Ziyuan Ma, Huajun Gong and Xinhua Wang
The purpose of this paper is to construct an event-triggered finite-time fault-tolerant formation tracking controller, which can achieve a time-varying formation control for…
Abstract
Purpose
The purpose of this paper is to construct an event-triggered finite-time fault-tolerant formation tracking controller, which can achieve a time-varying formation control for multiple unmanned aerial vehicles (UAVs) during actuator failures and external perturbations.
Design/methodology/approach
First, this study developed the formation tracking protocol for each follower using UAV formation members, defining the tracking inaccuracy of the UAV followers’ location. Subsequently, this study designed the multilayer event-triggered controller based on the backstepping method framework within finite time. Then, considering the actuator failures, and added self-adaptive thought for fault-tolerant control within finite time, the event-triggered closed-loop system is subsequently shown to be a finite-time stable system. Furthermore, the Zeno behavior is analyzed to prevent infinite triggering instances within a finite time. Finally, simulations are conducted with external disturbances and actuator failure conditions to demonstrate formation tracking controller performance.
Findings
It achieves improved performance in the presence of external disturbances and system failures. Combining limited-time adaptive control and event triggering improves system stability, increase robustness to disturbances and calculation efficiency. In addition, the designed formation tracking controller can effectively control the time-varying formation of the leader and followers to complete the task, and by adding a fixed-time observer, it can effectively compensate for external disturbances and improve formation control accuracy.
Originality/value
A formation-following controller is designed, which can handle both external disturbances and internal actuator failures during formation flight, and the proposed method can be applied to a variety of formation control scenarios and does not rely on a specific type of UAV or communication network.
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Waheed Ur Rehman, Xinhua Wang, Yingchun Chen, Xiaogao Yang, Zia Ullah, Yiqi Cheng and Marya Kanwal
The purpose of this paper is to improve static/dynamic characteristics of active-controlled hydrostatic journal bearing by using fractional order control techniques and optimizing…
Abstract
Purpose
The purpose of this paper is to improve static/dynamic characteristics of active-controlled hydrostatic journal bearing by using fractional order control techniques and optimizing algorithms.
Design/methodology/approach
Active lubrication has ability to overcome the unpredictable harsh environmental conditions which often lead to failure of capillary controlled traditional hydrostatic journal bearing. The research develops a mathematical model for a servo feedback-controlled hydrostatic journal bearing and dynamics of model is analyzed with different control techniques. The fractional-order PID control system is tuned by using particle swarm optimization and Nelder mead optimization techniques with the help of using multi-objective performance criteria.
Findings
The results of the current research are compared with previously published theoretical and experimental results. The proposed servo-controlled active bearing system is studied under a number of different dynamic situations and constraints of variable spindle speed, external load, temperature changes (viscosity) and variable bearing clearance (oil film thickness). The simulation results show that the proposed system has better performance in terms of controllability, faster response, stability, high stiffness and strong resistance.
Originality/value
This paper develops an accurate mathematical model for servo-controlled hydrostatic bearing with fractional order controller. The results are in excellent agreement with previously published literature.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2020-0272
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Vilma Seeberg, Heidi Ross, Jinghuan Liu and Guangyu Tan
This chapter reviews the status of Education For All (EFA) in China and identifies four gaps: between rural and urban residents, between residents of geographic regions, between…
Abstract
This chapter reviews the status of Education For All (EFA) in China and identifies four gaps: between rural and urban residents, between residents of geographic regions, between ethnicity groups, and between the genders. It turns to examine the educational situation and interests of girls weighed down by the crushing burden of multiple disadvantages in “left-behind” Western China. Based on analysis of macro-level socio-economic and educational conditions, along with rich micro-level data on girls’ vigorous pursuit of education, the authors argue that the changing conditions of rural girls’ lives and their education can best be understood from a critical empowerment perspective. Summarizing the global discourse and cross national evidence on the benefits of girls’ education, the chapter and looks beyond a utilitarian perspective and argues for the cogency of a critical empowerment framework. Filled with telling stories and case studies of Han Chinese, Tibetan, and Muslim girls, this chapter proposes that prioritizing girls’ education in Western China is crucial and required for achieving the MDG of gender parity. Even though girls are often stranded by family financial conditions, their actions and ideas seeing education as their future reflect a changing gender identity and role in the family and society. The fieldwork suggests that educating girls promotes localized development, reduces dangerous levels of economic gaps and social instability, but also advances hard to measure effects: personal and civil empowerment, and sustainable, harmonious cultural change – as well as MDG.
