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Article
Publication date: 28 May 2021

Zhiwen Hou and Fanliang Bu

The purpose of this study is to establish an effective tracking algorithm for small unmanned aerial vehicles (UAVs) based on interacting multiple model (IMM) to take…

Abstract

Purpose

The purpose of this study is to establish an effective tracking algorithm for small unmanned aerial vehicles (UAVs) based on interacting multiple model (IMM) to take timely countermeasures against illegal flying UAVs.

Design/methodology/approach

In this paper, based on the constant velocity model (CV), the maneuvering adaptive current statistical model (CS) and the angular velocity adaptive three-dimensional (3D) fixed center constant speed rate constant steering rate model, a small UAV tracking algorithm based on adaptive interacting multiple model (AIMM-UKF) is proposed. In addition, an adaptive robust filter is added to each model of the algorithm. The linear Kalman filter algorithm is attached to the CV model and the CS model and the unscented Kalman filter algorithm (UKF) is attached to the CSCDR model to solve the nonlinearity of the 3D turning model.

Findings

Monte-Carlo simulation comparison with the other two IMM tracking algorithms shows that in the case of different movement modes and maneuvering strength of the UAV, the AIMM-UKF algorithm makes a good trade-off between the amount of calculation and filtering accuracy, which can maintain more accurate and stable tracking and has strong robustness. At the same time, after testing the actual observation data of the UAV, the results show that the AIMM-UKF algorithm state estimation trajectory can be regarded as an actual trajectory in practical engineering applications, which has good practical value.

Originality/value

This paper presents a new small UAV tracking algorithm based on IMM and the advantages and practicability of this algorithm compared with existing algorithms are proved through experiments.

Details

Aircraft Engineering and Aerospace Technology, vol. 93 no. 4
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 6 September 2011

Pengxin Han, Rongjun Mu and Naigang Cui

The purpose of this paper is to address the flaws of traditional methods and fulfil the special fault‐tolerant re‐entry navigation requirements of reusable boost vehicle (RBV).

Abstract

Purpose

The purpose of this paper is to address the flaws of traditional methods and fulfil the special fault‐tolerant re‐entry navigation requirements of reusable boost vehicle (RBV).

Design/methodology/approach

A kind of improved estimation method based on strong tracking unscented Kalman filter (STUKF) is put forward. According to the fact that the traditional state χ2‐test‐based fault diagnosis method is incompetent to detect the signal point small jerks and slowly varying fault in the measurement, a kind of original fault diagnosis technology based on STUKF is used to check the working states of navigation sensors.

Findings

The comparisons with χ2‐test method under typical failure distributions validate the perfect state tracking and fault diagnosis performances of this improved method.

Practical implications

This kind of state estimation and fault diagnosis method could be used in the navigation and guidance systems for many kinds of aeronautical and astronautical vehicles.

Originality/value

A kind of novel strong tracking state estimation filter is used, and a kind of very effective fault diagnosis criterion is put forward for the navigation of RBV.

Details

Aircraft Engineering and Aerospace Technology, vol. 83 no. 5
Type: Research Article
ISSN: 0002-2667

Keywords

Book part
Publication date: 19 November 2013

Janice Aurini and Scott Davies

In this chapter we draw on research from Canada to develop a framework for understanding the variety of forms of supplementary education and their position within broader…

Abstract

Purpose

In this chapter we draw on research from Canada to develop a framework for understanding the variety of forms of supplementary education and their position within broader organization fields of education. The chapter asks: What is the nature and organizing logic of supplementary education in Canada? and, How does supplementary education relate to public schools in Canada?

Design/methodology/approach

Data come from a variety of secondary sources.

Findings

Distributed between three relatively autonomous settings – state, market, and nonprofit – supplementary education exhibits tremendous variety in its use value to parents, instructional content, and organizational form. Supplementary education is popular among Canadian parents and appears to be growing, yet it has failed to fundamentally alter the technical core of Canadian schooling, processes that stratify students, and child and family usage of their time or income. Supplementary education’s inability to penetrate these processes reflects its peripheral position within the broader organizational field of Canadian schooling.

Originality/value

The adoption of an organizational field approach generates new ways of thinking about determinants, forming and organizing logics of supplementary education both nationally and comparatively.

Details

Out of the Shadows: The Global Intensification of Supplementary Education
Type: Book
ISBN: 978-1-78190-816-7

Keywords

Article
Publication date: 9 May 2008

Clinton O. Longenecker and Laurence S. Fink

This paper aims to determine the key criteria used by managers in rapidly changing organizations to make promotion decisions.

2389

Abstract

Purpose

This paper aims to determine the key criteria used by managers in rapidly changing organizations to make promotion decisions.

Design/methodology/approach

A survey was conducted of 311 managers from over 100 different US service and manufacturing enterprises experiencing rapid organizational change. Managers were asked to identify no more than five factors that were most critical in their organization to actually getting promoted. Results were content analyzed.

