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Article
Publication date: 2 May 2022

Mati Ullah, Chunhui Zhao and Hamid Maqsood

The purpose of this paper is to design a hybrid robust tracking controller based on an improved radial basis function artificial neural network (IRBFANN) and a novel…

Abstract

Purpose

The purpose of this paper is to design a hybrid robust tracking controller based on an improved radial basis function artificial neural network (IRBFANN) and a novel extended-state observer for a quadrotor system with various model and parametric uncertainties and external disturbances to enhance the resiliency of the control system.

Design/methodology/approach

An IRBFANN is introduced as an adaptive compensator tool for model and parametric uncertainties in the control algorithm of non-singular rapid terminal sliding-mode control (NRTSMC). An exact-time extended state observer (ETESO) augmented with NRTSMC is designed to estimate the unknown exogenous disturbances and ensure fast states convergence while overcoming the singularity issue. The novelty of this work lies in the online updating of weight parameters of the RBFANN algorithm by using a new idea of incorporating an exponential sliding-mode effect, which makes a remarkable effort to make the control protocol adaptive to uncertain model parameters. A comparison of the proposed scheme with other conventional schemes shows its much better performance in the presence of parametric uncertainties and exogenous disturbances.

Findings

The investigated control strategy presents a robust adaptive law based on IRBFANN with a fast convergence rate and improved estimation accuracy via a novel ETESO.

Practical implications

To enhance the safety level and ensure stable flight operations by the quadrotor in the presence of high-order complex disturbances and uncertain environments, it is imperative to devise a robust control law.

Originality/value

A new idea of incorporating an exponential sliding-mode effect instead of conventional approaches in the algorithm of the RBFANN is used, which makes the control law resistant to model and parametric uncertainties. The ETESO provides rapid and accurate disturbance estimation results and updates the control law to overcome the performance degradation caused by the disturbances. Simulation results depict the effectiveness of the proposed control strategy.

Article
Publication date: 13 December 2021

Mati Ullah, Chunhui Zhao, Hamid Maqsood, Mahmood Ul Hassan and Muhammad Humayun

This paper aims to design an adaptive nonlinear strategy capable of timely detection and reconstruction of faults in the attitude’s sensors of an autonomous aerial vehicle with…

Abstract

Purpose

This paper aims to design an adaptive nonlinear strategy capable of timely detection and reconstruction of faults in the attitude’s sensors of an autonomous aerial vehicle with greater accuracy concerning other conventional approaches in the literature.

Design/methodology/approach

The proposed scheme integrates a baseline nonlinear controller with an improved radial basis function neural network (IRBFNN) to detect different kinds of anomalies and failures that may occur in the attitude’s sensors of an autonomous aerial vehicle. An integral sliding mode concept is used as auto-tune weight update law in the IRBFNN instead of conventional weight update laws to optimize its learning capability without computational complexities. The simulations results and stability analysis validate the promising contributions of the suggested methodology over the other conventional approaches.

Findings

The performance of the proposed control algorithm is compared with the conventional radial basis function neural network (RBFNN), multi-layer perceptron neural network (MLPNN) and high gain observer (HGO) for a quadrotor vehicle suffering from various kinds of faults, e.g. abrupt, incipient and intermittent. From the simulation results obtained, it is found that the proposed algorithm’s performance in faults detection and estimation is relatively better than the rest of the methodologies.

Practical implications

For the improvement in the stability and safety of an autonomous aerial vehicle during flight operations, quick identification and reconstruction of attitude’s sensor faults and failures always play a crucial role. Efficient fault detection and estimation scheme are considered indispensable for an error-free and safe flight mission of an autonomous aerial vehicle.

Originality/value

The proposed scheme introduces RBFNN techniques to detect and estimate the quadrotor attitude’s sensor faults and failures efficiently. An integral sliding mode effect is used as the network’s backpropagation law to automatically modify its learning parameters accordingly, thereby speeding up the learning capabilities as compared to the conventional neural network backpropagation laws. Compared with the other investigated techniques, the proposed strategy achieve remarkable results in the detection and estimation of various faults.

Details

International Journal of Intelligent Unmanned Systems, vol. 11 no. 2
Type: Research Article
ISSN: 2049-6427

Keywords

Article
Publication date: 18 April 2016

Sherif El-Halaby and Khaled Hussainey

The authors explore the level and determinants of compliance with Accounting and Auditing Organization for Islamic Financial Institution’s (AAOIFI) financial and governance…

2267

Abstract

Purpose

The authors explore the level and determinants of compliance with Accounting and Auditing Organization for Islamic Financial Institution’s (AAOIFI) financial and governance standards by Islamic banks (IBs).

Design/methodology/approach

The sample consists of 43 IBs across eight countries. The authors use ordinary least squares regression analyses to examine the impact of bank-specific characteristics and corporate governance (CG) mechanisms concerned with Board of Directors (BOD) and Sharia Supervisory Board (SSB) on the levels of compliance with AAOIFI standards.

Findings

The paper finds that the average compliance level based on AAOIFI standards concerning the SSB is 68 per cent; corporate social responsibility (CSR) is 27 per cent; and presentation of financial statements (FSs) is 73 per cent. The aggregate disclosure based on the three indices is 56 per cent. The analysis also shows that size, existing Sharia-auditing department, age and CG of SSB are the main determinants of compliance levels.

Originality/value

The determinants of compliance with AAOIFI standards for IBs around the world have not been explored before, and therefore, this paper is the first of its kind to this issue.

Details

International Journal of Islamic and Middle Eastern Finance and Management, vol. 9 no. 1
Type: Research Article
ISSN: 1753-8394

Keywords

Article
Publication date: 20 March 2024

Gopal Krushna Gouda and Binita Tiwari

The COVID-19 outbreak disrupted the business environment and severely affected the morale and performance of the employees. Further, the Indian automobile industry witnessed major…

Abstract

Purpose

The COVID-19 outbreak disrupted the business environment and severely affected the morale and performance of the employees. Further, the Indian automobile industry witnessed major setbacks and drastically impacted sector in COVID-19. Talent agility is an emerging concept in the field of HRM that will foster innovations and productivity in the automobile industry. Thus, this study aims to explore the barriers to building in-house agile talents in the Indian automobile industry in the new normal.

Design/methodology/approach

The barriers of talent agility were identified through a literature review and validated through experts’ opinions. This study used a hybrid approach, which combines Interpretive Structural Modelling-Polarity (ISM-P) and decision-making trial and evaluation laboratory (DEMATEL) to develop a hierarchical structural model of the barriers, followed by classification into cause and effect groups.

Findings

The result of the multi-method approach identified that shortage of skills and competencies, lack of IT infrastructure, lack of ambidextrous leaders, lack of smart HRM technologies and practices, lack of attractive reward system/career management, poor advanced T&D, poor industry, institute interface and financial constraints are the critical barriers.

Practical implications

It can provide a strategic roadmap for automobile manufacturers to promote talent agility in the current wave of digitalization (Industry 4.0). This study can help the managers to address and overcome the barrier and hurdles in building talent agility.

Originality/value

This study is unique in that it addresses the contemporary issues related to talent agility in the context of the Indian automobile industry in the current rapidly changing environment. This study developed a holistic integrated ISM(P)-DEMATEL hierarchical framework on the barriers of talent agility indicating inner dependency weights, i.e., the strength of interrelationship between the barriers.

Details

Journal of Modelling in Management, vol. 19 no. 4
Type: Research Article
ISSN: 1746-5664

Keywords

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