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Article
Publication date: 28 December 2020

Active fault-tolerant control of rotation angle sensor in steer-by-wire system based on multi-objective constraint fault estimator

Qinjie Yang, Guozhe Shen, Chao Liu, Zheng Wang, Kai Zheng and Rencheng Zheng

Steer-by-wire (SBW) system mainly relies on sensors, controllers and motors to replace the traditionally mechanical transmission mechanism to realize steering functions…

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Abstract

Purpose

Steer-by-wire (SBW) system mainly relies on sensors, controllers and motors to replace the traditionally mechanical transmission mechanism to realize steering functions. However, the sensors in the SBW system are particularly vulnerable to external influences, which can cause systemic faults, leading to poor steering performance and even system instability. Therefore, this paper aims to adopt a fault-tolerant control method to solve the safety problem of the SBW system caused by sensors failure.

Design/methodology/approach

This paper proposes an active fault-tolerant control framework to deal with sensors failure in the SBW system by hierarchically introducing fault observer, fault estimator, fault reconstructor. Firstly, the fault observer is used to obtain the observation output of the SBW system and then obtain the residual between the observation output and the SBW system output. And then judge whether the SBW system fails according to the residual. Secondly, dependent on the residual obtained by the fault observer, a fault estimator is designed using bounded real lemma and regional pole configuration to estimate the amplitude and time-varying characteristics of the faulty sensor. Eventually, a fault reconstructor is designed based on the estimation value of sensors fault obtained by the fault estimator and SBW system output to tolerate the faulty sensor.

Findings

The numerical analysis shows that the fault observer can be rapidly activated to detect the fault while the sensors fault occurs. Moreover, the estimation accuracy of the fault estimator can reach to 98%, and the fault reconstructor can make the faulty SBW system to retain the steering characteristics, comparing to those of the fault-free SBW system. In addition, it was verified for the feasibility and effectiveness of the proposed control framework.

Research limitations/implications

As the SBW fault diagnosis and fault-tolerant control in this paper only carry out numerical simulation research on sensors faults in matrix and laboratory/Simulink, the subsequent hardware in the loop test is needed for further verification.

Originality/value

Aiming at the SBW system with parameter perturbation and sensors failure, this paper proposes an active fault-tolerant control framework, which integrates fault observer, fault estimator and fault reconstructor so that the steering performance of SBW system with sensors faults is basically consistent with that of the fault-free SBW system.

Details

Journal of Intelligent and Connected Vehicles, vol. ahead-of-print no. ahead-of-print
Type: Research Article
DOI: https://doi.org/10.1108/JICV-08-2020-0007
ISSN: 2399-9802

Keywords

  • Active fault-tolerant control
  • Fault estimation
  • Sensors failure
  • Steer-by-wire

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Article
Publication date: 7 November 2016

The tool-wear characteristics of flexible printed circuit board micro-drilling and its influence on micro-hole quality

Lijuan Zheng, Chengyong Wang, Xin Zhang, Xin Huang, Yuexian Song, Kefeng Wang and Lunqiang Zhang

Micro-holes are drilled and plated in flexible printed circuit boards (FPCs) for connecting circuits from different layers. More holes, with diameters smaller than 0.3 mm…

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Abstract

Purpose

Micro-holes are drilled and plated in flexible printed circuit boards (FPCs) for connecting circuits from different layers. More holes, with diameters smaller than 0.3 mm, are required to be drilled in smaller areas with flexible circuits’ miniaturization. The micro-hole quality of micro-drilling is one of the biggest issues of the flexible circuit manufacturers’ production. However, it is not easy to control the quality of micro-holes. The purpose of this study was to conduct research on the tool wear characteristics of FPC drilling process and its influence on micro-hole quality to improve the micro-hole quality of FPC.

Design/methodology/approach

The tool-wear characteristics of micro-drills after FPC drilling were observed. The influence of spindle speed, feed rate, number of drilled holes and entry board materials on tool-wear was analyzed. The hole qualities of FPC micro-drilling were measured and observed. The relationship between tool-wear and hole quality was analyzed.

