Bus Manufacturers Research Articles

Application of agent based simulation for evaluating a bus layout design from passengers’ perspective

This paper shows that agent based simulation can evaluate the performance of different bus layout designs from passengers’ perspective, thus helping bus manufacturers to design new layouts that are more attractive for passengers. Including agent-based simulation in the bus design process is an inexpensive and efficient procedure to evaluate new design concepts (wheel-well position, number of doors, etc.) in relation to the preferences, needs and expectations of current and future passengers. Its main advantage is that these new design concepts are evaluated well before manufacturing the first physical prototype. Bus passengers are modelled and simulated as autonomous agents. Eight different types of passengers, which were elaborated from observations of actual passengers, have been modelled. Passengers’ preferences and features have been implemented using a calibrated making decision algorithm. The paper also presents two case-studies to analyse the sensitivity of the performance of two different bus layouts with different number and distributions of passengers.

Modular route bus design – A method of meeting transport operation and vehicle manufacturing requirements

This research examines the problem of route bus specification and vehicle manufacturability. In order for bus operators to provide transport services, a range of vehicle configurations must be available from bus manufacturers, generating variety which has a negative impact on the manufacturing process. Larger part inventories, uncontrolled labour tasks and more troublesome maintenance are known impacts of this variety. This research identifies the functional necessities in route bus interior design and reduces the problems in bus manufacture and operation caused by specification diversity by proposing a modularised system of bus design. In particular, it makes recommendations as to how bus configuration should be carried out, ensuring an optimum mix of operational and manufacturing needs: 1.Determine user needs before the bus specification process.2.Designs to be developed by the manufacturer in response to user needs.3.This design should be standardised where possible, as suggested by the user needs.4.Where user needs dictate product variations, apply a mass customisation approach to accommodate these needs.The recommendations are communicated in design proposals for a modular bus interior, demonstrated by four cases designed to meet the present status quo of bus interior design and predictions for the future of the field.

Study, Evaluation and Implementation of Improvement in a compressed Air Plant

This paper presents the study of a compressed air generation system in a bus manufacturer, being evaluated the operation of the compressors to identify the electric energy consumption. A maintenance plan is elaborated to correct the air system leaks and also proposes the reuse of thermal energy generated by the compressors. Initially, as for the purpose of this paper, a revision of fundamentals related to thermodynamics transformation, are presented. Afterwards, some important electric energy concepts will lead to the understanding of the energy consumption of the compressors. Then, an overview about compressed air generation systems will be showed with the goal of understanding techniques of energetic efficiency. The tools used in this study for collecting data were the software of a compressor manufacturer with pressure transducers, and an energy analyzer. The basic concepts and their uses will be shown along this paper. The proposal of electric energy consumption reduction was achieved with the installation of compressor operation managers, there was a reduction nearly 60,600 kWh per month, which provided a monthly savings of R$19,400.00, validating the collected data. For heat recovery from the cooling air compressors, externally finned coils were sized to heat water up to 55 ºC and used in a process of heating rubber gaskets. For air leakage reduction, a working methodology to perform the corrective and preventive maintenance has been prepared, and a control system in the form of internal audit. This allowed the reduction of the air leakage was almost 50%. http://dx.doi.org/10.18226/23185279.v1iss1p11

Study on Key Technologies Based on the Bus Rollover Security

In order to reduce the traffic accident acused by roller, this study finds out the breakthrough point from the cause-effect relationship and function achievement mechanism aspects and studies key technologies based on the bus rollover security. The research directions mainly include lowering the height of the mass center to the greatest extent, shortening the span between side windows or making improvements on the sectional dimension of side pillars, strengthening the soldering joints of side body, ensuring the continuity of close loop structures and employing high-strength steels. Research results demonstrate that the proposed improvement directions and measures designed to enhance bus rollover security are rational and effective and they can provide beneficial guidance and reference for security design in the bus manufacturing.

