Modern manufacturing systems seem to be shifting from mass production to mass customisation, which means that systems must be able to manage changes in customer demands and requirements, new technology as well as environmental demands. This in turn leads to an increase in product variants that need to be assembled. To handle this issue, well designed and presented information is vital for assembly workers to perform effective and accurate assembly tasks. In this thesis the main focus has been to find factors that affect human performance in manual assembly. A literature review was made on the subject of manufacturing and usability as well as basic cognitive abilities used to utilise information, such as memory. This investigation identified applicable factors for assessing human cognitive performance within the research field of manufacturing. The thesis further investigates how some of these factors are handled in manual assembly, using case studies as well as observational studies. The results show that how material and information are presented to the assembler needs to be considered in order to have a positive effect on the assembly operation. In addition, a full factorial experimental study was conducted to investigate different ways of presenting material and information at the workstation while using mixed assembly mode with product variants. The material presentation factor involved the use of a material rack compared to using an unstructured kit as well as a structured kit and the information presentation factor involved using a text and number instruction compared to a photograph instruction. The results showed that using a kit is favourable compared to the traditional material rack, especially when using a structured kit combined with photographic instruction. Furthermore, the use of unstructured kits can lead to better productivity and reduced perceived workload, compared to a material rack. Although they are perhaps not as good as using a structured kit, they most likely bring a lower cost, such as man-hour consumption and space requirements. However, the number of components in an unstructured kit needs to be considered in order to keep it on a manageable level. As a conclusion, several scenarios were developed in order to understand how different assembly settings can be used in order to improve human performance at the assembly workstation.

No description available.

The objective of this study was to assess low to high levels of Cognitive Workload by measuring heart rate and cortical blood flow in real-time. Four conditions were implemented into a within-subjects experimental design. Two conditions of difficulty and two conditions of trial order were used to illicit different levels of workload which will be analyzed with psychophysiological equipment. Functional Near-Infrared Spectroscopy (fNIRS) has become more prominent for measuring the blood oxygenation levels in the prefrontal cortex of individuals operating in hazardous work environments, students with learning disabilities, and in research for military training. This is due to the fNIR device being highly mobile, inexpensive, and able to produce a high-spatial resolution of the dorsolateral prefrontal cortex during executive functioning. Heart Rate will be measured by an Electrocardiogram, which will be used in concordance with fNIR oxygenation levels to predict if an individual is in a condition that produces low or high mental workload. Successfully utilizing heart rate and blood oxygenation data as predictors of cognitive workload may validate implementing multiple physiological devices together in real-time and may be a more accurate solution for preventing excessive workload.

Unmanned Aerial Vehicles (UAV), often referred to as drones, have seen increased use in search and rescue (SAR) missions. Traditionally, these missions involve manual control of each drone for aerial surveillance. As UAV autonomy progresses, the next phase in drone technology consists of a shift to autonomous collaborative multi-drone operations, where drones function collectively in swarms. A significant challenge lies in designing user interfaces that can effectively support UAV pilots in their mission without an overload of information from each drone and of their surroundings. This thesis evaluates important human factors, such as situational awareness (SA) and cognitive workload, within complex search and rescue scenarios, with the goal of increasing trust in multi-drone systems through the design and testing of various components. Conducting these user studies aims to generate insights for the future design of multi-drone systems. Two prototypes were developed with a multi-drone user interface, and simulated a stressful search and rescue mission with high cognitive workload. In the second prototype, a heatmap guided UAV pilots based on the lost person model. The prototypes were tested in a conducted user study with experienced UAV pilots in different SAR organizations across Sweden. The results showed variability in SA while monitoring drone swarms, depending on user interface components and SA levels. The prototypes caused significant cognitive workload, slightly reduced in the heatmap-equipped prototype. Furthermore, there was a marginal increase in trust observed in the prototype with the heatmap. Notably, a lack of manual control raised challenges for the majority of participants and many desired features were suggested by participants. These early expert insights can serve as a starting point for future development of multi-drone systems. / The HERD project, supported by the Innovation Fund Denmark for the DIREC project (9142-00001B)

