Real-time calibration algorithm of magnetometer for spinning projectiles

Sensor Review ◽  
2019 ◽  
Vol 40 (2) ◽  
pp. 227-236
Author(s):  
Xiaoming Zhang ◽  
Chen Lei ◽  
Jun Liu ◽  
Jie Li ◽  
Jie Tan ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Measurement Error ◽  
Real Time ◽  
Linear Model ◽  
Magnetic Measurement ◽  
Calibration Method ◽  
The Body ◽  
Estimation Accuracy ◽  
Content Type ◽  
The Past

Purpose In spite of the vehicle, magnetic field interference can be reduced by some measures and techniques in ammunition design and manufacturing stage, the corruption of the vehicle magnetic field can still reach hundreds to thousands of nanoteslas. Besides, the magnetic field that the ferromagnetic materials generate in response to the strong magnetic field in the vicinity of the body. So, a real-time and accurate vehicle magnetic field calibration method is needed to improve the real-time measurement accuracy of the geomagnetic field for spinning projectiles. Design/methodology/approach Unlike the past two-step calibration method, the algorithm uses a linear model to calibrate the magnetic measurement error in real-time. In the method, the elliptical model of magnetometer measurement is established to convert the coefficients of hard and soft iron errors into the parameters of the elliptic equation. Then, the parameters are estimated by recursive least square estimator in real-time. Finally, the initial conditions for the estimator are established using prior knowledge method or static calibration method. Findings Studies show the proposed algorithm has remarkable estimation accuracy and robustness and it realizes calibration the magnetic measurement error in real-time. A turntable experiments indicate that the post-calibration residuals approximate the measurement noise of the magnetometer and the roll accuracy is better than 1°. The algorithm is restricted to biaxial magnetometers’ calibration in real-time as expressed in this paper. It, however, should be possible to broaden this method’s applicability to triaxial magnetometers' calibration in real-time. Originality/value Unlike the past two-step calibration method, the algorithm uses a linear model to calibrate the magnetic measurement error in real-time and the calculation is small. Besides, it does not take up storage space. The proposed algorithm has remarkable estimation accuracy and robustness and it realizes calibration the magnetic measurement error in real time. The algorithm is restricted to biaxial magnetometers’ calibration in real-time as expressed in this paper. It, however, should be possible to broaden this method’s applicability to triaxial magnetometers’ calibration in real-time.

Two-step calibration method for three-axis magnetic sensor error based on particle swarm optimization

Sensor Review ◽  
2020 ◽  
Vol 40 (5) ◽  
pp. 577-583
Author(s):  
Yanxia Liu ◽  
Zhikai Hu ◽  
JianJun Fang
Keyword(s):  
Magnetic Field ◽  
Fitness Function ◽  
Particle Swarm ◽  
Calibration Method ◽  
Magnetic Sensors ◽  
Earth’S Magnetic Field ◽  
Swarm Optimization ◽  
Error Matrix ◽  
Content Type ◽  
Earth's Magnetic Field

Purpose The three-axis magnetic sensors are mostly calibrated by scalar method such as ellipsoid fitting and so on, but these methods cannot completely determine the 12 parameters of the error model. A two-stage calibration method based on particle swarm optimization (TSC-PSO) is proposed, which makes full use of the amplitude invariance and direction invariance of Earth’s magnetic field vector. Design/methodology/approach The TSC-PSO designs two-stage fitness function. Stage 1: design a fitness function of the particle swarm by the amplitude invariance of the Earth’s magnetic field to obtain a preliminary error matrix G and the bias error B. Stage 2: further design the fitness function of the particle swarm by the invariance of the Earth’s magnetic field to obtain a rotation matrix R, thereby determining the error matrix uniquely. Findings The proposed TSC-PSO can completely determine 12 unknown parameters in error model and further decrease the maximum fluctuation error of the Earth’s magnetic field amplitude and the absolute error of heading. Practical implications The proposed TSC-PSO provides an effective solution for three-axis magnetic sensor error compensation, which can greatly reduce the price of magnetic sensors and be used in the fields of Earth’s magnetic survey, drilling and Earth’s magnetic integrated navigation. Originality/value The proposed TSC-PSO has significantly improved the magnetic field amplitude and heading accuracy and does not require additional heading reference. In addition, the method is insensitive to noise and initialization conditions, has good robustness and can converge to a global optimum.

