Today’s demand on forklift trucks performance and efficiency is high. The productivity is important but also the experience while handling the forklift. The handling has to be simple and genuine to make the driver feel confident and safe. To achieve high performance steering in articulated trucks, a hydraulic power system is often used.Simulation software are a powerful tool in development processes. The program gives the industry a possibility to develop, analyze and evaluate constructions and models more efficient.The purpose of this master thesis is to identify and increase the knowledge about the main challenges in the hydraulic steering system in an articulated forklift. The hydraulic system has been modelled in the simulation software Hopsan and validated against data from measurements performed on the forklift. The different challenges have been identified based on tests and the simulation results. For a deeper understanding of the system a literature study, mainly about the key components, has been done during the master thesis. A number of suggestions for improvement have been developed with focus on increasing the steering performance. The concepts and ideas have been evaluated and tested in the simulation model.The project resulted in a validated simulation model of the articulation and a number of suggested improvements on the hydraulic steering system.

En undersökning om Simulation inom utbildningsområdet, med hjälp av medieteknik. I artikeln diskuteras bland annat hur erfarenhet-baserad undervisning, som en digitalsimulation med fysiska kontroller, kan vara ett utmärkt tillägg för hur man undervisar. Dessutom kan det vara ett sätt att ge en individ mer självförtroende och får hen att mer tänkaundermedvetet hur arbetet kan göras bättre. För att utreda detta har arbetet fokuserat på en typav simulation, nämligen inom truckkörning. Undersökningen har också samarbetat med Volvo Car Body Components för att se vad de upplever som risker inom truckkörning, och vad som då borde fokuseras på en sådan simulation.Simulation har sedan presenterats för deltagare med och utan kompetens i truckkörning, föratt sedan utreda om de känner att de skulle kunnat använda upplevelsen undermedvetet somerfarenhet för framtida strävanden. Det är diskuterbart om resultatet på undersökningen är användbar eller inte, då mängden avdeltagare kunde har varit större. Dock kan det argumenteras för att arbetet gjort ger chansenför flera undersökningar inom simulation-baserad undervisning att kunna visa att bara för ettsätt av utbildning funkar, betyder inte det att det finns det sätt att göra något bättre.

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.

Forklifts that are capable of lifting heavy loads and reaching high lift heights are required by stan-dards to have an overhead guard to protect the operator from falling objects. The same standardsspecify a standardized procedure for testing the strength of these overhead guards. The test in-volves dropping ten 45 kg wooden cubes and a heavy timber load onto the overhead guard. Thesedestructive tests are time-consuming and expensive, and it is the purpose of this master’s thesis todevelop a methodology for simulating this kind of test using the finite element method with a largedisplacements, explicit scheme using the solver RADIOSS by Altair. This was achieved by firstdesigning, constructing, and testing a physical prototype of an overhead guard to use as a referencefor a finite element methodology to be validated against. The work has also included tensile testingof the overhead guard material, and this was done both to obtain material data from the sametype of material as the prototype, and to get Johnson-Cook material parameters, which are hardto come by in the literature. Next, a basic finite element model was created which showed a verylarge discrepancy compared to the physical test results. An extensive investigation into aspectssurrounding finite element modeling and material modeling was undertaken, and resulted in a fi-nal model which overestimated the displacements by about 40 % only. The remaining inaccuracyis believed to mostly stem from inadequate strain-rate sensitivity data, caused by limitations inavailable resources for material testing.

With the advent of Industry 4.0 and the Internet of Things, collecting data on Cyber-Physical systems has become the norm practice in large scale industries. By collectingrelevant data, it is possible to monitor the health status of whole systems or specificcomponents within them. Such practices allow for historical maintenance strategies suchas reactive maintenance or preventive maintenance to be phased out.In this thesis two separate algorithms are presented, both designed to identify contaminationlevels in the hydraulic pressure filters of forklifts. Furthermore, in contrast torelevant literature for similar applications only sensory data from the hydraulic pump’smotor current and hydraulic fluid pressure at the load was used. More specifically, theproposed algorithms are based on trends observed in the relationship between the measurementsand how it changes over time. The algorithms were evaluated on data fromfour forklifts used in Toyota’s factory. The forklifts had been collecting data while usedin production for over a year.The results indicate strong evidence that both algorithms can be used to detect degradationin the hydraulic system. This is especially true for one forklift where it was knownthat the damage at the time of replacement was substantial. However, it cannot be trulyestablished without further testing whether the algorithms detect degradation in the filteror pump.