Speed measurement

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High accuracy speed measurement for rotary motor based on DSP

High accuracy speed measurement for rotary motor based on DSP

In the induction motor drive system, in order to meet the requirements of high-performance control, closed-loop speed control is needed, so the induction motor speed is required. In high-performance induction motor speed control system, the accuracy of speed measurement makes great impact on the performance of motor speed control system [5].

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Wireless Wind Speed Measurement Based on Three–Axis Ultrasonic Anemometer

Wireless Wind Speed Measurement Based on Three–Axis Ultrasonic Anemometer

In the experiment, we successfully build a three-dimensional wind speed measurement system with wireless network, ultrasonic sensors, upper computer, etc. In this paper, aiming at the engineering requirements of the airship on the atmospheric environment, a convenient and reliable wind speed and direction measurement method is proposed. We provide a design idea for the airship and other occasion which requires strict requirements on performance or measurement parameters.

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Development of an Electronic Speed Measurement System for Evaluating the Accuracy of GNSS Receivers and Statistical Analysis of Their Performance in Speed Measurements

Development of an Electronic Speed Measurement System for Evaluating the Accuracy of GNSS Receivers and Statistical Analysis of Their Performance in Speed Measurements

Research activities were also conducted with calibrated GPS simulators [11-13]. At the same time it is worth mentioning that testing with GPS simulators does not provide any real world challenge to the receivers under test and can mainly discover issues when the receivers have bugs in their speed measurement algorithms. Simulators are not effectively capable to simulate multipath, changes in ionosphere or any other factors influencing speed errors in GNSS measurements. In [11] and [12] tests are also described with the calibrated test vehicle in the real world environment. However, in [11] the focus was on one specific GPS receiver only and it appears that testing was conducted on a highway with relatively good GNSS visibility. This caused a receiver to perform really well all along the journey. As a result, the research [11] cannot provide statistical information on the performance of a number of GPS receivers or a combined solution, say GPS and GLONASS. It is necessary to emphasize, however, that this research uses a speed measurement system named Correvit for GNSS speed testing and Correvit represents quite an advanced speed measurement solution. Its stated accuracy equals to 0.5% [14]; however, it is unclear how speed records produced by Correvit were synchronized with UTC and what the UOM of the test equipment might be if Correvit speed records are not in perfect synchronization with UTC. The research [12] and [15], while also focusing on practical tests with the test vehicles, also focus on GPS only receivers rather than multi constellation receivers and the receivers under test are of the same complexity. Therefore, it is unclear if consumers/researchers can extrapolate the conclusions of this research on high end, medium range or low grade receivers. Finally, the research [12] and [15] do not specifically focus on challenging GNSS environments or testing of multi-constellation receivers, for example, working with GPS and GLONASS.

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The Vehicle Counting, Classification and Speed Measurement Using AMR Sensors

The Vehicle Counting, Classification and Speed Measurement Using AMR Sensors

The AMR sensor comprises of the Si or glass board, and the thin film of amalgam framed on the board. The central element of compound is ferromagnetic metals, for example, Ni and Fe. The protection of the framed ferromagnetic thin movie metal differs as per the quality of the connected attractive recorded with the particular heading. Since its protection changes as indicated by the particular heading of the attractive recorded, the sensor is called AMR (Anisotropic Magnet Resistance) sensor. In the proposed system HMC-58831 AMR sensor is used. The Arduino board can access the data from the sensor via its analog pins. The data then access by the PC. This data is then pass through MATLAB for image processing where a kalman filter is used to find estimates of vehicle characteristics for classification, then this predicted data is further process for useful feature extraction and then it is classify based on the features. The output can be seen on the MATLAB. Speed measurement performed on Arduino (Arduino IDE software used for programming Arduino board) whereas classification of vehicles performed on MATLAB.

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PORTABLE ROADSIDE SENSORS FOR VEHICULAR COUNTING, CLASSIFICATION AND SPEED MEASUREMENT