A core employment market based on modem information and communications technology (ICT) and human resources (HR) management can fundamentally overcome the shortcomings of a…
Abstract
A core employment market based on modem information and communications technology (ICT) and human resources (HR) management can fundamentally overcome the shortcomings of a traditional employment market, in which the problems of an imbalance in the relationship between employers and employees are antagonistically alleviated by independent trade unions and other similar means. Core employment means the portion of total employment closely related to modem entrepreneurial innovation - the employment of directly or indirectly aiding in conducting, promoting, protecting and expanding innovation with entrepreneurship. The severe industrial conflicts existing currently in Korea and China can probably be resolved by economic and social measures other than confrontational trade unions, as long as the efforts are made in an expansion of core employment by the government, enterprises and individuals.
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Sociology of sport in China has evolved from being an “exotic” subject to a localized subject over the past 35 years. It is closely associated with social changes, sports policy…
Abstract
Sociology of sport in China has evolved from being an “exotic” subject to a localized subject over the past 35 years. It is closely associated with social changes, sports policy and athletic achievement of China. As a discipline of humanitarian and social sciences of sport, it is taught in virtually all universities with sports majors. There are about 500 scholars specializing in sport sociology in the country. Textbooks written by Chinese and foreign scholars are published. Academic papers on sport sociology are often published in the 15 accredited core sports journals. The most productive authors are from universities and the developed provinces and municipalities. The established research areas of sport sociology are extensive. These include national identity, athlete mobility, Olympic legacy, sport for all, sports industry issues, feminist studies, community sport, sport for the aged and disabled, etc. However, there are few studies with critical analysis and only a few in the areas of sport and religion, sport and race, and deviance in sport in China. Various kinds of financial support at different levels are available in the country. Empirical research is common with literature review, questionnaire, case study, and interview being the most frequently used methods. However, sport sociology is not considered as a major topic but as a research direction and it is not accepted widely by mainstream sociology. The future of sport sociology is promising, but not without challenges.
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The cities, for the most part, appeared up until the middle of the 1990s to be islands within the larger Chinese political economy in which job-secure workers could be certain…
Abstract
The cities, for the most part, appeared up until the middle of the 1990s to be islands within the larger Chinese political economy in which job-secure workers could be certain that their livelihood, health, education, and living abodes would evermore undergird their and their children's sustenance. At least until the late 1980s, urbanites who stuck with the state sector even considered good treatment on the job a kind of birthright, an entitlement that was sure to be enforced. In the cities, true, there had always been the disadvantaged after 1949 – those without offspring or spouses, the disabled, and people unable to support themselves. But this relatively tiny batch of individuals generally survived in the shadows and out of sight, subsisting – but just barely – as members of the “three withouts” on a mere pittance, in the form of meager “social relief” disbursed by civil affairs departments.8
The purpose of this paper is to investigate the trend of transatlantic strategic convergence and policy coordination in response to Chinese trade practices and technological…
Abstract
Purpose
The purpose of this paper is to investigate the trend of transatlantic strategic convergence and policy coordination in response to Chinese trade practices and technological competition, specifically in the critical minerals sector.
Design/methodology/approach
The research draws on primary and secondary source material to identify evidence of and examine the drivers, manifestations and prospects for effective US-European efforts to advance the shared aim of reducing vulnerabilities in critical minerals supply chains.
Findings
The interests of the USA and Europe would be best served by prioritizing their own security, diversification and resilience strategies while seeking areas of common ground and constructive engagement with China.
Research limitations/implications
The research offers a fresh perspective on the growing alignment and persistent gaps in US and European perspectives on China’s rising influence and assertive behavior.
Originality/value
The research highlights the vital role of critical minerals in national security, economic competitiveness, technological advancement and sustainable resource management. It underscores the shared recognition on both sides of the Atlantic that securing a stable supply of critical minerals – essential for maintaining strategic capabilities, driving innovation and ensuring long-term economic prosperity – necessitates tighter transatlantic coordination as well as constructive engagement with China.
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In modern China, sports and nationalism always have close connection, and nationalism is the important reason for the promotion of Chinese sports. However, the relationship…
Abstract
In modern China, sports and nationalism always have close connection, and nationalism is the important reason for the promotion of Chinese sports. However, the relationship between Chinese sports and nationalism in globalised China could be much more examined by academics, as well as its influencing factors. This chapter selects the Beijing 2008 Olympic Games as the context and representative three Chinese sports heroes in the period of globalisation to study. The findings show that in some extent, Beijing 2008 Olympic Games and three Chinese sports heroes represent the national image of China in the globalised world, also bearing the burden of washing away historical humiliation and pursuing national glory. Furthermore, it is manifested that China have a complex nationalism in the process of hosting the 2008 Olympic Games. Under the influence of mass media, market economy and sports professionalisation, nationalism still exists in Chinese sports, but people gradually start to reflect on the ‘Juguo Tizhi’, the traditional Chinese sports system and the concept of ‘winning glory for the nation’. The relationship between Chinese nationalism and sports shows the important implications of rapid Chinese sports development.