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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.
31

Integrering av säkerhetsaspekter i produktutvecklingsprocessen av semiautonoma gaffeltruckar / Integration of Safety Aspects in the Product Development Process of Forklifts

Bazarkhuu, Dagvadorj, Dannert, Evelina January 2021 (has links)
Gaffeltruckar är motordrivna fordon som används flitigt inom industrin för att transportera gods. Automatiseringen av dessa är ett steg i linje med digitaliseringen av industrin och ett prioriterat säkerhetsarbete, och då semiautonoma truckar anses säkrare ökar både utbud och efterfrågan på dessa. Syftet med denna rapport var att undersöka hur företag involverar användare samt integrerar säkerhetsaspekter i sin produktutvecklingsprocess av semiautonoma gaffeltruckar för att minimera risken för personskador. Även synen på automatisering bland användare och tillverkare studerades, samt vilka möjligheter och utmaningar som automatiseringen medför. Forskningsfrågorna besvarades med hjälp av en litteraturstudie och en intervjustudie med fem respondenter från tre olika företag. Resultaten från intervjustudien sammanställdes och jämfördes med den teoretiska referensramen i en efterföljande analys och diskussion. Studien visade att säkerhetsaspekterna beaktas och integreras systematiskt i början av produktutvecklingsprocessen. Tillverkarna såväl som användarna ansåg att säkerhet är en allt viktigare aspekt som upplevs ha blivit mycket bättre under bara de senaste tio åren och säkerhetsaspekterna har utvecklats till att bli mer av hygienfaktorer som måste uppnås på grund av lagkrav och regleringar. En upptäckt som gjordes var därför att användare i regel inte involveras i syfte att integrera säkerhetsfunktioner utan snarare för att möta behov som är svårare att definiera och som handlar om hur produkten ska kännas och upplevas vid användning; såsom körkänsla och ergonomi. Det finns goda möjligheter att öka säkerheten med hjälp av automatisering av gaffeltruckar. Många tillbud och olyckor uppstår på grund av mänskliga faktorer, såsom missförstånd och ouppmärksamhet. Att reducera eller eliminera den mänskliga delen skulle troligen bidra till färre problematiska situationer och misstag, vilket kan rädda liv. Andra möjligheter är kopplade till produktivitet, där det bland annat finns ekonomiska vinster att hämta när industrin effektiviseras. Samtidigt finns det alltid utmaningar i samband med stora digitala omställningar. Automatiseringen av materialhanteringen innebär en investering som behöver godkännas och genomföras, vilket även kräver förarbete och efterforskning. Just bristande kunskap var något som framhävdes som ett hinder, men varken bland användare eller tillverkare ansågs hindrena större än möjligheterna. / Forklifts are motor-driven vehicles which are frequently used for the transportation of goods in the industry. The automation of these is a step in the right direction when it comes to digitalization and prioritized safety work, and as semi-autonomous forklifts are regarded as safer, both the supply and the demand for them are increasing. The aim of this report was to investigate how companies involve users and integrate safety aspects in their product development process of semi-autonomous forklifts to minimize the risk for bodily injuries. Furthermore, the view on automation among users and manufacturers was studied, along with the possibilities and challenges automation entails. The research questions were answered through a literature study and an interview study with five respondents from three different companies. The results from the interview study were compiled and compared with the theoretical source in a subsequent analysis and discussion. The study showed that safety aspects are regarded and integrated systematically during the start of the product development process. The manufacturers as well as the users believed that safety is an aspect which is becoming more and more important and which is perceived as having improved immensely during the last ten years. The safety aspects have evolved into more of hygiene factors which need to be reached due to legislative demands and regulations. A finding from this study was therefore that users were not involved with the purpose to integrate safety functions but rather to meet demands which are more difficult to define and which concern how the product should feel and be perceived in usage, such as driving sense and ergonomics. There are good possibilities to increase safety by automation. Many mishaps and accidents originate from human factors, such as misunderstandings and lack of attention. Reducing or eliminating the human contribution would probably lead to fewer problematic situations and mistakes, which could save lives. Other possibilities are in productivity, where there are financial profits to gain when streamlining the industry. However, there are always challenges related to large, digital transitions. Automation of the material handling means an investment which needs to be approved and realized, which also requires preparatory work and research. Lack of knowledge was a suggested obstacle, but neither the users nor the manufacturers considered the obstacles larger than the possibilities.
32