PORTABLE ROADSIDE SENSORS FOR VEHICULAR COUNTING, CLASSIFICATION AND SPEED MEASUREMENT

This paper has proposed a portable and low-cost sensing system based on magnetic sensors that can be placed adjacent to the road and be used for traffic counting, speed measurement, and vehicle classification in the lane adjacent to the sensors. The vehicle classification and speed measurement in this paper are enabled using multiple spatially separated magnetic sensors. Through experimental data from 188 vehicles, it is shown that the traffic counting accuracy of the system is 99%. A method is also proposed to make the system robust to the traffic in the nonadjacent lane. The false calls caused by the traffic in the nonadjacent lane, if uncorrected, can cause an 8% detection Error. However, using the proposed method, the error reduces to 1%. Speed estimation is done by placing two magnetic sensors 0.9 m longitudinally apart and taking the cross-correlation between the signals from the two sensors. Digital signal processing methods are adopted to reduce the computation effort. The speed estimation method is verified by mounting a test vehicle with a GPS. Experimental results show a maximum of 2.5% error in speed estimates over the range of 5–27 m/s (11–60 mi/h). Vehicle classification is performed based on the magnetic length and average magnetic height of vehicles. Vehicle length is estimated by multiplying the detection time by the estimated speed. The average vertical magnetic height is estimated using two magnetic sensors that are vertically spaced by about 0.3 m. Finally, it is shown that the sensing system can be used to reliably count the number of right turns at an intersection, with an accuracy of 95%. The challenge in counting the number of right turns is the false calls created by larger straight-driving vehicles, which, if uncorrected, cause 31% overdetection. Two methods are proposed based on using two and four magnetic sensors, which totally eliminate this error. Finally the report we shown in Computer.

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High-speed camera-based measurement system for aeroacoustic investigations

High-speed camera-based measurement system for aeroacoustic investigations

Non-invasive, optical measurements of the acoustic parti- cle velocity (APV), i.e. the sound-related particle oscillation velocity (Hann and Greated, 1999; Taylor, 1976) and the flow velocity (Thompson and Atchley, 2005), were realized by us- ing laser Doppler anemometry (LDA). These systems detect the Doppler-shifted frequency of light scattered at single par- ticles moving with the flow with negligible slip and provide data rates in the range of several 10 MSamples s −1 (Hann and Greated, 1999). Standard LDA systems yield a point-wise measurement, which objects the requirement of an imaging technique. Enhanced LDA sensor principles with a linear (known as profile sensor) and planar (known as field sen- sor) measurement volume have been presented (Voigt et al., 2008; Meier and Roesgen, 2012). However, for all LDA prin- ciples the measurement rate equals the random particle rate passing the measurement volume observed by one detector element. Hence, a high-speed measurement with a constant measurement and data rate is not possible.

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High-speed interferometric FBG interrogator with dynamic and absolute wavelength measurement capability

High-speed interferometric FBG interrogator with dynamic and absolute wavelength measurement capability

The interferometer (OPD 4.6 mm) was an all-fiber con- struction, fabricated by splicing the pigtails of 1x2 and 3x3 couplers. To isolate the MZI from vibration and to hinder heat transfer between the arms during thermal tuning, the device was bonded to a glass slab by epoxy. Tuning was achieved by resistive heating an L = 4 cm section of one fiber arm. Heat conduction was facilitated by thermal grease. The ADC unit sampled at 4 kHz, and each set of four data points were averaged. After switching between the two FBGs, this provided a measurement rate of 500 Hz per sensor.

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Ultrasonic metal sheet thickness measurement without prior wave speed calibration

Ultrasonic metal sheet thickness measurement without prior wave speed calibration

In conventional ultrasonic thickness gauging of metals, a piezoelectric transducer is placed on a sample surface, and is used to generate and detect ultrasonic bulk waves within the sample [1]. The thickness is calculated from the transit time of a wave that reverberates through the thickness of the sample, using a calibration bulk wave speed. For ease of coupling the ultrasound from the transducer to the sample, a compression wave probe is usually used. The reasons to perform thickness gauging on a sample are multifarious, ranging from manufacturing quality control, through to in-service corrosion monitoring of key plant or structural components.

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EDLT: An Extended DLT to Enhance Load Balancing in Cloud Computing

EDLT: An Extended DLT to Enhance Load Balancing in Cloud Computing

In recent years, with rapid development of network and internet technology, more people are logging to internet to acquire information, to shop and to have fun. Consequently the volume of data and client requests increase which requires more computation and processing on servers. Due to the growing number of requests to use cloud services, one of the main challenges in this respect, is load balancing. In this article, an enhanced approach to DLT has been proposed for load balancing. To evaluate this approach, measurement/report time has been used. Measurement/report time in simultaneous reporting is less than sequential reporting since in sequential reporting some clients receive almost zero load from the server. The number of effective clients in this case is less than simultaneous reporting. Therefore, as the number of clients connected to a server increases, an extra completion time remains which is almost similar in both simultaneous and sequential cases. Thus if the number of clients of a server increases, completion time will decrease and with the increase of clients number connected to a server in a cloud, completion time may be enhanced up to satiation (in sequential reporting) But when reporting starts and stops, completion time can be considerably decreased through adding more clients to a server. Moreover, experiment findings indicate that as the ratio of server failure rate to client failure rate increases, measurement/report time increases and measurement/report time in simultaneous case is less than sequential case. Future works can be as following: first, in DLT, workload is distributed over two layers but if a layer is added between server and client, processing will become faster. Second, instead of connecting each client to a single server, each client can be connected to multiple servers.