Findings

Top ten factors influencing promotion decisions included: getting desired results/strong performance track record; possessing strong business networks; interpersonal/communication skills; strong knowledge‐experience base; demonstrating a strong work ethic; ability to build teams and being a team player; personality, attitude, and ego factors; solving a major problem or getting a “big hit;” demonstrating character, integrity, and trustworthiness; and, preparation and being in the right place at the right time.

Research limitations/implications

Results indicate what organizations are currently using to make decisions but it does not provide a normative guide for what organizations should be using. Also, further research should attempt to differentiate dimensions used at each level of management.

Practical implications

The results provide a useful guide for managers who are looking for a leg up in the competitive fight for promotions. Results also suggest criteria to be considered when organizations update management assessment tools to better reflect the demands on managers working in the new global business environment.

Originality/value

The study focuses on promotions in rapidly changing organizations and uses a sample that is very familiar with how organizations actually make promotion decisions.

Details

Career Development International, vol. 13 no. 3
Type: Research Article
ISSN: 1362-0436

Keywords

Article
Publication date: 19 November 2021

Yanbiao Zou and Hengchang Zhou

This paper aims to propose a weld seam tracking method based on proximal policy optimization (PPO).

Abstract

Purpose

This paper aims to propose a weld seam tracking method based on proximal policy optimization (PPO).

Design/methodology/approach

By constructing a neural network based on PPO and using the reference image block and the image block to be detected as the dual-channel input of the network, the method predicts the translation relation between the two images and corrects the location of feature points in the weld image. The localization accuracy estimation network (LAE-Net) is built to update the reference image block during the welding process, which is helpful to reduce the tracking error.

Findings

Off-line simulation results show that the proposed algorithm has strong robustness and performs well on the test set of curved seam images with strong noise. In the welding experiment, the movement of welding torch is stable, the molten material is uniform and smooth and the welding error is small, which can meet the requirements of industrial production.

Originality/value

The idea of image registration is applied to weld seam tracking, and the weld seam tracking network is built on the basis of PPO. In order to further improve the tracking accuracy, the LAE-Net is constructed and the reference images can be updated.

Details

Industrial Robot: the international journal of robotics research and application, vol. 49 no. 4
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 21 August 2017

Yanbiao Zou, Jinchao Li and Xiangzhi Chen

This paper aims to propose a set of six-axis robot arm welding seam tracking experiment platform based on Halcon machine vision library to resolve the curve seam tracking issue.

Abstract

Purpose

This paper aims to propose a set of six-axis robot arm welding seam tracking experiment platform based on Halcon machine vision library to resolve the curve seam tracking issue.

Design/methodology/approach

Robot-based and image coordinate systems are converted based on the mathematical model of the three-dimensional measurement of structured light vision and conversion relations between robot-based and camera coordinate systems. An object tracking algorithm via weighted local cosine similarity is adopted to detect the seam feature points to prevent effectively the interference from arc and spatter. This algorithm models the target state variable and corresponding observation vector within the Bayes framework and finds the optimal region with highest similarity to the image-selected modules using cosine similarity.

Findings

The paper tests the approach and the experimental results show that using metal inert-gas (MIG) welding with maximum welding current of 200A can achieve real-time accurate curve seam tracking under strong arc light and splash. Minimal distance between laser stripe and welding molten pool can reach 15 mm, and sensor sampling frequency can reach 50 Hz.

Originality/value

Designing a set of six-axis robot arm welding seam tracking experiment platform with a system of structured light sensor based on Halcon machine vision library; and adding an object tracking algorithm to seam tracking system to detect image feature points. By this technology, this system can track the curve seam while welding.

Details

Industrial Robot: An International Journal, vol. 44 no. 5
Type: Research Article
ISSN: 0143-991X

Keywords

Open Access
Article
Publication date: 4 December 2020

Fangli Mou and Dan Wu

In recent years, owing to the rapidly increasing labor costs, the demand for robots in daily services and industrial operations has been increased significantly. For…

Abstract

Purpose

In recent years, owing to the rapidly increasing labor costs, the demand for robots in daily services and industrial operations has been increased significantly. For further applications and human–robot interaction in an unstructured open environment, fast and accurate tracking and strong disturbance rejection ability are required. However, utilizing a conventional controller can make it difficult for the robot to meet these demands, and when a robot is required to perform at a high-speed and large range of motion, conventional controllers may not perform effectively or even lead to the instability.

Design/methodology/approach

The main idea is to develop the control law by combining the SMC feedback with the ADRC control architecture to improve the robustness and control quality of a conventional SMC controller. The problem is formulated and solved in the framework of ADRC. For better estimation and control performance, a generalized proportional integral observer (GPIO) technique is employed to estimate and compensate for unmodeled dynamics and other unknown time-varying disturbances. And benefiting from the usage of GPIO, a new SMC law can be designed by synthesizing the estimation and its history.

Findings

The employed methodology introduced a significant improvement in handling the uncertainties of the system parameters without compromising the nominal system control quality and intuitiveness of the conventional ADRC design. First, the proposed method combines the advantages of the ADRC and SMC method, which achieved the best tracking performance among these controllers. Second, the proposed controller is sufficiently robust to various disturbances and results in smaller tracking errors. Third, the proposed control method is insensitive to control parameters which indicates a good application potential.

