While the active dynamic stability of automobiles has increased over the past 17 years there have been very few similar advances made with electrically powered wheelchairs. This lack of improvement has led to a long standing acceptance of less-than-optimal stability and control of these wheelchairs. Accidents due to loss of stability are well documented. Hence, the healthcare industry has made several efforts for improved control of electric powered wheelchairs (EPWs) to provide enhanced comfort, safety and manoeuvrability at a lower cost. In response, an area of stability control was identified that could benefit from a feedback control system using solid state sensors. To design an effective closed–loop feedback controller with optimal performance to overcome instabilities, an accurate model of wheelchair dynamics needed to be created. Such a model can be employed to test various controllers quickly and repeatedly, without the difficulties of physically setting a wheelchair up for each test. This task was one central goal of this research. A wireless test-bed of a front wheel drive (FWD) wheelchair was also developed to validate a dynamic wheelchair model. It integrates sensors, a data control system, an embedded controller, and the motorised mechanical system. The wireless communication ensures the integrity of sensor data collected and control signals sent. The test-bed developed not only facilitates the development of feedback controllers of motorised wheelchairs, but the collected data can also be used to confirm theories of causes of dynamic instabilities. The prototype test-bed performed the required tasks to satisfaction as defined by the sponsor. Data collected from live tests in which the test-bed followed set patterns, was processed and analysed. The patterns were designed to induce instability. The analysis revealed that an occupied wheelchair is more stable than an unoccupied wheelchair, disproving an initial instability theory proposed in this research. However, a proximal theory explaining over-steer is confirmed. Two models of the FWD test-bed were created. First, a dynamic model inherited from prior research, based on equations of motion was tested and enhanced based on measured data. However, even with alterations to correct parameter values and variables in the equations, a complete model validation was not possible. Second, a kinematic model was created with a factor to compensate for dynamics not normally accounted in kinematic models. The kinematic model was partially validated versus the measured data. Although, still highly accurate, there is room for improvement in this model. Both models contained a sub-system drive motor model, to account for input forces to the FWD wheelchair system model, which is fully validated.

-Design of a conceptual bus using results to determine current trends in public transport. -Integration of electronic mirrors to increase safety, use of clean electrical components without emissions, use of lidar sensor built into the lights, air purification -Electric bus design in terms of design, production technology and ergonomics, production of a physical model and posters. -Work brings insight into current trends in public transport, and offers solutions for integration into design.

Flight testing methods are developed to find the drag polar for small UAVs powered by electric motors with fixed-pitch propellers. Wind tunnel testing was used to characterize the propeller-motor efficiency. The drag polar was constructed using data from flight tests. The proposed methods were implemented for a small UAV. A drag polar was found for this aircraft with CDo equal to 0.021, K1 equal to 0.229, and K2 equal to -0.056. This drag polar was then used to find the following performance parameters; maximum velocity, minimum velocity, velocity for maximum range, velocity for maximum endurance, maximum rate of climb, maximum climb angle, minimum turn radius, maximum turn rate, and maximum bank angle. Applications in UAV control and mission planning are also proposed.

Submitted by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2018-09-17T17:22:44Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_impressao.pdf: 2956113 bytes, checksum: e6a4b36626de2a1892da7e9ffd7ac14a (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2018-09-17T17:22:55Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_impressao.pdf: 2956113 bytes, checksum: e6a4b36626de2a1892da7e9ffd7ac14a (MD5) / Made available in DSpace on 2018-09-17T17:22:55Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_impressao.pdf: 2956113 bytes, checksum: e6a4b36626de2a1892da7e9ffd7ac14a (MD5) Previous issue date: 2018-08-10 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Currently, diverse existing training environments help new users of electric powered wheelchairs (EPW) learn how to drive, acquaint and improve their abilities with these assistive devices. Several authors are developing such environments, and most of them use virtually simulated wheelchairs. Despite the similarities between virtual and real wheelchairs, it is easier to drive the real device because representation of the wheelchair physical behavior is still a problem for virtual simulated environments. Concerning the driving methods, most of them are based on a joystick, which does not give the opportunity for users to test, practice and acquaint themselves with new technologies, such as driving through eye movements. This work implements and tests a more realistic approach for a training environment dedicated to new users of EPW. The proposed system is based on a real EPW controlled by teleoperation, and it is flexible enough to attend to multiple driving methods. An architecture that allows a user to send command messages to control a real EPW through the Internet was implemented to validate the system. The implemented driving methods were conventional joystick, eye-tracker and a generic human-machine interface. For the system’s evaluation, scenarios were created considering the implemented driving methods, and also scenarios considering a long distance teleoperation. The experimental results suggest that new users can practice safely using a real EPW through the Internet, even in a situation with a communication delay of 130.2 ms (average). Furthermore, the proposed system showed potential for attending new EPW users with different types of disabilities and to be a low-cost approach that could be applied in developing countries. / Atualmente, diversos ambientes de treinamento existentes ajudam novos usuários de cadeira de rodas motorizada (CRM) a aprender a comandar, se familiarizar e aprimorar suas habilidades. Vários autores estão desenvolvendo esses ambientes, e a maioria deles está usando CRM virtualmente simulada. Apesar das semelhanças entre a CRM virtual e a real, observouse que é mais fácil comandar o dispositivo real. Isso ocorre porque nesses ambientes virtuais, a representação do comportamento físico da CRM ainda é um problema. Outro aspecto observado, foi a respeito dos métodos de condução, onde a maioria dos trabalhos utiliza apenas o joystick. Porém, esse método não oferece a oportunidade a usuários com deficiência severa de aprender a comandar a partir de novas tecnologias, como por exemplo, o rastreamento ocular. Para superar essas dificuldades, este trabalho propõe, implementa e valida uma abordagem mais realista, a qual é baseada em treinamento por teleoperação e por múltiplos métodos de condução. Foi implementada uma arquitetura que permite ao usuário enviar comandos remotamente para comandar uma CRM real a longas distâncias. Os métodos de condução implementados foram por joystick, eye-tracker e por meio de uma interface humanomáquina genérica. Para a avaliação do sistema, foram criados cenários considerando diferentes configurações. Os resultados experimentais sugerem que novos usuários podem praticar com segurança utilizando uma CRM real através da Internet, mesmo em uma situação com delay de 130,2 ms (média). O sistema proposto mostrou potencial em atender novos usuários de CRM com diferentes tipos de deficiência, bem como de ser uma abordagem de baixo custo com possibilidade de ser aplicada em países em desenvolvimento.

