TRANSMISSION TRANSIENTS PRODUCED IN RANGE SHIFTING - A DIGITAL COMPUTER SIMULATION 710246

The development of a new automatic power shifting transmission often involves many hours of prototype testing to optimize such vital factors as gear arrangement, clutch design, and rate of clutch pressure application. However, prediction of expected test results through the use of mathematical models can greatly reduce the time and cost required for that optimization.

A generalized computer program was written to predict transient speeds and torques, clutch energy absorption, and vehicle dynamics during range shifts. The program utilizes a time-increment method of simulation. The error produced in the time-increment method and the means of circumventing this error are significant points of interest covered in this paper.

This program has been used successfully to study shift phenomena in existing transmissions and to aid in evaluation of new transmission gear arrangements. Similar programs are suggested for other simulation work where non-linear and discontinuous functions need to be studied.