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1 – 10 of 834Yonghua Li, Hao Yin and Qing Xia
This study aims to research the influence of non-probabilistic design variables on interval robust optimization of electric multiple units (EMU) brake module, therefore obtain the…
Abstract
Purpose
This study aims to research the influence of non-probabilistic design variables on interval robust optimization of electric multiple units (EMU) brake module, therefore obtain the reasonable of design variables of the EMU brake module.
Design/methodology/approach
A robust optimization model of the EMU brake module based on interval analysis is established. This model also considers the dimension tolerance of design variables, and it uses symmetric tolerance to describe the uncertainty of design variables. The interval order relation and possibility degree of interval number are employed to deal with the uncertainty of objective function and constraint condition, respectively. On this basis, a multiobjective robust optimization model in view of interval analysis is established and applied to the robust optimization of the EMU brake module.
Findings
Compared with the traditional method and the method proposed in the reference, the maximum stress fluctuation of the EMU brake module structure is smaller after using the method proposed in this paper, which indicates that the robustness of the maximum stress of the structure has been improved. In addition, the weight and strength of the structure meet the design requirements. It shows that this method and model introduced in this research have certain feasibility.
Originality/value
This study is the first attempt to apply the robust optimization model based on interval analysis to the optimization of EMU structure and obtain the optimal solution set that meets the design requirements. Therefore, this study provides an idea for nonprobabilistic robust optimization of the EMU structure.
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Shaodi Zhao, Yan Yin, Jiusheng Bao, Xingming Xiao, Zengsong Li and Guoan Chen
The friction between brake pair causes an intense temperature rise on interface during braking, which affects the braking performance seriously. Therefore, building an accurate…
Abstract
Purpose
The friction between brake pair causes an intense temperature rise on interface during braking, which affects the braking performance seriously. Therefore, building an accurate testing method for frictional temperature rise (FTR) is a prerequisite.
Design/methodology/approach
Facing braking conditions of automobiles, an experimental system for testing of FTR based on preset thermometry method (PTM) was established. The FTR was collected by the PTM and the variation laws as well as the cause of errors were analyzed by experiments. The deviations between tested and real temperature were corrected based on tribology and heat theories. Finally, an online prediction method for FTR was pointed out.
Findings
After correction, the temperature curve accords well with the laws of tribology and thermal theories. The corrected FTR at braking end point is approximately equal to the authentic temperature test by hand thermometer.
Originality/value
This study eliminated the hysteresis phenomenon of temperature rise sequence and lays a foundation for online accurate monitoring and warning of brake friction temperature rise. It has important theoretical and practical value for expanding the monitoring and improvement of brake performance.
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Edward D. Arnheiter and Hendrik Harren
Benefits of modularity are being limited by the lack of agreement over terminology. Neither researchers nor managers use the same typology, complicating comparisons of modular…
Abstract
Purpose
Benefits of modularity are being limited by the lack of agreement over terminology. Neither researchers nor managers use the same typology, complicating comparisons of modular strategies.
Design/methodology/approach
Presents existing problem, then develops comprehensive and necessary typology. Examples illustrate practical use of the typology, and help reader understand implications on product design and future research.
Findings
Development of modularity typologies, including their characteristics and implications for product design and production systems, has been minimal. A well‐defined typology for soft modules exists, but literature on categorization of hard modules is limited. Most existing definitions of modularity are related to a common type called manufacturing modularity.
Practical implications
Each type of modularity is characterized by a different set of design attributes. For example, appearance, durability, and ergonomics are important for product‐use modularity, while accessibility, recycling and cost are key considerations for limited life modularity. Designers must understand these different characteristics in order to design products that address relevant customer needs such as cost, customization, serviceability and upgradeability that can give product a competitive edge in the marketplace. When developing individual modules, focus on core characteristics of that module type. When developing a multiple module type product, balance characteristics of the interdependent module types in order to ensure that the product meets customer needs.
Originality/value
Four types of modularity are defined: manufacturing, product‐use, limited life and data access. New products often incorporate all four types in order to address both the needs of the customers as well as the manufacturer.