Findings

The result showed that the tool-wear characteristics of FPC micro-drilling was similar to the tool-wear characteristics of rigid printed circuit board (RPC) micro-drilling. Abrasive wear occurred on both the main cutting edges and the chisel edges of micro-drills, even though there was no glass fiber reinforcing the cloth inside FPC. Resin adhesion was observed on the chisel edge. The influence of feed and number of drilled holes on tool-wear was significant. Tool-wear significantly influences the hole quality of FPC. Tool-wear will largely decrease the hole position accuracy of FPC micro-holes. Tool-wear will increase the thickness of PI nail heads and the height of exit burrs. Fracture was the main difference between tool wear of FPC and RPC micro-drilling. Resin adhesion of RPC was much more severe than FPC micro-drilling. Increasing the spindle speed properly may improve tool life and hole quality.

Originality/value

The technology and manufacturing of FPC has been little investigated. Research on micro-drilling FPC and research data is lacking so far. The micro-hole quality directly affects the reliability of FPC. Thus, improving the micro-hole quality of FPC is very important.

Details

Circuit World, vol. 42 no. 4
Type: Research Article
DOI: https://doi.org/10.1108/CW-08-2015-0040
ISSN: 0305-6120

Keywords

  • Micro-drills wear
  • Micro-drilling
  • Flexible printed circuit board
  • Micro-hole quality

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Article
Publication date: 10 June 2019

An adaptive model predictive approach for automated vehicle control in fallback procedure based on virtual vehicle scheme

Wei Xue, Rencheng Zheng, Bo Yang, Zheng Wang, Tsutomu Kaizuka and Kimihiko Nakano

Automated driving systems (ADSs) are being developed to avoid human error and improve driving safety. However, limited focus has been given to the fallback behavior of…

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Abstract

Purpose

Automated driving systems (ADSs) are being developed to avoid human error and improve driving safety. However, limited focus has been given to the fallback behavior of automated vehicles, which act as a fail-safe mechanism to deal with safety issues resulting from sensor failure. Therefore, this study aims to establish a fallback control approach aimed at driving an automated vehicle to a safe parking lane under perceptive sensor malfunction.

Design/methodology/approach

Owing to an undetected area resulting from a front sensor malfunction, the proposed ADS first creates virtual vehicles to replace existing vehicles in the undetected area. Afterward, the virtual vehicles are assumed to perform the most hazardous driving behavior toward the host vehicle; an adaptive model predictive control algorithm is then presented to optimize the control task during the fallback procedure, avoiding potential collisions with surrounding vehicles. This fallback approach was tested in typical cases related to car-following and lane changes.

Findings

It is confirmed that the host vehicle avoid collision with the surrounding vehicles during the fallback procedure, revealing that the proposed method is effective for the test scenarios.

Originality/value

This study presents a model for the path-planning problem regarding an automated vehicle under perceptive sensor failure, and it proposes an original path-planning approach based on virtual vehicle scheme to improve the safety of an automated vehicle during a fallback procedure. This proposal gives a different view on the fallback safety problem from the normal strategy, in which the mode is switched to manual if a driver is available or the vehicle is instantly stopped.

Details

Journal of Intelligent and Connected Vehicles, vol. 2 no. 2
Type: Research Article
DOI: https://doi.org/10.1108/JICV-06-2019-0007
ISSN: 2399-9802

Keywords

  • Model predictive control
  • Automated vehicles
  • Fallback
  • Sensor failure
  • Virtual vehicle scheme

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Article
Publication date: 26 June 2020

Investigation of burr formation and its influence in micro-drilling hole of flexible printed circuit board

Zhiyuan Li, Lijuan Zheng, Chengyong Wang, Xin Huang and Jiechi Xie

The flexible printed circuit (FPC) board with the characteristic of light and thin strengthened confronted the growing miniaturization requirements of the electronic…

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Abstract

Purpose

The flexible printed circuit (FPC) board with the characteristic of light and thin strengthened confronted the growing miniaturization requirements of the electronic product and the popularity of wearable devices. The reliability of circuit could be influenced by the hole quality of FPC, such as burrs, which is one of the major problem in FPC.