MULTI-MATERIAL DESIGN OPTIMIZATION OF A BUS BODY STRUCTURE

In the recent years the safety and eco-friendliness have gained much of attention of the automotive stakeholders. These two characteristics are especially important in the case of mass transportation vehicles, such as buses or coaches, which are in continues use for long periods of time, covering significant distances. In such situations, the economical aspects play major role for the transportation companies which try to minimize operational costs of their fleet, by choosing vehicles with reduced fuel consumption. In order to obtain improvements in all the mentioned areas and hence to strengthen their position on the market, bus manufacturers have recently turned their attention to multimaterial design strategies. Structures built in that manner consist not only of regular steel parts, but contain also a mix of components made from various lightweight materials like aluminum alloys or composites, which allow for significant reduction in vehicle curb weight. However, due to the differences in mechanical characteristics which are especially evident in the case of laminates, the material substitution is not a straightforward task. In order to find the material distribution pattern that meets all the requirements, a great number of prototypic numerical models must be prepared and tested. To ease the search for the final solution, optimization techniques can be applied into the design process, allowing for automatic design modifications and assessment of the obtained results. The paper presents an attempt of enhancing the operational characteristics of a bus body structure with simultaneous reduction in the structural weight. In order to find the optimal component configuration, a multimaterial optimization was employed and supplemented by sensitivity and robustness analyses. Such a technique helps to discriminate the over-optimized solutions that are often pointed out as the most desirable by the optimization algorithms which neglect the uncertainties of the analysed system.

HYBRID MODELLING OF AN URBAN BUS

Sophisticated virtual prototyping methods have become a standard in the modern vehicle design process. Unfortunately, in many cases automobile manufacturers (in particular bus manufacturers) still do not take advantage of numerical de­sign techniques, basing instead on intuition and experience. In this paper hybrid modelling of an urban bus is presented. A hybrid bus model links different types of modelling that can be used to perform a wide range of virtual analyses of vehicle static and dynamic behaviour. The major objective of development and usage of a complex model is to reduce a time and cost of vehicle design process improving vehicle quality at the same time. The main advantage instead is a possibility to exploit a model for different performances of vehicle subsystems. A hybrid model representing real vehi­cle behaviour consists of three modelling techniques commonly used in automotive industry: multibody modelling, finite element modelling and multi- port (block) modelling. A full model has been developed via commercial software which ensures its availability among automotive engineers.

The Innovative Financing Model for Electronic Bus Development

The development of electric bus is crucial to the energy efficiency and CO2 reduction policies around the world. The research and manufacture technology of electric buses and batteries have matured in Taiwan, resulting in an established industrial chain. The development is promising. However, obstacles, such as the lack of infrastructure, high cost to build a bus, insufficient maintenance and servicing system and lack of essential knowledge to run an electric bus operation, are blocking the way for the development of electric bus. To solve them, we worked with electric bus manufacturer and bus services with experience in electric bus operations for operation diagnosis. The diagnosis revealed that the “financial pressure from operational capitals” is the top factor making the operation of electric bus difficult. In particular, the high cost to build one has the greatest impact. Secondly, an analysis on the models of traditional leasing and charging by mileage was performed to find out the strengths of both. An innovative and practically feasible financing model was developed by combining the separation of bus and electricity and green financing. Finally, an actuarial calculation was conducted to validate the effects of the model which is likely to minimize the operation risks for bus companies.

BRT and BHLS around the world: Explosive growth, large positive impacts and many issues outstanding

A survey of Bus Rapid Transit BRT and Bus of High Level of Service BHLS around the world indicates that there are about 120 cities with bus corridors, with 99 of the cities entering into the list in the last 12 years. The existing bus corridors comprise about 280 corridors, 4300 km, 6700 stations and use 30,000 buses, serving about 28 million passengers per day. In 2010–2011, 19 cities completed new systems − 16 in the developing world – and seven cities expanded their current systems. By late 2011, about 49 new cities were building systems, 16 cities were expanding their corridors, and 31 cities were in initial planning. This impressive growth may be attributed in part to the successes of Curitiba, Bogotá, México City, Istanbul, Ahmedabad and Guangzhou. These cities show low cost, rapid implementation and high performance BRTs, with significant positive externalities. Interesting trends are emerging, such as the implementation of citywide integrated bus systems, improved processes for private participation in operations, increased funding from national governments, and growth of bus manufacturers and technology providers. Despite the growth, there are some outstanding issues: BRT and BHLS do not have a single meaning and image and are often regarded as a “second best” as compared to rail alternatives. In addition several systems in the developing world suffer problems resulting from poor planning, implementation and operation, due to financial, institutional and regulatory constraints. The BRT and BHLS Industry are in their “infancy” and there is need for consolidation and concerted effort.