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Leiting Zhao, Kan Liu, Donghui Liu and Zheming Jin
This study aims to improve the availability of regenerative braking for urban metro vehicles by introducing a sensorless operational temperature estimation method for the braking…
Abstract
Purpose
This study aims to improve the availability of regenerative braking for urban metro vehicles by introducing a sensorless operational temperature estimation method for the braking resistor (BR) onboard the vehicle, which overcomes the vulnerability of having conventional temperature sensor.
Design/methodology/approach
In this study, the energy model based sensorless estimation method is developed. By analyzing the structure and the convection dissipation process of the BR onboard the vehicle, the energy-based operational temperature model of the BR and its cooling domain is established. By adopting Newton's law of cooling and the law of conservation of energy, the energy and temperature dynamic of the BR can be stated. To minimize the use of all kinds of sensors (including both thermal and electrical), a novel regenerative braking power calculation method is proposed, which involves only the voltage of DC traction network and the duty cycle of the chopping circuit; both of them are available for the traction control unit (TCU) of the vehicle. By utilizing a real-time iterative calculation and updating the parameter of the energy model, the operational temperature of the BR can be obtained and monitored in a sensorless manner.
Findings
In this study, a sensorless estimation/monitoring method of the operational temperature of BR is proposed. The results show that it is possible to utilize the existing electrical sensors that is mandatory for the traction unit’s operation to estimate the operational temperature of BR, instead of adding dedicated thermal sensors. The results also validate the effectiveness of the proposal is acceptable for the engineering practical.
Originality/value
The proposal of this study provides novel concepts for the sensorless operational temperature monitoring of BR onboard rolling stocks. The proposed method only involves quasi-global electrical variable and the internal control signal within the TCU.
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Zhang Ming, Nie Hong, Wei Xiao‐hui, Qian Xiaomei and Zhou Enzhi
The purpose of this paper is to introduce a co‐simulation method to study the ground maneuvers of aircraft anti‐skid braking and steering.
Abstract
Purpose
The purpose of this paper is to introduce a co‐simulation method to study the ground maneuvers of aircraft anti‐skid braking and steering.
Design/methodology/approach
A virtual prototype of aircraft is established in the multibody system dynamics software MSC.ADAMS/Aircraft. The anti‐skid braking control model, which adopts the multi‐threshold PID control method with a slip‐velocity‐controlled, pressure‐bias‐modulated (PBM) system, is established in MATLAB/Simulink. EASY5 is used to establish the hydraulic system of nose wheel steering. The ADAMS model is connected to block diagrams of the anti‐skid braking control model in MATLAB/Simulink, and is also connected to the block diagrams of nose wheel steering system model in EASY5, so that the ground maneuvers of aircraft anti‐skid braking and steering are simulated separately.
Findings
Results are presented to investigate the performance of anti‐skid braking system in aircraft anti‐skid simulation. In aircraft steering simulation, the influence of two important parameters on the forces acting on the tires is discussed in detail, and the safe area to prevent aircraft sideslip is obtained.
Originality/value
This paper presents an advanced method to study the ground maneuvers of aircraft anti‐skid braking and steering, and establishes an integrated aircraft model of airframe, landing gear, steering system, and anti‐skid braking system to investigate the interaction of each subsystem via simulation.
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Lalit Narendra Patil, Hrishikesh P. Khairnar and S.G. Bhirud
Electric vehicles are well known for a silent and smooth drive; however, their presence on the road is difficult to identify for road users who may be subjected to certain…
Abstract
Purpose
Electric vehicles are well known for a silent and smooth drive; however, their presence on the road is difficult to identify for road users who may be subjected to certain incidences. Although electric vehicles are free from exhaust emission gases, the wear particles coming out from disc brakes are still unresolved issues. Therefore, the purpose of the present paper is to introduce a smart eco-friendly braking system that uses signal processing and integrated technologies to eventually build a comprehensive driver assistance system.
Design/methodology/approach
The parameters obstacle identification, driver drowsiness, driver alcohol situation and heart rate were all taken into account. A contactless brake blending system has been designed while upgrading a rapid response. The implemented state flow rule-based decision strategy validated with the outcomes of a novel experimental setup.
Findings
The drowsiness state of drivers was successfully identified for the proposed control map and set up vindicated with the improvement in stopping time, atmospheric environment and increase in vehicle active safety regime.
