The design of automatic transmissions is a challenging task due to complex power flows and high variability of architectures. To overcome those difficulties a methodology is proposed which uses computational design synthesis to generate transmission designs. The methodology is efficiently dealing with the complexity and variability of transmissions while the engineer is focusing on the application of his engineering knowledge. An analysis of 1022 patented transmissions is shown and highlights the trend of increasing complexity in order to achieve higher capability. The generation of innovative transmission designs is presente d producing designs with improved properties.

Most modern automatic automotive transmissions are complex mechanical systems composed of multiple planetary gearsets that are connected by shafts, clutches and brakes. Creating a design that supports the desired transmission ratios while requiring a minimal amount of components is a challenging task that is commonly tackled by an engineer with experience and intuition. This paper introduces an approach for the exhaustive synthesis of automotive transmissions composed of two planetary gearsets, two clutches and two brakes that can be deployed in automotive drivetrains. By modeling the components of an automotive transmission based on their possible mechanical connections and additional user-defined specifications a constraint satisfaction problem is derived. An iterative solving process exhaustively generates all possible transmission design with the specified set of components. Further the generated designs are filtered and analyzed such that the designer is served only with unique, valid and useful transmission designs. Finally a set of generated, novel 4-speed transmission designs is presented.