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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
481

Systerstädernas cykelsatsningar: En analys av möjligheterna för ökad cykeltrafik i en sydskandinavisk kontext

Roth, Andreas, Nilsson, André January 2015 (has links)
I det hållbara planeringsidealet anses cykeln vara en viktig del av en fungerande trafiklösning, trots detta tenderar många städer ha problem att uppnå deras egna mål för ökad cykeltrafik. Studien analyserar Malmös och Köpenhamns cykelplanering och cykelvägsstruktur utifrån aktuell cykeltrafikforskning, i syfte att undersöka vilka strategier och förutsättningar som städerna har gemensamt, och vad som skiljer dem åt. Målet för studien är att få svar på hur, och i vilken mån Malmös cykeltrafikandel kan öka utifrån Köpenhamns exempel, och att få en vidare förståelse för de utmaningar som den framtida cykelplaneringen står inför. Studiens metod tar ansats ur fältstudier av fyra cykelfrämjande städer i Europa. Sammanställningen av fältstudierna resulterar i att tre cykelstrategier identifieras som gemensamma för de fyra cykelfrämjande städerna. Därefter analyseras Köpenhamns och Malmös cykelprogram utifrån de tidigare nämnda cykelstrategierna. Analysen fastslår att Köpenhamn borde ses som en framstående cykelstad och möjliggör för en jämförande analys mellan Köpenhamns och Malmös cykelsatsningar. Den jämförande analysen mellan Köpenhamns och Malmös cykelsatsningar avslutas med en redovisning och tolkning av resultaten från analysen.För att kunna förstå cykelprogrammens spatiala relation till städerna de är tänkta att implementeras i används en space syntax-analys. Genom att undersöka satsningarnas rumsliga kontext i förhållande till det befintliga cykelvägsystemet kan en djupare förståelse för cykelsatsningarnas omfattning och orsak uppnås.Studiens resultat identifierar tre strategier som är direkt kopplade till andelen cykeltrafik i städer. Den fastställer även att trots cykelsatsningarnas övergripande likheter, skiljer implementeringen och omfattningen av dessa satsningar sig åt mellan Köpenhamn och Malmö. Infrastrukturens stora påverkan på cykelutvecklingen i stort framgår även det i studiens resultat. Studien visar även på hur de båda städernas cykelprogram förhåller sig till cykelns socialt utjämnande egenskaper. Resultatet visar att det finns indikationer från båda städernas framtida cykelplanering på att dessa utjämnande egenskaper har fått en lägre prioritering allt efter cykeltrafiken anpassas till starkare samhällsgrupper. / In the sustainable planning paradigm, the bicycle is seen as playing an important role of combining effective, environmentally friendly, and space conserving transport to the compact city. Despite its overall positive effect on city life, many cities seem to struggle to achieve the goal of increased bicycle traffic. This study studies the similar strategies and efforts used by bicycle friendly European cities through current research literature, in order to analyze Malmö’s and Copenhagen’s efforts to increase their bicycle traffic. The goal of the study is to examine Malmö’s potential for increased bicycle traffic through Copenhagen’s bicycle planning strategies, and to get a deeper understanding of the challenge’s that may face the future field of bicycle planning. The study’s method starts in field studies of four bicycle friendly European cities. The compilation of the field studies identifies three bicycle planning strategies as mutual for all four cities. The mutual bicycle strategies are then used as a tool and benchmark for the analysis of Copenhagen´s and Malmoe´s municipal bicycle program. To understand the spatial relation between the cities bicycle strategies and the street network that they are supposed to be implemented in, a space syntax-analysis is performed. The results from the comparative analysis of the cities bicycle programs and the space syntax-analysis is then summarized and discussed. The result of the study identifies three crucial criteria’s that according to the study has a high possibility of affecting a city’s bicycle share. It also points to the importance of a well-developed bicycle infrastructure to achieve a higher level of competitiveness for the bicycle as a mode of transport. The study also highlights the socially balancing properties of the bicycle as a mode of transport, and the concern of losing these properties due to bicycle planning strategies that is starting to be adapted in order to attract people from more affluent social groups.
482

