The characteristics of an automotive passenger seat in response to vibrational excitations are examined and an active vibration isolation system incorporating smart materials is designed, built, and tested. Human sensitivity to vibration is discussed. Characteristics of road roughness are discussed and used to implement a representative test input to a passenger seat system. extsc{Matlab} is used to model the car seat and vehicle system with four degrees of freedom to determine actuator requirements. Selection and implementation of a low--profile, prestressed piezoceramic device into an active seat suspension system is described, and experimental results of the actuator assembly performance are presented. Vibration isolation is realized in an experimental setup representing one quarter of a seat and passenger's total mass, using one actuator assembly (representing one corner of the seat suspension). For an input power spectrum representative of a passenger vehicle environment, the smart material actuator assembly, as applied to a quarter seat experimental setup, is proven to be capable of isolating vibration with an isolation frequency of 2Hz and no resonant peak, versus 6Hz and a resonant peak of 2g/g for an actual passenger seat tested. / Master of Science

This research is concerned with exploring the relationship between car driving and musculoskeletal troubles and following on from this investigating methods which could aid the automotive industry in the design and evaluation of car seats. The thesis is divided into two parts. Part I describes the development and results of an epidemiological survey undertaken with data obtained from two sample groups. Study 1 was an interview survey (based on the Nordic Questionnaire) of 600 members of the British public, randomly selected within the strata of age and gender. Study 2 used the same interview, but with two carefully chosen groups of police officers (n=200). The results indicated that car drivers (especially those who drove as part of their job) appeared to be at risk in terms of reported discomfort and sickness absence due to low back trouble. Evidence from this and other studies has also indicated that drivers with the most adjustable driving packages may benefit in terms of both reduced discomfort and reduced sickness absence. This provided the background for the subsequent research in Part II and some impetus for car manufacturers to consider health issues in the design of car workstations. Part II involved a series of three experiments designed to investigate methodologies which could be used by manufacturers to predict car seat discomfort The literature was reviewed to identify suitable predictive techniques which would be robust enough to provide information to the automotive industry in 'real world' situations. The technique of interface pressure measurement had already generated interest in some seat manufacturers and was therefore selected for investigation. As a result of the findings in experiment 1, established guidelines for a comfortable driving posture may need to be modified. The other two experiments were designed to create discomfort in subjects firstly by varying foam hardness and secondly by varying posture. A clear, simple and consistent relationship between interface pressure and discomfort in realistic driving situations was not identified. Future studies using this technique should provide information regarding such factors as gender, the body mass index, anthropometric data, posture and foam hardness due to the confounding nature of these variables.

Children are more vulnerable in vehicles compared to adults in collisions. Two main reasons are the different body structure between these two and vehicles are more designed to fit adults. Children’s head is larger relative to their body mass and their neck muscle ligaments are still not fully developed. Children are therefore in need of a restraint system that match their anatomy to make them protected during transportation in vehicles. Crash tests have shown that if children up to the age of five use rear-facing child car seats are the chances reduced of injuries by five times compared to front-facing. This report describes the development project of a concept which enables to fasten a rear-facing child car seat with the car seat belt. The objective was to design the fastening components for a rear-facing child car seat that suits children up to five years and considering the regulations, ECE R44, and the Swedish Plus test. This is a Master thesis that has been in collaboration with Company Xand Havd Group in Gothenburg. The project aimed to deliver a digital concept of the fastening components with information about the material, manufacturing methods, product costs, and design form. Also, was the aim to gather information through the project on what it takes to develop a rear-facing child car seat. The project consisted of five phases: planning, pre-study, ideation, detailed design and at last presentation of the result. The first phase was to plan and coordinate the project. A pre-study was then made investigating the products on the market, interviews with both users and experts regarding safety for children in vehicles, relevant literature for developing a child car seat was also collected and regulations were studied. The ideation phase developed ideas and three concepts were taken forward for development. One concept was chosen after decision making and the concept was more detailed designed in CAD.The result is presented through a CAD model which illustrates the design form and chosen material. The result is a concept that fastens the car seat belt with two hooks which can be connected to the child car seat base. In the base is two buckles designed to connect with the hooks, which uses the same fastening way used in the vehicles to fasten passengers. This is supposed to increase the usability of the installation. Material, manufacturing methods and product costs have been considered and are presented with the result.

There are lots of elements involved in the design of a car. This study, which is inspired by the brief of BMW group, explores the seating unit of cars with regard to prototypical activities, such as, listening to music, working, looking outside etc. The current study proposes that these external stimuli have an effect on comfort experience and felt emotions. So, this study explores the relationship between types of music and activities typically performed by car passengers and emotion and comfort perception, through performing a within subject design empirical study. A car seat provided by BMW group was used to test the above mentioned relationships. Data was collected through a self-report questionnaire, heart rate equipment, a pressure mat and analyzed separately for each condition. Results of the study show that there is a successful emotion induction by task and music individually, and partly on task*music interaction. A comparison of congruent and non-congruent situations, i.e. high arousal music and high arousal task or low arousal music and low arousal task, showed that differences occur in subjects&rsquo / reported level of arousal. Furthermore, the results of the study indicated that comfort is related to valance factors, independent of arousal levels. Lastly, physiological measurements showed that only task has a significant effect on heart rate, implicating for the complexity of linking physiological data to emotion and comfort.

