An effective method for calculating crossed span distance of overhead line based on three-dimensional inclination algorithm

Rotor-stator axial gap is a key design parameter that directly affects the efficiency and safety of large rotating machines. With optimum axial clearance value determined, the rotating machine can work with the highest efficiency. To realize active clearance control (ACC) of rotating machinery, high-precision non-contact online measurement of the axial gap must be carried out. However, traditional measurement methods are challenged by the extreme working environment, such as extreme temperature, high rotating speed, and narrow space conditions; no mature measurement method was reported to realize the high accuracy, non-contact, and online performance required by the axial gap measurement. In this paper, a rotor-stator axial gap measurement method is proposed based on frequency scanning interferometry, and the mathematical model of axial clearance measurement is established. The weak reflection signal of lens and time delay estimation algorithm is employed to undermine the impact of probe pigtail length drift caused by the temperature change under extreme conditions. The axial gap measurement prototype based on sweep frequency ranging was developed, and the measurement and system calibration was carried out. The experimental results verify the effectiveness and accuracy of the method. The drift of the system was less than 20μm in 30 minutes with millimeter level pigtail drift, and the measurement accuracy was better than 50μm.

The double-ended excitation self-balancing bridge excitation method is a capacitance measurement method with rather a high measurement accuracy currently. However, the reference impedance of the electric bridge limits the traditional self-balancing excitation measurement method, making it difficult to achieve high accuracy and a wide range of capacitance sensor measurements. In the proposed paper, frequency adjustment method is introduced to enable impedance matching between the measured capacitance and the reference resistance. The measurement range is broadened as well as maintaining the accuracy of the capacitance measurement. The measurement circuit is composed of a reference resistor, a bridge in series with the measured capacitance and an operational amplifier follower circuit. First, we roughly measure the input impedance of the operational amplifier and the capacitive reactance of the capacitance under test using a two-step excitation method. Then, the best excitation frequency is calculated to match the reference resistor according to the capacitive reactance under test, and the input impedance of the operational amplifier is re-estimated with the best frequency. Finally, we complete the accurate measurement of the capacitive reactance under test through the use of dual excitation. The experimental results demonstrate the method’s high accuracy measurement within the range of 1.6 pF–16 nF, with the reference resistance set at 1 MΩ and the excitation frequency adjusted between 10 and 100 kHz. Additionally, dual excitation stability testing verifies relative standard deviations in the range of 0.01%–0.12%. Experiments on filter capsule sensing detection show that the proposed frequency adjustment measurement method can perform highly sensitive capacitive sensing measurements under the influence of parasitic effects.

Improving the accuracy of insulation resistance measurements of a single arm unbalanced bridge using a parameter matching design and filtering algorithm for battery packs used in electric ships

The research purpose is to solve the problems of low efficiency, low accuracy, and high cost of traditional environmental landscape mapping and landscape volume measurement methods in the artistic design of college campus landscape and make up the defects that the traditional campus monitoring is vulnerable to adverse weather, which results in low monitoring accuracy. Primarily, a binocular stereo vision measurement based on Scale Invariant Feature Transform (SIFT) matching algorithm is proposed, which can realize accurate collection of environmental spatial information and measurement of landscape volume without contact in the process of campus landscape design. Then, the visual monitoring system of college landscape based on the Internet of Things (IoT) is constructed to realize real‐time monitoring and early warning of human damage to campus landscape. The proposed method is verified by actual measurement of different objects and simulation experiments using simulation software. Ultimately, the application of visual sensors in artistic design of college campus landscape is analysed by literature analysis. The results show that (1) the error of the improved binocular stereo vision measurement designed here is 52.32% and 59.69% lower than that of the traditional measurement method when measuring the same object with different volumes and the volumes of different objects, respectively, which indicates that the measurement accuracy of the new method is higher. (2) The proposed landscape visual monitoring method based on IoT improves the image recognition accuracy by 21% compared with the traditional digital image monitoring method. The average recognition time is shortened by 12 ms, which ensures the accuracy and improves the recognition efficiency. (3) Through the analysis of existing literature, it is found that the binocular stereo vision sensor can be used to monitor the whole process of landscape construction in real time. The sensor can be combined with social networks, mobile terminals, and physiological monitoring equipment to comprehensively analyse and evaluate people’s preference for campus landscape. The proposed method has broad application prospects in campus landscape design, construction, and maintenance. The research purpose is to provide important technical support for the improvement of the overall image of the college campus and even the city for the design of landscape environment and the technical upgrading of maintenance work in the college campus.