Dynamic Modelling and Optimal Control of Autonomous Heavy-duty Vehicles

Chari, Kartik Seshadri January 2020 (has links)
Autonomous vehicles have gained much importance over the last decade owing to their promising capabilities like improvement in overall traffic flow, reduction in pollution and elimination of human errors. However, when it comes to long-distance transportation or working in complex isolated environments like mines, various factors such as safety, fuel efficiency, transportation cost, robustness, and accuracy become very critical. This thesis, developed at the Connected and Autonomous Systems department of Scania AB in association with KTH, focuses on addressing the issues related to fuel efficiency, robustness and accuracy of an autonomous heavy-duty truck used for mining applications. First, in order to improve the state prediction capabilities of the simulation model, a comparative analysis of two dynamic bicycle models was performed. The first model used the empirical PAC2002 Magic Formula (MF) tyre model to generate the tyre forces, and the latter used a piece-wise Linear approximation of the former. On top of that, in order to account for the nonlinearities and time delays in the lateral direction, the steering dynamic equations were empirically derived and cascaded to the vehicle model. The fidelity of these models was tested against real experimental logs, and the best vehicle model was selected by striking a balance between accuracy and computational efficiency. The Dynamic bicycle model with piece-wise Linear approximation of tyre forces proved to tick-all-the-boxes by providing accurate state predictions within the acceptable error range and handling lateral accelerations up to 4 m/s2. Also, this model proved to be six times more computationally efficient than the industry-standard PAC2002 tyre model. Furthermore, in order to ensure smooth and accurate driving, several Model Predictive Control (MPC) formulations were tested on clothoid-based Single Lane Change (SLC), Double Lane Change (DLC) and Truncated Slalom trajectories with added disturbances in the initial position, heading and velocities. A linear time-varying Spatial error MPC is proposed, which provides a link between spatial-domain and time-domain analysis. This proposed controller proved to be a perfect balance between fuel efficiency which was achieved by minimising braking and acceleration sequences and offset-free tracking along with ensuring that the truck reached its destination within the stipulated time irrespective of the added disturbances. Lastly, a comparative analysis between various Prediction-Simulation model pairs was made, and the best pair was selected in terms of its robustness to parameter changes, simplicity, computational efficiency and accuracy. / Under det senaste årtiondet har utveckling av autonoma fordon blivit allt viktigare på grund av de stora möjligheterna till förbättringar av trafikflöden, minskade utsläpp av föroreningar och eliminering av mänskliga fel. När det gäller långdistanstransporter eller komplexa isolerade miljöer så som gruvor blir faktorer som bränsleeffektivitet, transportkostnad, robusthet och noggrannhet mycket viktiga. Detta examensarbete utvecklat vid avdelningen Connected and Autonomous Systems på Scania i samarbete med KTH fokuserar på frågor gällande bränsleeffektivitet, robusthet och exakthet hos en autonom tung lastbil i gruvmiljö. För att förbättra simuleringsmodellens tillståndsprediktioner, genomfördes en jämförande analys av två dynamiska fordonsmodeller. Den första modellen använde den empiriska däckmodellen PAC2002 Magic Formula (MF) för att approximera däckkrafterna, och den andra använde en stegvis linjär approximation av samma däckmodell. För att ta hänsyn till ickelinjäriteter och laterala tidsfördröjningar inkluderades empiriskt identifierade styrdynamiksekvationer i fordonsmodellen. Modellerna verifierades mot verkliga mätdata från fordon. Den bästa fordonsmodellen valdes genom att hitta en balans mellan noggrannhet och beräkningseffektivitet. Den Dynamiska fordonsmodellen med stegvis linjär approximation av däckkrafter visade goda resultat genom att ge noggranna tillståndsprediktioner inom det acceptabla felområdet och hantera sidoacceleration upp till 4 m/s2 . Den här modellen visade sig också vara sex gånger effektivare än PAC2002-däckmodellen. v För att säkerställa mjuk och korrekt körning testades flera MPC varianter på klotoidbaserade trajektorier av filbyte SLC, dubbelt filbyte DLC och slalom. Störningar i position, riktining och hastighet lades till startpositionen. En MPC med straff på rumslig avvikelse föreslås, vilket ger en länk mellan rumsdomän och tidsdomän. Den föreslagna regleringen visade sig vara en perfekt balans mellan bränsleeffektivitet, genom att minimering av broms- och accelerationssekvenser, och felminimering samtidigt som lastbilen nådde sin destination inom den föreskrivna tiden oberoende av de extra störningarna. Slutligen gjordes en jämförande analys mellan olika kombinationer av simulerings- och prediktionsmodell och den bästa kombinationen valdes med avseende på dess robusthet mot parameterändringar, enkelhet, beräkningseffektivitet och noggrannhet.
483

