Experimental Methodologies for Automotive Non-Manual Transmission Systems

This research activity is focused on the development of new experimental methodologies for Non-Manual Transmissions, in particular for the calibration of the software that runs inside the Transmission Control Unit (TCU). Calibration is still an activity performed on vehicle but, due to several reasons, it is always more necessary to move it from Road to Rig: this concept allows to move a part of the development process of a new vehicle from the road to the test benches. Perform calibration on the road means to work directly on prototypes vehicles, that have high costs, and to be subject to external conditions that make the maneuvers not repeatable. On the other hand, work on bench assure, for sure, repeatability, so no influences of external conditions; a single test bench is able to simulate different types of vehicle, with a significant cost reduction. This research activity was scheduled in two main parts. The first, that concerns the development of the test bench used during the whole activity, a Transmission Test Bench in which the gearbox is physically present and all the other elements, such as engine and vehicle, are simulated: configuration, building of simulation models, calibration of these models, creation of test patterns. The second, that concerns the development of new experimental calibration methodologies: using the repeatability of the test bench, it was possible to reproduce many maneuvers on the bench and it was possible to improve the management of this maneuver, and then test the new solutions on vehicle, with good results. Moreover, the punctual characterization of certain components is possible, due to the precision and reliability of the test bench: in particular, the activity is focused on thermal behavior of gearbox and clutches, clutches friction coefficient function of temperature, clutches dynamic response. The self-developed experimental methodologies were built both off-line than on-line (real time) with the simulation models of the bench; with the test patterns built in the first phase of the research activity, it was possible to create automated calibrations tools that allow to actuate autonomously the system, read the output, optimize the result via self-developed estimation algorithm, and actuate again the system with the new calculated value, in order to find the best compromise for certain physical aspects. Due to the confidentiality of the contents, all the graphs represented in this work have no indications of units and values.