This thesis work is focused on the design of a mechanism for the passenger’s seat of a Volvo S80. This mechanism will facilitate the problems arised when somebody with limited mobility, either permanent or temporal, is entering or exiting the vehicle. The main aim is to obtain an affordable device that enhances the life of those with reduced mobility, but paying special attention to those who do not receive any kind of economical help from the government. The idea is to be able to move the seat to the outside of the car so that one can seat with no special effort. Then, the mechanism, manually, performs the movements to bring it back to the inside. The concept of being manual is to avoid electronic devices that will surely increase the cost. In this project, a possible design solution has been developed. A model was created with Autodesk Inventor 2012. The three basic positions of the mechanism were studied to determine the structural behavior of the product. For these studies, a load compensating the weight of a human was applied and the stresses and the deformation were analyzed by Finite Element Methods and the study was concluded when the safety factor was over 2.

Car seats for smaller children, offers very good protection incase of a collision. Unfortunately for the parents’ sake , these car seats is heavy to handle outside the car. For example back and forth home and short errands around town. In other words, all those times when you decide to just take out the car seat and carry it instead of place the baby in a baby carrier. By analyzing where and how the car seat is being used. How best to carry heavier loads up to about 15 kg as a car seat with the child can weigh and by taking into account the child ’s and the parents anatomy. This work led to a concept on how this problem can be solved. Various technical principle solutions have been developed and evaluated. The chosen solution has then been further developed by various design approaches where form and expression has been the important part. The main body of the new solution is a softer inner which you lifts out when you leave the car. The baby sits in a carrier that the parent carries in front of their body. Remaining in the car is a chair-like base with ”click” fasteners that lock the softer part in place when it´s placed in the car, with the baby in it. The major benefits of solving it this way is that the baby is carried in front of the body without oblique loaded lifting on the spine. While the solution also itself weighs several pounds less than the current car seats. It also frees the parents both hands by carrying the child this way. All this leads to a gentler living for the parents.

This master´s thesis deals with a design of an electric stroller. This alternative means of transport for a parent and a child was designed based on a design and technical analysis. This product allows independent and fast movement in the city. Using the product requires an introduction of a new arrangement of streets, with designated communications for micromobility. Modern technologies are used in the concept of the designed product. The advantage of the design concept is that the product can be used as a classic electric scooter.

The aim of this work is to assess the possibilities of using numerical simulation tools in the process of laser welding of the guide rail of a car seat. In the diploma thesis, a description of the components and the problem, which consists in the deformation of the groove of the guide rail, was made. A description was made of the manufacturing operations that the components go through. The positives of selected welding methods were evaluated and the choice of those used in production was justified. A description of the issues of laser welding, deformation and the use of simulation tools was made. The influence of individual production operations was evaluated in terms of the size and nature of deformations. Using the Visual – Mesh, Visual – Weld and Visual – Assembly simulation tools, which are products of the French company ESI Group, the same state of the simulated and real process was achieved. Subsequently, a proposal for the elimination of deformations and its verification using a simulation tool could be approached. The use of a spacer wedge, which acts on the most deformed places of the groove, was proposed. By its application, the resulting deformations were eliminated or significantly reduced. In the last part of the work, a technical and economic evaluation was made, taking into account the current global crisis and the important role of the automotive industry.

This master thesis deals with creation of computational model for stress - strain analysis of front car seat folding mechanism. The calculation has been done using FEM for static and dynamic load case. The results displayed the critical area of mechanism and determined the value of force when the safety of mechanism is not guaranteed and the force when the mechanism failure occurs. According to results from both load cases was made a statement that is necessary to model the dynamic load cases respecting the load time course.

In the United States, motor vehicle crashes are one of the leading causes of unintentional injury death and disability for children ages 1'15 years. Despite local, state, and federal legislative and educational efforts, children continue to be restrained improperly and thus face harm. Identifying behaviors and barriers that place child occupants at risk is crucial for implementing focused, injury-prevention programs and policies. The purpose of this study was to evaluate the effectiveness of Connecticut's child passenger safety law that was strengthened in 2005. This study involved a multifactorial approach to predicting child seat use, guided by Roger's diffusion of innovations as the theoretical framework. The analysis determined if there was a difference in the prevalence of car seat use before as compared to after law implementation and identified variables that best predicted the use of car seats and premature transition to a seat belt. Using Connecticut's Crash Data Repository, a logistic regression analysis indicated that car seat use was 1.3 times more likely post law (OR 0.75; 95% CI: 0.65-0.86) and that in particular, children ages 4, 5, and 6 (combined) were most positively affected by the law (OR 0.67; 95% CI 0.54-0.82). Driver sex, crash time of day, child age, and child seating position were all determined to be significant predictors of whether or not a child was in a child safety seat. Additionally, these variables were also determined to be predictors of early transition to use of a lap/shoulder belt (versus child seat). The social change implication of this study is that identifying predictors of car seat use and early transition helps to formulate and implement injury prevention measures that could in turn help to decrease medical costs, save lives, and prevent injuries.