Non-Coupled and Mutually Coupled Switched Reluctance Machines for an E-Bike Traction Application: Pole Configurations, Design, and Comparison

Howey, Brock January 2018 (has links)
This dissertation contains a comprehensive analysis of both non-coupled and mutually coupled switched reluctance motors with concentrated windings for an electric bicycle traction application. Multiple pole configurations are analyzed and compared for each motor type. Includes magnetic design, thermal analysis, and structural analysis. A prototype is designed, manufactured, and validated. / This thesis discusses the design of both a conventional non-coupled switched reluctance motor (CSRM) and a mutually-coupled SRM (MCSRM) for an exterior rotor e-bike application. Several novel pole configurations were analyzed for each machine type, and the performance of the final CSRM and MCSRM designs were compared for this application. A commercially available e-bike permanent magnet synchronous motor (PMSM) was purchased, reverse engineered, and validated to define the geometry constraints and performance targets for the designs. Since switched reluctance motors do not use rare-earth permanent magnets, they are often seen as a potential low-cost alternative to permanent magnet machines. The goal of this research is to explain the relative advantages of CSRMs and MCSRMs when compared to PMSM machines for a direct-drive e-bike application. The final CSRM and MCSRM designs are analyzed in detail; electromagnetic, controls, thermal, and structural considerations are all studied. A prototype of the final CSRM design was manufactured and validated experimentally, using a dynamometer setup. The finalized CSRM design is shown to be competitive with the PMSM machine when considering torque output, and is superior in terms of peak efficiency, and high speed torque performance. However, the CSRM noise output and torque ripple were not compared to the PMSM, and a less-common asymmetric-bridge converter is required for the CSRM, which may hinder the ability for the machine to be implemented into existing e-bike packages. The high speed torque performance of the MCSRM is shown to be inferior to both the CSRM and PMSM, as is the torque quality and efficiency. The MCSRM is shown to be highly resistant to saturation which gives it the potential for high torque output at low speed (if thermal limits are not breached), though low saturation levels also contribute to low machine power factor. The MCSRM may be better suited to lower speed, high torque applications, for this reason. / Thesis / Doctor of Philosophy (PhD) / This thesis studies the design process and analysis of two different motor types, for an electric bicycle application. They are designed to replace a commercially available permanent magnet synchronous motor (PMSM). This type of motor is typically expensive due to the rare-earth magnet material it requires. The two motors discussed in this thesis are switched reluctance motors (SRMs), which do not require magnet material, and thus have the potential to save cost (in addition to other benefits). One of the SRMs has magnetic fields that are independently controlled (CSRM), and one has fields that are controlled together to produce torque (MCSRM). The magnetics, control, thermal, and structural aspects of the CSRM and MCSRM are studied in detail. Novel geometry considerations (i.e. novel pole configurations) which impact the magnetics of each machine are compared to find the best-performing configuration for each machine type.
484