Evaluation of Model-Based Design Using Rapid Control Prototyping on Forklifts / Utvärdering av modelbaserad utveckling med Rapid Control Prototyping på gaffeltruckar

Jansson, Lovisa, Nilsson, Amanda January 2019 (has links)
The purpose of this thesis is to evaluate Rapid Control Prototyping which is apart of the Model-Based Design concept that makes it possible to convenientlytest prototype control algorithms directly on the real system. The evaluation ishere done by designing two different controllers, a gain-scheduled P controllerand a linear Model Predictive Controller (mpc), for the lowering of the forks of aforklift.The two controllers are first tested in a simulation environment. The thesis con-tains two different simulation models: one physical where only minor parameteradjustments are done and one estimated black-box model. After evaluating thecontrollers in a simulation environment they are tested on a real forklift with areal-time target machine.The designed controllers have different strengths and weaknesses as one is non-linear and single variable, the P controller, and the other linear and multivariable,thempc. The P controller has a smooth movement in all situations without be-ing slow, unlike thempc. The disadvantage of the P controller compared to thempcis that there is no guarantee that the P controller will keep the speed limit,whereas thempcapproach gives such a guarantee.The better performance of the P controller outweighs the speed limit guaranteeand thus a conclusion is drawn that the nonlinearities of the system has a largereffect than the multivariable aspect. Also, another conclusion drawn is that work-ing with Model-Based Design and Rapid Control Prototyping makes it possibleto test many different ideas on a real forklift without spending a lot of time onimplementation. / Syftet med detta examensarbete är att utvärdera Rapid Control Prototyping vil-ket är en del av modellbaserad utveckling som gör det möjligt att enkelt testamodeller av styralgoritmer direkt på det riktiga systemet. Utvärderingen är gjordgenom att testa två olika regulatorer, en P-regulator med parameterstyrning ochen linjär modelbaserad prediktionsregulator (mpc), för sänkningen av gafflarnapå en truck.De två regulatorerna testas först i en simuleringsmiljö. I arbetet används två olikasimuleringsmodeller: en fysikalisk där endast mindre parameterjusteringar görsoch en estimerad black-box modell. Efter att regulatorerna utvärderas i simule-ringsmiljön testas de även på en riktig truck med hjälp av automatisk kodgenere-ring och exekvering på en dedikerad hårdvaruplattform.De konstruerade regulatorerna har olika för- och nackdelar eftersom en är olinjäroch envariabel, P-regulatorn, och en är linjär men flervariabel,mpc:n. P-regulatornhar en mjuk rörelse i alla lägen utan att bli för långsam, till skillnad frånmpc:n.Nackdelen med P-regulatorn, jämfört medmpc:n är att det inte finns någon ga-ranti för att P-regulatorn håller hastighetsbegränsningen sommpc:n gör.P-regulatorns bättre prestanda överväger garantin om att hålla hastighetsbegräns-ningen och därför dras slutsatsen att olinjäriteterna i systemet överväger effekter-na av det faktum att det också är flervariabelt. En annan slutsats är att modell-baserad utveckling och Rapid Control Prototyping gör det möjligt att testa fleraolika idéer på en riktig gaffeltruck utan att spendera för mycket tid på implemen-tationen.
33

Design vysokozdvižného vozíku / Design of Forklift

Macháček, Jan January 2013 (has links)
Master thesis concerns with a design of forklift truck. The result proposed in the thesis uses existing technologies but combines them in new context to gain better qualities of a lift truck especially in relation to user-friendliness and ergonomics. Shaping works on functional demands which are understood as a basis for further developments towards the aesthetical outcome.
34

