Cross Calibration by FFT Equalization

1997 ◽  
Vol 119 (2) ◽  
pp. 236-242 ◽  
Author(s):  
K. Peleg

The classical calibration problem is primarily concerned with comparing an approximate measurement method with a very precise one. Frequently, both measurement methods are very noisy, so we cannot regard either method as giving the true value of the quantity being measured. Sometimes, it is desired to replace a destructive or slow measurement method, by a noninvasive, faster or less expensive one. The simplest solution is to cross calibrate one measurement method in terms of the other. The common practice is to use regression models, as cross calibration formulas. However, such models do not attempt to discriminate between the clutter and the true functional relationship between the cross calibrated measurement methods. A new approach is proposed, based on minimizing the sum of squares of the differences between the absolute values of the Fast Fourier Transform (FFT) series, derived from the readings of the cross calibrated measurement methods. The line taken is illustrated by cross calibration examples of simulated linear and nonlinear measurement systems, with various levels of additive noise, wherein the new method is compared to the classical regression techniques. It is shown, that the new method can discover better the true functional relationship between two measurement systems, which is occluded by the noise.

2021 ◽  
pp. 67-74
Author(s):  
S. V. Biryukov ◽  
◽  
L. V. Tyukina ◽  
A. V. Tyukin ◽  
◽  
...  

Measurement and control of the intensity levels of inhomogeneous electric fields with high accuracy is quite a difficult task. The solution to this problem is connected both with the development of new sensors and methods for measuring the electric field strength. The creation of new high-precision electrical induction sensors has exhausted its capabilities at the current level of technology and technology. Therefore, new ideas are needed for solving the problems of high-precision measurement of the electric field strength. One of these ways is the development of new measurement methods. Existing measurement methods characterized by the complexity of the measurement processes, suitability in some cases, and unsuitability in others, do not provide the desired metrological characteristics. Therefore, the work related to the development of methods for measuring the intensity of inhomogeneous electric fields does not stand still, and is relevant. The aim of the study is to create a new method for measuring the strength of electric fields using known sensors, which makes it possible to significantly reduce the error in measuring inhomogeneous electric fields. The idea of constructing a new measurement method is formed. The idea of the method is that in the presence of two physical quantities measured with different sign values of the error, the average value of the physical quantity will always be closer to the true value. Based on this, a new method for measuring the intensity of inhomogeneous electric fields is proposed, associated only with the original measurement process. The measurement method id named «Average value method» (MSZ). The estimation of the error of this method shows a decrease in the measurement error to +5 % with the full spatial measurement range 0a1. Using the «Average value method» it is possible to achieve a significant increase in the accuracy of measuring the strength of inhomogeneous electric fields in a wide spatial range of measurements in comparison with known methods


Author(s):  
B. Boguski ◽  
A. Kahraman ◽  
T. Nishino

A new method of measuring planet load sharing of planetary gear sets is proposed in this paper. The method uses strain gauges mounted directly on the planet pins to measure continuously the loads carried by the planets assembled in a fixed carrier. Example 4-planet gear sets of different planet phasing conditions are procured and tested with a family of planet carriers having various levels and combinations of planet pinhole position errors to demonstrate the measurement method. As the radial floating capability of the central members is critical to planet-to-planet load sharing, a companion proximity-based measurement system is also implemented to measure the radial motions of the floating sun gear under various planet phasing and carrier pinhole error conditions. It is shown that both measurement methods are effective in characterizing the loads carried by planets.


2012 ◽  
Vol 134 (7) ◽  
Author(s):  
B. Boguski ◽  
A. Kahraman ◽  
T. Nishino

A new method of measuring planet load sharing of planetary gear sets is proposed in this paper. The method uses strain gauges mounted directly on the planet pins to measure continuously the loads carried by the planets assembled in a fixed carrier. Example 4-planet gear sets of different planet phasing conditions are procured and tested with a family of planet carriers having various levels and combinations of planet pinhole position errors to demonstrate the measurement method. As the radial floating capability of the central members is critical to planet-to-planet load sharing, a companion proximity-probe based measurement system is also implemented to measure the radial motions of the floating sun gear under various planet phasing and carrier pinhole error conditions. It is shown that both measurement methods are effective in characterizing the loads carried by planets.


2019 ◽  
Vol 29 (3) ◽  
pp. 778-796 ◽  
Author(s):  
Patrick Taffé

Recently, a new estimation procedure has been developed to assess bias and precision of a new measurement method, relative to a reference standard. However, the author did not develop confidence bands around the bias and standard deviation curves. Therefore, the goal in this paper is to extend this methodology in several important directions. First, by developing simultaneous confidence bands for the various parameters estimated to allow formal comparisons between different measurement methods. Second, by proposing a new index of agreement. Third, by providing a series of new graphs to help the investigator to assess bias, precision, and agreement between the two measurement methods. The methodology requires repeated measurements on each individual for at least one of the two measurement methods. It works very well to estimate the differential and proportional biases, even with as few as two to three measurements by one of the two methods and only one by the other. The repeated measurements need not come from the reference standard but from either measurement methods. This is a great advantage as it may sometimes be more feasible to gather repeated measurements with the new measurement method.