Formal Modelling of Cruise Control System Using Event-B and Rodin Platform

Predut, S., Ipate, F., Gheorghe, Marian, Campean, Felician 28 June 2018 (has links)
no / Formal modelling is essential for precisely defining, understanding and reasoning when designing complex systems, such as cyberphysical systems. In this paper we present a formal specification using Event-B and Rodin platform for a case study of a cruise control system for a hybrid propulsion vehicle and electric bicycle (e-Bike). Our work uses the EventB method, a formal approach for reliable systems specification and verification, being supported by the Rodin platform, based on theorem proving, allowing a stepwise specification process based on refinement. We also use, from the same platform, the ProB model checker for the verification of the B-Machine and iUML plug-in to visualize our model. This approach shows the benefits of using a formal modelling platform, in the context of cyberphysical systems, which provides multiple ways of analysing a system. / Romanian National Authority for Scientific Research, CNCS-UEFISCDI, project number PN-III-P4-ID-PCE-20160210.
485

[en] ANALYSIS OF THE VARGENS URBAN STRUCTURING PLAN, RIO DE JANEIRO, WITH CONSIDERATIONS ON SUSTAINABLE URBAN MOBILITY, INFRASTRUCTURE AND SOCIO-ENVIRONMENTAL CONDITIONS / [pt] ANÁLISE DO PLANO DE ESTRUTURAÇÃO URBANA DAS VARGENS, RIO DE JANEIRO, COM CONSIDERAÇÕES SOBRE MOBILIDADE URBANA SUSTENTÁVEL, INFRAESTRUTURA E CONDIÇÕES SÓCIO AMBIENTAIS

FLAVIA MORETZ SOHN CANTHE 27 June 2024 (has links)
[pt] A pesquisa faz uma análise crítica do Plano de Estruturação Urbana de Vargens, das características geofísicas locais, a infraestrutura atual, os serviços de transporte, a relação entre esses e a população, as alternativas modais, a preservação da ecologia urbana e os nós de conflito detectados no projeto conhecido como PEU das Vargens, apresentado pela prefeitura do Rio de Janeiro. Na busca por referências bem sucedidas de planejamento e prática da mobilidade urbana sustentável pelo mundo, o movimento para desestimular o uso do veículo individual motorizado e fomentar o uso dos meios de transporte ativo e o coletivo menos poluente, é através de infraestrutura integrada onde as malhas rodoviária, ferroviária e cicloviária se desenvolvem e se complementam. O modelo do planejamento da mobilidade em Berlim foi usado como referência das iniciativas de planejamento e práticas de humanização da territorialidade para a unificação sócio-espacial da cidade antes dividida. A bicicleta é inserida no planejamento viário, e cada vez mais assume o papel de principal modal para curtas e médias distâncias e também como alimentadora do sistema de transporte ferroviário urbano e regional, o equivalente ao nosso VLT e trem. O estudo dos casos e os dados obtidos permitiram identificar medidas tangíveis para a mitigação dos impactos urbanos negativos ao meio ambiente e sugerir alternativas para enfrentar os desafios da mobilidade em Vargens, visando à ampla acessibilidade e equidade na distribuição do espaço público de circulação, valorizando a caminhabilidade e mobilidade ativa, na direção de um modelo de mobilidade urbana sustentável, que equilibre o adensamento demográfico e a adaptação às mudanças climáticas para a baixada das Vargens. / [en] This research provides a Vargens region - PEU Vargens Urban Development Plan critical analysis for the city of Rio de Janeiro. It suggests a mobility plan prioritizing urban sustainability, adaptation to climate changes and density growth. The aim was to propose a less-polluting, more-inclusive mobility system, integrated with available road transportation. The study analyses local geophysical characteristics, current urban infrastructure, transportation services, the relationship between these factors and population needs, alternative modes, preservation of urban ecology, and conflict points noted in the ongoing project proposed by the municipality of Rio de Janeiro, regarding the mobility development plan described at PEU. German cities examples are used as a reference, especially Berli s mobility model, regarding public initiatives to encourage new generations to opt for non-polluting active individual transportation and less-polluting mass transportation. The principal instrument in humanizing territoriality is the bicycle, especially for short and medium distances. For longer distances, where the railway lines assume the main role, bicycles should have free access and be the main feeders of the transport system. The case study´s data allowed the author to identify and suggest alternatives in order to confront the challenges of mobility in Vargens, especially focusing on ample accessibility, with equity in distributing public circulation, throughout routes designed to ensure safety, comfort on journeys, and valuing walkability and active mobility, and above all, focusing on taking tangible measures to reduce negative environmental urban impacts.Initially an intense bibliographical research on intelligent urban planning was done, to understand norms and public policies focused on traffic plans; the network of the main roads and cycleways of the city of Rio de Janeiro and its integration with the public transit system, the usual routes and the capacity forintegration among the modalities. For the analysis of socioeconomics, we used census data and the spatial distribution map of IBGE’s social development indices. An online quiz was developed and applied, presenting questions about safety, routes and modalities in order to understand wishes and needs of the local community, in the goal of a humanized urban development.
486