Manufacturing strategies for time based competitive advantages

PurposeThe main purpose of this paper is to investigate the current manufacturing strategies and practices of bus manufacturers in China, and to propose a framework of manufacturing strategies for time‐based competitive advantages.Design/methodology/approachThe conceptual research framework is devised from a review of the literature, and case studies are used to investigate the manufacturing strategies and practices in place in the case companies. Data are collected through semi‐structured interviews and secondary documentation.FindingsThe results show that, with over‐capacity in the Chinese bus manufacturing industry, success is no longer determined by high productivity or low price; a quick response to the customers' tailored demands is essential in a climate of fierce competition. The suggested best practices for time‐based competitive advantages comprise building technical centers and post‐doctoral research stations, applying modularity logic, adopting radio frequency identification (RFID), and optimizing processes by, for example, involving customers and integrating inbound and outbound logistics.Research limitations/implicationsThe research results are limited within the context of the bus manufacturing industry in China.Practical implicationsThe research results help both the practitioners and the researchers gain a better understanding of the practices of Chinese bus manufacturers from the perspective of time‐based competitive advantage. The proposed strategies and best practices have the potential to improve the manufacturing performance of this type of manufacturer.Originality/valueThis paper shows the big picture of manufacturing strategy and practice of bus manufacturers in the Chinese automobile industry. Furthermore, it presents a manufacturing strategy framework with best practice guidance to gain a time‐based competitive advantage.

Study on Rollover Security Based on the Bus Middle Body Frame

Based on the middle body frame of a Half-integral bus which a bus manufacturer mainly produces in China, this paper discusses analyses and improvements for rollover security of the bus middle body frame with TRIZ methodology and TRIZ tools. On the basis of forming mechanism of bus rollover, a breakthrough point has been found from cause and effect relationship and function achievements aspect; some customized measures are therefore proposed. It focuses on the stiffness design of side pillars and the strength enhancement of soldering joints. Applying CAE analysis based on Ls-dyna, the results show that the deformation and deformation mode of the bus middle body frame have been greatly improved during bus rollover, which fulfills the requirements of the force of ECE R66 Rollover Security Regulations and validates the correctness of suggested measures.

Proposal of a new method for effectiveness evaluation in the product design and development process

This paper addresses the subject of product design process evaluation from the designer's point of view. Based on the results of a preliminary research phase a comprehensive questionnaire is drawn up, and applied to a selected group of designers in the automotive industry, comprising Brazilian plants of two major car manufacturers, two Tier 1 suppliers and one lorry and bus manufacturer. Data provided by the answers are compiled, presented and discussed within each organizational environment. A combined analysis is then carried out in order to identify those management actions that are considered by the automotive industry as being more important for both assuring and evaluating the effectiveness of the product design and development process. Management actions are classified according to criteria supplied by the ISO quality management standards. Finally, based on the evaluation, management action indicators are defined and a single and flexible effectiveness index is proposed, which can be calculated using both company and industry data for evaluation and benchmark purposes.

Multi-item dynamic lot-sizing with delayed transportation policy

We optimize ordering and inbound shipment decisions for a manufacturer that sources multiple items from a single supplier. The objective is to satisfy the requirements in the production plan with minimum transportation and inventory holding costs over a multi-period planning horizon. Transportation costs are charged to the manufacturer on a per truck shipment basis. We investigate the option of delaying a less-than-full truckload shipment to the next period, by utilizing the safety stocks as needed. We analyze the impact of delaying shipments on both cost and service levels in stochastic environments through experiments with data from a bus manufacturer. The results indicate that the proposed policy reduces both holding and transportation costs without creating much stock-out risk.

