Online Estimation of Clutch Drag Torque in Wet Dual Clutch Transmission Based on Recursive Least Squares

This paper focuses on developing an estimation method of clutch drag torque in wet DCT. The modelling of clutch drag torque is investigated. As the main factor affecting the clutch drag torque, dynamic viscosity of oil is discussed. The paper proposes an estimation method of clutch drag torque based on recursive least squares by utilizing the dynamic equations of gear shifting synchronization process. The results demonstrate that the estimation method has good accuracy and efficiency.

• Hongkui Li
• Tongli Lu
• Jianwu Zhang

• Clutch drag torque
• wet DCT
• dynamic viscosity
• recursive least squares.

[1] Galvagno E, Velardocchia M, Vigliani A. Dynamic and kinematic model of a dual clutch transmission (J). Mechanism and Machine Theory, 2011, 46(2011): 794-805.
[2] Walker P D, Zhang N, Tamba R, et al. Simulation of drag torque affecting synchronisers in a dual clutch transmission (J). Japan J Indust Appl Math, 2011, 28: 119-140.
[3] Gustavsson A. Development and Analysis of Synchronization Process Control Algorithms in a Dual Clutch Transmission (D). Sweden: Linkopings University, 2009.
[4] Kitabayashi H, Li C Y, Hiraki H. Analysis of the Various Factors Affecting Drag Torque in Multiple-Plate Wet Clutches (J). SAE 2003-01-1973, 2003.
[5] Yuan Y, Liu E A, Hill J. An Improved Hydrodynamic Model for Open Wet Transmission Clutches (J). ASME, Journal of Fluids Engineering, 2006, 129: 333-337.
[6] Li H Y, Jing Q, Ma B. Modeling and Parametric Study on Drag Torque of Wet Clutch (C)// Proceedings of the the FISITA 2012 World Automotive Congress, China, 2013: 21-30.
[7] Hu J B, Peng Z X, Yuan S H. Drag Torque Prediction Model for Wet Clutches (J). Chinese Journal of Mechanical Engineering, 2009, 22(2): 238-243.
[8] Yuan S H, Peng Z X, Jing C B. Experimental research and mathematical model of drag torque in single-plate wet clutch (J). Chinese Journal of Mechanical Engineering, 2011, 24(1): 91-97.
[9] Zhou X X, Walker P D, Zhang N, et al. Numerical and experimental investigation of drag torque in a two-speed dual clutch transmission (J). Mechanism and Machine Theory, 2014, 79(2014): 46-63.