Evaluation of Traction Control Systems for an Electric Forklift Truck

Karlsson, Mattias, Johansson, Sebastian January 2021 (has links)
This thesis evaluates different controllers for traction control on an electric forklift truck and has been done in cooperation with Toyota Material Handling Manufacturing Sweden. The need for a traction control system has increased with the introduction of lithium-ion batteries replacing the older lead-acid batteries, reducing the battery weight and therefore the downward force on the driving wheel increasing the risk for slip. The forklift truck was modelled using Simulink and validated by experiment. Different possible control strategies were investigated and three were chosen for implementation in simulation. These were controllers based on Model Following Control, Maximum Transmissible Torque Estimation and Sliding Mode Control. Model Following Control makes use of a nominal model to compare actual wheel speed values with nominal wheel speed values to determine if slip is occurring, Maximum Transmissible Torque Estimation makes use of a closed-loop disturbance observer to compute the maximum transmissible torque possible without inducing slip and using it as a limitation on the input signal, and Sliding Mode Control uses different functions to \say{slide} along a sliding surface to stay around a specific slip value. All three controller types were developed both as speed controlled and torque controlled. All of the controllers could reduce slip heavily in simulation. The Maximum Transmissible Torque Estimation controller reduced slip the most and kept oscillations at a minimum, but was not as responsive as the others to driver commands. The conclusion was that the controller of choice would depend on the working environment of the forklift truck. In a low friction environment where slip is expected to occur often, the Maximum Transmissible Torque Estimation controller is advisable, while the other two would be a better choice for environment with low slip occurrence. The use of torque control, while often better with regards to decreasing slip, could not be advised due to a perceived increase in implementation cost.
35

Hållbarhetsutvärdering - LCSA Analys : av trucksystem inom intern materialhantering / Sustainability – LCSA Analys : of forklift systems within internal material handling