This work deals with designs of drive for two types electric powered tricycles (type for outdoor and indoor). Designs comprise general conception of drive. We selected optimal electric motors in terms of research electric engines and calculations. Next, we proposed batteries. The last part describes design power circuit and general financial expenses.

I en tid kännetecknat av en strävan efter ett mer hållbart samhälle, med utformade långsiktiga klimatmål för förnyelsebara energikällor och minskade utsläpp, arbetar fordonsutvecklare med att ta fram alternativ till förbränningsmotorer. För att nå satta klimatmål och samtidigt förbättra arbetsmiljön med minskat buller anses en elektrisk drivlina som ett troligt alternativ. För tunga fordon såsom lastbilar som ofta utrustas med tillsatsutrustning som kranar, tippbara flak eller cementroterare är beroende av ett kraftuttag för att driva hydraulpumpar och generatorer. Vid en omställning till elektrisk drivlina är det inte längre säkert att möjligheten kvarstår att ta kraft från drivlinan. Detta har lett till en efterfrågan på elektriskt separat drivna kraftuttag uppstått på marknaden. Syftet med denna studie är att undersöka och få en förståelse för inom vilket effektområde och vilken typ av elektrisk motor som är bäst lämpad för att separat driva ett kraftuttag. Målet är att med denna kunskap utveckla en modell som förenklar valet av lämplig elektrisk motor för ett givet fall av kraftuttag. Modellen testas med en effekt på 60 kW vilket resulterade i att en lågvarvig axial flux BLDC-motor anses bäst lämpad. Detta då en lågvarvig elektrisk motor kräver lägre utväxling för att uppfylla krävt vridmoment, vilket ger en lägre totalvikt. Totalvikt för testad effekt hamnar på 78,6 kg, vilket är tre gånger det funktionella kravet. Studien ger en indikation på att det med givna krav enbart är försvarbart att driva kraftuttag med separata elektriska motorer vid låga effekter, runt 10 kW. / In a time characterized by an endeavor for a more sustainable society. With formulated long-term climate targets for renewable energy sources and reduced emissions, vehicle developers are working to develop alternatives to internal combustion engines. In order to achieve set climate targets and at the same time improve the working environment with reduced noise, an electric driveline is considered a likely alternative. For heavy vehicles such as trucks that are often equipped with auxiliary accessories such as cranes, tipper trucks or cement rotators are dependent on a power take-off to drive hydraulic pumps and generators. When switching to an electric driveline, it is no longer certain that the possibility remains to take power from the driveline. This has led to a demand for electrically driven power take-offs on the market. The purpose of this study is to investigate and gain an understanding of the power range and type of electric motor that is best suited to drive a power take-off separately. The goal is to use this knowledge to develop a model that simplifies the choice of a suitable electric motor for a given case of power take-off. The model is tested with an output of 60 kW, which resulted in a low-speed axial flux BLDC-motor being considered best suited. This is because a low-speed electrical motor requires a lower gear ratio to meet the required torque, which gives a lower total weight. The total weight for the tested effect ends up at 78,8 kg, which is three times the functional requirement. The study gives an indication that with given requirements it is only justified to operate power take-offs with separate electric motors at low powers, around 10 kW.