<div>Vehicle automation is developing at a rapid rate worldwide. However, even lower levels of automation, such as SAE Level-1, are expected to reduce drivers’ workload by controlling either speed or lane position. At the same time, however, drivers’ engagement in secondary tasks may make up for this difference in workload displaced by automation. Previous research has investigated the effects of adaptive cruise control (ACC) on driving performance and workload, but little attention has been devoted to Lane Keeping Systems (LKS). In addition, the influence of secondary cognitive tasks on Level-1 driving performance is also not well understood.</div><div><br></div><div>The first goal of this thesis study was to examine the effects of secondary cognitive tasks and driving condition on driving performance. The second goal was to examine the effects of secondary cognitive tasks and driving condition on heart rate related measurements that reflect changes in workload. Both a novel nano-sensor and a commercial ECG sensor were used to measure heart rate. Thus, the third goal was to compare the capability of a nano-sensor in detecting changes in heart rate and heart rate variability with a commercially available ECG sensor. Twenty-five participants drove a simulated vehicle in manual, ACC and LKS driving conditions, while performing a secondary cognitive (N-back) task with varying levels of difficulty.</div><div><br></div><div>Results showed that more difficult cognitive secondary tasks were beneficial to driving performance in that a lower standard deviation of lane departure (SDLD) and a lower standard deviation of vehicle speed (SDVS) were both observed. Heart rate and NASA-TLX workload scores were significantly higher in the most difficult secondary task and in the manual driving conditions. However, heart rate variability measures (SDNN, RMSSD, pNN50, LF Power and HF Power) indicated lower variability under more difficult secondary tasks. This thesis suggests that nanotechnological devices may serve as a potential alternative to other heart rate measuring technology. Limitations in detecting minor heart rate changes between different driving conditions and in heart rate variability measuring were also acknowledged.</div>

There are different reasons that may collaborate for a human activity to result in damages in one s physical health. Generally, they characterize risk situations that can be avoided, if identified. One of these risks is related to the skill level that a person has to process information, react to his surroundings and make decisions in order to perform an activity, which is determined by the allocation of the mental resources demanded by the activity for its execution. When this allocation is inappropriate, there is a higher possibility for some kind of accident related to the activity to happen due to cognitive overload. This way, it is proposed the development of a model for the inference of such cognitive workload based on models from psychology, especially the skill-rule-knowledge model, concepts from ubiquitous computing and different techniques for the measurement of the cognitive workload. This dissertation is a part of the project Activity Project, which aims to develop a context-aware middleware for the inference and prediction of risks in activities. / Existem diferentes motivos que podem colaborar para que uma atividade humana resulte em danos à saúde física de um indivíduo. De modo geral, eles caracterizam situações de risco que podem ser evitadas, caso identificadas. Um destes motivos diz respeito ao nível da habilidade de uma pessoa em processar informações, reagir ao seus arredores e tomar decisões para a realização de uma atividade, o qual é determinado pela alocação de recursos mentais demandados por ela para a sua execução. Quando esta alocação é inadequada, há uma maior possibilidade de que algum tipo de acidente relacionado à atividade ocorra devido à sobrecarga cognitiva. Dessa forma, propõe-se o desenvolvimento de um modelo para a inferência deste esforço cognitivo a partir de modelos da psicologia, em especial o modelo comportamental habilidade-regra-conhecimento, conceitos da computação ubíqua e de diferentes técnicas para o mensuramento do esforço cognitivo. Testes foram realizados em um dataset público e os resultados obtidos demonstram ser viável a inferência do esforço cognitivo de forma não-intrusiva em um sistema ubíquo a partir da análise do desempenho do indivíduo. Esta dissertação é parte integrante do projeto Activity Project, o qual visa desenvolver um middleware sensível ao contexto para a inferência e predição do risco em atividades.

