Integration of Active Chassis Control Systems for Improved Vehicle Handling Performance

This thesis investigates the principle of integration of vehicle dynamics control systems by proposing a novel control architecture to integrate the brake-based electronic stability control (ESC), active front steering (AFS), normal suspension force control (NFC) and variable torque distribution (VTD). A nonlinear 14 degree of freedom passive vehicle dynamics model was developed in Matlab/Simulink and validated against commercially available vehicle dynamics software CarSim. Dynamics of the four active vehicle control systems were developed. Fuzzy logic and PID control strategies were employed considering their robustness and effectiveness in controlling nonlinear systems. Effectiveness of active systems in extending the vehicle operating range against the passive ones was investigated. From the research, it was observed that AFS is effective in improving the stability at lower lateral acceleration (latac) region with less interference to the longitudinal vehicle dynamics. But its ability diminishes at higher latac regions due to tyre lateral force saturation. Both ESC and VTD are found to be effective in stabilising the vehicle over the entire operating region. But the intrusive nature of ESC promotes VTD as a preferred stability control mechanism at the medium latac range. But ESC stands out in improving stability at limits where safety is of paramount importance. NFC is observed to improve the ability to generate the tyre forces across the entire operating range. Based on this analysis, a novel rule based integrated chassis control (ICC) strategy is proposed. It uses a latac based stability criterion to assign the authority to control the stability and ensures the smooth transition of the control authority amongst the three systems, AFS, VTD and ESC respectively. The ICC also optimises the utilisation of NFC to improve the vehicle handling performance further, across the entire operating regions. The results of the simulation are found to prove that the integrated control strategy improves vehicle stability across the entire vehicle operating region

Apollo command and service module stabilization and control system design survey

Summarized design survey of Apollo command and service module stabilization and control syste

Exploração de realidade virtual para suporte ao laboratório de psicologia experimental

Threat processing is a psychology field that studies how the emotional response to fear stimuli is processed under unawareness. Researchers study this area by presenting to participants threat inducing stimuli in visual unawareness conditions, using visual suppression paradigms in the experimental psychology labs. These paradigms require that two different images are shown to each eye to create the unaware state. One such paradigm is breaking-Continuous Flash Suppression (bCFS). The traditional methods use special equipment to display a different image to each eye. However, these have several unappealing factors, such as expensiveness or effectiveness. Virtual Reality (VR) is a technology that has seen its use increase in recent research studies, showing promising results. In this regard, in collaboration with the Department of Education and Psychology, it is proposed to evaluate VR technology as a suitable alternative to current traditional methods through experimental data collection sessions. An application system is developed to perform threat processing experiments implementing the bCFS paradigm that allows the data collection, supporting VR, and the current traditional methods, satisfying a list of requirements created to guide its development. The application developed is capable of performing the experiments required and collecting the resulting data analysis, supporting VR and the traditional methods. The experiment setup is achieved via a configuration file that allows setting various parameters to produce different experiment conditions. The system is capable of displaying stimuli accurately, containing other functionalities such as image calibration, and runtime troubleshooting features. The software application developed allows, in its current state, the experimental data collection to validate Virtual Reality as a suitable technology for the experimental psychology lab.O processamento de ameaça é uma área da psicologia que estuda como é processada a resposta emocional a estímulos de medo sob inconsciência. Os investigadores estudam esta área apresentando estímulos ameaçadores a participantes em condições de inconsciência visual, usando paradigmas de supressão visual, em laboratórios de psicologia experimental. Estes paradigmas exigem que duas imagens diferentes sejam mostradas a cada olho para criar o estado de inconsciência. Um desses paradigmas é a "breaking- Continuous Flash Suppression" (bCFS). Os métodos tradicionais usam equipamento especial para exibir uma imagem diferente para cada olho. No entanto, estes têm vários factores insatisfatórios, como o custo ou a eficácia. A Realidade Virtual (RV) é uma tecnologia cujo uso tem vindo a aumentar em estudos recentes e tem-se mostrado promissora. Nesse sentido, em colaboração com o Departamento de Educação e Psicologia, propõe-se avaliar se a tecnologia RV será uma alternativa adequada para substituir os métodos tradicionais actuais através de sessões experimentais de recolha de dados. É desenvolvida uma aplicação para realizar experiências de processamento de ameaça com o paradigma bCFS que permite a recolha de dados, suportando RV e os métodos tradicionais atuais, satisfazendo uma lista de requisitos criada para orientar o seu desenvolvimento. A aplicação desenvolvida é capaz de realizar as experiências necessárias e fazer a recolha dos dados resultantes para a análise, suportando RV e os métodos tradicionais. A configuração da experiência é feita através de um ficheiro de configuração que permite definir vários parâmetros que produzem diferentes condições na experiência. O sistema da aplicação é capaz de exibir estímulos com precisão, incluindo outras funcionalidades, como a calibração de imagem e recursos de resolução de problemas em tempo de execução. A aplicação de software desenvolvida permite, no seu estado actual, a recolha de dados experimentais para validar a Realidade Virtual como uma tecnologia adequada para o laboratório de psicologia experimental.Mestrado em Engenharia Informátic