Dahlberg, Erik, Fohlén, Weronica January 2018 (has links)
Allt fler organisationer väljer att jobba med hållbar utveckling, på grund av att det kan ses som en konkurrenskraft. Att arbeta med hållbar utveckling kan innefatta att utföra hållbarhetsutvärderingar, vilket kan göras genom metoden LCSA analys. Syftet med det här arbetet är att utvärdera och analysera ett producerande företags nuvarande klimatpåverkan sett till koldioxidekvivalentutsläpp från intern materialhantering som sker med dieseltruckar. Vidare syftar även arbetet till att visa hur en hållbarhetsutvärdering kan utföras för att påvisa ekologisk, ekonomisk samt social påverkan. I arbetet utförs en hållbarhetsutvärdering av trucksystem, för att identifiera det teoretiskt bästa alternativet, i jämförelse med ett fallföretags nuläge. Den metod som används för hållbarhetsutvärderingen är LCSA analys. Utöver resultatet från hållbarhetsutvärderingen tas även hänsyn till gränssnittet mellan teoretiskt och praktiskt bästa trucksystemalternativ.  Fallföretaget Volvo GTO i Skövde, har i dagsläget 18 dieseldrivna motviktstruckar, vilka har olika kapacitet och varierande arbetsuppgifter. Det nuvarande drivmedlet för samtliga truckar är Diesel Mk1. Fallföretagets flöden i dagsläget ställer generellt höga krav på truckarnas tekniska kapacitet gällande exempelvis åkhastighet, körning i uppförslutning, dragkraft samt lyft- och sänkhastighet. De 18 dieseltruckarna bidrog under år 2017 med ett klimatpåverkande utsläpp om cirka 237 ton koldioxidekvivalenter, sett till hela livscykeln för Diesel Mk1 samt truckflottans totala drifttider.  Gällande hållbarhetsutvärderingen LCSA analys, utförs den på trucksystem drivna av Diesel Mk1, HVO-Diesel, blybatterier samt litiumjonbatterier inom kapaciteterna 3,5, 5 och 8 ton. Analysen tar hänsyn till de tre pelarna inom hållbar utveckling.  Vidare tas hänsyn till trucksystemens tekniska specifikationer, vilket jämförs mot den nuvarande dieseltruckflottan. Generellt kan en lägre teknisk prestanda ses hos de eldrivna trucksystemen, vilket kan påverka möjligheten att implementera de hos fallföretaget. Teoretiskt lägst ekologisk och social påverkan kan ses hos de litiumjonbatteridrivna trucksystemen, lägst påverkan inom den ekonomiska pelaren har blybatteridrift. Ställt mot fallföretagets nuvarande flöden och behov, rekommenderar författarna HVO-Dieseldrivna trucksystem, då de har samma tekniska kapacitet samt lägre ekologisk och social påverkan. Avgränsningar har gjorts för analyserna i rapporten, gällande processgränser och påverkande faktorer. För framtida hållbarhetsutvärderingar rekommenderar författarna att större processgränser och fler påverkande faktorer tas hänsyn till, för att identifiera samtlig påverkan inom pelarna. I rapporten återfinns exempel på påverkan utanför valda processgränser, såsom utsläpp som påverkar över tid och exploatering. Under arbetets gång har informationsgap uppmärksammats inom olika områden. När det gäller forskning kring hållbarhetsutvärderingar saknas beprövade metoder. Därför efterfrågas enklare analysmetoder inom hållbar utveckling. Gap i forskning angående truckteori är något som också uppmärksammats. / The amount of organizations that choose to work with sustainability is increasing due to the potential competitiveness it causes. Working with sustainability may include sustainability evaluations, which can be done through the LCSA analysis method. The purpose of this report is to evaluate and analyze a manufacturing company's current climate impact due to carbon dioxide equivalent emissions from diesel-powered forklifts within internal material handling. Further, the report aims to illustrate how a sustainability evaluation can be conducted to identify ecological, economic and social impact. In the report, a sustainability evaluation of forklift systems is performed to identify the theoretically best alternative, compared to a case company's current situation. The method used for the sustainability evaluation is LCSA analysis. In addition to the results of the sustainability evaluation, the interface between theoretically and practically best forklift system alternatives is considered.  The case company Volvo GTO in Skövde, currently have 18 diesel-powered forklifts, which have different capacities and functions. The current fuel for all forklifts is Diesel Mk1. The flows today generally set high demands on the forklifts technical capacity, for example on, travel speed, climbing ability, traction force and lifting and lowering speed. In the year 2017, the 18 diesel-powered forklifts contributed with a climate impact of approximately 237 tonnes of carbon dioxide equivalents, considering the entire life cycle of Diesel Mk1 and the forklift fleets total run time.  Regarding the sustainability evaluation LCSA analysis, it is performed on forklift systems powered by Diesel Mk1, HVO-Diesel, lead acid batteries and lithium-ion batteries within the capacities 3.5, 5 and 8-tonne. The analysis considers the three pillars of sustainability. Further, the technical specifications of the forklift systems are considered and compared with the current diesel-powered fleet. Generally, a lower technical capacity can be seen in the electric forklift systems, which may affect the ability to implement those at the case company. Theoretically lowest ecological and social impact can be seen within the lithium-ion battery-powered forklift systems, the lowest impact on the economic pillar is seen in the lead acid battery systems. Based on the case company's current flows and demands, the authors recommend HVO-Diesel-powered forklift systems, as they have the same technical capabilities as well as lower ecological and social impacts. Limitations has been set for the reports analyzes, regarding process boundaries and impact indicators. For future sustainability evaluations, the authors recommend that wider process boundaries and more impact indicators are applied to identify the total impact within the pillars of sustainability. The report comprehends examples of impact beyond selected process boundaries, such as emissions affecting over time or exploitation. During the progress of this report, information gaps have been discovered in different areas. Regarding research of sustainability evaluations, proven methods are lacking. Therefore, established methods for evaluation are desired. A gap in research of forklift theory has also been noted.
36