As one of the important quality indicators of organic heat carrier, the determination method of Viscosity Parameter has been greatly developed in recent years. In this paper, the traditional and new measurement methods have been summarized and introduced. Then it analyzed the current status and the existing problems of the measurement methods of Viscosity Parameter in our country, and it also prospected the development of the measurement methods of Viscosity Parameter of organic heat carrier. The new measurement method in recent years can be expected to viscosity measurement methods in the field of organic heat carrier along the following direction of development: (1)The traditional measurement methods will be further development and application; (2)The optical measurement techniques will be the most promising method for real-time measurement of viscosity in the organic heat carrier; (3) By using the method of modern data acquisition and processing to improve the traditional organic heat carrier viscosity measurement technology.

Assessing a Novel Method of Calculation of the Cobb Angle for Scoliosis: Interexaminer Reliability and Student Satisfaction

The authors have developed a slit-lamp mounted digital photography system. This ensures that the patient's head is consistently positioned in the same plane in relation to the camera and generates standardized images of the eyelids, which are then analyzed using commercially available computer measurement software. The aim of this study was to assess the repeatability and reproducibility of this system compared with traditional methods of eyelid measurement. Both eyes of 10 patients were photographed and then measured by three clinicians using a handheld ruler for five eyelid parameters (i.e., palpebral aperture, superior marginal reflex distance, inferior scleral show, levator function, and upper eyelid skin crease height). The photographs were then assessed using computer software by the same clinicians (twice by a consultant and once by a clinical fellow and a specialist registrar). At all times, each observer was masked to their colleagues' results. Data were analyzed using Bland-Altman plots. There was a good level of agreement between measurements obtained by computer analysis of digital photographs and measurements obtained by traditional methods. A higher level of reproducibility (interobserver variability) was demonstrated in all digital measurements compared with those obtained by handheld ruler. Repeatability (intraobserver variability) with the digital photograph technique was also high and consistent for each of the five eyelid parameters. These results suggest that a digital photography system with computer analysis is comparable to, and offers advantages over, traditional methods of measurement. This system offers a simple, standardized, and rapid method of patient assessment with important applications in electronic patient records, audit, and research.

Background: The authors have developed a slit-lamp mounted digital photography system. This ensures that the patient's head is consistently positioned in the same plane in relation to the camera and generates standardized images of the eyelids, which are then analyzed using commercially available computer measurement software. The aim of this study was to assess the repeatability and reproducibility of this system compared with traditional methods of eyelid measurement. Methods: Both eyes of 10 patients were photographed and then measured by three clinicians using a handheld ruler for five eyelid parameters (i.e., palpebral aperture, superior marginal reflex distance, inferior scleral show, levator function, and upper eyelid skin crease height). The photographs were then assessed using computer software by the same clinicians (twice by a consultant and once by a clinical fellow and a specialist registrar). At all times, each observer was masked to their colleagues' results. Data were analyzed using Bland-Altman plots. Results: There was a good level of agreement between measurements obtained by computer analysis of digital photographs and measurements obtained by traditional methods. A higher level of reproducibility (interobserver variability) was demonstrated in all digital measurements compared with those obtained by handheld ruler. Repeatability (intraobserver variability) with the digital photograph technique was also high and consistent for each of the five eyelid parameters. Conclusions: These results suggest that a digital photography system with computer analysis is comparable to, and offers advantages over, traditional methods of measurement. This system offers a simple, standardized, and rapid method of patient assessment with important applications in electronic patient records, audit, and research.