scholarly journals A decade of supply chain collaboration and directions for future research

2015 ◽  
Vol 20 (6) ◽  
pp. 613-630 ◽  
Author(s):  
Claudine Antoinette Soosay ◽  
Paul Hyland
Keyword(s):  
Supply Chain ◽  
Supply Chains ◽  
Holistic Approach ◽  
The Body ◽  
Future Research ◽  
Supply Chain Collaboration ◽  
Content Type ◽  
Humanitarian Supply Chains ◽  
The Past ◽  
Body Of Knowledge

Purpose – This paper aims to conduct a systematic review of the literature on supply chain collaboration published over a 10-year period from 2005 to 2014. It explores the nature and extent of research undertaken to identify key themes emerging in the field and gaps that need to be addressed. Design/methodology/approach – The authors review a sample of 207 articles from 69 journals, after using an iterative cycle of defining appropriate search keywords, searching the literature and conducting the analysis. Findings – Key themes include the meaning of collaboration; considerations for supply chain collaboration theory; emerging areas in collaboration for sustainability, technology-enabled supply chains and humanitarian supply chains; and the need for a more holistic approach, multi-tier perspectives and research into B2C collaborations. Research limitations/implications – The paper provides discussion and scope for future research into the area which would contribute to the field tremendously. Originality/value – There have been very few reviews in the past on supply chain collaboration, and this is one of the first extensive reviews conducted to address how well the body of knowledge on supply chain collaboration corresponds with our contemporary society.

Testing the impact of physiological stress response on police performance during critical job tasks

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Lois James ◽  
Michael S. Goldstein ◽  
Peter Lecy ◽  
Stephen Mase
Keyword(s):  
Heart Rate ◽  
Nervous System ◽  
Real Time ◽  
Police Officers ◽  
Physiological Stress ◽  
The Body ◽  
Stress Profile ◽  
Content Type ◽  
Body Of Knowledge ◽  
The Impact

PurposeTo add to the existing body of knowledge on the relationship between stress and job performance in policing, we monitored police officers' physiology using Hexoskin shirts while they responded to simulated scenarios.Design/methodology/approachWe employed mixed repeated measures (baseline, intervention, post-intervention), between groups (treatment vs control group) design. Using this approach, our aims were (1) to determine whether an individualized physiological stress profile—a combination of heart rate (HR), heart rate variability (HRV), sympathetic nervous system (SNS) index and parasympathetic nervous system (PNS) index—could be developed for each participant; (2) to investigate the association between physiological stress and scenario performance and (3) to pilot test an intervention for decreasing physiological stress in real time.FindingsWe found that it was possible to individualize physiological stress profiles for each participant that alerted us when the participant was becoming stressed. We also found that physiological stress was significantly and negatively/inversely associated with scenario performance. However, our intervention to try and decrease participants' stress in real time was not successful. Several key lessons can be taken from our attempt that could inform future efforts in this area.Research limitations/implicationsThis was a small pilot study, precluding generalizability of results. Furthermore, our intervention was simplistic and potentially affected by an experimenter effect. Future research should explore better ways to intervene when officers are becoming physiologically stressed to help them overcome stress in real time and safeguard against the cumulative effects of stress on health and performance.Originality/valueThis research adds to the body of knowledge on physiological stress and job-task performance in police officers.

