Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 309-316).

M.Phil. / This study identifies and evaluates dynamic models used to characterise the dynamic stiffness and phase angle of hydraulic elastomeric mounts that are primarily used as engine and operator cab isolators in vehicular applications. Linear models developed for hydraulic elastomeric mounts are analysed for their suitability to be used to characterise the dynamic stiffness and its phase angle in the low and high frequency range. A sensitivity analysis provides insight into the parameters with a high level of sensitivity to changes in model parameters. The models selected from the linear analysis are enhanced and updated by performing a quasi-linear analysis to compensate for the dynamic behaviour of certain parameters. Non-linear dynamic behaviour of the decoupler is also investigated. These models are then verified experimentally. To set-up an analytical model that can be used to predict the dynamic characteristics of the hydraulic elastomeric mount it is necessary to develop a physical model from which the system differential equations are extracted. From the physical model flow continuity equations and fluid momentum equations are developed to obtain an expression that describe the fluid response in the inertia track and decoupler respectively. Lumped parameter mechanical models are developed next from which equivalent differential equations are derived to describe the internal dynamics of the hydraulic mount. These differential equations along with the transmitted force equation directly derived from the physical model are used to develop the dynamic stiffness transfer function. Time domain input displacement and output transmitted force data are taken at a specific frequency and amplitude, and are used to generate hysteresis loops to extract the dynamic stiffness and phase angles. For most of the computational effort, both analytical and experimental, MATLAB programs are written to perform curve fitting, FFT calculation, numerical integration and dynamical simulation. Emphasis is placed on the dynamic considerations of hydraulic mount design in the automotive industry and where machines are subjected to shock and vibration. The results and techniques used to model and the mounts are useful to designers in the field of shock and vibration isolation. Finally, the aim of the work is to keep the dynamic models as simple as possible, to be used effectively in the identification of the structural dynamic characteristics of hydraulic elastomeric mounts. To avoid complexity two models are used to describe the dynamics of the mount, one model for the low frequency, large amplitude conditions and one for the high frequency, small amplitude conditions. The information is then used to determine how the mount will respond under certain dynamical conditions.

M.Comm. / The subject of the study is the way in which the coordinated marketing-logistics interface through the fourteen coordination techniques creates a sustainable competitive advantage. The investigation is limited to the passenger car manufactures in South Africa (SA). The literature has acknowledged that marketing and logistics are inseparable and managers from these functions have been working on the relationship in order to use it as a competitive advantage strategy. The fourteen marketing-logistics interface coordination techniques were identified in order to assist these managers to improve the interface and increase the level of cooperation with the intention of achieving a sustainable competitive through the interface. The use of fourteen marketing-logistics interface was not tested during the identification process of such techniques and it is important to find out if they are used in the passenger car industry in SA. Each of the fourteen coordination techniques differs on the basis of the level of use in the passenger car manufacturing organisations. Some techniques are mostly used in organisations than others. For example, top management support and information sharing are mostly used in these organisations while unified department and third-party intervention are not used and there is no plan to use them. There are techniques that have very high- to-high impact on the interface. It is important for the organisations to focus on those techniques that have very high and high impact on the interface since this can assist in improving cooperation between marketing and logistics and create the interface that can serve as a way to a sustainable competitive advantage. The level of cooperation between marketing and logistics functions in the manufacturing organisations in the passenger car industry was measured followed by questions relating to the use, the impact and the importance of the fourteen marketing-logistics interface coordination techniques in order to build and improve the cooperation and create a sustainable competitive advantage through the interface. Other techniques, except the predetermined fourteen techniques were identified however most respondents stated that organisations use the fourteen existing techniques. Some techniques such as a top management support, joint outings and information sharing were mostly used by organisations. It is interesting to note that mostly used does not imply that the technique has a high to very high impact on the interface. Although joint outing is mostly used it was found to have a moderate impact on the marketing-logistics interface. Recommendations provided should be applied in order to identify the difference in cooperation between marketing and logistics before and after the study. The marketing-logistics interface coordination can be a strategic tool for creating a sustainable competitive advantage if there is high level of cooperation between marketing and logistics through the use of coordination techniques.

By ventilating the vehicle’s interior during a soak, the peak cooling load is reduced and therefore the air-conditioning needs less power. This in turn translates to a smaller air-conditioning unit which would consume less power, be lighter and more compact. This solar driven ventilation of the vehicle’s interior during a soak is defined as precooling. During this project the best precooling strategy for passenger vehicles was found by investigating and testing different precooling strategies and evaluating them according to their thermodynamic performance, their potential implementation and their influence on the required cooling performance of the airconditioning cycle. The best performances were achieved by strategies with a high air flow rate and a relatively low air inlet temperature. Two categories of precooling strategies were examined: natural convection and forced convection strategies. Openings in the vehicle’s body that fit to all strategies had to be found; with a big potential concerning their thermodynamic performance and other aspects like prevention against water penetration. The best investigated precooling strategies proved to be the one which used the design outlet as an inlet and the opening of the HVAC as an outlet. With these openings a good air flow through the whole cabin can be guaranteed. In addition to that the strategy only uses existing openings of the body which prevent against water penetration. The required installation space for this strategy already exists and can be considered for the package of next generation vehicles.

