Automatic Transmission Power Flow Matrix Representation

Abstract: The project has worked with the function and structure of epicyclical automatic transmissions. The goal of the project has been to find a mathematical way of representing the transmissions setup and possible power flows. Furthermore the project has included the generation of all theoretically possible matrix representations of two simple planetary gear sets in MATLAB as the base for a future optimization model. The result of the project is a large quantity of matrix representations of the two planetary gear sets and their connections and shafts. The result from the MATLAB program has been verified by comparing the structure and the number of solutions to all manually derived setups. The result from the program can be considered to be complete for two planetary gears but to extend the analysis to more complex planetary gears and gearboxes with more than two sets, another method is suggested. The generation process in this project has been rather complex and time consuming. The conclusions drawn from this project is that it is possible to represent many epicyclical automatic transmissions in matrix form. An optimization program based on this type of matrix would simplify the design of new, more complex and more efficient epicyclical transmissions leading to more efficient vehicles. Key words: automatic transmission, planetary gear, matrix representation