Conceptualizing the body and the logics of performing

2015 ◽  
Vol 21 (3) ◽  
pp. 345-371
Author(s):  
Deryk Stec
Keyword(s):  
Design Methodology ◽  
Physical Space ◽  
Art Music ◽  
The Body ◽  
Content Type ◽  
Excessive Heat ◽  
The Past ◽  
The Social ◽  
Performance Teams

Purpose This paper aims to examine how residues of ancient images have influenced one’s perspectives on management. Increased attention has been given to the absence of bodies within discussions of organisations; however, far less attention has been given to the interplay between organisations and images of one’s body. Design/methodology/approach By comparing the perceived benefits of studying sport (e.g. passion, embodiment and action) with the tensions that existed between athletic performances and an ancient image of the body, this paper draws attention to residuals that exist within discussions of organisations. Findings In a context where an image of the body encouraged moderation, the appropriate levels of heat, and the development of an immaterial and eternal soul, athletic performances, which were physical, extreme, focused on the body and generated excessive heat, were often problematic. These problems are then examined within the literature discussing current issues in management. Research limitations/implications Sport has the potential to facilitate one’s understanding of issues that management, consistent with ancient images of the body, has traditionally neglected (i.e. extremes, passion) and the possibilities of using embodied cognition to enhance our understandings of performance, teams and leading are discussed. Social implications As scientists become increasingly concerned about the long-term consequences of the reduced opportunities for cultural programs (sport, art, music, etc.), revisiting one’s assumptions is increasingly important, especially as athletics and philosophy once shared the same physical space. Originality/value By describing how residues from historical images of the body have influenced the thinking about organizing, this paper highlights the connection between the social and the biological and demonstrates how vestiges from the past influence contemporary discussions.

scholarly journals Two-layer nanofluid flow and heat transfer in a horizontal microchannel with electric double layer effects and magnetic field

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Qingkai Zhao ◽  
Hang Xu ◽  
Longbin Tao
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Double Layer ◽  
Electric Double Layer ◽  
Lower Layer ◽  
Fluid Velocity ◽  
Heat Transfer Process ◽  
The Body ◽  
Nanofluid Flow ◽  
Content Type

Purpose The purpose of this paper is to investigate the immiscible two-layer heat fluid flows in the presence of the electric double layer (EDL) and magnetic field. The effects of EDL, magnetic field and the viscous dissipative term on fluid velocity and temperature, as well as the important physical quantities, are examined and discussed. Design/methodology/approach The upper and lower regions in a horizontal microchannel with one layer being filled with a nanofluid and the other with a viscous Newtonian fluid. The nanofluid flow in the lower layer is described by the Buongiorno’s nanofluid model with passively controlled model at the boundaries. An appropriate set of non-dimensional quantities are used to simplify the nonlinear systems. The resulting coupled nonlinear equations are solved by using homotopy analysis method. Findings The present work demonstrates that increasing the EDL thickness and Hartmann number can restrain the fluid flow. The Brinkmann number has a significant role in the enhancement of heat transfer. It is also identified that the influence of EDL effects on microflow cannot be ignored. Originality/value The effects of viscous dissipation involved in the heat transfer process and the body force because of the EDL and the magnetic field are considered in the thermal energy and momentum equations for both regions. The detailed derivation procedure of the analytical solution for electrostatic potential is provided. The analytical solutions can lead to improved understanding of the complex microfluidic systems.

Remaining useful life estimation of metropolitan train wheels considering measurement error

2018 ◽  
Vol 24 (4) ◽  
pp. 422-436 ◽  
Author(s):  
Zengqiang Jiang ◽  
Dragan Banjevic ◽  
Mingcheng E. ◽  
Andrew Jardine ◽  
Qi Li
Keyword(s):  
Measurement Error ◽  
Health Management ◽  
Rapid Development ◽  
State Space Model ◽  
Economic Benefits ◽  
Remaining Useful Life ◽  
The Body ◽  
Discrete State ◽  
Content Type ◽  
Useful Life