Optimizing Sustainable Mobility : Coordination Strategies for Developing Bicycle Highways in Skåne

Åsberg, Sofia January 2024 (has links)
Today’s urban planners and scholars emphasize the necessity of a shift towards sustainable modes of transport. Among these, bicycle highways have emerged as an innovative infrastructure solution. Characterized by their broader lanes and separation from other transport modes, they offer a safer and more efficient alternative to traditional bike lanes. However, the implementation of bicycle highways presents challenges as they cross several municipal borders and involve multiple stakeholders across various governmental levels. This thesis explores the advantages and challenges of implementing bicycle highways in Skåne. By interviewing eight officials working with bicycle highway planning at various governmental levels, the thesis aims to explore and analyze the gaps in translating frameworks, such as multi-level governance, into practice. It also investigates the differences in frameworks, values, and attitudes to explore how these variations affect the conditions and efforts for collaboration across various governmental scales. The thesis discovers multiple advantages perceived by officials within the field in terms of a higher-quality design of the bicycle infrastructure, while also discovering the challenges of implementing such infrastructure. It also recognizes that collaboration within various governmental scales is needed to develop seamless bicycle highways. Different approaches among road actors related to prioritized values, allocation of budgets, political ideals, and timeframes are identified, and could affect the effectiveness of collaboration across scales. However, attitudes continue to be a crucial factor in the success of bicycle highways between urban areas.
487

Cykeln i den moderna staden : En kvalitativ studie av cykelinfrastruktur och dess roll i stadsplaneringen / The Bicycle in the Modern City : A qualitative study of bicycle infrastructure and its role in urban planning

Szanto, Linda, Lundberg, Ann-Sofie January 2024 (has links)
With the increasingly undeniable severity of the global climate crisis, changes must be made to limit the negative effects of transportation. Since the beginning of the 20th century, the car has taken over the infrastructure of cities and their designs. The bicycle has become a leading hope for sustainable transportation within cities. Different strategies and methods for encouraging the switch from car to bike include penalties for car use (such as high parking fees etc.) or incentives for bike use (such as prioritized bike infrastructure).   This thesis focuses on the role of bicycle infrastructure in promoting the bicycle as a sustainable mode of transportation, especially as an alternative to the car. This is achieved through a case study on the City of Malmö, by reviewing their strategic documents, interviews with traffic planners and the chairman of the Malmö-Lund chapter of Cykelfrämjandet (an organisation for the promotion of bicycles), and an analysis of current bike paths in Malmö.  The city of Malmö is building to change the context of mobility through restructuring the infrastructure of the city towards more sustainable transportation. By changing the layout of the main streets of the city into more active urban areas with priority for pedestrians, bicyclists, and public transportation they will be reclaimed as public spaces. Speeds will be lower and crossings more frequent to create a safer, more attractive, and more sustainable city landscape. The bicycle is to be further prioritised through extensive development of the network of bike paths and the implementation of superbike paths. This extended accessibility will give the bike further competitiveness towards car users.
488

PARKERINGSPLANERING FÖR NYA TYPER AV FORDON : Utformningsförslag inom Västerås stad zon 1 för parkering av nya miljövänliga transportmedel