In-car communication systems (ICCS) are becoming more frequently used by drivers. ICCS are used in order to minimise the driving distraction due to using a mobile phone while driving. Several usability studies of ICCS utilising speech user interfaces (SUIs) have identified usability issues that can affect the workload, performance, satisfaction and user experience of the driver. This is due to current speech technologies which can be a source of errors that may frustrate the driver and negatively affect the user experience. The aim of this research was to design a new multimodal interface that will manage the interaction between an ICCS and the driver. Unlike the current ICCS, it should make more voice input available, so as to support tasks (e.g. sending text messages; browsing the phone book, etc), which still require a cognitive workload from the driver. An adaptive multimodal interface was proposed in order to address current ICCS issues. The multimodal interface used both speech and manual input; however only the speech channel is used as output. This was done in order to minimise the visual distraction that graphical user interfaces or haptics devices can cause with current ICCS. The adaptive interface was designed to minimise the cognitive distraction of the driver. The adaptive interface ensures that whenever the distraction level of the driver is high, any information communication is postponed. After the design and the implementation of the first version of the prototype interface, called MIMI, a usability evaluation was conducted in order to identify any possible usability issues. Although voice dialling was found to be problematic, the results were encouraging in terms of performance, workload and user satisfaction. The suggestions received from the participants to improve the system usability were incorporated in the next implementation of MIMI. The adaptive module was then implemented to reduce driver distraction based on the driver‟s current context. The proposed architecture showed encouraging results in terms of usability and safety. The adaptive behaviour of MIMI significantly contributed to the reduction of cognitive distraction, because drivers received less information during difficult driving situations.

A substantial number of whiplash injuries are reported for motor vehicle accidents which produce little or no structural damage to the automobile. These injuries are predominantly associated with rear-end type accidents affecting passengers of the struck vehicle. Since passengers of the striking vehicles are not reporting as many injuries for the same accidents, occupant and vehicle dynamics experienced during low speed-rear impacts were proposed to be a major source of the whiplash claims. A review of previous research revealed that little information exists for this type of accident. In general, vehicle safety research and government regulations have been directed towards occupant mortality - not injury - in frontal collisions. Occupant dynamics research has been limited to sled testing, using modified seat structures, or out-of-date vehicle models. Full scale, rear impact, crash testing has concentrated on high impact speeds (above 30 km/h) where significant structural deformation occurs. A research program was designed to investigate the occupant and vehicle dynamics during low speed - rear impacts. Experimental research was undertaken to document the structural performance of vehicles, noting the impact speeds necessary to initiate the crush mechanisms in the rear portion of the vehicle. To facilitate this testing, a pendulum impactor, based on the government test procedures, was designed and built to consistently reproduce impact speeds below 20 km/h. A total of 56 rear impact tests were conducted with 1977-1982 Volkswagen Rabbits. The vehicle wheels were locked to represent a vehicle stopped in traffic - the most commonly reported whiplash producing accident. An anthropometric test dummy was used to represent a front seat passenger during the tests. High speed video recordings of the tests were digitized to provide kinematic information on the occupant and vehicle response. Accelerometers were incorporated into the last 24 tests to monitor the acceleration levels at the bumper mount, seat mount and within the dummy. Information obtained from this testing suggested that permanent structural damage was only visible when an impact speed between 14 and 15 km/h was experienced by the vehicle. Very little frame deformation occurs for impact speeds below this value. Below this threshold, the vehicle frame can be considered rigid; vehicle response being dominated by the compliance of the bumper and suspension systems as well as sliding of the locked wheels. The accompanying occupant response was a differential rebound of the head and shoulders off the seatback and head restraint. This relative motion between the head and torso was evident in each test and increases the potential for injury. Typical occupant response observed consisted of an initial loading and deflection of the seatback due to the occupant's inertia followed by the release of this stored spring energy as the occupant was catapulted forward. It is this elastic behaviour of the seatback which is the likely cause of whiplash injury. Resulting head velocities were found to be in the order of 1.5 - 2 times the resulting vehicle speed. Initial occupant postures which increased the distance between the torso and seatback tended to increase the dynamic loading experienced by the passenger. Analytical modelling of the vehicle was initiated as the groundwork for full occupant-vehicle simulation. A finite element model of the vehicle frame, bumper, and suspension was created. Previously obtained empirical information suggested that a non-linear bumper and suspension system connected to a rigid frame would be an acceptable approximation. A parametric analysis of bumper stiffness and braking conditions was conducted in a 30 simulation matrix. General kinematic trends of the tests were observed in the simulations, however, limitations in the material properties introduced a much stiffer response than that experimentally observed. Results from this study show that little protection is offered to an occupant during a rear end collision. Impact energy management within the vehicle may not be adequate to prevent injury. Improved occupant protection requires the highly elastic behaviour of the vehicle frame and seatback to be attenuated. This will eliminate the amplification of vehicle motion through the seatback to the occupant. / Applied Science, Faculty of / Mechanical Engineering, Department of / Graduate

Recent industry reports evidence a marked increase in consumer interest in purchasing green automobiles (Hybrid Cars, 2011). With the introduction of the Escape Hybrid vehicle in 2004, Ford Motor Company made an indelible mark on the automobile industry as the first American automaker to produce a hybrid sport utility vehicle. In this paper, we examine how Ford emerged from a cloud of greenwashing allegations to become celebrated for its green practices.

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In recent years automobile safety has become more and more important.The braking device contributes largely to the problem of safe driving.

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