Design and implementation of variable braking force system on a two wheeler

Abstract

In this research work, a variable braking force system is designed and applied to a motor cycle rear wheel to control the maximum braking force which is developed between the tyre and the ground, for reducing the stopping distance of the motor cycle and thereby improving the motor cycle safety and riders. In variable braking force system, the effective radius of the disc is varied by moving the position of the caliper along the radial direction over the disc of the braking system based on the pillion load on the motor cycle. Hence the maximum braking force developed between the ground and the tyre is controlled based on pillion load on the motor cycle if the friction is present between the tire and ground. In other words, the maximum traction capacity between the tyre- road system is utilized. A typical motor cycle is selected to accommodate the variable braking force system. The centre of gravity which is measured by adopting a suitable method is required to design the braking system of the motor cycle. An optimum brake disc radius is determined based on the pillion load and vehicle geometry of the typical motor cycle, keeping rider weight and hydraulic brake line pressure constant. Moreover, the effective disc radius is determined for the various loads which are acting on the pillion of the motorcycle. The motorcycle which is selected for implementing variable braking force system, has a drum brake. Since the drum brake is not suitable to vary the effective disc radius, it is replaced with disc brake that is available in the new model of the same motor cycle. The disc brake that is procured, needs to be modified to implement the variable braking force system. In the new disc brake, modification work is done on brake caliper and its holder, disc and wheel hub of the motor cycle for achieving the variable braking force. In that modification work caliper and its holder are designed in three different methods.