Thunberg, Stefan, Johansson, Sofia January 2021 (has links)
Purpose: This study aims to produce a design proposal of standard parkings for future environmentally friendly vehicles that can be used everywhere. It also submits a proposal for a part within Västerås city zone 1 where curbside car park can be replaced. Method: An external analysis containing a questionnaire study, interviews with experts in municipalities in 4 other selected cities, Örebro, Uppsala, Gent and Copenhagen combined with a literature study and a case study of the city of Västerås parkingzone 1 was performed. All material were collected to analyze how to design and were to place parkings for ecological environmentally friendly vehicles. Results: The results shows that a lot can be done in Västerås in terms of parking. The design and layout must include more types of vehicles as well as better amenities and security. This study gives suggestions and example of how to design and plan parkingspace for the future. Conclusions: The conclusion is that there are factors that slows the process down. The knowledge is great with the planners department but the information and knowledge in the population is lacking as well as the will and determination at the municipal politicians. There is also an architectural aspect on the shaping of parkings that don’t follow the user ́s needs. Another conclusion is that a wider variety of parking is needed in the future.
489

Evaluation of Active Rear Steering through Multi-Body Simulation / Utvärdering av Aktiv Bakaxelstyrning genom Multibody-System Simuleringar

Rossi, Matteo, Bertoli, Gabriele January 2021 (has links)
The goal of this thesis work is to evaluate and quantify the advantages and disadvantages of Active Rear Steering (ARS). The evaluation is carried out through Multi-Body System (MBS) simulations. An analytical model has been developed to better understand the basic dynamics of vehicles equipped with rear steering. In parallel, a high fidelity MBS model is developed in Simpack. This model includes suspension kinematics and compliance, allowing for detailed analyses of steering hardware performance. Next, different control strategies aiming at improving manoeuvrability, stability and agility are implemented in Simulink. In order to assess their effectiveness, the high fidelity model is utilised by running co-simulation with Simulink. Manoeuvrability is assessed through constant steer, constant radius and ramp steer manoeuvres. Stability is assessed through transient manoeuvres such as step steer and sine with dwell. Agility is assessed through step steer and frequency response. Ultimately, also a subjective assessment is carried out by means of Volvo Cars' dynamic driving simulator. The conclusion from the assessment is that the drivers feel the all wheel steered vehicle more stable during evasive manoeuvres. It is concluded that for manoeuvrability the minimum turning radius is reduced by 19 % at low velocity; this implies that the steering angle request is reduced at low velocity, while it is increased at high velocity. A slightly higher steering angle request at high velocity might be beneficial since the driver would be able to control the vehicle in a wider range of steering wheel angles. For agility the results are contradicting: on the one hand, according to the step steer rise time difference between lateral acceleration and yaw rate, the controlled vehicles are performing worse than the passive vehicle; on the other hand, according to the frequency response analysis, both the delays between steering input and yaw rate and between lateral acceleration and yaw rate are reduced up to respectively 75 % and 46 % for the considered frequency range. Finally, for stability, the yaw rate overshoot from a step steer can be reduced up to 65 % at high velocity and the sideslip angle can always be reduced. The vehicle equipped with ARS outperforms the passive vehicle in the sine with dwell manoeuvre. / Målet med detta examensarbete är att utvärdera och kvantifiera fördelarna och nackdelarna med Active Rear Steer (ARS) för Volvo Cars. Utvärderingen utförs genom Multi-Body System (MBS) simuleringar. En analytisk modell har utvecklats för att bättre förstå den grundläggande dynamiken i fordon utrustade med bakhjulsstyrning. Parallelt utvecklades en MBS-modell med hög precision i Simpack. Denna modell inkluderar hjulupphängningens kinematik och eftergivlighet, vilket möjliggör detaljerade analyser av styrhårdvarans prestanda. Därefter implementeras olika kontrollstrategier som syftar till att förbättra manövrerbarhet, stabilitet och agilitet i Simulink. För att bedöma deras effektivitet används MBS-modellen för att köra co-simulering med Simulink.Manövrerbarhet bedöms genom konstant styrning, konstant radie och rampstyrning. Stabilitet bedöms genom transienta manövrar som stegstyrning och sinus med fördröjning. Agilitet bedöms genom stegstyrning och frekvensrespons. Slutligen görs också en subjektiv bedömning med hjälp av Volvo Cars dynamiska körsimulator. Slutsatsen från bedömningen är att förarna anser att fordonet upplevs vara mycket stabilare vid undanmanövrar. Vidare är slutsatsen att för manövrerbarhet minskar den minsta svängradien med 19 % vid mycket låg hastighet; detta innebär att styrvinkel reduceras vid låg hastighet, medan den ökar vid hög hastighet. En något högre styrvinkeln kan vara fördelaktig eftersom föraren skulle kunna styra fordonet i ett större rattvinkelområde. För agilitet är resultaten motsägelsefulla: å ena sidan, enligt stegstyrningstidsskillnaden mellan lateral acceleration och girhastighet, fungerar de aktiva fordonen sämre än det passiva fordonet; å andra sidan, enligt frekvensresponsanalysen, reduceras både fördröjningarna mellan girhastighet och styrvinkel och mellan lateral acceleration och girhastighet upp till ungefär 30 %. Slutligen, för stabilitet, kan girhastighetens översläng från en stegstyrning minskas upp till 65 % vid hög hastighet och avdriftsvinkeln kan alltid minskas. Fordonet som är utrustat med ARS överträffar det passiva fordonet i manövern sinus med fördröjning.
490