Safety Optimization of Material Handling Forklift Truck Operations

Conde Carvalhal, Carlos January 2020 (has links)
The prevention of incidents and injuries is fundamental for any industry activity since those events may result in serious economic, environmental, and human losses. Due to the centralization of Linde filling operations within Sweden, several of their plants are being phased out to move the production to Enköping. The elevated raise of Linde's production led to a high increase of forklift drivers and stock levels and consequently brought up the number of incidents related to forklift driving. This thesis aims to obtain knowledge to mitigate forklift truck related safety hazards as well as understand how to eliminate risks and unsafe situations at this type of operation. This project was divided into 3 phases. Phase I consisted of understanding operations routines and its safety risks, assessing Enköping site internal state (with a safety survey, and several visits and interviews), and benchmarking the most common practices based on other companies' forklift-related processes (with visits and interviews). In phase II, parallelly to ISite software implementation, studies utilizing different engineering tools (Spaghetti Diagram, VSM, Fishbone Diagram, and FMEA) were performed in order to gather information and understand how to optimize the site's forklift-related safety. In this phase, a tailored observational KPI was developed in order to assess the site independently of incident measurement regarding four groups: Site, Pedestrian activity, Forklift operation, and Forklift operator behavior. In phase III, all data acquired was discussed, and conclusions were made based on the data analysis and discussions of the results of Phase II implementation allied with the theoretical references. The survey findings showed the high degree of importance given to safety at Linde in Enköping. It also revealed, in addition to all engineering tools applied, which elements should be focused in order to optimize the forklift trucks operational safety (mainly related to Technology dimension). Based on the benchmark comparison, it is possible to allege that the absence of a maintenance facility is the main disadvantage of Linde in Enköping. In contrast, the usage of I-Site fleet management software represents an important step towards safety. The I-Site knowledge and the awareness of its benefits grew among management and operators as setup issues, and technical malfunctioning was eliminated. The observational KPI has obtained preliminary overall values above 0,82 for all groups (on a scale of 0 to 1), proving itself capable of measuring the safety performance and identifying risks and unsafe situations. / Att förebygga incidenter och skador är grundläggande för all branschaktivitet eftersom dessa händelser kan leda till allvarliga ekonomiska, miljömässiga och mänskliga förluster. På grund av centraliseringen av Lindes fyllningsverksamheten inom Sverige har flera av deras anläggningar fasats ut för att flytta produktionen till Enköping. Den utökade produktionen på Linde Enköping skapade behov av fler truckförare, högre lagernivåer och ökade följaktligen antalet incidenter relaterade till gaffeltruck. Avhandlingen syftar till att få kunskap för att mildra säkerhetsrisker för gaffeltruckar samt förstå hur man kan eliminera risker och osäkra situationer vid denna typ av verksamhet. Detta projekt delades in i tre faser. Fas I bestod av att förstå driftsrutiner och dess säkerhetsrisker, utvärdera det interna tillståndet på Linde Enköpings arbetsplats (med en säkerhetsundersökning, flera besök och olika intervjuer) och benchmarka de vanligaste metoderna baserat på andra företags gaffeltruckrelaterade processer (med besök och intervjuer). I fas II, parallellt med I-Site-programvaruimplementering, utfördes studier med olika tekniska verktyg (Spaghetti Diagram, VSM, Fishbone Diagram och FMEA) för att undersöka och förstå hur man optimerar verksamhetens gaffeltruckrelaterade säkerhet. I denna fas utvecklades en skräddarsydd observations-KPI för att utvärdera verksamheten oberoende av att mäta incidenter avseende fyra grupper: Plats, fotgängare, gaffeltruck och beteende för gaffeltruck. I fas III diskuterades alla förvärvade data, slutsatser gjordes baserade på dataanalysen och diskussionerna om resultaten av fas II-implementering tillsammans med teoretiska referenser. Undersökningsresultaten visade hur högt säkerhet prioriteras vid Linde Enköping. Den avslöjade också, utöver alla tillämpade konstruktionsverktyg, vilka element som bör fokuseras på för att optimera truckens driftssäkerhet (främst relaterad till teknikdimension). Baserat på den benchmarking som genomfördes är det möjligt att hävda att frånvaron av underhållsanläggning är den största nackdelen med Linde i Enköping. Däremot är användningen av mjukvara för I-Site-flottanhantering ett viktigt steg mot säkerheten. Kunskapen om I-SITE och medvetenheten om dess fördelar växte bland ledningen och operatörerna när installationsproblem och tekniska funktionsfel eliminerades. Utfallen för observations-KPI har erhållit preliminära totalvärden över 0,82 för alla grupper (i en skala från 0 till 1), och visar sig kapabel att mäta säkerhet i genomförande samt att identifiera risker och osäkra situationer.
37