Implementation challenges in mass customisation: route bus design

The implementation of Mass Customisation (MC) in bus manufacture presents two difficulties in light of current MC theory – the application of MC in a bespoke industry and the creation of capital goods. Bespoke industries are characterised by customer involvement and customised goods; i.e., meeting the needs of customers but not efficient manufacture. MC for capital goods presents differences from needs elicitation methods, and changes the theory surrounding product value, customers and utility. These issues are explored through the specific challenges met in the bus bodywork industry. The research opens the discussion on bespoke manufacturing, finds that bespoke and capital goods industries can benefit from MC, and ultimately uses this contrast to contribute to existing MC theory.

13LBA S100A4 transcripts in blood of colon, rectal, and gastric cancer patients: development of a new blood-based assay for improved diagnosis and prognosis

Over the last twenty years, the Research and Testing Institute in Pilsen (former SKODA Research Company) has been developing a methodology of computational and experimental investigation of strength and fatigue life of bodies of road vehicles for mass passenger transport. The methodology includes multibody dynamic simulations, FEM stress analysis, test bench testing and stress measurement during the service of a prototype vehicle aiming the evaluation of data about its fatigue life. The first presented case study demonstrates an example of using the methodology in the design stage of a trolleybus. There is a bus manufacturer that plans to include accelerated fatigue testing on special test tracks as a final test to demonstrate a satisfactory operational fatigue life of the vehicle in a shorter time. In real urban traffic and on the test circuit, extensive stress measurements on a number of structural details and components have been carried out and analysed. In collaboration with the Regional Technological Institute, which is the research centre of the Faculty of Mechanical Engineering of the University of West Bohemia, fatigue life was calculated for critical structural details and components of various parts of the bus. Based on these calculations, the development potential was assessed and planning of accelerated tests on proving grounds was considered.

The design and aerodynamics of commercial vehicles

Improving transport efficiency is an ongoing challenge for bus and truck manufacturers. Especially aerodynamics offer a high potential in terms of reducing fuel consumption and emissions of trucks and buses. MAN reaches with a aerodynamic-optimised semitrailer tractor a CW value of 0.30.

Minimização e reutilização de resíduos na etapa de preparação de chassi em uma indústria automobilística

Bus manufacturing process comprises the following steps: chassis receiving, chassis preparing, body assembly, painting and finishing. Liquid and solid wastes are generated during the process. This study aims to identify mechanisms to minimize the generation of solid waste in the step of chassis preparation. The study followed the methodology of cleaner production by CNTL. Components withdrawal is responsible for the greatest variety and quantity of waste generated during chassis preparing step. Some components are used by the company, but it still represents a small amount of the total generated wastes. Among the components with the possibility of reuse are: washers, nuts, bolts, diesel oil and seatbelts. Panels and metal chairs wastes could be avoided. The total savings related to the techniques of reuse and minimization of the selected components may reach R$ 152.892.90 during the period of one year (base year 2006). Key words: cleaner production, reuse of waste, automotive industry, industrial solid waste, solid waste prevention.

Crash and safety assessment program for paratransit buses

This paper describes an assessment program for paratransit buses concerning their crashworthiness and safety of passengers. The program developed by the authors was approved by the Transit Office of the Florida Department of Transportation as a part of the Florida Vehicle Procurement Program (FVPP) in August 2007. Several valuable, worldwide vehicle safety standards were adopted in it with modifications addressing the bus construction process and relevance of particular structural components in crash events. Passenger compartment structure, which needs to be protected against the most dangerous accidents such as a side impact and a rollover, is a major area of concern in the standard. Lack of such standards may result in poor crashworthiness characteristics of the bus structure and in severe injuries and possible passenger fatalities. Either full-scale experiments or numerical standardized simulations were proposed as equivalent approval methods for paratransit buses. Selected results for partially validated Finite Element (FE) models and the nonlinear explicit dynamic code LS-DYNA were used to demonstrate a numerical approach for a bus structure approval. The FE models can also be used to assist the bus manufacturer in an effort to improve the crashworthiness of the new bus designs. The procedure described in this paper was implemented to monitor crashworthiness resistance of the paratransit buses distributed and operated in the state of Florida.

