Vehicle platooning has been heavily studied the last decade. A transportation system formed by electric vehicles driven by control systems with the help of on-board sensors, wireless inter-vehicle communication, and wireless recharge capability has been shown to increase highway capacity, transportation safety, reduce travel time, save energy, and release human drivers from stress. Two layers of control are required to automate a platoon, the low-level vehicle control, and the upper-level platoon control which seeks to maintain the constant spacing of the platoon, and avoid collisions. In order to have a robust platoon, the vehicle control system needs to be robust to gain variations. Simulations were run in Matlab's Simulink to compare how well a vehicle control system would behave in the presences of nonlinearities and disturbances. The integer order and fractional order controllers were designed with the same specications. Fractional order controllers present better performance with no overshoot for the speed servo, and faster response for the steering system. For platoon control, the necessity is to achieve string stability. The bi-directional and leader-follower architectures have been shown to achieve string stability. Still, what happens to all the benets of platooning when a malicious vehicle (attacker) attempts to perturb the system? This malicious attack could be the result of a company trying to sabotage the operation of another's in order to make it spend more energy than required, and thus raise its transportation costs. By using Matlab, a simulation platform was designed. It was used to simulate the response of a robust platoon to an optimal attack prole, generated by Matlab's genetic algorithm. To calculate the energy expenditure a model for a 1995 Honda Accord LX from cappielo's analysis is used. Two scenarios are considered: 1) the attacker intends to make the whole platoon spend extra energy, and 2) the attacker focuses on affecting only one victim. The greatest amount of extra energy expenditure for the rst scenario was obtained with the bi-directional architecture and a size 3 platoon (140%). The leader-follower architecture limited this peak value to 94% for a size 8 platoon. In order to really prot from the benets of platooning, a platoon size 8 or more is recommended. In this desirable range, the bi-directional control law manages to limit the extra energy expenditure to 80% (size 8) to only 35% (size 20). For the leader-follower and a size 20 platoon, the optimal attack produced an extra 65% expenditure. For the second scenario, with the bi-directional architecture the attacker could make the victim spend up to 122% (size 10). Still, this depends on both the attacker's and the victim's position. For instance, with the attacker in position 2, only 8% extra energy was observed. The leader-follower architecture allowed between 80% to 110% in any position for the attacker while in front of the victim (the attacker cannot affect the victim from behind). Regenerative braking in all cases saved between 35% to 50% of the energy that would be otherwise lost by the use of dissipative brakes. In order to create an operational platoon system, that is as robust as possible to the attack, the recommended platoon size is 12 or more. The use of regenerative braking capable vehicles is a must. The control system should be the fastest possible, and make use of the bi-directional architecture to limit energy expenditure. The implementation of an attacker or defective vehicle detection system is recommend, taking the measure of making the attacker=defective vehicle reposition to the last in the platoon.

Children with autism spectrum disorders often have deficits in the area of social skills. Because of this deficit many children with autism avoid engaging in play activities with typically developing peers. The purpose of this study was to identify the utility of a photographic activity schedule, with embedded scripts, to teach three children with autism to play a complex social game with typically developing peers. In this study we used activity schedules to train children with autism to play hide-and-seek in a group with typically developing peers. All participants were prompted using physical guidance to follow the activity schedules to play hide-and-seek. Two activity schedules were present during teaching sessions, one was the seeker schedule and the other was the hider schedule. Each group member played the role of the seeker once and then the game ended. All of the participants were able to follow the activity schedules to play hide-andseek. We then systematically faded the activity schedules to the least intrusive version necessary. We were able to fade all of the scripts and several components of the activity schedules. For two of the three participants with autism we were able to fade the schedule from two binders to a visual cue displaying the order of the seekers. For the third participant we were able to fade one binder and the majority of the components in the second binder. The participants were able to continue to play hide-and-seek with the faded versions of the schedules in a novel environment and 2-weeks after treatment concluded.

L’objectif principal de cette thèse est de développer une méthodologie qui permette de définir des sollicitations simplifiées représentatives des sollicitations réelles rencontrées en exploitation, c’est-à-dire équivalentes en sévérité vis-à-vis du phénomène d’amorçage de fissure par fatigue mécanique. Cette méthodologie doit être adaptée aux problèmes multi-paramètres car les sollicitations subies par les roues ferroviaires sont multidimensionnelles (chargement vertical et latéral) et indépendantes. Enfin, la thèse vise aussi à proposer une approche fiabiliste globale du problème de fatigue des roues, qui pourra être une extension de la méthode Contrainte-Résistance aux cas des sollicitations multi-entrée. Un critère de fatigue pour l’acier des roues est identifié à partir des nouveaux essais. / The main objective of this PHD thesis is to develop a method for the definition of simplified equivalent loads representative of real loads (the severity is equivalent from fatigue phenomenon point of view). This method must be adapted to multi-input problems because loads applied on wheels are multi-dimensional (vertical and lateral loads) and independent. Finally, the thesis also aims to provide a comprehensive approach to fatigue-reliability problem of the wheels, which can be an extension of the stress-strength method for multi-input loads. A fatigue criterion for the railway will is presented and identified using a new test campaign.

