Proposed Measurement System Research Articles

3D deformation measurement of rotating blades based on concentric ring calibration and GPU-SIFT feature point searching

Image grayscale matching and camera calibration are two key technologies for measuring the three-dimensional deformation of rotating blades. To address the issues of low accuracy in extracting corresponding points caused by unclear grayscale boundaries of traditional chessboard calibration patterns and the high computational complexity of image matching algorithms in high-speed and high-resolution scenarios, this paper proposes a method for measuring the three-dimensional deformation of rotating blades based on concentric circle calibration and GPU-SIFT feature point search. Firstly, a concentric circle calibration method based on arc segment combination for extracting circle center is proposed. By fitting the circular calibration pattern with extracted marker points, errors introduced by unclear grayscale boundaries of chessboard patterns are avoided, thereby improving the accuracy of calibration parameters. Secondly, an image matching algorithm based on GPU-SIFT feature point search is presented. By optimizing the storage location of scale space process data, the performance of the SIFT algorithm is maximized, leading to improved image matching speed. Lastly, the calculation of displacement and strain fields is achieved using the P3P theory and local least squares fitting method, respectively. The experimental results show that the proposed system and method for 3D deformation measurement achieve a strain measurement accuracy of 80 με. Moreover, they successfully measure the surface deformation of turbofan blades under the conditions of 3000 rpm and 6000 rpm. Through this method, it can improve the deformation measurement capability of large engine manufacturers for high-speed rotating blades and provide reliable technical support.

A measurement system for enteric CH4 emissions monitoring from ruminants in livestock farming

In this paper, a proposal for an Internet-of-Things (IoT) based measurement system dealing with the enteric methane (CH4) emission monitoring from ruminants is presented. Herein, a brief overview of the recent advances in sensors technologies and their IoT integration for realizing measurement systems able to monitor the CH4 emissions in ruminants is also presented. Nowadays, it is confirmed that CH4 emissions, which are mainly produced during normal fermentation of feeds by the rumen microorganisms, are part of the Green-House Gas (GHG) emissions. Therefore, a classification of the existing measurement methods, sensing technologies and their impact on the animal’s welfare is presented. The proposed measurement system, together with its sensing elements and the developed data acquisition system are also reported in this paper. A preliminary disposal and field trials of the developed system in a farm facility is given.

Scaled dynamic loading tests on seismic isolation bearing excluding the contamination of friction and inertia forces

Conventional seismic isolation-bearing testing facilities require moving horizontal platens under high compression. However, these dynamic moving platens inevitably lead to the friction and inertial forces generated by large vertical loads and inertial forces due to the dynamic mass action of the moving platen, which eventually affects the accuracy of the measured force. To solve this problem, the authors have proposed a direct reaction force measurement system (horizontal-vertical separated type) that can exclude the contamination of friction and inertial forces. Measuring pure reaction forces without the contamination of friction forces and inertia is crucial for the reliability of test results. In this paper, prior to the construction of large-scale facility, reduced-size–mockup dynamic tests were conducted using the proposed measurement concept, and its validity and accuracy were discussed. Furthermore, this system was applied to hybrid simulation tests, and the significant improvement of the proposed measurement system was observed.

A double-sided surface scanning platform for sapphire substrate quality assessment

With excellent mechanical and optical properties, sapphire substrate becomes a very important industrial material especially for LED manufacturing. Its quality control requires two tasks, double-sided surface profiling and defect detection. In this paper, a 3D surface scanning system is proposed as a platform for sapphire substrate inspection. During the scanning process, the height information of both upper and lower surfaces is measured by a chromatic confocal probe. For lateral positioning feedback, an in-house developed sensor, namely, image grating, is introduced in this paper. For these inspection processes, there are three challenges: 1) the motion error in the vertical direction, 2) simultaneous measurement of both upper and lower surfaces, and 3) lateral positioning error in a large scanning area. To address these challenges, three key technologies were developed: 1) real-time motion error compensation based on a fringe interferometer, 2) a double-sided measurement for transparent specimen without the pre-knowledge of its refractive index, and 3) planar image grating pair for accurate 2D displacement feedback. The experimental results showed that the proposed measurement system was able to achieve 50 nm accuracy of the standard deviation when measuring the step height of gauge blocks. When the system measured 4-inch double-sided polished sapphire substrate, the measurement repeatability of TTV (Total Thickness Variation) was within 60 nm; and that of warpage was within 10 nm. As a side product, refractive index can also be measured using the proposed system, and experimental results showed respectable consistency.