Behavioral Transportation: The Role of Psychological, Cognitive, and Social Factors in Distracted Driving Behavior

Gabaldon, Janeth 07 1900 (has links)
Logistics 4.0 suggests that increased automation can enhance performance, while Logistics 5.0 emphasizes the advantages of a modern workforce that combines humans and emerging technologies. However, the logistics industry needs a deeper understanding of human factors, an area that has been overlooked so far. To bridge this research gap, this dissertation investigated distracted driving behavior among individuals involved in transportation and logistics-based applications. This investigation employed both qualitative and quantitative research methods. Essay 1 focuses on a systematic literature review (SLR) that comprehensively analyzes published research on self-response studies regarding distracted driving behavior. The study identifies five overarching categories of distractions: (a) cell phone-related, (b) technology-related, (c) nontechnology-related, (d) psychological, and (e) personality. The findings underscore the substantial research conducted on self-reported distractions associated with cell phones and technology. Essay 2 employs the protection motivation theory (PMT) to develop hypotheses that predict the engagement of young drivers in texting while driving (TWD). In addition to TWD, the survey also included cognitive failure to examine the indirect effects of PMT on TWD within a mediation framework. The results, obtained through structural equation modeling with 674 respondents aged 18-25, indicate that several factors including response cost, threat vulnerability, cognitive failure, self-efficacy, and threat severity influence TWD behavior. Essay 3 investigates the influence of young drivers' respect for safety, neutralization techniques, and polychronicity on distracted driving behavior (DDB), based on the cognitive dissonance theory (CDT). The findings, drawn from 326 respondents aged 22-29 years, indicate that drivers who prioritize safety (respect for safety) are less likely to engage in DDB. Lastly, Essay 4 takes a survey-based approach to explore how factors such as respect for safety, polychronicity, and cognitive failure influence the likelihood of engagement in distractions among industrial operators, specifically forklift drivers, in warehouse and distribution centers (WDCs). The study's results indicate that cognitive failure has a negative impact on forklift drivers' distracted driving behavior, while polychronic tendencies help drivers avoid engaging in distracted behavior.
38