NASA Tech Briefs, April 1993

Topics include: Optoelectronics; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences

Electronic/electric technology benefits study

The benefits and payoffs of advanced electronic/electric technologies were investigated for three types of aircraft. The technologies, evaluated in each of the three airplanes, included advanced flight controls, advanced secondary power, advanced avionic complements, new cockpit displays, and advanced air traffic control techniques. For the advanced flight controls, the near term considered relaxed static stability (RSS) with mechanical backup. The far term considered an advanced fly by wire system for a longitudinally unstable airplane. In the case of the secondary power systems, trades were made in two steps: in the near term, engine bleed was eliminated; in the far term bleed air, air plus hydraulics were eliminated. Using three commercial aircraft, in the 150, 350, and 700 passenger range, the technology value and pay-offs were quantified, with emphasis on the fiscal benefits. Weight reductions deriving from fuel saving and other system improvements were identified and the weight savings were cycled for their impact on TOGW (takeoff gross weight) and upon the performance of the airframes/engines. Maintenance, reliability, and logistic support were the other criteria

Index to 1985 NASA Tech Briefs, volume 10, numbers 1-4

Short announcements of new technology derived from the R&D activities of NASA are presented. These briefs emphasize information considered likely to be transferrable across industrial, regional, or disciplinary lines and are issued to encourage commercial application. This index for 1985 Tech Briefs contains abstracts and four indexes: subject, personal author, originating center, and Tech Brief Number. The following areas are covered: electronic components and circuits, electronic systems, physical sciences, materials, life sciences, mechanics, machinery, fabrication technology, and mathematics and information sciences

Preliminary design studies of an advanced general aviation aircraft

The preliminary design results are presented of the advanced aircraft design project. The goal was to take a revolutionary look into the design of a general aviation aircraft. Phase 1 of the project included the preliminary design of two configurations, a pusher, and a tractor. Phase 2 included the selection of only one configuration for further study. The pusher configuration was selected on the basis of performance characteristics, cabin noise, natural laminar flow, and system layouts. The design was then iterated to achieve higher levels of performance

Castell: a heterogeneous cmp architecture scalable to hundreds of processors

Technology improvements and power constrains have taken multicore architectures to dominate microprocessor designs over uniprocessors. At the same time, accelerator based architectures have shown that heterogeneous multicores are very efficient and can provide high throughput for parallel applications, but with a high-programming effort. We propose Castell a scalable chip multiprocessor architecture that can be programmed as uniprocessors, and provides the high throughput of accelerator-based architectures. Castell relies on task-based programming models that simplify software development. These models use a runtime system that dynamically finds, schedules, and adds hardware-specific features to parallel tasks. One of these features is DMA transfers to overlap computation and data movement, which is known as double buffering. This feature allows applications on Castell to tolerate large memory latencies and lets us design the memory system focusing on memory bandwidth. In addition to provide programmability and the design of the memory system, we have used a hierarchical NoC and added a synchronization module. The NoC design distributes memory traffic efficiently to allow the architecture to scale. The synchronization module is a consequence of the large performance degradation of application for large synchronization latencies. Castell is mainly an architecture framework that enables the definition of domain-specific implementations, fine-tuned to a particular problem or application. So far, Castell has been successfully used to propose heterogeneous multicore architectures for scientific kernels, video decoding (using H.264), and protein sequence alignment (using Smith-Waterman and clustalW). It has also been used to explore a number of architecture optimizations such as enhanced DMA controllers, and architecture support for task-based programming models. ii

A system for aiding the user assimilation of acquired motorsport data

A racing car is a complex machine, featuring many adjustable components, used to influence the car's performance and tune it to a circuit, the prevailing conditions and the driver's style. A race team must continually monitor the car's performance and a race engineer communicates with the driver to decide how best to optimise the car as well as how to extract most from the driver himself. Analysis of acquired vehicle performance data is an intrinsic part of this process. This thesis presents an investigation into methods to aid the motorsport user's assimilation of acquired vehicle performance data. The work was directly prompted by personal experience and published opinion. These both find that the full potential of acquired data in motorsport is seldom realised, primarily because of the time available to analyse data with the resources available to a racing team. A complete solution including data management methods and visualisation tools was conceived here as a means of addressing these issues. This work focuses on part of the overall solution concept; the development of a visualisation application giving the user a detailed and realistic three-dimensional replay of a data set. The vehicle s motion is recreated from acquired data through a kinematic vehicle model driven by measured damper and ride height data. Ground displacement is computed from wheel speed and accelerometer measurements as well as a new optical sensor approach aiming to achieve better accuracy. This implements a two dimensional auto-correlation of doubly exposed ground images, calibrated to distance on the basis of an integrated ride height measurement. Three sensor units are used to allow not only displacement but also heading data to be derived. The result of the work described in this thesis is the proof of principle of both a display and sensor system, both of which were deemed worthy of further study and development to fully meet the demands of the motorsport application. The visualisation tool presented a new and applicable method of viewing acquired data, whilst the sensor was proven as a new method of deriving vehicle position data, from potentially low cost hardware.EThOS - Electronic Theses Online ServiceGBUnited Kingdo