The influence of seat structure and passenger weight on the rollover crashworthiness of an intercity coach*

A rollover event is one of the most crucial hazards for the safety of passengers and the crew riding in a bus. In past years it was observed that the deforming body structure seriously threatens the lives of the passengers after the accident, and thus the rollover strength has become an important issue for bus and coach manufacturers. Today the European regulation “ECE-R66” is in force to prevent catastrophic consequences of such rollover accidents, thereby ensuring the safety of bus and coach passengers. According to the said regulation the certification can be gained either by full-scale vehicle testing, or by analysis techniques based on advanced numerical methods (i.e., nonlinear explicit dynamic finite element analysis). The quantity of interest at the end is the bending deformation enabling engineers to investigate whether there is any intrusion in the passenger survival space along the entire vehicle. In this paper, explicit dynamic ECE-R66 rollover crash analyses of a stainless-steel bus under development were performed and the strength of the vehicle is assessed with respect to the requirements of the official regulation. Subsequently, starting from a baseline design, different considerations which are not currently mentioned in the regulation (i.e., passenger and luggage weight) and some worst case assumptions, such as the influence of the seat structure, were investigated. The nonlinear explicit dynamics code LS-DYNA as a solver and ANSA and LS-PREPOST softwares as FEA pre/post-processors were utilized throughout the bus rollover analysis project. The FEA model was generated by using PCs running on Linux Suse operating system, whereas the LS-DYNA solutions were performed on a multiple-processor workstation running on an AIX UNIX operating system. During the first stage, a verification of the analysis procedure following regulation ECE-R66 was performed. The verification of analysis is a compulsory requirement of the regulation, as it is the technical service's responsibility (TÜV Süddeutschland in this case) to verify the assumptions used in the finite element analysis. The investigations indicated that the introduction of belted passengers increases the energy to be absorbed during rollover significantly (37% greater than the baseline), which severely impacts the rollover behavior of the pillars. When the vehicle is fully loaded (including passenger weight and luggage mass) the situation gets even worse. Even the tough center of gravity of the vehicle is lowered, and the total mass increases, which in turn gives the maximum intrusion. *This paper was originally presented at the 9th International LS-DYNA users conference, Detroit, MI, USA in June 2006, and published in the subsequent conference proceedings [14].

Life-cycle assessment of diesel, natural gas and hydrogen fuel cell bus transportation systems

The Sustainable Transport Energy Programme (STEP) is an initiative of the Government of Western Australia, to explore hydrogen fuel cell technology as an alternative to the existing diesel and natural gas public transit infrastructure in Perth. This project includes three buses manufactured by DaimlerChrysler with Ballard fuel cell power sources operating in regular service alongside the existing natural gas and diesel bus fleets. The life-cycle assessment (LCA) of the fuel cell bus trial in Perth determines the overall environmental footprint and energy demand by studying all phases of the complete transportation system, including the hydrogen infrastructure, bus manufacturing, operation, and end-of-life disposal. The LCAs of the existing diesel and natural gas transportation systems are developed in parallel. The findings show that the trial is competitive with the diesel and natural gas bus systems in terms of global warming potential and eutrophication. Emissions that contribute to acidification and photochemical ozone are greater for the fuel cell buses. Scenario analysis quantifies the improvements that can be expected in future generations of fuel cell vehicles and shows that a reduction of greater than 50% is achievable in the greenhouse gas, photochemical ozone creation and primary energy demand impact categories.

Model for mapping Knowledge Management in product development: a case study at a truck and bus manufacturer

Knowledge Management (KM) is an essential process to support New Product Development (NPD). This paper proposes a model for mapping knowledge management capability in NPD based on the occurrence of knowledge conversions in NPD dimensions. There are four conversions related to two types of knowledge: tacit and explicit (socialisation, externalisation, combination and internalisation). The dimensions of NPD are: strategy, organisation, activity and resource. The model has been applied to the real case of a truck and bus manufacturer to diagnose the knowledge conversions of its NPD. This case, the first to validate the model, also served to improve the model's content.