Interface Development for Semi-Autonomous Trucks : Visual and Auditory Feedback

Eriksson, Frida, Andersson, Märta January 2015 (has links)
Vehicles are becoming increasingly autonomous, as automotive industries are investing in innovative technology. Therefore the technology becomes more available and affordable, making it possible for Toyota Material Handling Europe (TMHE) to introduce automated features in their trucks. Vehicles that have a forward collision warning system, and thus are partly autonomous, are involved in less accidents than those without. In manufacturing industries there is currently a problem with truck collisions and an automated solution might be a suitable way to prevent these. When implementing an automation device, human machine interaction and user-friendliness are aspects to keep in mind during the development. The thesis concerns how autonomous features can assist the truck driver, and how to provide the driver with intuitive feedback. The purpose was to ensure the drivers’ and surrounding personnel’s safety as well as increase the productivity. Research was performed regarding in what situation an assisting device is needed and how to communicate information in an intuitive manner to help the driver in this situation. A conceptual interface was developed that allows communication between the driver and a future all-knowing system, that tracks all objects and personnel in a warehouse. The drivers have had a central role in the process. The observations were performed in the TMHE warehouse to identify situations. The most perilous and frequent situation was when drivers need to focus both in the fork and drive wheel directions simultaneously. This either puts the surroundings or the driver in danger. A conceptual interface was developed to help the driver in this situation. This resulted in a concept implementable in both current and future trucks, to harmonise the solution and ensure a safe warehouse environment. A lo-fi prototype was constructed and evaluated iteratively with drivers to ensure the quality and usability of the concept. The resulting feedback solution consists of sounds from speakers mounted in the headrest and a display interface with warning symbols. The sounds are directional to notify the driver if the danger is to the left or right behind his back. If the danger is only semi-close, the driver receives a warning, but if it is very close, the truck is stopped autonomously. The symbols appear on the display simultaneously as the sounds are heard, to provide further feedback. Additionally, an Autonomous Positioning feature has been developed, that consists of symbols and buttons on the display interface, as well as an alert sound from the display to indicate the system’s activation and deactivation. Safety is enhanced since neither personnel nor trucks are in risk of collision when implementing the concept. As the concept helps the driver position the truck effortlessly towards the pallet the productivity is also improved.
39

Produktionsflödesanalys : Förstudie av nya produktionsflöden för golvprodukter / Productions flow analysis : Preliminary study of new production flows for floor products

Svensson, Joel, Ideström, Gabriel January 2019 (has links)
Examensarbetet genomfördes i samarbete med Tarkett AB i Ronneby med syfte att konstruera ett nytt produktionsflöde vilket ska minska stopp i flödet samt nå en produktionsökning på 15%. Det nya flödet ska sedan planeras i den givna hallen. Leanprinciper är grunden för det nya flödet och metoder som värdeflödesanalys och ledningsverktyg används för att göra en nulägesbeskrivning. Information samlades in genom observationer som utfördes genom “att gå längs flödet”, intervjuer och teorin kring lean för att analysera flödet. Värdeflödesanalys gjordes på det befintliga flödet för att sedan kunna skapa framtida flöden. Idégenerering utfördes för att få fram olika koncept till nya alternativa flöden. Dessa koncept har sedan utvärderats genom verktyg och med generell bedömning. Ett koncept har valts ut att gå vidare med för fortsatt analys och försök att planera i den givna hallen för att få en förståelse hur flödet skulle fungera med de begränsningar som finns. En värdeflödesanalys gjordes för det befintliga flödet för att få överblick och ta fram värdehöjande och icke värdehöjande aktiviteter. Flödet begränsas av produktionsstopp på grund av aktiviteter som är icke värdehöjande och en flaskhals i produktionen som begränsar hastigheten på hela flödet. Alternativa flöden har tagits fram. Det flöde som valdes är ett lådflöde där materialet fylls i lådor för att sedan skickas vidare till maskinen som producerar golv av materialet. Lådorna kan fyllas 15 % snabbare men flaskhalsen kan fortfarande ej ta emot denna ökning. Lösningen blir kontinuerligt flöde på alla processer som det går att ha ett kontinuerligt flöde och ett buffertlager som förbrukas med jämna mellanrum där material i lådor minskar produktionsstopp eftersom lådorna ej är direkt kopplade till resten av linjen och därmed inte blir direkt påverkad utan fortsatt tillverkning kan ske. Flaskhalsen kan inte reduceras, men med lådflöde kan buffertlager användas. Med detta kan material från extrudern (råmaterial) som egentligen skulle gå till att fylla lådor skickas mot en annan linje. Detta leder till att två linjer kör samtidigt och här finns produktionsökningen. Genom att undvika produktionsstopp som orsakas av det befintliga flödet kan det ge en produktionsökning på närmare 8 % och möjlighet att köra flera linjer samtidigt kan ge ytterligare produktionsökning men är svår att uppskatta. En fortsatt analys behöver genomföras av flödet innan det kan implementeras i verkligheten. / This bachelor thesis was made with the support from Tarkett AB, Ronneby. The purpose of this task was to construct a new production flow, which should minimize the stop time and also increase the production ratio with 15%. The basics for lean principles were used in order to come up with the new production flow. Also methods like value flow analysis and the seven management tools were used to make a status report of today's production flow. Information was gathered from observations, which came from inspections of the machines that are meant to be used in the new flow, interviews and also theory about lean production. A value stream mapping was made on the already existing production flow, in order to create new ideas for the new production flow. These ideas were then evaluated with tools and general assessment, where the best concept was chosen to move on with further analysis. The next step was to plan the placement of machines and plan the forklift traffic at the given area. This will gave an understanding on how the new flow could work with the known limitations. The result shows a value flow analysis for the already existing production flow, which gives an overview on how to collect value-added and non-valueadded activities. The flow is restricted by stoppages due to the non-valueadded activities and bottlenecks. Alternative flows have been considered in the result, but the chosen flow is called box flow. With this concept the material will be filled in big boxes that can hold up to 1.1 tons of granulate. These boxes will then be stored in a warehouse until it’s collected and sent towards the machine which will use the material to produce the given amount of floor mat. The boxes can be filled 15 % faster, but the bottleneck will still not be able to keep up with this production increase. This was solved with a continuous flow on all processes and a buffer stock that will need to be continuously consumed from time to time. The bottleneck won’t increase in production speed, but with the box flow a buffer stock can be used. With this flow the material from extrusion (raw material) can be sent to other production lines. Which leads to two lines running simultaneously and here is the production increase. By avoiding production stops that are inflicted by the existing production flow, a production increase that is closer to 8 % can be performed and a possibility to increase it even further if more production lines can run at the same time. However, the production increase when taking the other production lines to account is hard to estimate. A continued analysis needs to be carried through to implement the new flow at Tarkett.
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Estimativa do estado de carga de baterias em robôs móveis autônomos / Battery state of charge estimation in autonomous mobile robots