Design/methodology/approach

In this paper, micro-drill with a diameter of 0.1 mm was used to drill the double-sided flexible copper clad laminate. The thrust force, the burr and tool wear were investigated. The influencing factors of the height of the burrs were studied. The relationship between the thrust force and the height of the burrs was also explored. Finally, the formation mechanism of burrs was analyzed.

Findings

The entrance burrs were usually less than the exit burrs. The burr height increased with the feed per rotation. The height of the burr increased with the increase of the thrust force for the plastic deformation of the copper foil was dominant. The abrasion of the drill gave rise to increase the height of burr. In micro-hole drilling, the growth of burrs can be suppressed effectively by reducing the clearance between the FPC and the backup plate. The thrust force would be controlled in a certain range to reduce the burr with specific drilling parameters. There existed a certain relationship of Gaussian distribution between the height of the burrs and the thrust force of FPC.

Originality/value

The reliability of the integrated circuit was directly affected by the burrs of the FPC. This research on the formation mechanism of FPC burrs and forecast of burr height provided a firm foundation for further work in the area of improvement of the micro-hole quality.

Details

Circuit World, vol. 46 no. 4
Type: Research Article
DOI: https://doi.org/10.1108/CW-05-2019-0049
ISSN: 0305-6120

Keywords

  • Thrust force
  • Burrs
  • FPC
  • Micro-hole

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Article
Publication date: 15 May 2017

Migration in response to climate change and its impact in China

Yi Sun, Chengjin Xu, Hailing Zhang and Zheng Wang

Climate change will have a significant impact on China’s potential agricultural production and change the distribution of the population in various regions of China, thus…

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Abstract

Purpose

Climate change will have a significant impact on China’s potential agricultural production and change the distribution of the population in various regions of China, thus producing population migration. This paper aims to analyze China’s population migration in response to climate change and its socio-economic impact.

Design/methodology/approach

In this paper, the Potential Agriculture Production Index is introduced as an analytical tool with which to estimate the scale of the population migration induced by climate change. Also, this paper constructs a multi-regional computable general equilibrium (CGE) model and analyzes the effect of change in the population distribution pattern on regional economies, regional disparity and resident welfare.

Findings

The key finding of this paper is that, as a result of changes in potential agricultural production induced by climate change, the Circum-Bohai-Sea region, the industrialized region and the industrializing region, which are the main destination regions of the migrating population, will face a severe labor shortage. In response to population migration, the economic growth rate of the immigrating population regions has accelerated. Correspondingly, the economic growth rate of the emigrating population regions has decreased. In addition, the larger the scale of population migration is, the larger the economic impact is. Migration increases inner-regional disparity and decreases inter-regional disparity. However, overall regional disparity is only somewhat decreased.

Originality/value

This paper introduces a Potential Agriculture Production Index to estimate the scale of the population migration and introduce a multi-regional CGE model to analyze the correlated social-economic impacts.

Details

International Journal of Climate Change Strategies and Management, vol. 9 no. 03
Type: Research Article
DOI: https://doi.org/10.1108/IJCCSM-05-2016-0061
ISSN: 1756-8692

Keywords

  • Climate change
  • Migration
  • Household welfare
  • Multi-regional CGE model
  • Potential agricultural productivity
  • Regional disparity

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Article
Publication date: 2 November 2015

The entry drilling process of flexible printed circuit board and its influence on hole quality

Lijuan Zheng, Chengyong Wang, Xin Zhang, Yuexian Song, Lunqiang Zhang and Kefeng Wang

The purpose of this study is to present the entry drilling process of flexible printed circuit board (FPCs) and its influence on hole quality, especially hole location…

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Abstract

Purpose

The purpose of this study is to present the entry drilling process of flexible printed circuit board (FPCs) and its influence on hole quality, especially hole location accuracy. Compared with the traditional PCB drilling process, the technology of drilling FPCs is facing more problems, such as hole location accuracy, smear on the hole wall surface, burned hole wall surface, etc. Moreover, the materials of FPCs are quite different from the rigid printed circuit boards (RPCs). FPCs no longer contain glass fiber cloths to reinforce resin, resulting in flexibility. Micro-hole quality is the most important issue in FPC drilling. Suggestions were given to obtain higher hole qualities and higher FPC reliability.