Purpose The purpose of this paper is to develop an approach for estimating the remaining useful life (RUL) of metropolitan train wheels considering measurement error. Design/methodology/approach The paper proposes a wear model of a metropolitan train wheel based on a discrete state space model; the model considers the wheel’s stochastic degradation and measurement error simultaneously. The paper estimates the RUL on the basis of the estimated degradation state. Finally, it presents a case study to verify the proposed approach. The results indicate that the proposed method is superior to methods that do not consider measurement error and can improve the accuracy of the estimated RUL. Findings RUL estimation is a key issue in condition-based maintenance and prognostics and health management. With the rapid development of advanced sensor technologies and data acquisition facilities for the maintenance of metropolitan train wheels, condition monitoring (CM) is becoming more accurate and more affordable, creating the possibility of estimating the RUL of wheels using CM data. However, the measurements of the wheels, especially the wayside measurements, are not yet precise enough. On the other hand, few existing studies of the RUL estimation of train wheels consider measurement error. Practical implications The approach described in this paper will make the RUL estimation of metropolitan train wheels easier and more precise. Originality/value Hundreds of million yuan are wasted every year due to over re-profiling of rail wheels in China. The ability to precisely estimate RUL will reduce the number of re-profiling activities and achieve significant economic benefits. More generally, the paper could enrich the body of knowledge of RUL estimation for a slowly degrading system considering measurement error.

scholarly journals The Triple Threat of Cryptococcosis: It’s the Body Site, the Strain, and/or the Host

mBio ◽  
2012 ◽  
Vol 3 (4) ◽  
Author(s):  
John R. Perfect
Keyword(s):  
The Body ◽  
Past Century ◽  
Human Immune System ◽  
Separate Species ◽  
Content Type ◽  
The Past ◽  
The Status ◽  
Causative Agents ◽  
Life Threatening ◽  
Human Immune

ABSTRACT Cryptococcosis is the leading invasive fungal infection in the world today. Over the past century, the causative agents, Cryptococcus neoformans and Cryptococcus gattii, have risen from the status of medical curiosities to common but life-threatening central nervous system pathogens. In an elegant experimental pathobiology study of these two organisms carried out by Ngamskulrungroj et al., there are three matters that merit further discussion. First is the question of whether there is a variable specific pathobiology for each yeast strain. Does it make biological and clinical sense to designate C. neoformans and C. gattii as two separate species? Second is the matter of how the organisms differ pathologically at the site of infection. Finally, there is the possibility that the human immune system responds differently to each species. Although no single study can provide definitive mechanistic answers to the important questions, this experimental pathology study and its discussion clearly frame the issues to be dissected.

A novel data glove using inertial and magnetic sensors for motion capture and robotic arm-hand teleoperation

2017 ◽  
Vol 44 (2) ◽  
pp. 155-165 ◽  
Author(s):  
Bin Fang ◽  
Fuchun Sun ◽  
Huaping Liu ◽  
Di Guo
Keyword(s):  
Motion Capture ◽  
Low Cost ◽  
Magnetic Measurement ◽  
Calibration Method ◽  
Magnetic Sensors ◽  
Robotic Arm ◽  
Input Device ◽  
Content Type ◽  
Data Glove ◽  
Accuracy Of Measurements

Purpose The purpose of this paper is to present a novel data glove which can capture the motion of the arm and hand by inertial and magnetic sensors. The proposed data glove is used to provide the information of the gestures and teleoperate the robotic arm-hand. Design/methodology/approach The data glove comprises 18 low-cost inertial and magnetic measurement units (IMMUs) which not only make up the drawbacks of traditional data glove that only captures the incomplete gesture information but also provide a novel scheme of the robotic arm-hand teleoperation. The IMMUs are compact and small enough to wear on the upper arm, forearm, palm and fingers. The calibration method is proposed to improve the accuracy of measurements of units, and the orientations of each IMMU are estimated by a two-step optimal filter. The kinematic models of the arm, hand and fingers are integrated into the entire system to capture the motion gesture. A positon algorithm is also deduced to compute the positions of fingertips. With the proposed data glove, the robotic arm-hand can be teleoperated by the human arm, palm and fingers, thus establishing a novel robotic arm-hand teleoperation scheme. Findings Experimental results show that the proposed data glove can accurately and fully capture the fine gesture. Using the proposed data glove as the multiple input device has also proved to be a suitable teleoperating robotic arm-hand system. Originality/value Integrated with 18 low-cost and miniature IMMUs, the proposed data glove can give more information of the gesture than existing devices. Meanwhile, the proposed algorithms for motion capture determine the superior results. Furthermore, the accurately captured gestures can efficiently facilitate a novel teleoperation scheme to teleoperate the robotic arm-hand.

