All-terrain vehicle(ATV) is very popular in Europe and North America because of its excellent riding performance. The Design of suspension and steering mechanism is one of the most important parts in ATV design, because it is much related to the riding performance of ATVs. Therefore, this research focuses on investigating the design of suspension and steering mechanism for ATVs. There are two main objectives to be achieved in this research. One is to build the analysis theory, and the other is to develop a systematic design process of suspension and steering mechanism for ATVs. Firstly, we survey papers about suspension and steering mechanism to find its basic functions and properties. Secondly, we use engineering design method to classify the design requirements and frame the design process. Thirdly, we list new suspension and steering mechanisms by applying the creative mechanism design procedure, then separate the new mechanisms separate into two types. One type is suitable only for back-wheel drive vehicles, and the other type is suitable for back-wheel drive and four-wheel drive vehicles. Finally, we complete the kinematic design of the type1.1(double-wishbone) and type8.3(new mechanism) suspension and steering mechanisms based on the Genetic algorithm (GA), and we can obtain the better mechanism dimensions than Yamaha 660 and 450 ATV.

All-Terrain Vehicles, usually called ATVs, are a popular product in the leisure sport market. The steering mechanisms is one of the important components of ATVs to obtain better maneuverability. The purpose of this work is to develop a systematic design procedure for the steering mechanisms of ATVs. First, the particularities and the requirements of ATVs are investigated to induce the basic characteristics. Second, to carry out the creative design of steering mechanisms by using the systematic procedure of creative mechanism design. Third, to deduce the analytic theory of angle displacement, torque and stability for the design of steering mechanisms. Then a computer aided analysis program are written. Finally, to establish the quantitative design specification of the steering mechanisms of ATVs. Then the dimension synthesis and the steering mechanism to integrate with body of ATVs are illustrated with an example.

It¡¦s easy to get the complication of shoulder by using the traditional type of driving a wheelchair, and the move speed of a wheelchair is upper with motor-driven, so makes shimmy or slide usually appearing on caster when the wheelchair is steering .On the other hand, the drive mechanism of wheelchair by single-wheel was developed by the members of MEVL at the same time that this paper was written. Because of these reasons above, this paper analyze the type of steering mechanism and the patents of wheelchair¡¦s steering mechanism first, secondly find the fittest steering mechanism type for a wheelchair. Furthermore, this paper also discusses some irregular conditions of a caster and theirs reasons and how to prove them when a wheelchair is steering or moving with high speed by using several simpler mode of mechanics, such as caster shimmy, the slip angle of a caster, and some irregular cases when wheelchair is driven by single wheel. Finally this paper will design a new type steering mechanism for wheelchair by applied the results of research that above-mentioned, this new steering mechanism not only improve the traditional steering mode of a wheelchair, also avoid several irregular condition above occurring in the caster, moreover, it can be enabled or disabled by user anytime. So this paper expects that the performance of a wheelchair will be raised after the new type steering mechanism is designed.

Avhandlingen presenterar resultatet av ett examensarbete i maskindesign på KTH. Uppgiften utfördes för ABB AB, Corporate Research.ABB vill undersöka en ny drivlinjekonstruktion för lågkostnadsautomatisering. ABB Robotiks har begränsat utbud av produkter rörande mobila plattformar. Det finns en stor marknadspotential för samarbetsrobotar på mobila plattformar bland kunder med både låg och hög grad av automation.I denna rapport diskuteras en möjlig designlösning av drivlinan för en mobil robotplattform. Generellt är utformningen av en robust drivlina för mobilplattform en komplex uppgift eftersom inte alla arbetsförhållanden är lika i en industriell installation. Till exempel kan vissa industriområden för logistik och andra för tung teknik etc. Idag finns det mycket fa designer av mobila industriplattformar konstruerade för ojämn yta, ytor med sprickor, stötar och liknande ojämna egenskaper. Befintliga industriella lösningar är utformade för jämna ytor inom gränserna for golvdesignen och överensstämmer också med lasterna på plattformens drivlina. En robust lösning föreslås i denna rapport. Detta baseras på en litteraturöversikt med konstruktionsarbete inkluderande lättillgängliga billiga komponenter samt modellutvärdering för att klara specifikationen av grova golv ojämnheter. Studien för att implementera en stötdämpare baserad drivlinjemodul har också inkluderats för att undersöka möjligheten att ha ett sådant drivsystem. Andra funktioner inkluderar också en inbyggd styrenhet som gör den mer kompakt genom att minska ledningar runt plattformen. Prestanda utfördes i en simuleringsmiljö för att se stötdämparens beteende. Den slutliga konstruktionen versionen byggdes som prototyp för vidare utvärdering i test. / This thesis presents the result of a master thesis in Machine Design at KTH. The task was performed for ABB AB, Corporate Research.ABB wants to investigate in a new driveline designs for low cost automation. ABB robotics doesn’t have any products concerning mobility application. There is a huge market potential for collaborative robots on mobile platforms with customers with both low and high budget of automation.This report discusses one possible design solutions of the driveline for a mobile robot platform. Generally, designing a robust driveline for mobile platform is a complex task since not all working conditions are alike in an industrial setup. For instance, some industrial area might for logistics, some might be for heavy engineering, etc. Moreover, there aren’t industrial platforms designed for uneven surface, surfaces having cracks, bumps and similar uneven features. The ones which can cope unevenness are for extreme off-road military conditions. Existing industrial solutions are designed for even surfaces within limits and the floor design is also in accordance to the platform driveline. A robust solution is proposed here after conducting a literature review with solid evidence and evaluation for the same to sustain rough floor designs with readily available inexpensive components. Study for implementing a shock absorber-based driveline module has also been included within to look at a possibility to have such a drive system. Other features also include an on-board controller which reduces the hassle of wiring around the complete platform. The performance was conducted on a simulation environment to see the behaviour of the shock absorber. The final design was prototyped for further evaluation.