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Advanced Bench Test Methodology for Generating Wet Clutch Torque Transfer Functions for Enhanced Drivability Simulations
ISSN: 0148-7191, e-ISSN: 2688-3627
Published December 19, 2019 by SAE International in United States
Annotation ability available
A wet clutch continues to play a critical role for step-ratio automatic transmissions and finds new utilities in hybrid and electrified propulsion systems. A torque transfer function is often employed in practice for sophisticated clutch slip controls. It provides a simple, yet practical framework to represent clutch torque as a function of actuator force. An accurate transfer function is also increasingly desired in today's vehicle design process to enable upfront assessment of clutch controls through simulations. The most common approach is based on Coulomb's linear friction model, where the coefficients are adaptively identified based on vehicle data. However, it is generally difficult to tune Coulomb's model for hydrodynamic behaviors even if the reference vehicle data are available. It also remains a challenge to produce in-vehicle clutch behaviors on a component test bench to determine realistic transfer function before prototype vehicles are built. SAE#2 test procedure is the industry standard for evaluating clutch frictional behaviors. It is a viable tool for durability assessment, but not designed to characterize hydrodynamic behaviors for clutch controls. This research focuses on the development of a methodology to generate realistic clutch transfer functions using an advanced engagement bench tester. The test stand is equipped with programmable slip and force controllers to replicate both torque phase and inertia phase of gear shifting. It accommodates a clutch module, not only the clutch pack, to reproduce actual in-vehicle lubrication conditions. The clutch behaviors are characterized for various combinations of operating conditions. The bench test data are compared with SAE#2 data to highlight the sensitivity of hydrodynamic behaviors to force and slip profiles. A regression technique is utilized to represent clutch behaviors as a transfer function in non-linear forms using data from the advanced tester. Shift simulations are conducted to demonstrate the value of realistic transfer functions to enable upfront drivability assessment for control development.
- Hiral Haria - Ford Motor Company
- Yuji Fujii - Ford Motor Company
- Gregory M. Pietron - Ford Motor Company
- Anna Sun - Ford Motor Company
- Takahiro Tsuchiya - F.C.C. CO., LTD.
- Masatoshi Miyagawa - F.C.C. CO., LTD.
- Shinji Nakamura - F.C.C. CO., LTD.
- Matthew Wendel - F.C.C. CO., LTD.
- Hiroya Miyoshi - F.C.C. CO., LTD.
- Pengchuan Wang - University of Michigan
- Nikolaos Katopodes - University of Michigan
CitationHaria, H., Fujii, Y., Pietron, G., Sun, A. et al., "Advanced Bench Test Methodology for Generating Wet Clutch Torque Transfer Functions for Enhanced Drivability Simulations," SAE Technical Paper 2019-01-2340, 2019, https://doi.org/10.4271/2019-01-2340.
- Fujii, Y., Kapas, N., Tseng, J., “Clutch Wet,” Encyclopedia of Automotive Engineering, Wiley & Sons, 2014.
- Haria, H., Pietron, G., Meyer, J., Fujii, Y., Wang, P., Katopodes, N., “In-Vehicle Characterization of Wet Clutch Engagement Behaviors in Automatic Transmission Systems,” SAE Int. J. Passeng. Cars - Mech. Syst., 11 (5), 369-375, 2018.
- Fujii, Y., Tobler, W., Pietron, G., Cao, M., Wang, K., "Review of Wet Friction Component Models for Automatic Transmission Shift Analysis," SAE Technical Paper 2003-01-1665, 2003.
- Wu, H., “A review of porous squeeze films,” Wear, 47, 371-385, 1978.
- Ting, L., “Engagement behavior of lubricated porous annular disks,” Wear, 34, 159-182, 1975.
- Natsumeda, S., Miyoshi, T., "Numerical simulation of engagement of paper based wet clutch facing." Journal of Tribology, 116 (2), 232-237, 1994.
- Berger, E., Sadeghi, F., Krousgrill C., "Finite element modeling of engagement of rough and grooved wet clutches," Journal of Tribology, 118 (1), 137-146, 1996.
- Deur, J., Petric, J., Asgari, J., Hrovat, D., "Modeling of Wet Clutch Engagement Including a Thorough Experimental Validation," SAE Technical Paper 2005-01-0877, 2005.
- Wang, P., "Multi-physics Wet Clutch Modeling," PhD dissertation, Mechanical Engineering, University of Michigan, 2018.
- Haria, H., Fujii, Y., Pietron, G., Wang, P., Katopodes, N., Miyagawa, M., Tsuchiya, T., Nakamura, S., Wendel, M., Miyoshi, H., “Application of Empirical Asperity Contact Model to High Fidelity Wet Clutch System Simulations,” SAE Technical Paper 2019-01-1301, 2019.
- Haria, H., Fujii, Y., Pietron, G., Miyagawa, M., Tsuchiya, T., Nakamura, S., Wendel, M., Miyoshi, H., Hou, S., Wang, P., Katopodes, N., “Development of Empirical Asperity Contact Model for Wet Friction Material,” SAE Technical Paper 2019-01-0346, 2019.
- Cao, M., Wang, K., Fujii, Y., Tobler, W., “Development of a Friction Component Model for Automotive Powertrain System Analysis and Shift Controller Design based on Parallel-Modulated Neural Networks,” Journal of Dynamic Systems, Measurement, and Control, 127, 382-405, 2005.
- Fujii, Y., Snyder, T., Waldecker, R., Tobler, W., Davis, L., Scherzer, M., Zander, D., "Dynamic Characterization of Wet Friction Component under Realistic Transmission Shift Conditions," SAE Technical Paper 2006-01-0151, 2006.
- Simcenter AMESIM 17, Siemens PLM Software Inc., https://www.plm.automation.siemens.com/global/en/products/simulation-test/propulsion-system-simulation.html (Accessed on April 29, 2019).