Predictive engineering processes for motorcycle dynamics

This study is an investigation into the use of computer aided handling and stability analysis for motorcycles. In particular it considers Triumph Motorcycles Ltd., delving into Triumph's background, their strategy and the likelihood of them using virtual techniques for stability and handling analysis. Additionally, this work reviews current knowledge of motorcycle dynamics analysis and builds on it. A novel way of studying the steering feel has been developed by analysing the response of the steer torque equation for the Sharp 1971 [1] and 1994 [2] models. The individual contributors to this equation are identified and the important ones are investigated further. One conclusion of this study is that in reduced cornering and camber conditions the steer angle of the motorcycle, for a given steering input torque, increases when compared to standard operating conditions. The steer angle also increases further as the speed increases. An update to a previous motorcycle model [3] has been made by revising the parameter set, so that it is more applicable to a modem sports motorcycle. The rider model and relaxation length description have also been improved upon. The results show that the new motorcycle has been made more manoeuvrable by the alterations to the parameters. An optimal preview steering control system for cars [4] has been taken, improved upon and used with the newly developed motorcycle model discussed above. The results from this novel work allow a designer to alter parameters and see how this affects the motorcycles steering demands, path following, etc. It was shown that an increase in the front wheel inertia makes the motorcycle feel like the steering is heavier, and an increase in the front wheel radius and wheelbase make the steering feel lighter. Future work into non-linear analysis is recommended and improved rider and tyre modelling is also desired.