Modeling of a Dry Dual Clutch Utilizing a Lever-Based Electromechanical Actuator

Abstract

The paper proposes a dynamic model of an automotive dry dual clutch system, which comprises submodels of a lever-based electromechanical actuator and a dual clutch assembly. The model is developed by using the bond graph approach, and it can be used for clutch design, analysis, and control tasks. Special attention is devoted to modeling of friction, compliance, and lever geometry effects, as they are the ones that predominantly determine the accuracy of clutch static curve description and computational efficiency of the model. Several custom-designed test rigs are utilized for the purpose of collecting the experimental data needed for model parameterization and validation. Experimental validation demonstrates a good modeling accuracy for a wide range of operating parameters.

Modeling of dry dual-clutch axial dynamics

“…Each clutch is engaged by an electric servomotor by a screw drive, a lever-based mechanical actuator, and an associated engagement bearing (see Figure 1(a) and (d) and the papers by Deur et al 13 and Ivanović et al 19 ). The actuator engagement bearing force input is boosted by a diaphragm spring lever to generate the axial (normal) force on the pressure plate.…”

“…The actuator model was proposed and experimentally validated in the paper by Deur et al, 13 together with a basic clutch assembly model. The basic clutch model did not include (i) the effects of the variations in the COF of the clutch with the temperature, the slip speed, and the normal force, 14, 15 (ii) the clutch thermal dynamics and thermal expansion submodels, 16 and (iii) the effect of wear and the wear compensation mechanism.…”

“…The basic clutch model did not include (i) the effects of the variations in the COF of the clutch with the temperature, the slip speed, and the normal force, 14, 15 (ii) the clutch thermal dynamics and thermal expansion submodels, 16 and (iii) the effect of wear and the wear compensation mechanism. 17 The main novelty of this paper is in proposing a significantly revised and extended clutch model in comparison with the basic model from the paper by Deur et al, 13 in order to account for all the aforementioned effects, thus significantly expanding its applicability for control-oriented and hardware-design-oriented simulation studies.…”

Modeling and experimental validation of lever-based electromechanical actuator for dry clutches

“…Substituting equations (20)- (22) into equations (10), (13), (14), (15), (16), and (18) yields the expression as below…”

“…In most dry clutches, the mechanical connection between the friction plate and the actuator is a diaphragm spring whose stiffness is nonlinear with respect to the deformation. 13,14 Moreover, the stiffness has a negative phase for the sake of maintaining the spring force and the clutch torque capacity in case that the deformation becomes small due to wear. [15][16][17] But during dynamic process of clutch engagement, the negative stiffness induces instability, which may cause poor tracking performance of the desired normal force.…”