A human-centered approach when developing new support systems in vehicles has the potential to enable the driver to make safe decisions in the transition between manual and automatic control. However, careful considerations have to be taken. Not only would the design of the systems, in terms of interface be important, but also what kind of activities the systems support. The aim of this study was to identify an appropriate activity to support the cognitive processes for truck drivers, develop an interface for this activity, and evaluate it in driving situations. This was executed in three sub-studies: the Pre-study, the Design-study, and the Evaluation study. In the Pre-study, the aim was to investigate for what kind of driver-related activity distribution and long haulage truck drivers need a driver support and interface. This was investigated via contribution from truck drivers, HMI/Ergonomics experts, as well as engineers. The activity chosen to support was detecting objects around the vehicle. However, reconsiderations were made due to constrains in the simulator. Suggested by Scania’s Vehicle Ergonomics group a holistic system was chosen; an interface approach enabling for more technologies to be included within the same interface, reducing the amount of modalities a driver can be exposed to. The Design-study addressed the aim of designing an interface for the Holistic system with truck drivers’ cognitive workload in focus. A LED-prototype was built running along the window edges inside the cab of Shania’s Vehicle Ergonomics groups’ simulator, to create warning signal concepts. Literature findings, the LED-prototype, and the simulator were used in an iterative process to design and improve warning signal concepts, until two final concepts were created. The holistic system informs of hazards around and near the vehicle by lighting the area risky objects occurs to guide drivers’ attention and this was done either with 1) the informative display or, 2) the directional display. The Informative display conveys information of a hazard location and type, and the Directional display exclusively conveys information of the hazard location. The Evaluation study explored how drivers were affected by, and how they perceived, the holistic interface design regarding mental workload and hazard detection. A user simulator test was designed to collect data within the areas of ‘Event detection’, ‘Workload’, ‘Driving performance’ and ‘Subjective opinion’. Fourteen professional truck drivers assessed three conditions: 1) Baseline (driving without a system), 2) the Informative display, and, 3) the Directional display, while being exposed to potential hazards. To further increase workload, a secondary task was performed at the end of each condition. The results showed that the Informative display did not only result in more ‘Detection hits’, instances when a driver responded to a present hazard, but also significantly decreased reaction time to detect a hazard. However, in terms of acceptance, the two concepts were considered equally preferred. As the Informative display showed to be more efficient in terms of hazard detection, this should be investigated further. A holistic interface enables for more systems to be included within the same interface, reducing the amount of alarms and modalities drivers are exposed to if designed skillfully. Thus, more support systems can be included in future vehicles, without causing unnecessary distraction when applying a holistic interface approach. / Ett människocentrerat förhållningsätt vid utveckling av nya stödsystem i fordon möjliggör för förare att ta säkra beslut i övergången mellan manuell kontroll och automation. Men noggranna överväganden måste tas. Inte bara systemets utförande i form av gränssnittet är av stor vikt, utan även vilken typ av aktivitet som stöds. Syftet med denna studie var att identifiera en lämplig aktivitet att stödja lastbilsförares kognitiva processer, utveckla ett gränssitt för denna aktivitet och utvärdera gränssnittet i en körsituation. Detta utfördes i tre substudier: Förstudien, Designstudien samt Utvärderingsstudien. Förstudiens syfte var att undersöka för vilken typ av körrelaterad aktivitet distributions- och långtransportförare behövde ett förarstöd och gränssitt. Detta undersöktes med bidrag från lastbilsförare, HMI/Ergonomi experter samt ingenjörer. Den valda aktiviteten blev upptäcka objekt framför och kring lastbilen. Dock ändrades den valda aktiviteten på grund av begräsningar i simulatorn. Förslaget från Scanias Ergonomigrupp för förarhytten blev ett Holistiskt system istället; en gränssnittsstrategi som möjliggör att fler tekniker och system att inkluderas i samma gränssnitt, vilket minskar antalet modaliteter en förare kan bli utsatt för.  Designstudien behandlar syftet beträffande utformningen av gränssnittet för det holistiska systemet med avseende på lastbilsförares kognitiva belastning. En LED-prototyp byggdes, denna löpte längs med fönsterkanten i förarhytten på Scanias Ergonomigrupps simulator, för att skapa varningssignals-koncept. Resultat från litertur, LED-prototypen och simulatorn användes i en iterativ process för att utveckla och förbättra varningssignalerna. Det holistiska systemet informerar om faror runt fordonet genom att tända ljus i det område riskfyllda objekt upptäckts för att leda förarens uppmärksamhet och detta görs med något av de två utvecklade koncepten: 1) det informativa varningskonceptet eller 2) det riktningsgivande konceptet. Det informativa konceptet förmedlar information om farans placering och typ, medan det riktningsgivande varningskonceptet enbart förmedlar information om farans placering. Utvärderingsstudien utforskade hur förare påverkades av och hur de upplevde det holistiska gränssnittet med avseende på mentalbelastning och upptäckten av faror. Ett användartest i en simulatorutvecklades för att samla in data inom områdena Upptäckt av faror, Mentalbelastning, Körförmåga samt Subjektiv uppfattning. Fjorton professionella förare bedömde tre tillstånd: 1) Baslinje (körning utan ett system), 2) det informativa varningskonceptet och 3) det riktningsgivande varningskonceptet, medan de blev utsatta för potentiella faror. För att öka den mentala belastningen utfördes en sekundäruppgift vid slutet av varje tillstånd. Resultaten visade att det Informativa varningskonceptet inte enbart resulterade i fler upptäckta faror, tillfällen då förare reagerade på en närvarande fara, utan även signifikant minskade reaktionstider att upptäcka faror. Däremot föredrogs båda koncepten i samma utsträckning med avseende på acceptans. Då det informativa varningskonceptet visades sig mest effektivt gällande upptäckten av faror borde denna undersökas vidare. Ett holistiskt gränssitt möjliggör för fler system att inkluderas i samma gränssitt och minskar mängden alarm och modaliteter som en förare kan utsättas för om det designas skickligt. Om ett holistiskt gränssnitt tillämpas kan därmed fler stödsystem innefattas i framtida fordon utan att orsaka oönskad distraktion.