Cooperative 3D tunnel measurement based on 2D–3D registration of omnidirectional laser light

AbstractIn this study, we proposed a high‐density three‐dimensional (3D) tunnel measurement method, which estimates the pose changes of cameras based on a point set registration algorithm regarding 2D and 3D point clouds. To detect small deformations and defects, high‐density 3D measurements are necessary for tunnel construction sites. The line‐structured light method uses an omnidirectional laser to measure a high‐density cross‐section point cloud from camera images. To estimate the pose changes of cameras in tunnels, which have few textures and distinctive shapes, cooperative robots are useful because they estimate the pose by aggregating relative poses from the other robots. However, previous studies mounted several sensors for both the 3D measurement and pose estimation, increasing the size of the measurement system. Furthermore, the lack of 3D features makes it difficult to match point clouds obtained from different robots. The proposed measurement system consists of a cross‐section measurement unit and a pose estimation unit; one camera was mounted for each unit. To estimate the relative poses of the two cameras, we designed a 2D–3D registration algorithm for the omnidirectional laser light, and implemented hand‐truck and unmanned aerial vehicle systems. In the measurement of a tunnel with a width of 8.8 m and a height of 6.4 m, the error of the point cloud measured by the proposed method was 162.8 and 575.3 mm along 27 m, respectively. In a hallway measurement, the proposed method generated less errors in straight line shapes with few distinctive shapes compared with that of the 3D point set registration algorithm with Light Detection and Ranging.

Expanding a laboratory model for evaluating relapse of caregiver nonadherence.

Caregiver adherence to treatment plans is likely maintained by negative reinforcement and can contact extinction when child responding relapses. When caregiver adherence contacts extinction, caregiver nonadherence, such as reinforcing their child's challenging behavior, relapses, threatening treatment efficacy. Previous laboratory models demonstrating the relapse of caregiver nonadherence only evaluated treatment for behavior maintained by social-positive reinforcement, not that maintained by social-negative reinforcement. These models only measured caregiver nonadherence as discrete events, which cannot capture the magnitude of each error. The present study was an evaluation of the relapse of caregiver nonadherence during simulated treatments for escape-maintained challenging behavior. First, caregivers placed demands in a home-like setting and a research confederate responded to these demands in a manner mimicking clinical clients. Next, caregivers were taught to implement treatment in a clinical setting and the confederate's behavior gradually improved. Last, caregivers returned to the home-like setting and confederate challenging behavior relapsed. Nonadherence relapsed for all caregivers, demonstrating the need for additional research on methods for mitigating caregiver relapse during treatment of children's challenging behavior and the usefulness of the proposed measurement system for future research.

A differential miniaturized thickness measurement calibration system based on laser triangulation sensors

Steel plate thickness inspection is important in high-precision steel processing and manufacturing. Traditional inspection methods use manual contact measurement, which has low inspection efficiency and large human error, so we proposed a differential non-contact thickness measurement system based on laser triangulation sensors. Firstly, we designed a differential measurement structure by placing the laser triangulation sensors on the top and bottom of the steel plate to be measured, so that the data from the top and bottom sensors can be sampled and the steel plate thickness can be calculated simultaneously. Secondly, based on the principle of error averaging effect, we proposed a multi-point measurement averaging method to take multiple points on the surface of the steel plate and calculate the average value as the thickness of the steel plate. Further, to improve the measurement system’s long-term stability, the temperature drift is corrected by the polynomial fitting method. Finally, the experiment proves that the repeatability accuracy of our proposed measurement system can reach ±0.5um and the measurement drift is better than ±0.1% of the steel plate thickness.