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On the theory of SODAR measurement techniques (final reporting on WP1, EU WISE project NNE5 2001 297)

On the theory of SODAR measurement techniques (final reporting on WP1, EU WISE project NNE5 2001 297)

If the wind speed is calculated from the instantaneous peaks detected from the spectra, one important problem becomes apparent: The higher the range gate the lower is the signal-to-noise ratio as the sound is absorbed in air and the scattered power decreases. This result in erroneous peak positions from the peak finding algorithm and the resulting wind profiles look “jumpy” both in space and in time. Therefore, it is very common to apply consistency checks and/or averaging. As the essence of a good SODAR system is in how it handles data quality and consistency in a noisy environment, not much is know about the algorithms and techniques actually employed by the manufacturers. However, there are some typical techniques that are commonly used in research instruments and it is therefore likely, to find those in commercial systems as well:

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Load Balancing Algorithm In Task Scheduling Process Using Cloud Computing

Load Balancing Algorithm In Task Scheduling Process Using Cloud Computing

Here we consider the following two cases. In the first case the measurement and reporting time is plotted against the number of slaves corresponding to a master, where the link speed b is varied and measurement speed a is fixed. In the second case, the measurement and reporting time is plotted against the number of slaves corresponding to master, where link speed b is fixed and measurement speed a is varied. Load balancer is a key element in resource provisioning for high available cloud solutions, and yet its performance depends on the traffic offered load. We develop a discrete event simulation to evaluate the performance with respect to the different load points. The performance metrics were the average waiting time inside the balance as well as the number of tasks. The performance study includes evaluating the chance of immediate serving or rejecting incoming tasks.

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Technologies of Physical Monitoring and Mathematical Modeling for Estimation of Ground Forest Fuel Fire Condition

Technologies of Physical Monitoring and Mathematical Modeling for Estimation of Ground Forest Fuel Fire Condition

Probes of a profile of temperature in ground layer were presented in the form of four transitive boxes 10 with cables of five meters to logger in stationary and mobile variants (having on five digital single temperature gauges DS18B20 on half-meter wires for measurement of various adjusted temperature profiles of a ground on different depths from a surface). Also there are gauges 7 for humidity of ground (TRIME-PICO32) and 8 for conductivity of water were presented in installations. Control, gathering, accumulation and data transmission in variants 1, 2 and 3 made by the registrar (AKL2 - GSM-modem), executed on the basis of microcircuits. In its case 6 is accumulator. The GSM-modem and the gauge of atmospheric pressure also located.

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Validation of three-component wind lidar sensor for traceable highly resolved wind vector measurements

Validation of three-component wind lidar sensor for traceable highly resolved wind vector measurements

by means of single aerosols at heights from 5 to 250 m. The high spatial and temporal resolution of the bistatic system leads to a reduced measurement uncertainty of the wind speed compared to conventional monostatic systems, as clearly evidenced by comparison measurements with a wind met mast in a wind energy test field. Based on the well-defined geometry, the known wavelength and the pre- cise frequency evaluation, the novel system has the poten- tial for traceable wind speed measurements in flat as well as in complex terrain. For a detailed analysis and validation, a new wind tunnel test facility was constructed at PTB that enables the measurement uncertainty of the bistatic system to be determined quantitatively as accurate characterization measurements of the wind tunnel flow-quality evidence. A first validation measurement with the wind tunnel test fa- cility yields a deviation between the bistatic lidar and the LDA reference clearly below 0.1 %, revealing the high preci- sion of the bistatic lidar. Due to its unique characteristics, the novel system is exceptionally qualified to improve the mea- surement capability and accuracy of site and wind resource assessments, power curve measurements, and calibrations of conventional lidar systems.