No description available.

Den snabba utvecklingen av autonomi och fjärrstyrning för obemannade enheter har lett till ett behov inom militären att utforska samspelet mellan användare och olika obemannade enheter, för att kartlägga behov för framtida gränssnitt. Det finns ett tydligt behov av alternativa gränssnitt till de handhållna styrdon som används i dagsläget, då dessa har visat sig ha begränsningar gällande situationsmedvetenhet och kognitiv förmåga hos operatören - något som är särskilt viktigt i högrisksituationer. Det finns vidare belägg för att ett armburet styrdon har potential att möta dessa behov hos framtida gränssnitt. Denna studie undersöker därför möjliga utformningar för ett armburet gränssnitt, och utreder hur väl konceptuella utformningar passar det specifika användningsområdet avsutten spaning i högrisksituation för markförband. Genomgående är fokus att genom en iterativt och användarcentrerad studie kartlägga och precisera behov samt generera konceptuella prototyper utifrån detta. Inledningsvis görs en litteraturstudie, vars resultat sammanställs i ett antal designprinciper för utformning av gränssnitt för obemannade fordon inom militära sammanhang. Principerna används vidare i idé- och konceptgenereringen samt vid framtagandet av lofi-prototyper. Lofi-prototyperna som visualiserar olika koncept för armburna gränssnitt utvärderas därefter i ett användartest med fokusdiskussioner. Detta är den första av två iterationer i användarstudien. Vidare utvecklas ett slutgiltigt helhetskoncept, vilket utvärderas i det andra användartestet. Fokus i studien har vid det här laget riktat in sig specifikt mot användningsområdet avsutten spaning i högrisksituationer för markförband, och utvärderar genom storytelling hur väl ett armburet gränssnitt passar användningsområdet. Resultaten från det första användartestet visar att ett armburet gränssnitt bör utformas som ett komplement till ett huvudstyrdon, samt att det är viktigt att det utformas utifrån soldatnas utrustning och miljö genom att vara litet, lätt och tåligt. Vidare visar resultatet att gränssnittet bör fokusera på mottagandet av information framför att skicka information, och att det bör utformas i syfte att ge användaren snabba, kortfattade notiser om viktig information som enkelt läses av på armen utan att soldaten behöver avbryta sina arbetsuppgifter eller lägga ned sitt vapen. Fysiska knappar, ljusdisciplin samt vibrationer som återkoppling är andra aspekter som resultatet visar är intressanta att undersöka vidare. Resultatet från första iterationen används för att utveckla ett slutgiltigt slutkoncept till det andra användartestet, vilken gestaltas i en prototyp i lera som visualiserar storleken på gränssnittet, likt en smartklocka, och ett antal fysiska knappar. Genom storytelling där deltagarna får ha på sig prototypen på armen och leva sig in i ett realistiskt scenario utvärderas hur väl denna typ av gränssnitt passar användaren och användningsområdet. Resultatet från det andra användartestet visar att ett litet, smidigt gränssnitt på armen som ger snabb, kortfattad information är fördelaktigt i högrisksituationer och spaningssituationer där man behöver gömma sig eller agera dolt. Gränssnittet behöver därmed inte kunna ge detaljerad information och ha avancerad interaktion, utan bör istället fungera i syfte att på ett tyst och snabbt sätt ge en varning genom exempelvis en vibration eller en symbol på skärmen. Således kan användaren få snabba, direkta alert-notiser som signalerar nivån av fara – vilket är efterfrågat i just högrisksituationer – innan man genom exempelvis radiokommunikation kan få mer detaljerad information om faran. Ett annat viktigt resultat från användarstudien är att gränssnittet inte enbart bör fokusera på information från och interaktion med obemannade enheter, utan även interaktion med människor. Det kan exempelvis vara genom att få information från en plutonchef, och kunna bekräfta mottagandet av informationen och eventuellt även kunna svara med korta, förutbestämda textmeddelanden. Detta tillsammans med resultatet om att gränssnittet bör fokusera på mottagande av information gör att studiens fokus ändras från det initiala: interaktion med obemannade enheter, till att istället fokusera på mottagande av information från andra soldater, chefer samt obemannade system. Slutsatser som dras är att gränssnittet bör vara utformat som ett litet, smidigt kompletterande gränssnitt på armen, som ger användaren snabba, direkta notiser med kortfattad information som exempelvis signalerar fara, för att det ska passa användningsområdet. Vidare dras slutsatsen att mängden funktioner som är autonoma i systemet påverkar både utformningen och situationsmedvetenhet, och att detta är ett komplext och till viss del motsägande område att undersöka vidare. Framtida studier anses således kunna beröra områden såsom hur mycket autonomi som är eftersträvansvärt samt hur haptisk återkoppling kan användas i högrisksituationer. / The rapid development of autonomy and