Online measurement system of slab front-end bending in hot rough rolling based on line structured light vision

Front-end bending is one of the most significant defects of slabs in hot rough rolling. To address the lack of effective methods to detect slab front-end bending in hot rolling, a measurement system based on line structured light vision is proposed in this paper. Line structured light lasers and area-scan cameras are arranged on the supports on both the exit and entrance of a roughing mill. First, the calibration of the measurement system is completed by camera calibration and the random sampling consistency algorithm. Second, multiple regions of interest gray thresholds and the Steger algorithm are used to realize laser centerline extraction on the surface of a large-scale and high-temperature slab. Last, the actual value of the slab front-end bending is obtained and calculated through coordinate transformation. The proposed measurement system can detect slab front-end bending in real time and the relative mean deviation is 0.93%.

Non-interference NDIR detection method for mixed gases based on differential elimination

A multi-gas NDIR (non-dispersive infrared spectroscopy) detection system consisting of two broadband light sources and multiple detectors is established, and an interference-free method for measuring mixed gases based on differential elimination NDIR is proposed. By developing a differential model, the sensor response SR is only dependent on the optical path L, the concentration C, and the absorption constant k of the gas to be measured, independent of other factors (the light source drift, ambient temperature, humidity, etc.). Likewise, multi-gas measurements can be achieved in this method by altering and increasing the type and number of detectors. As an example of two-gases measurement, a three-dimensional surface C−SR is constructed by calibration, with the known two gas concentrations (CO2: 0–5000 ppm, CH4: 0–3000 ppm) are used as independent variables, and the sensor responses SR1 and SR2 are used as dependent variables, respectively. The predicted correlation coefficient and root mean square error can reach 0.9985 and 0.0024. The proposed measurement system is smaller, less expensive, and more stable than conventional multi-channel detection system. A more robust method is provided for detecting various gases.

Small Size and Low‐Cost TENG‐Based Self‐Powered Vibration Measuring and Alerting System

AbstractVibration measurement systems containing sensors, signal conditioning, and data acquisition devices, are important for monitoring motors, gearboxes, turbines, etc. Microelectromechanical and piezoelectric sensors are predominantly used for vibration measurements. However, they are not cost‐effective, flexible in design, and incapable of self‐powering. Recently, triboelectric nano‐generator (TENG)‐based vibration sensors have been considered as a possible alternative to resolve this problem, and tremendous progress has been achieved. Previous work on TENG‐based sensors is limited to optimizing the sensor design, while the signal conditioning and data acquisition of TENG signal still need investigation for actual applications. This work develops a TENG‐based vibration measurement device and self‐powered alerting system that is integrated with the signal condition and data acquisition systems. The experimental results show that the proposed measurement system successfully measures signals within the range of 0–1800 Hz frequency. Meanwhile, the TENG generates a high output, up to 80 V and 0.55 µA from small size TENG area (3.6 cm2). The signal is adequate to harvest energy for self‐powering to drive alerting components (harvest 320 mJ in 36 h, which drives alarming for duration of 1.5 s). The proposed device is cost‐effective (30 $), small (105 cm3), and consumes less power (0.18 W) in comparison to commercial devices.

Phase-Derived Ranging Based Fiber Transfer Delay Measurement Using a Composite Signal for Distributed Radars with Fiber Networks

Fiber transfer delay (FTD) variations influence the coherence of distributed radars with fiber networks, resulting in a performance degradation in target detecting and imaging. To measure and compensate for the variation, a phase-derived ranging based FTD measurement using a composite signal is proposed. The composite signal comprises a sinusoidal component and a linear frequency modulation (LFM) component. As the composite signal passes through a fiber under test (FUT), the sinusoidal component generates a phase shift that corresponds to the FTD. The phase shift can be represented by two parameters: the number of complete periods of 2π that can be estimated by using the LFM component, and a phase shift less than 2π that be measured employing the sinusoidal component. When using the proposed measurement system to measure FTD variations in a distributed radar, only an additional sinusoidal component is needed, which minimizes interference with radar signals. Moreover, the proposed measurement system can share core function modules such as signal generation and process modules with distributed radars, which enhances the compatibility and reduces the overall complexity. Experiments are carried out to measure a variable optical delay line and a long optical fiber. The experiment results verify the feasibility of the measurement system and show that a measurement range of more than 15 km, an accuracy of ±0.1 ps and a measurement time of 105 ms can be achieved.