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Calcification of thyroid nodules increases shear-wave speed (SWS) measurement: using multiple calcification-specific SWS cutoff values outperforms a single uniform cutoff value in diagnosing malignant thyroid nodules

Calcification of thyroid nodules increases shear-wave speed (SWS) measurement: using multiple calcification-specific SWS cutoff values outperforms a single uniform cutoff value in diagnosing malignant thyroid nodules

Several factors can affect the results of elastography, particularly calcification in nodules [15-17]. Veyrieres et al. [17] reported that calcification in thyroid nodules increased SWS values on pSWS measurement, thus resulting in higher number of false positive nodules when a uniform cutoff value of SWS was applied for non- calcified and calcified nodules. Some prior studies simply excluded calcified nodules from their analysis to avoid this problem [18]. However, excluding calcified nodules in SWS analysis may miss a significant number of true malignant nodules, because calcified nodules account

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Intelligent heating of a room

Intelligent heating of a room

measurements for which only one dT is unequal to zero and then taking the average. It is repeated for different values of b(exponent), resulting in a list of slopes for different b’s. The fourth and last step is the determination of the exponent and is done by comparing the measurement points with all the different slopes. Best representation is the slope that agrees most with the measurements. This process is repeated for all the different state combinations.

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High-Speed Stickiness Detector Measurement: Effect of Temperature Settings and Relative Humidity

High-Speed Stickiness Detector Measurement: Effect of Temperature Settings and Relative Humidity

We selected 150 commercial cotton bales representing a wide range of stickiness and types of contamination from whiteflies, aphids, and physiological sugars. Samples came from three different growing regions. Fifty bales came from Area 1, known to have large whitefly populations and very few aphids. Fifty bales came from Area 2, where both types of insects coexist. Fifty bales came from Area 3, where large populations of aphids and very few whiteflies exist. The bales were broken and two samples per bale were taken. The sugars present on the contaminated lint were identified and quantified using high-performance liquid chromatography (Dionex Corporation, Sunnyvale, CA). In addition, each sample was tested on the high-speed stickiness detector (CIRAD, Montpellier, France).

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A Tracking algorithm for Super speed Maneuvering Target Based on Velocity Measurement

A Tracking algorithm for Super speed Maneuvering Target Based on Velocity Measurement

This paper aimed at the problem of super-speed maneuvering target tracking in the 3D space, proposes a self-adaption algorithm which using the radial velocity to track super-speed maneuvering target. Compared with VSMM algorithm, this algorithm has more simple structure, smaller amount of computations. The simulation results show that this algorithm has great improvement in tracking accuracy, maneuver detection speed and convergence rate. Tracking the super-speed maneuvering target more accurate, fast and stable. The new tracking algorithm has some value for project practice.

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Ramp heating in high-speed transient thermal measurement with reduced uncertainty

Ramp heating in high-speed transient thermal measurement with reduced uncertainty

The uncertainty associated with the convective heat transfer coefficient obtained in transient thermal measurement is often high, especially in high-speed flow. The present study demonstrates that the experimental accuracy could be much improved by an actively controlled ramp heating instead of the conventional step-heating approach. A general design guideline for the proposed ramp-heating method is derived theoretically and further demonstrated by simulation cases. This paper also presents a detailed experimental study for transonic turbine blade-tip heat transfer. A repeatable, high-resolution tip heat transfer coefficient contour is obtained through transient infrared measurement with the proposed ramp-heating method. Detailed uncertainty analysis shows that the resulting heat transfer coefficient uncertainty level is much lower than the experimental data currently available in the open literature. The ramp-heating approach is especially recommended to the high-speed heat transfer experimental research community to improve the accuracy of the transient thermal measurement technique.

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Measurement analysis for handover 
		initiation procedure in a high speed train environment

Measurement analysis for handover initiation procedure in a high speed train environment

As been observed during the measurement, it can be summarized that most of the users are using data mobile and make the call at night. From the map, most of Kuala Lumpur areas are covered by WCDMA coverage which has better signal quality and higher data rate compared to GSM network. People in urban area mostly served with WCDMA coverage to satisfy their usage need and their demand to have a higher data rates. By referring to the indicator of WCDMA, it can be seen that Mid Valley has the weakest signal strength level. This might due to tall buildings in the vicinity area blocking the received signal strength by the users onboard the train.

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An alternative speed of light measurement experiment for a senior physics laboratory

An alternative speed of light measurement experiment for a senior physics laboratory

The time difference between the reference beam and the reflected beam are determined with the use of the calibrated time base of the oscilloscope. There are a number of unknown phase shifts in this experiment, namely, the phase shifts in the electronics involved in the laser modulation and in the detector and also in the connecting cables. These unknowns will remain constant for each of the distances over which the experiment is performed and a plot of the time difference versus distance will produce a straight line. A least squares fit produces the line of best fit and the speed of light is provided from the inverse of the slope.

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