Abstract
A method and its computerised implementation are proposed for the modelling of planetary transmission systems. Using a computer symbolic scripting environment, a number of idea class objects and appropriate methods to manipulate them are defined, implementing all the relationships that govern the system kinematics, mechanical efficiency and geometric compatibility. The outcome is a system of equations involving the most pertinent design and performance parameters, which allow a systematic interrogation of the relationships between system design and performance. This method is particularly useful for the synthesis and design of novel automotive planetary transmissions, where very early in the design process an analytical solution to several inverse problems is required, making the proposed computerised symbolic modelling indispensable.