Autonulling-Based Multichannel Impedance Measurement System for Capacitive Sensors

Capacitive sensors are widely used in a variety of contact and noncontact sensing applications. Low-power consumption and the small size of the capacitive sensors with high sensitivity make them an excellent choice for sensor arrays for the Internet of Things. The conventional capacitance measurement solutions, such as capacitance-to-digital converters FDC1004 from Texas Instruments and AD7746 from Analog Devices, provide excellent resolution but are limited by the number of channels and small measurement range. In this letter, we present a multichannel high-accuracy and wide-range impedance measurement system for capacitive sensors. The proposed system is based on lock-in amplification and autonulling techniques for accurately measuring the sensor capacitance. The proposed system utilized a time-division multiplexing-based approach with a frequency divider network for easy reconfigurable multichannel measurement. A prototype of the proposed system for 16-channel impedance measurement was built and tested. The proposed system was tested for different measurement ranges from 40 to 3000 pF, recording a resolution as low as 0.2 pF for capacitance measurement on all channels.

Selected issues of optimising parameters on square riggers to maximise speed

AbstractDue to the exceptional complexity of the propulsion system (sails), square-riggers form a special group of sailing vessels. In modern pleasure and sport sailing, simple Bermuda (triangular) sailing rigging prevails, which is widely discussed in the literature, both in terms of theory and numerous experiments. The literature on the theory on square-riggers is, in turn, limited mainly to the description of good sailing practice developed over the centuries. Its important element was maximising vessel speed, but this discussion has not been documented by scientific research. This paper presents the significant parameters influencing the speed of a square-rigged sailing vessel and selects those which are the most important from the point of view of its maximisation. The paper also proposes methods and measurement systems which optimise selected parameters affecting the achievement of higher speeds. The paper describes the types of speeds of typical sailing vessels, provides a historical synthesis of sailing ships with respect to their speed, and presents a selection and description of the parameters affecting the speed of modern square-rigged vessels. The paper ends with a proposed method and measurement system for experimental research aiming at rigging optimisation in a square-rigged sailing vessel from the point of view of maximising its speed.

A measurement system toward to skill analysis of wall painting using a roller brush

In this study, we describe a measurement system aiming to skill analysis of wall painting work using a roller brush. Our proposed measurement system mainly comprises an RGB-D sensor and a roller brush with sensors attached. To achieve our requirements in understanding roller operation, we developed an algorithm that is suitable to estimate the roller part pose with high accuracy. We also show a method to generate a swept map that can be used for both visualization and evaluation. In the proof experiment, a dataset for actual painting work was collected using the proposed measurement system. Then, the dataset was analyzed, and the quality of the work was quantitatively evaluated by comparing skilled and unskilled persons.

Perspectives of Patients With Orthopedic Trauma on Fully Automated Digital Physical Activity Measurement at Home: Cross-sectional Survey Study.