Abstract. The state attaches great importance to the issue of the right to the use of rural land. At present, China is carrying out a large-scale mapping and confirmation of rural house sites and rural houses. The traditional measurement method mainly adopts total station or RTK manual measurement method, which is characterized by high work intensity, complex operation procedure and labor-consuming. There are hundreds of thousands of villages in China. With the development of science and technology, it is an inevitable trend to use new technologies in rural cadastral surveys to improve their efficiency and quality. LiDAR scanning technology has the advantages of high efficiency, flexibility, reliability, and high accuracy, which meet the requirements of tasks and schedules that are difficult to complete with traditional measurement methods. This paper is based on the AS-300H multi-platform LiDAR system of Huace Navigation, which integrates UAV and vehicle LiDAR for cadastral surveying and mapping. It proves that LiDAR using in rural cadastral mapping has low labor intensity, high efficiency and accuracy. At the same time, the advantages and disadvantages of LiDAR technology for cadastral mapping are also summarized and elaborated, which has a good reference and significance for those who are currently conducting rural housing and cadastral mapping work.

Objective To design and evaluate a new method for measuring the center of rotation of the hip joint, and to compare it with the traditional methods. Methods Data of healthy hips of 120 total hip arthroplasty (THA) patients (120 hips) and bilateral hips of 20 healthy volumteers (40 hips) were collected. A series of X-rays and magnetic resonance imaging (MRI) were taken from each patient with the hip joint abductted at differenct angles (0°, 7.5°, 15°, and 22.5°). The motion track of rotation center was obtained by comparing these X-ray and MRI images. The preoperative and postoperative data of 67 surgical patients who underwent two different measurement methods before surgery were compared. Results Compared with traditional measurement methods, the accuracy of our new method was significantly improved; the results of hip MRI verified the objectivity and accuracy of our new method; preoperative measurements and postoperative follow-up results showed that our new method had a better clinical effect than traditional measurements. Conclusions The team′s innovative new measurement method based on pelvic orthotopic X-ray photographs with different abduction angles of the hip shows more accurate data than traditional measurement methods and shows better clinical results. Key words: Tomography, X-ray; Magnetic resonance imaging; Arthroplasty, replacement, hip; Photogrammetry

Quantitative phase microscopy (QPM) has recently become indispensable technology for label-free quantitative analysis of various biological cells and tissues, such as, sperm cells, liver sinusoidal cells, cancerous cells, red blood cells etc. The key parameters controlling measurement accuracy and capability of QPM system depends on its spatial and temporal phase sensitivity. The spatial phase sensitivity of QPM is governed by coherence properties of light source and temporal stability depends on optical interferometric configuration. Most of the QPM techniques utilize highly coherent light sources like lasers benefited by their high spatial and temporal coherence, and brightness. But high spatio-temporal coherence leads to occurrence of speckle noise and spurious fringes leading to inhomogeneous illumination and poor spatial phase sensitivity. We have developed QPM systems using partially spatially coherent monochromatic (PSCM) light sources which guarantees high contrast interferograms over large field-of-view to increase space-bandwidth product of QPM system by ten-times and demonstrated ten-fold improvement in spatial-phase sensitivity and phase measurement accuracy compared to coherent laser light. By means of using PSCM with common path configuration we could also achieve ten-fold temporal phase stability. We have demonstrated advantages of PSCM based QPM in various industrial and bio-imaging applications. Experimental results of reduced speckle noise, free-from spurious fringes, spatial phase sensitivity using industrial objects are demonstrated and compared with highly coherent light using single mode fiber. Finally, phase map of biological samples is also presented with high accuracy in phase measurement. Thus, the use of PSCM light in phase microscopy, holography of realistic objects, i.e., industrial and biological samples leads to high accuracy in the measurement of quantitative information.