An exploration of harmony in architecture, design, and sustainable community development. / Master of Architecture

Create new ones so the old can live dignified and survive new ones.

<p>The objectives of this investigation were to experimentally and analytically evaluate the  performance of a valve train cam and oscillating roller follower mechanism. Of particular interest  was the effect of operating conditions on the slide-to-roll ratio (SRR) of the roller follower. In order to experimentally measure the SRR at the cam-roller contact, a valve train test rig  (VTTR) was utilized. The VTTR contained a section of a heavy-duty diesel engine valve train that  was instrumented with encoders and Hall effect sensors to measure the camshaft and roller  follower angular velocities as a function of operating parameters.  To corroborate the experimental with analytical results, a numerical model for the cam and  oscillating roller follower was developed. In this modeling approach, the roller angular velocity  was determined via a torque balance between the frictional torque of the pin-roller follower and  cam-roller follower interfaces. The pin-roller friction was obtained by developing a time-dependent hydrodynamic journal bearing model with variable speed and load. Friction maps were  developed for the cam-roller follower interface using a ball-on-disk EHD2 rig to capture the  friction behavior across a range of entraining velocities, contact pressures, and SRRs. Additional  areas of investigation included thermal effects and wear in the pin-roller contact. Overall, good agreement was obtained between the experimental and analytical roller  follower angular velocity, with the normalized RMS errors less than 7%, across all operating  conditions investigated. The analytical investigation determined that thermal effects in the pin-roller contact are insignificant for the typical operating conditions. However, it was shown that the  pin-roller friction torque is critical in causing roller follower slip, as the SRR greatly increases  once the pin-roller friction torque is greater than the cam-roller friction torque. Finally, pin-roller  local wear was demonstrated to have detrimental effects on the SRR of the roller follower once a  critical wear depth was reached. </p>

Based on an initiative to increase the punctuality on Swedish railways in the short term, this study on potential for increased punctuality by adjustments in the train time schedule on The Western Main Line was initiated. This was done by examining alternatives with different adjustments based on today’s timetable. The goal with the study was to increase the punctuality for the highspeed trains on The Western Main Line by five percentage points. Additionally, the study had a purpose of testing if the Swiss concept of Taktfahrplan could be applicable on a Swedish railway. The adjustments of the timetable were based on three parameters that have impact on the robustness of a timetable; dwell time, allowance and headway between trains. Those were the parameters that were tested. Based on a literature study and data on today’s delays, punctuality and dwell times for the highspeed trains, the current situation could be analyzed. The analysis showed that the trains of today’s timetable departed densely in the mornings, the biggest amounts of trains were near the big cities, punctuality had improved from 2019 to 2020, problematic points with large delays existed around Hallsberg and Falköping and the performed dwell times were longer than the planned ones for every station. Based on the analysis of today’s situation, three case alternatives as well as an alternative for comparison were created. In case alternative 1, dwell times were extended for the highspeed trains stops, in alternative 2, allowance was added and in alternative 3, headway was extended at the start stations. Time schedules for the alternatives were created in RailSys and were then simulated on a selected stretch with a disturbance filter that was based on real distributions of delay. The results did not show considerable difference in punctuality for the case alternatives. However, alternative 1 and 2 showed improvement, while the punctuality was reduced in alternative 3. A fourth alternative was created, where the two cases that had led to improvement were combined. After simulation of alternative 4, it could be established that it was the case that provided the highest improvement in punctuality. A Taktfahrplan (regular departures and station meetings) was made in RailSys that showed how well such a timetable was applicable for the highspeed trains on The Western Main Line. The results turned out well because meeting spots for these trains, at half hour traffic and the selected stopping patterns, occurred most evidently at Katrineholm C, but also at Södertälje syd, Skövde C and Herrljunga. The conclusions of the study were that none of the alternatives led to a 5-percentage increase in punctuality. However, three cases led to increased punctuality, while one case produced decreased punctuality. The parameters that produced the highest increase in punctuality was the combination of dwell time and allowance adjustments. The consequences of the adjustments were longer planned driving times for the trains and lower capacity utilization on the track. Lastly, it was established that Taktfahrplan was applicable for the highspeed trains on The Western Main Line, but further analysis would be required before implementation, especially with consideration to planning for practical introduction.