The automated digital surveillance of physical activity at home after surgical procedures could facilitate the monitoring of postoperative follow-up, reduce costs, and enhance patients' satisfaction. Data on the willingness of patients with orthopedic trauma to undergo automated home surveillance postoperatively are lacking. The aims of this study were to assess whether patients with orthopedic trauma would be generally willing to use the proposed automated digital home surveillance system and determine what advantages and disadvantages the system could bring with it. Between June 2021 and October 2021, a survey among outpatients with orthopedic trauma who were treated at a European level 1 trauma center was conducted. The only inclusion criterion was an age of at least 16 years. The paper questionnaire first described the possibility of fully automated movement and motion detection (via cameras or sensors) at home without any action required from the patient. The questionnaire then asked for the participants' demographics and presented 6 specific questions on the study topic. In total, we included 201 patients whose mean age was 46.9 (SD 18.6) years. Most of the assessed patients (124/201, 61.7%) were male. Almost half of the patients (83/201, 41.3%) were aged between 30 and 55 years. The most stated occupation was a nine-to-five job (62/199, 30.8%). The majority of the participants (120/201, 59.7%) could imagine using the proposed measurement system, with no significant differences among the genders. An insignificant higher number of younger patients stated that they would use the automated surveillance system. No significant difference was seen among different occupations (P=.41). Significantly more young patients were using smartphones (P=.004) or electronic devices with a camera (P=.008). Less than half of the surveyed patients (95/201, 47.3%) stated that they were using tracking apps. The most stated advantages were fewer physician visits (110/201, 54.7%) and less effort (102/201, 50.7%), whereas the most prevalent disadvantage was the missing physician-patient contact (144/201, 71.6%). Significantly more patients with a part-time job or a nine-to-five job stated that data analysis contributes to medical progress (P=.047). Most of the assessed participants (120/201, 59.7%) stated that they would use the automated digital measurement system to observe their postoperative follow-up and recovery. The proposed system could be used to reduce costs and ease hospital capacity issues. In order to successfully implement such systems, patients' concerns must be addressed, and further studies on the feasibility of these systems are needed.

Dynamic attitude measurement taken by monocular line scan vision.

Attitude measurements are important parameters for condition monitoring of precision machines. We develop an angle measurement method based on monocular line scan vision to dynamically measure the attitude of shafts. The proposed measurement system, which consists of a single line scan camera, a parallel laser light source, and a triangular mirror, does not require fixation of a sensor on the shaft. The measurement system uses the line scan camera to capture the projection of the shaft. The light source is diffused by a cylindrical lens to yield parallel directional light. Then the parallel directional light is reflected by a fixed-angle mirror and projected onto the projection plane. The captured image can be considered a discrete time sequence. The attitude measurement principle based on linear monocular vision is derived. A double light-spot centroid algorithm is developed to obtain the centroid coordinates of the projection points. The proposed method is investigated by a simulation and experiment. The proposed method can also monitor the vibration of the shaft. The experimental results prove that the proposed method is effective and highly accurate.

Three-Phase Well-Flow-Measurement and Well-Testing Unit Provides Accuracy, Agility

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper URTeC 3719030, “Not Measured, Not Improved: Agile Three-Phase Well-Flow-Measurement and Well-Testing Unit,” by Bali Singh and Bruce Gerrard, SPE, Apache, and David Reasoner, SPE, NeoTek Energy, et al. The paper has not been peer reviewed. _ The complete paper highlights well-test challenges, provides an overview of common problems, and describes the broader impact of inaccurate or infrequent well tests, with a focus on production testing of wells in the Permian Basin. Many of these challenges, however, apply to onshore oil and gas fields around the world. To overcome the measurement challenges in a cost-effective manner, the industry has taken multiple approaches to create various inline test devices with limited success. The authors introduce a measurement system that is agile for transport and can be installed anywhere with a small footprint while delivering reasonably accurate results. Introduction Measurement-system design included the following requirements: - Able to measure oil, water, and gas flow rates with reasonable accuracy - Agility allowing the system to be moved rapidly and easily by using a trailer behind a work truck - Installable and operational within 6 hours - Maximum 8×8-ft footprint - Must run standalone or in series with any other measurement system for validation testing - No requirement for additional infrastructure—capable of operation under its own power and communication with cellular or satellite phones and modems Theory and Methods Industry Practices: Importance of Accurate Well Tests. The standard test requirement for regulatory reporting in most provinces and states in North America is two 24-hour well tests per month. The 2 or more days of testing in a test separator, and the remaining days tested in a group separator, are used to estimate total monthly production volume allocated to the well. A sales meter is used to measure group production from a satellite for allocating revenues to the working-interest (WI) holders of each well or lease. In almost all fields, the production measured at the sales node does not match the combined production from multiple group lines that are run into the sales line. This poses a challenge because the sum of group lines is different from the volume measured by the sales meter. The challenge is addressed by prorating the difference between the sales meter and group lines back to the individual wells, called the proration factor. In the event of disagreement among WI owners, a large proration factor may cause custody-transfer issues. The good news is that the industry has developed many products used in specific applications to increase testing frequency and accuracy. The proposed measurement system fits well into this application and into much broader measurement categories. The measurement system was tested at Apache with highly favorable results and is ready to be deployed to optimize production allocation, well-test accuracy, and metering accuracy.