As an important physical quantity to describe the resistance of fluid to flow, viscosity is an essential property of fluids in fluid mechanics, chemistry, medicine, as well as hydraulic engineering. While traditional measurement methods, including the rotating-cylinder method, capillary tube method and falling sphere method, have significant drawbacks especially in terms of accuracy, response time and the sample must be made to move. In this work, a novel Beer-Lambert law-based method was proposed for the viscosity measurement. Specifically, this work demonstrates that viscosity can be quantitatively reflected by spectral line intensity, and castor oil was selected due to its viscous temperature properties (viscosity has been accurately measured under different temperature), and its transmission spectrum at different temperatures ranging from 10 to 50°C was detected firstly. Then, the principal component analysis (PCA) was employed to obtain the intrinsic features of the transmission spectrum. Finally, the processed data was utilized to train and verify the radial basis function (RBF) neural network. As a result, the accuracy of the predictions conducted by means of the RBF reached 98.45%, which indicates the complicated and non-linear relationships between spectra formation and viscosity can be depicted well by RBF. The results show that the real-time in-situ optical detection method adopted in this work represents a great leap forward in the viscosity measurement, which fundamentally reforms the traditional viscosity measurement methods.

Energy consumption is a critical evaluation index of embedded systems. It has a direct connection with battery life and maintainability. Traditional energy consumption measurement methods are not fully automated, requiring manual intervention and repetitive operations. A new design of an automatic energy consumption measuring platform is proposed to liberate researchers from this work. In this design, ready-made measuring instruments are used, together with specially developed software and auxiliary hardware, to automate the process of energy consumption measurement. A series of test sets are also designed to verify its capabilities of automated measurement. Comparing with traditional measurement methods, our design of the platform has similar accuracy and is capable of providing real-time energy consumption data as well as unattended automated measurements.

The purpose of this study is to use wireless sensor technologies to develop a system for frailty measurement and detection with multimedia interactive games that allows users to collect and manage their personal frailty information automatically at home. The assessment software we designed is a game-like system, which increases the motivation for participation among the elderly. The system has five components: (1) a series of frailty measurement and detection games, (2) an electronic grip strength meter to measure the subject's grip strength and reaction time, (3) an electronic pressure pad (with a pressure sensor) to detect slowness in movement, weakness, weight loss and balance impairment, (4) a functional reach measuring instrument to measure body extension, and (5) a Home-based Information Gateway, which collects all of this data and predicts frailty trends. We designed an experiment to test the overall system performance, and, to test the validity and reliability, we compared these tools with traditional frailty measurement methods. The results show that there is a correlation between frailty results from our test and results from the traditional measurement methods. They also show that our system is a high specificity prediction tool that can be used to assess frailty.

Background: Vehicle centroid height is an important parameter in vehicle control systems. It plays an important role in vehicle roll stability and handling stability. At present, there are mainly static and dynamic measurement methods such as swing method, mass reaction method, marking method and so on. These static measurement methods often require a fixed suspension to make the measurement process time-consuming and laborious, and measurement errors will occur when the suspension is not fixed firmly, and it is impossible to measure the mass center position of spring-loaded mass and non-spring-loaded mass. Objective: Therefore, it is of great practical significance to study a high accuracy, low cost and fast measurement method of vehicle centroid height. We revised and summarized all patents relating to methods for estimating vehicle centroid height. And a new method of centroid measurement is designed in this paper. Methods: According to the change of tire flattening radius and suspension, the change of spring and non-spring mass center height when vehicle axle load changes, the method of delineation is used to calculate the change of tire flattening radius and suspension; According to the relationship between vehicle tilt angle and front and rear axle load, the principle of moment balance and the principle of mass balance, it determines the geometric relationship between the variables, and to take the moment of the contact point between the front wheel and the ground, the moment balance equation is established, and the height of the vehicle mass center, spring load and non-spring load mass center in the horizontal position of the vehicle are obtained. Results: This measurement method is different from the existing static measurement of vehicle centroid height, it does not need the fixed suspension, only need to measure several dimensions, we can avoid heavy labor and safety accidents brought by the fixed suspension, it can also reduce the measurement error caused by fixation, but also can draw the centroid location of the sprung mass and unsprung mass. The measurement method is simple, economical and accurate, and is widely applicable on two-axle vehicles. Conclusion: The purpose of this paper is to provide a static and accurate measurement method of vehicle centroid height, so as to solve the problem that the current static measurement method of vehicle centroid height needs fixed suspension, and measurement errors will occur when the suspension is not fixed properly, so it is impossible to measure the centroid position of spring-loaded mass and non-spring-loaded mass.