Mechanical Combined Braking System Design and Validation for Scooter 2014-01-2485

The behaviour of scooter undergoing braking is critical in terms of both performance and passenger safety. The brakes are the single-most important safety component on scooter, and are charged with the vital task of stopping the moving vehicle. The basic goals of braking systems are to decelerate a vehicle during stopping, to maintain vehicle speed during downhill operation, and to hold a vehicle stationary on a grade.

Like many other aspects of scooter design, brake hardware is conventionally designed as a compromise between the different performance requirements. Furthermore, a factor of safety is designed into the components to assume best performance during ideal testing conditions, this could lead to a limiting performance in unfavourable conditions [5]. New developments in combined braking devices will give brake designers the freedom to control brake force without compromise, in order to ensure optimal braking and vehicle stability under all conditions. This thesis will investigate some of the possibilities in this area.

This work presents a study on the development of combined braking system for scooters with two different types of suspension configurations and its implications on scooter braking behaviour and stability. First, a simplified scooter model is used for highlighting basic phenomena which occur during braking and for developing a combined braking strategy. Then, braking performance is analysed using a detailed multi-body model, which takes into account all relevant characteristics of a scooter such as geometry, mass and inertia distribution, non linear suspension and tire properties. Finally, stability analysis is carried out for two different types of suspension configurations, showing that combine braking system may significantly improves vehicle stability.