Localization of Magnetometer Sensor Based on Magnetic Gradient

2013 ◽  
Vol 706-708 ◽  
pp. 840-844
Author(s):  
Zhou Yu ◽  
Chang Han Xiao ◽  
Huan Wang ◽  
Guo Hua Zhou
Keyword(s):  
Magnetic Field ◽  
Measurement Error ◽  
Magnetic Measurement ◽  
High Accuracy ◽  
Magnetic Sensors ◽  
Genetic Optimization ◽  
Magnetic Gradient ◽  
Simulation Results ◽  
The Magnetic Field ◽  
Genetic Optimization Algorithm

An adaptive weighted approach based on magnetic gradient was proposed in order to localize the magnetometer sensor and correct magnetic measurement error caused by the position deviation. During the process of localization, the magnetic field produced by various combinations of current-carrying coils was calculated and analyzed firstly. The weighted factors of the objective function were determined on the basis of the magnetic gradient in the predetermined position of vertical magnetic sensors. Then the genetic optimization algorithm was applied to find the optimum of the function. An example of coil combination was analyzed and utilized. The simulation results show that the proposed method is effective to localize the magnetometer sensor, and it can be applied in engineering for its convenience and high accuracy.

Automatic measuring and processing system of audio sensing for real-time arc height control of pulsed GTAW

Sensor Review ◽  
2014 ◽  
Vol 34 (1) ◽  
pp. 51-66 ◽  
Author(s):  
Na Lv ◽  
Jiyong Zhong ◽  
Jifeng Wang ◽  
Shanben Chen
Keyword(s):  
Real Time ◽  
Linear Model ◽  
Environmental Noise ◽  
Sound Signal ◽  
Pulse Interference ◽  
Content Type ◽  
Height Control ◽  
Pulsed Gtaw ◽  
Arc Sound ◽  
Arc Sound Signal

Purpose – Surface forming control of welding bead is the fundamental study in automated welding. Considering that the vision sensing system cannot extract the height information of weld pool in pulsed GTAW process, so this paper designed a set of automatic measurement and control technology to achieve real-time arc height control via audio sensing system. The paper aims to discuss these issues. Design/methodology/approach – The experiment system is based on GTAW welding with acoustic sensor and signal conditioner. A combination denoising method was used to reduce the environmental noise and pulse interference noise. After extracting features of acoustic signal, the relationship between arc height and arc sound pressure was established by linear fitting. Then in order to improve the prediction accuracy of that model, the piecewise linear fitting method was proposed. Finally, arc height linear model of arc sound signal and arc height is divided into two parts and built in two different arc height conditions, which are arc height 3-4 and 4-5-6 mm. Findings – The combination denoising method was proved to have great effect on reducing the environmental noise and pulse interference noise. The experimental results showed that the prediction accuracy of linear model was not stable in different arc height changing state, like 3-4 and 4-5-6 mm. The maximum error was 0.635588 mm. And the average error of linear model was about 0.580487 mm, and the arc sound signal was accurately enough to meet the requirement for real-time control of arc height in pulse GTAW. Originality/value – This paper tries to make a foundation work to achieve controlling of depth of welding pool through arc sound signal, then the welding quality control. So a new idea of arc height control based on automatic measuring and processing system through arc sound signal was proposed. A new way to remove environmental noise and pulse interference noise was proposed. The results of this thesis had proved that arc sound signal was an effective features and precisely enough for online arc height monitoring during pulsed GTAW.

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