An investigation into the effectiveness of core muscle strengthening on cycling performance in asymptomatic cyclists

Wiseman, Kate 08 April 2014 (has links)
Dissertation submitted in partial compliance with the requirements for the Masters’ Degree in Technology: Chiropractic, Durban University of Technology, 2013. / Background : Core strengthening may improve athletic ability by providing stability to the trunk, and as a result, stabilising the pelvis. The leverage from which cyclists generate power may be enhanced as a result of a stable pelvis, thereby improving the cyclist’s performance. In the popular, highly competitive sport of cycling, performance enhancement is much sought after. Despite its widespread use, research involving core strengthening in sporting situations is lacking, with studies investigating the effect of a core strengthening programme on cycling performance yet to be investigated. Objectives : To determine the participants’ cycling speed, power, cadence and completion time, and core strength in terms of objective findings, pre- and post- core strengthening intervention, in the whole sample and within the two age strata. To determine the participants’ heart rate in terms of objective findings, and the rate of perceived exertion in terms of subjective findings, pre- and post- core strengthening intervention, in the whole sample and within the two age strata. To determine the participants’ perception of change in speed, power and cadence post- intervention, in the whole sample and within the two age strata. Method : Forty-two asymptomatic cyclists performed two 1.5 km time trials, pre- and post- core strengthening intervention. Core strength assessments were performed pre- and post- intervention, using the Pressure Biofeedback Unit, and the maximum and average speed (km/hr), power (w) and cadence (rpm), and completion time (s) were recorded pre- and post- intervention, using the Computerised Electromagnetic Roller resistance Ergometer (Tacx Trainer). Heart rate and rate of perceived exertion (RPE) were recorded pre- and post- intervention, as well as the participant’s perception of change in speed, power, and cadence post- intervention. SPSS version 20 (SPSS Inc) was used to analyse the data, in the whole sample and stratified into two age strata. Results : ll cycling performance indicators, speed, power, cadence and completion time showed a significant improvement post- intervention, in the whole sample, and within the two age strata. Core strength indicators showed a significant improvement post- intervention, in the whole sample and within the two age strata. A significant decrease in rate of perceived exertion and corresponding heart rate measurements post- intervention was observed in the whole sample. Similarly, the younger age strata reflected a significant decrease in rate of perceived exertion, however heart rate measurements were not significant. In contrast, the older age strata showed significant changes in heart rate measurements, with no significance in rate of perceived exertion measurements. The majority of participants experienced an increased perception in all outcomes post- intervention. Conclusions: The results of this study found that core strengthening had a statistically significant effect (p < 0.001) on cycling performance, both in terms of objective and subjective findings. Future studies could address the effect of core strengthening in an endurance setting.

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