Originality/value
The present study adopted a unique approach and obtained a brake blending system for improved braking performance as well as overall safety enhancement with rapid control of the vehicle.
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Edward D. Arnheiter and Hendrik Harren
Companies are emphasizing modular designs and manufacturing approaches, but to stay competitive and retain market share they must continue to offer products and services of the…
Abstract
Purpose
Companies are emphasizing modular designs and manufacturing approaches, but to stay competitive and retain market share they must continue to offer products and services of the highest quality. Therefore, since modularity is increasingly popular and product quality is always critical, the purpose of this paper is to examine the impact of modular strategies on key quality dimensions.
Design/methodology/approach
This paper first presents an overview of modularity, and then outlines eight commonly used dimensions of quality. Each dimension is then examined in terms of how it can be affected by modularity.
Findings
It is shown that modular product design has a significant impact on key attributes of product quality. Six of the eight quality dimensions examined are potentially affected in a positive way by modularity, while five of the eight attributes are affected in a potentially negative manner by the use of modularity.
Practical implications
Since modularity can have both a positive and negative impact on quality, managers must proceed with caution when adopting modular strategies.
Originality/value
This is a seminal work because it considers the impact of modularity on the dimensions of quality. It is argued that the use of modularity should not be considered a panacea by companies searching for a quick solution. That is, there are potentially significant negative side effects associated with modularity.
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Younghwan Kim and Hyunseung Lee
This study aims to develop a safe, wearable clothing system that combines visibility-enhancing and emergency–accident-responding functions for two-wheeled vehicle (TWV) users'…
Abstract
Purpose
This study aims to develop a safe, wearable clothing system that combines visibility-enhancing and emergency–accident-responding functions for two-wheeled vehicle (TWV) users' safety assistance.
Design/methodology/approach
First, the wearable system (WS) allowing users to control turn signals, brake lights and emergency flasher only with head movements was developed. Second, multiconnected systems were developed between WSs and a smartphone application (AS), providing accident occurrence recognition, driving photo capture–storage and emergency notification functions. Third, usability testing in each function was performed to assess the operability of the systems.
Findings
The intuitive interface, which uses head movement as gesture commands, was effectively operated for controlling turn signals, brake lights and emergency flasher when driving, despite differences in user physique and boarding structure among TWVs. In addition, using Bluetooth low energy and Wi-Fi protocols simultaneously can establish automatic accident recognition–notification and driving photo capture–storage–display functions by linking two WSs with one AS.
Research limitations/implications
This study presents a case using relatively accessible technologies within the fashion industry to improve users' safety and provide fundamental data for convergence education for smart fashion products, highlighting the significance of this study in this convergence era.
Originality/value
The WSs and the AS of a TWV user visually evoke the attention of other drivers and pedestrians, reducing the risk of accidents; social contribution regarding public safety will be possible by allowing the system to autonomously inform emergencies and receive emergency medical treatment quickly when the accident occurred.
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Zeyang Zhou and Jun Huang
This study aims to learn the dynamic radar cross-section (RCS) of a deflection air brake.
Abstract
Purpose
This study aims to learn the dynamic radar cross-section (RCS) of a deflection air brake.
Design/methodology/approach
The aircraft model with delta wing, V-shaped tail and blended wing body is designed, and high-precision unstructured grid technology is used to deal with the surface of air brake and fuselage. The calculation method based on multiple tracking and dynamic scattering is presented to calculate RCS.
Findings
The fuselage has a low scattering level, and the opening air brake will bring obvious dynamic RCS effects to itself and the whole machine. The average indicator of air brake RCS can be lower than –0.6 dBm2 under the tail azimuth, while that of forward and lateral direction is lower. The mean RCS of fuselage is obviously higher than that of air brake, while the deflected air brake and its cabin can still provide strong scattering sources at some azimuths. When the air brake is opening, the change amplitude of the aircraft forward RCS can exceed 19.81 dBm2.
Practical implications
This research has practical significance for the dynamic electromagnetic scattering analysis and stealth design of the air brake.
Originality/value
The calculation method for aircraft RCS considering air brake dynamic deflection has been established.
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Abstract
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