Oliveira, Marcelo Manoel de 19 April 2013 (has links)
Cada vez mais robôs móveis autônomos estão sendo utilizados em diversas tarefas e em ambientes com elevado risco para atividades humanas que a paralisação de suas atividades podem gerar outros riscos, perdas e elevados custos. Assim, o estado de carga (SOC) de sistemas de baterias em robôs móveis autônomos é um parâmetro importante na prevenção de uma falha primária nessa aplicação, a ausência de energia. Este trabalho apresenta os métodos existentes na literatura para a determinação do estado de carga de baterias e as tecnologias de baterias disponíveis utilizadas em robôs móveis autônomos ou veículos autônomos guiados. A partir desses estudos foi desenvolvido um modelo de medida, baseado no modelo combinado e foram realizados testes de bancadas para levantamento dos parâmetros e características de três modelos de células de baterias: Lítio Polímero (Li-PO), Níquel-Cádmio (NiCd) e Lítio-Ferro-Polímero (LiFePO4). Com esses parâmetros, aplicou-se o método de estimativa de carga baseado na técnica do Filtro de Kalman Estendido (EKF). Através dos testes, analisou-se comparativamente a resposta do método proposto e a resposta do método OCV e a capacidade de carga real. / Autonomous mobile robots have being increasingly used in various tasks, environments and activities of high risk to human that the stoppage of its activities may generate other risks, losses and high costs. Thus the state of charge (SOC) of battery systems in autonomous mobile robots, is an important parameter to prevent a primary failure in this application, the lack of energy. The paper presents the existing methods in the literature to determine the battery state of charge and battery commercial technologies available used in an autonomous mobile robot or autonomous guided vehicle, from these studies a measurement model based on combined model was developed and testing benches for three cells models on Lithium Polymer Battery (Li-PO), Nickel Cadmium (NiCd) and lithium-iron-Polymer (LiFePO4) batteries were performed for lifting the parameters and apply the battery state of charge method based on the Extended Kalman Filter (EKF) technique. The tests were analyzed in order to observe the comparatively response of the proposed method, the OCV method and Real charge capacity.

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