Design/methodology/approach

The entry drilling process of FPC with different kind of entry boards was observed by a high-speed camera. The hole qualities of FPC micro-drilling, especially hole location accuracy and hole entrance quality, were measured. The relationship between entry boards and hole quality was analyzed.

Findings

Significant sliding occurred when drilling FPC with using no-entry board or pure aluminum plate entry board. On the contrary, no significant sliding occurred when using LC-110 or resin-coated aluminum foil (MVC) entry boards. The type, thickness and use-pattern of entry boards influenced hole location accuracy of FPCs seriously. In addition, entry board also influenced the micro-hole entrance quality and micro-hole diameter. The entrance quality of drilling FPC with LC-110 entry board was the best. The diameter variation of drilling FPC with MVC entry board was the smallest. The hole location accuracy decreased as the thickness of entry board increased. Thus, the best use-pattern of entry board was putting a LC-110 under MVC entry board, resulting in best entrance quality and hole location accuracy.

Originality/value

The technology and manufacturing of FPCs in China are obviously behind. Research of FPCs micro-drilling and research data are lacking so far. Thus, it is most necessary to improve the technology level of FPCs micro-drilling in China. Researches on hole quality, especially hole location accuracy of FPCs drilling, were performed in this paper. Suggestions were given to obtain higher hole quality of FPCs.

Details

Circuit World, vol. 41 no. 4
Type: Research Article
DOI: https://doi.org/10.1108/CW-11-2014-0054
ISSN: 0305-6120

Keywords

  • Flexible printed circuits
  • Entry boards
  • FPCs
  • Hole quality
  • Micro-drilling

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Article
Publication date: 3 May 2016

Micro drilling quality of the Cu/BT laminate for IC substrate

Shan Li, Li Juan Zheng, Cheng Yong Wang, Bing Miao Liao and Lianyu Fu

In an integrated circuit (IC) substrate, more fillers, including talcum powder and aluminium hydroxide, are added, which leads to much higher rigidity and hardness…

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Abstract

Purpose

In an integrated circuit (IC) substrate, more fillers, including talcum powder and aluminium hydroxide, are added, which leads to much higher rigidity and hardness compared with a traditional printed circuit board. However, the micro drilling of IC substrates is harder. This paper aims to test the drilling process of IC substrates to improve the drilling process and the micro hole quality.

Design/methodology/approach

Substrate drilling by a micro drill with 0.11-mm diameter was used under several drilling conditions. The influence of drilling conditions on the drilling process was observed. Drilling forces, drill wear and micro hole quality were also studied.

Findings

The deformation circle around holes, hole location accuracy, bugle hole and burrs were the major defects of micro holes that were observed during the drilling of the substrate. Reducing the drilling force and drill wear was the effective way to improve hole quality.

Originality/value

The technology and manufacturing of IC substrates has been little investigated. Research data on drilling IC substrates is lacking. The micro hole quality directly affects the reliability of IC substrates. Thus, improving the drilling technology of IC substrates is very important.

Details

Circuit World, vol. 42 no. 2
Type: Research Article
DOI: https://doi.org/10.1108/CW-03-2015-0006
ISSN: 0305-6120

Keywords

  • Drilling forces
  • Drills wear
  • Micro hole quality
  • The Cu/BT laminate for IC substrate

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Book part
Publication date: 4 December 2020

References

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Abstract

Details

Application of Big Data and Business Analytics
Type: Book
DOI: https://doi.org/10.1108/978-1-80043-884-220211010
ISBN: 978-1-80043-884-2

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Article
Publication date: 3 April 2020

Identifying the factors of China's seasonal retail sales of consumer goods using a data grouping approach–based GRA method

Zheng-Xin Wang, Ji-Min Wu, Chao-Jun Zhou and Qin Li

Seasonal fluctuation interference often affects the relational analysis of economic time series. The main purpose of this paper is to propose a new grey relational model…

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Abstract

Purpose

Seasonal fluctuation interference often affects the relational analysis of economic time series. The main purpose of this paper is to propose a new grey relational model for relational analysis of seasonal time series and apply it to identify and eliminate the influence of seasonal fluctuation of retail sales of consumer goods in China.