Measurement of 64 organic thin-film transistors in an array test structure using a relay-switch board for efficient evaluation of long-term reliability

We propose an efficient array measurement test structure to measure many devices and to obtain statistical characteristics of organic thin-film-transistors (OTFT) for long-term reliability evaluation of new devices under development in laboratories and those that cannot achieve sufficient yield. We propose to adopt different devices from the device under test for the array control circuit. We implemented a separate control circuit as a dedicated relay-switch board without device consolidation. This relay-switch board can also apply voltage stress to any number of devices under test for negative bias temperature instability evaluation. The interface issue between the chip and board is resolved with a flexible flat cable and an anisotropic conductive film. The proposed measurement system successfully measured the OTFT arrays in (sweep time of source measure unit) × (number of OTFTs) period, and only requires 84 min for 64 nOTFTs (n-type OTFT) (552 points/device), which corresponds to 1.3 min/device in the experiment.

Sub-Nyquist Sampling and Measurement of MPSK Signal Based on Parameter Matching

Accurate measurement of the M-ary Phase Shift Keying (MPSK) signal determined by finite parameters per unit of time is significant in engineering fields such as digital microwave and satellite communication. In this paper, we propose a sub-Nyquist sampling system with two channels for measuring characteristic parameters of MPSK signals based on the Finite Rate of Innovation (FRI) sampling theory. The carrier frequency parameter measurement process is modeled as a convex optimization problem, solvable using the parameter matching method on the estimated grid. The minimum harmonic frequency of the carrier is determined to build the exact grid, and the carrier frequency is estimated through a greedy search based on the given cost function. Even when the truth value of the carrier frequency is unknown, the discontinuity location parameters can be measured with high precision using the spectral estimation method on the Fourier coefficients of the MPSK signal. We propose an upper bound on the estimation error of this separable measurement method for signals with one segment. The amplitude and phase parameters can be measured by solving a least square problem. Our proposed measurement system, with lower hardware complexity, can accurately measure the MPSK signal with <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">K</i> segments by sampling only 2 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">K</i> +5 points in a period, at a much lower sampling rate than the carrier frequency. Numerical simulations and hardware experiments demonstrate the superior performance of our state-of-the-art measurement method.

Locating the Oil Leakage on Power Equipment via Ultraviolet-Induced Hyperspectral Imaging Technology

Oil leakage will cause abnormal temperature rise and discharge of oil-filled power equipment, which seriously threatens insulation reliability. In this paper, based on the synchronous fluorescence spectra (SFS) and excitation emission matrix (EEM) of mineral and vegetable oils, the ultraviolet-induced hyperspectral imaging (UV-induced HSI) measurement system is developed. Then, the fluorescence-reflectance spectra of oil traces and non-oil areas are determined via the proposed measurement system. Next, the influence factors of fluorescence-reflectance intensity, including UV source light power, detection angle degree and detection distance are discussed. By analyzing the fluorescence-reflectance intensity differences in fluorescence bands, principal component analysis (PCA) is applied for date dimension reduction and anomaly detection to realize oil leakage trace visualization. Finally, the validation test results prove that this method exhibits a general applicability for tracing mineral and vegetable oil leakage traces on different surface materials in indoor and outdoor conditions. This approach will improve the detection rate of oil leakage defects, and promote the intelligent level of operation and maintenance of power equipment.