2013 ◽  
Vol 347-350 ◽  
pp. 197-200
Author(s):  
Yu Gong ◽  
Jing Cai Zhang ◽  
Hong Qi Liu

In this paper, research on measurement methods of hole during the parts online detection has been made. Both diameter and position of the hole are going to be detected in the same measurement system. In order to obtain higher accuracy and efficiency, a comparative analysis test of using the contact probes, the inductive sensor, the laser sensor, the forward and back lighting CCD imaging have been achieved. Results show that the contact measurement using inductive sensor is more suitable for the system, for the reason that it has higher reliability and efficiency.


2021 ◽  
pp. 20-28
Author(s):  
Boris A. Lapshinov

In industrial technological processes associated with the heating of the processed material by microwave radiation, it is necessary to measure the temperatures of objects. Methods for measuring temperatures in the fields of technology using microwave heating systems are considered. The main possibilities, disadvantages and limitations of the used contact and non-contact (optical) measurement methods are determined. The requirements for temperature measurement systems under conditions of exposure to strong electromagnetic fields are listed. The possibilities of the spectral pyrometry method are especially noted.


Author(s):  
Joseph W. Palese ◽  
Sergio DiVentura ◽  
Ken Hill ◽  
Peter Maurice

Maintaining track geometry is key to the safe and efficient operations of a railroad. Failure to properly maintain geometry can lead to costly track structure failures or even more costly derailments. Currently, there exists a number of different methods for measuring track geometry and then if required, maintaining the track to return track geometry to specified levels of acceptance. Because of this need to have proper track geometry, tampers are one of the most common pieces of maintenance equipment in a railroad operation’s fleet. It is therefore paramount from both a cost and track time perspective to gain maximum efficiency from any one particular tamper. Track geometry is typically measured through a variety of contact and non-contact measurement systems which can mount on a variety of different platforms. With respect to a tamper, a push buggy projector system is typically used to measure track geometry, utilizing the tamper body as the basis for the reference system, Track geometry can be measured utilizing this technology during a prerecording run. Then, the software onboard the tamper analyzes the recorded data to determine the best fit and calculate throws that achieve a better track alignment, particularly in curves. During the tamping operation, the tamper buggy system and frame adjust the track. Due to its design, track geometry measurements can only be made at low speed (roughly 4mph) which can severely affect the efficiency of the tamper. To help decrease pre maintenance inspection times, an inertial based track geometry measurement system has been developed and integrated into the tamper’s operating software. This system can mount directly to the frame of a tamper and operate at hy-rail to very low speeds. Measurements made can be fed directly into the tamper control system to guide where and how track geometry adjustments need to be made. In addition, the capability to collect data during travel mode without the buggies extended allows for the collection of data at any time. Thus, data can be recorded when traveling back and forth to a stabling location, before and/or after grinding. This allows for synchronization of data at a later time to utilize for adjusting the track. Also, data can be collected post-work to allow for the comparison of pre and post geometry to allow for the determination of the effectiveness of a given tamping operation. Tampers equipped with this track geometry system facilitate the foundation for an enterprise solution. Data that is measured and collected can be sent to a cloud service, in real time that will provide exception reports, health status, and rail health trend analyses. Utilizing the available technology further optimizes response time in track maintenance. This paper will introduce this new method of mounting and completely integrating an inertial based track geometry system onto a tamper. In addition, studies will be presented which confirm the ability of this system to replicate the tamper’s projection based track geometry system. Finally, a comprehensive study on efficiency gains will be presented directly comparing a standard method of maintaining a segment via a tamper to this new method of using onboard inertial track geometry measurement.


2006 ◽  
Vol 3 (3) ◽  
pp. 987-1019 ◽  
Author(s):  
C. Fallico ◽  
E. Migliari ◽  
S. Troisi

Abstract. After pointing out the importance of the saturated hydraulic conductivity (ks) measurements and the difficulties and uncertainties that are present, and after recalling salient aspects of three well-known measurement methods of this parameter (i.e. constant-head tension infiltrometer (TI) method, constant-head pressure infiltrometer (PI) method and soil core (SC) estimates method), the results of an investigation on data which were obtained during a measurement campaign on an area of 800 m2, on a sandy loam hillslope, located in Southern Italy, were carried out again here. Three sets of values of ks, obtained with these measurement methods, were analyzed statistically, verifying that the log-normal distribution describes these better than the normal one; moreover, the more significant statistical parameters of each set were compared (average value , amplitude A, coefficient of variation CV and standard deviation SD), individualizing the more significant differences. The greatest value of hydraulic conductivity was found with method (PI), while the smallest with (SC) and the intermediate with (TI); these differences were translated into macroporosity and into the influence of the single measurement method. Moreover, referring to the possible factors affecting the results, the importance can be noted of the structure, the texture and the soil events, in terms of utilization, which can affect the measure of ks leading often to very different values even for similar soils, but with a different history, independently of the coincidence of the measurement points and they can be determining to explain the differences affecting the results obtained in analogous investigations by other researchers. Having confirmed that generalization is not possible, the need was emphasized to adopt the necessary devices relating to the specific measurement method, case by case, and to carefully explain the obtained results, in the light of the peculiarities and the limits of each situation. Finally, the results of similar statistical analysis carried out on a greater number of ks values, measured through the (TI) and (PI) methods are shown in this paper, with some statistical considerations on the increasing of the measurements number.


2002 ◽  
Vol 35 (8) ◽  
pp. 778-785 ◽  
Author(s):  
Kazuhiro Mae ◽  
Taisuke Maki ◽  
Kouichi Miura

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