remote control within unmanned vehicles has led to a need within the military to explore the interaction between users and various unmanned units, in order to map needs for future interfaces. There is a need for alternative interfaces to the hand-held control devices that are used today, as these have been shown to have limitations regarding situation awareness and cognitive workload of the operator – something that is particularly important in high-risk situations. There is further evidence that an arm mounted controller has the potential to meet these needs of future interfaces. This study therefore examines possible designs for an arm mounted interface and investigates how well conceptual designs fit the specific area of use; high-risk dismounted reconnaissance for ground units. Throughout, the focus is to map and specify needs through an iterative and user centered study and generate conceptual prototypes based on this. Initially, a literature study is carried out, the results of which are compiled into several design principles for the design of interfaces for unmanned vehicles in military contexts. The design principles are further used in idea and concept generation as well as in the development of lofi prototypes. The lofi prototypes that visualize different concepts for an arm mounted interface are then evaluated in a user test with focus discussions. This is the first of two iterations of the user study. Furthermore, a final overall concept is developed, which is evaluated in the second user test. At this point, the focus of the study has been directed specifically at the area of use for scouting in high risk situations for ground units and evaluates through storytelling how well an arm mounted interface fits the area of use. The results from the first user test show above all that an arm mounted interface should be designed as a complement to a main control unit, and that it is important that it is designed based on the soldiers' equipment and environment by being small, light and durable. Furthermore, the results show that the interface should focus on receiving rather than sending information, and that it should be designed to provide the user with quick, concise notices of important information that are easily read on the arm without the soldier having to interrupt his duties or put down his weapon. Physical buttons, light discipline and vibrations as feedback are other aspects that the results show is interesting to investigate further. The result from this first iteration is used to develop a final concept for the second user test, which is embodied in a prototype in clay that visualizes the size of the interface, like a smart watch, and several physical buttons. Through storytelling where the participants get to wear the prototype on their arm and experience a realistic scenario, it is evaluated how well this type of interface suits the user and the area of use. The results from the second user test show that a small, flexible interface on the arm that provides quick, concise information is beneficial in high-risk situations and reconnaissance situations where you need to hide or act covertly. The interface therefore does not need to be able to provide detailed information and have advanced interaction but should instead function with the aim of quietly and quickly giving a warning through, for example, a vibration or a symbol on the screen. Thus, the user can receive quick, direct alert notices that signal the level of danger – which is in demand in high-risk situations in particular – before, for example, radio communication can provide more detailed information about the danger. Another important result of the user study is that the interface should not only focus on information from and interaction with unmanned devices, but also interaction with people. This can be, for example, by receiving information from the command group or a platoon leader and being able to confirm receipt of the information and possibly also be able to respond with short, predetermined text messages. This together with the result that the interface should focus on receiving information causes the focus of the study to change from the initial: interaction with unmanned units, to instead focus on receiving information from other soldiers, managers, and unmanned systems. Conclusions drawn are that the interface should be designed as a small, flexible supplementary interface on the arm, which provides the user with quick, direct notifications with concise information such as signaling danger, in order for it to fit the area of use. Furthermore, it is concluded that the number of functions that are autonomous in the system affects both the design and situational awareness, and that this is a complex and somewhat contradictory area to investigate further. Future studies are thus considered to be able to touch on areas such as how much autonomy is desirable and how haptic feedback can be used in high-risk situations.

No description available.