This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Estimation of Wet Clutch Friction Parameters in Automotive Transmissions
Technical Paper
2015-01-1146
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
In this paper, a new algorithm for the off-line estimation of wet clutch friction parameters is proposed for automotive transmissions, motivated by the usefulness of such an algorithm for diagnosing the condition of the clutch and transmission fluid in service. We assume that clutch pressure is measured, which is the case in dual clutch transmissions (DCT). The estimation algorithm uses measured rotational speeds and estimated accelerations at the input and output sides of a clutch, measured clutch pressures, and a simplified dynamic model of clutch friction to estimate the viscous and contact components of clutch friction torque. Coefficient of friction data is generated using the contact friction torque. A Stribeck friction model is fit to the data, and parameters in the model are then calculated by applying linear least squares estimation.
The proposed estimation algorithm is tested using the simulation of a powertrain utilizing a DCT, where the clutch friction model incorporates a realistic level of fluid film squeeze dynamics. The algorithm is evaluated under ‘noiseless’ and ‘noisy’ conditions. In the ‘noiseless’ case, clutch accelerations and pressure derivatives are obtained by differentiating stored clutch speed and pressure signals. In the ‘noisy’ case, white-Gaussian noise is introduced to the stored signals, with a noise-to-signal amplitude ratio of 10% for speed signals and 5% for pressure signals. The clutch accelerations and pressure derivatives are then estimated using a Kalman filter, and results are presented for both ‘noiseless’ and ‘noisy’ cases. In both cases, friction parameters are estimated within 10% of their respective simulated values, with the estimation accuracy being generally better for the ‘noiseless’ case.
Recommended Content
Citation
Barr, M. and Srinivasan, K., "Estimation of Wet Clutch Friction Parameters in Automotive Transmissions," SAE Technical Paper 2015-01-1146, 2015, https://doi.org/10.4271/2015-01-1146.Also In
References
- Rizzoni , G. , and Srinivasan K. ME7236: Powertrain Dynamics Class Notes The Ohio State University 2012
- Grzesiak , A. , Lam , R. , Fairbank , D. , Martin , K. et al. Friction Clutches” in “Design Practices: Passenger Car Automatic Transmissions Warrendale SAE International 2012 10.4271/AE-29
- Berglund , K. , Marklund , P. , Larsson , R. , Pach , M. et al. Wet Clutch Degradation Monitored by Lubricant Analysis SAE Technical Paper 2010-01-2232 2010 10.4271/2010-01-2232
- Lam , R. , Chavdar , B. , and Newcomb , T. New Generation Friction Materials and Technologies SAE Technical Paper 2006-01-0150 2006 10.4271/2006-01-0150
- Barr , M. Dynamic Modeling, Friction Parameter Estimation, and Control of a Dual Clutch Transmission The Ohio State University 2014
- Deur , J. , Petric , J. , Asgari , J. , and Hrovat , D. Modeling of Wet Clutch Engagement Including a Thorough Experimental Validation SAE Technical Paper 2005-01-0877 2005 10.4271/2005-01-0877
- Ivanović , V. , Herold , Z. , Deur , J. , Hancock , M. et al. Experimental Characterization of Wet Clutch Friction Behaviors Including Thermal Dynamics SAE Int. J. Engines 2 1 1211 1220 2009 10.4271/2009-01-1360
- Karnopp , D. Computer-Simulation of Stick-Slip Friction in Mechanical Dynamic-Systems Journal of Dynamic Systems Measurement and Control-Transactions of the Asme 107 1 1985 100 03 10.1115/1.3140698
- Deur , J. , Asgari J. , and Hrovat D. Modelling of an Automotive Planetary Gear Set Based on Karnopp Model for Clutch Friction ASME 2003 International Mechanical Engineering Congress and Exposition 8 Washington, Dc, USA ASME 2003 10.1115/IMECE2003-41693
- Tersigni , S. , Henly , T. , Iyer , R. , Cleveland , C. et al. New Durability Testing of Dual Clutch Transmission Fluids SAE Technical Paper 2008-01-2397 2008 10.4271/2008-01-2397
- Yang , Y. , Lam , R. , and Fujii , T. Prediction of Torque Response During the Engagement of Wet Friction Clutch SAE Technical Paper 981097 1998 10.4271/981097
- Bai , S. , Maguire , J. , and Peng , H. Dynamic Analysis and Control System Design of Automatic Transmissions Warrendale SAE International 2013 10.4271/R-413
- Hebbale , K. V. , and Ghoneim Y. A. A Speed and Acceleration Estimation Algorithm for Powertrain Control the American Control Conference 1991 26 28 June 1991 0-87942-565-2 415 420