[pt] O objetivo deste trabalho é desenvolver dentro do programa FTOOL uma ferramenta para obtenção de envoltórias de esforços internos devido a cargas móveis. Envoltórias geralmente são obtidas através de interpolação de valores limites de seções pré-selecionadas ao longo da estrutura. Estes valores são obtidos com base no posicionamento da carga móvel em relação às linhas de influência dos esforços internos. A determinação de valores limites de um esforço em uma seção constitui um problema de otimização cujo objetivo é minimizar ou maximizar os valores dos esforços em relação à posição do tremtipo que percorre a estrutura. Porém, não existe uma expressão analítica que defina os valores limites de um esforço em uma seção para um dado trem-tipo, o que impossibilita o uso da maioria dos métodos clássicos de otimização para resolver o problema, porque esses métodos requerem, na maioria das vezes, o uso de pelo menos a primeira derivada da função objetivo em relação às variáveis de projeto. Portanto, este trabalho adotou algoritmos da Estratégia Evolutiva ( EE ) para determinar os valores limites devidos a cargas móveis. Foram feitas duas implementação distintas de Estratégia Evolutiva, conhecidas como EE − + ) 1 ( (lambda) e EE − + ) ( (lambda) (mi) . Além de utilizar algoritmos de EE para resolver o problema de envoltórias, foi desenvolvido um outro processo de solução denominado Força Bruta, que consiste em percorrer com o trem-tipo toda estrutura por passos pré-estabelecidos e calcular os valores dos esforços mínimos e máximos. Para a grande maioria dos casos, os resultados obtidos com a Estratégia Evolutiva foram corretos, porém, em alguns casos mais críticos, o valor exato da envoltória não é encontrado em algumas seções da estrutura, embora encontre um valor muito próximo a ele. Observou-se que os resultados da EE podem ser melhorados quando se enriquece a solução com uma estratégia econômica de posicionamento de cargas concentradas em cima de picos da linha de influência. / [en] The objective of this work is to develop a tool for obtaining envelopes of internal forces due to load-trains in the FTOOL software. Usually, envelopes are obtained through interpolation of limiting values on pre- selected sections along the structure. These values are obtained based on the positioning of the loadtrain in relation to influence lines of internal forces. The determination of limiting values of an effect at a section represents an optimization problem whose objective is to minimize or maximize the values of that effect in relation to the position of a load-train that passes along the structure. However, there is no analytical expression that defines a limiting value of an effect on a section for a specific load-train. Therefore, classical optimization methods cannot be used to solve this problem. Rather, the solution requires a method that does not require derivatives of the objective function. For this reason, this work adopts algorithms of the Evolution Strategy (ES) to achieve the limiting values due to load-trains. Two distinct algorithms of the ES, known as ES &#8722; + ) 1 ( (lambda) and ES &#8722; + ) ( (lambda) (mi) , were implemented. In addition to the ES algorithms to trace the envelopes, another process of solution called Force Brute was developed. It consists of moving the load-train in pre-determined steps along the structure and calculating minimum e maximum values. In general, the ES method converges to the correct solution. However, there are cases, depending on the complexity of the load-train, that the algorithms do not find the exact limiting value (although usually very close to it). It was observed that the ES results could be complemented and improved with results from an inexpensive solution in which concentrated loads are positioned on peak values of the influence lines.

京都大学 / 新制・課程博士 / 博士(工学) / 甲第23482号 / 工博第4894号 / 新制||工||1765(附属図書館) / 京都大学大学院工学研究科社会基盤工学専攻 / (主査)教授 森 信人, 准教授 原田 英治, 准教授 志村 智也 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

本研究では，差動機構としてニーズが高まりつつある遊星歯車機構に関して，回転伝達メカニズムの解明および振動騒音の低減にむけた駆動特性の解明を目的に体系的に研究をおこなった．軽負荷な回転伝達系としての差動遊星歯車機構を扱い，座標系や記号，瞬間中心の定義に基づき，PLC制御を用いた再現性の確保された試験機を用いて評価をおこない，Bond graphを用いたシミュレーション，ハイスピードカメラを用いた過渡応答の観察，および異なる歯面精度を組みあわせた振動騒音への影響の考察をおこなった． / 博士(工学) / Doctor of Philosophy in Engineering / 同志社大学 / Doshisha University