Originality/value

High-performance robot tracking control is the basis for further robot applications in open environments and human–robot interfaces, which require high tracking accuracy and strong disturbance rejection. However, both the varied dynamics of the system and rapidly changing nonlinear coupling characteristic significantly increase the control difficulty. The proposed method gives a new replacement of PID controller in robot systems, which does not require an accurate dynamic system model, is insensitive to control parameters and can perform promisingly for response rapidity and steady-state accuracy, as well as in the presence of strong unknown disturbances.

Details

Journal of Intelligent Manufacturing and Special Equipment, vol. 1 no. 1
Type: Research Article
ISSN: 2633-6596

Keywords

Article
Publication date: 6 July 2015

Xinlong Wang and Shuai Song

– The purpose of this paper is to improve the tracking performance of the tracking loops under high dynamic and severe jamming conditions.

Abstract

Purpose

The purpose of this paper is to improve the tracking performance of the tracking loops under high dynamic and severe jamming conditions.

Design/methodology/approach

First, as the two dominant measurement error sources of the tracking loops, the thermal noise jitter and the dynamic stress error are thoroughly analyzed. Second, a scheme of adaptive tracking loops, which could adaptively adjust the order and the bandwidth of tracking loops, is proposed. Third, real-time detections of the vehicle dynamics and the carrier-to-noise density ratio, and the adaptive bandwidth of the carrier loop are presented, respectively. Finally, simulations are operated to validate the excellent tracking performance of the adaptive tracking loops.

Findings

Based on the principle of minimizing the measurement errors, the loop order and bandwidth are adaptively adjusted in the proposed scheme. Thus, the anti-jamming capability and dynamic tracking performance of the tracking loops could be effectively enhanced.

Practical implications

This paper provides further study on the method of improving the tracking capability under complexly applied conditions of high dynamics and severe jamming.

Originality/value

The detections of carrier-to-noise density ratio and vehicle dynamics are used to adaptively adjusting the loop order and bandwidth, which could not only improve the measurement accuracy but also ensure the stable operation of tracking loops.

Details

Aircraft Engineering and Aerospace Technology: An International Journal, vol. 87 no. 4
Type: Research Article
ISSN: 0002-2667

Keywords

Article
Publication date: 25 May 2022

Bingwei Gao, Wei Shen, Ye Dai and Yong Tai Ye

This paper aims to study a parameter tuning method for the active disturbance rejection control (ADRC) to improve the anti-interference ability and position tracking of…

Abstract

Purpose

This paper aims to study a parameter tuning method for the active disturbance rejection control (ADRC) to improve the anti-interference ability and position tracking of the performance of the servo system, and to ensure the stability and accuracy of practical applications.

Design/methodology/approach

This study proposes a parameter self-tuning method for ADRC based on an improved glowworm swarm optimization algorithm. The algorithm is improved by using sine and cosine local optimization operators and an adaptive mutation strategy. The improved algorithm is then used for parameter tuning of the ADRC to improve the anti-interference ability of the control system and ensure the accuracy of the controller parameters.

Findings

The authors designed an optimization model based on MATLAB, selected examples of simulation and experimental research and compared it with the standard glowworm swarm optimization algorithm, particle swarm algorithm and artificial bee colony algorithm. The results show that the response time of using the improved glowworm swarm optimization algorithm to optimize the auto-disturbance rejection control is short; there is no overshoot; the tracking process is relatively stable; the anti-interference ability is strong; and the optimization effect is better.

Originality/value

The innovation of this study is to improve the glowworm swarm optimization algorithm, propose a sine and cosine, local optimization operator, expand the firefly search space and introduce a new adaptive mutation strategy to adaptively adjust the mutation probability based on the fitness value, improve the global search ability of the algorithm and use the improved algorithm to adjust the parameters of the active disturbance rejection controller.

Book part
Publication date: 27 October 2016

Amy M. Hageman and Dann G. Fisher

Tax professionals in public accounting firms must meet professional standards in working with their clients, but may also face pressure from both their clients and firms…

Abstract

Tax professionals in public accounting firms must meet professional standards in working with their clients, but may also face pressure from both their clients and firms when making ethical decisions. The purpose of this study is to examine the influence of client factors on tax professionals’ ethical decision-making. Furthermore, we also investigate how client service climate and different ethical climate types affect these ethical decisions. Based on an experimental design with 149 practicing tax professionals, results indicate that tax professionals are not swayed by client importance or social interaction with the client when making ethical decisions. However, tax professionals are more likely to engage in ethical behavior when their own accounting firm monitors and tracks the quality of client service, whereas unethical behavior is more common when public accounting firms emphasize using personal ethical beliefs in decision-making. The results of the study suggest the importance of strong policies and procedures to promote ethical decision-making in firms.

Details

Research on Professional Responsibility and Ethics in Accounting
Type: Book
ISBN: 978-1-78560-973-2

Keywords

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