innovative Research Team(in Science and Technology)in University of Yunnan Province。
文摘In a passive ultra-high frequency(UHF)radio frequency identification(RFID)system,the recovery of collided tag signals on a physical layer can enhance identification efficiency.However,frequency drift is very common in UHF RFID systems,and will have an influence on the recovery on the physical layer.To address the problem of recovery with the frequency drift,this paper adopts a radial basis function(RBF)network to separate the collision signals,and decode the signals via FM0 to recovery collided RFID tags.Numerical results show that the method in this paper has better performance of symbol error rate(SER)and separation efficiency compared to conventional methods when frequency drift occurs.
基金supported in part by the National Natural Science Foundation of China(61762093)the 17th Batch of Young and Middle-aged Leaders in Academic and Technical Reserved Talents Project of Yunnan Province(2014HB019)the Program for Innovative Research Team(in Science and Technology)in University of Yunnan Province
文摘Dynamic framed slotted Aloha algorithm is one of popular passive radio frequency identification(RFID) tag anticollision algorithms. In the algorithm, a frame length requires dynamical adjustment to achieve higher identification efficiency.Generally, the adjustment of the frame length is not only related to the number of tags, but also to the occurrence probability of capture effect. Existing algorithms could estimate both the number of tags and the probability of capture effect. Under large-scale RFID tag identification, however, the number of tags would be much larger than an initial frame length. In this scenario, the existing algorithm's estimation errors would substantially increase. In this paper, we propose a novel algorithm called capture-aware Bayesian estimate, which adopts Bayesian rules to accurately estimate the number and the probability simultaneously. From numerical results, the proposed algorithm adapts well to the large-scale RFID tag identification. It has lower estimation errors than the existing algorithms. Further,the identification efficiency from the proposed estimate is also higher than the existing algorithms.
基金This work was supported by Taif University Researchers Supporting Project(TURSP)under number(TURSP-2020/10),Taif University,Taif,Saudi Arabia.
文摘Machine Learning has evolved with a variety of algorithms to enable state-of-the-art computer vision applications.In particular the need for automating the process of real-time food item identification,there is a huge surge of research so as to make smarter refrigerators.According to a survey by the Food and Agriculture Organization of the United Nations(FAO),it has been found that 1.3 billion tons of food is wasted by consumers around the world due to either food spoilage or expiry and a large amount of food is wasted from homes and restaurants itself.Smart refrigerators have been very successful in playing a pivotal role in mitigating this problem of food wastage.But a major issue is the high cost of available smart refrigerators and the lack of accurate design algorithms which can help achieve computer vision in any ordinary refrigerator.To address these issues,this work proposes an automated identification algorithm for computer vision in smart refrigerators using InceptionV3 and MobileNet Convolutional Neural Network(CNN)architectures.The designed module and algorithm have been elaborated in detail and are considerably evaluated for its accuracy using test images on standard fruits and vegetable datasets.A total of eight test cases are considered with accuracy and training time as the performance metric.In the end,real-time testing results are also presented which validates the system’s performance.