Design/methodology/approach

First, the whole quarterly time series is divided into four groups by data grouping method. Each group only contains the time series data in the same quarter. Then, the new series of four-quarters are used to establish the grey correlation model and calculate its correlation coefficient. Finally, the correlation degree of factors in each group of data was calculated and sorted to determine its importance.

Findings

The data grouping method can effectively reflect the correlation between time series in different quarters and eliminate the influence of seasonal fluctuation.

Practical implications

In this paper, the main factors influencing the quarterly fluctuations of retail sales of consumer goods in China are explored by using the grouped grey correlation model. The results show that the main factors are different from quarter to quarter: in the first quarter, the main factors are money supply, tax and per capita disposable income of rural residents. In the second quarter are money supply, fiscal expenditure and tax. In the third quarter are money supply, fiscal expenditure and per capita disposable income of rural residents. In the fourth quarter are money supply, fiscal expenditure and tax.

Originality/value

This paper successfully realizes the application of grey relational model in quarterly time series and extends the applicable scope of grey relational model.

Details

Grey Systems: Theory and Application, vol. 10 no. 2
Type: Research Article
DOI: https://doi.org/10.1108/GS-11-2019-0055
ISSN: 2043-9377

Keywords

  • Total retail sales of consumer goods
  • GRA model
  • Seasonal fluctuation
  • Data grouping method

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Case study
Publication date: 17 October 2012

A new business model to Chinese style agricultural industrialization

Zheng Wang and Guiping Lin

Start-ups in emerging markets, entrepreneurship, business models and strategy.

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Abstract

Subject area

Start-ups in emerging markets, entrepreneurship, business models and strategy.

Study level/applicability

The case is suitable for MBA and EMBA graduate and undergraduate students in strategic management, finance and the relevant areas.

Case overview

This case provides a real-life entrepreneurial situation in agricultural industry in China. The protagonist of the case is the founder and CEO of the start-up Harvest Agricultural Technology and Development Company Limited (Harvest). From his perspective, the case depicts the current business environment for private companies in China, and presents the opportunities and challenges a new start-up faces in this environment. Agricultural industry plays an important role in the Chinese economy. Especially because in China land is owned by the state or collective, agricultural industrialization has more significance and experiences greater difficulties. The company in the case explores the situation of integrating the different stakeholders of agricultural production and delivery given the current political and economic environment. The case describes the characteristics and quality that a typical Chinese entrepreneur has and questions why such factors matter so much in China. The case emphasizes the strategic planning process of Harvest and its unprecedented business model design. The case also touches upon the growth pattern of entrepreneurial companies in China. All the above issues deserve discussion and in-depth analysis.

Expected learning outcomes

After studying this case, students should be able to: describe the business environment in China and identify the stakeholders of the agricultural industry in China; describe the process and value chain of agriculture production and delivery by adopting management models if necessary; discuss the personality and quality of the founder and CEO and compare his characteristics with that of western entrepreneurs and analyse why these characteristics are helpful (or detrimental) to the start-up company; analyse the development of business model designs, and identify the merits, drawbacks and risks of each version of business model; analyse the competitive advantages of Harvest, and identify the key resources and capacities with management models if necessary; discuss different possibilities of Harvest's future with evidence and process analysis; discuss whether the business model and the development strategy of Harvest are applicable to other companies or industries; discuss how setting the goal of going public on the first day Harvest was founded will affect the development of the company; and compare the business models of Harvest with other companies serving as a platform in a different industry (i.e. Taobao marketplace).

Supplementary materials

Teaching notes are available for educators only. Please contact your library to gain login details or email support@emeraldinsight.com to request teaching notes.

Details

Emerald Emerging Markets Case Studies, vol. 2 no. 8
Type: Case Study
DOI: https://doi.org/10.1108/20450621211312956
ISSN: 2045-0621

Keywords

  • Business model
  • Agricultural industrialization
  • Entrepreneurship
  • Integrated solutions
  • Modelling
  • China
  • Business enterprise
  • Business formation
  • Emerging markets

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