This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Modeling and Parameter Estimation of Automatic Transmission for Heavy-Duty Vehicle Using Dual Clutch Scheme
ISSN: 0148-7191, e-ISSN: 2688-3627
To be published on September 15, 2020 by SAE International in United States
This paper focuses on the modeling of the heavy-duty vehicle drivetrain with automatic transmission by using dual clutch scheme. The planetary gear set in the automatic transmission has complicate structure and is difficult to understand. The advantage of the dual clutch scheme is that it can be used to represent the complex planetary gear set intuitively, which is a great help to understand the gear shifting process. It is also suitable for being used in the controller due to its low order. Some assumptions are required to convert the planetary gear set to the dual clutch model. The heavy-duty vehicle can be converted to the dual clutch model, because it satisfies the assumptions due to its heavy engine, vehicle inertia. This paper also proposes that how to estimate the system parameters needed to represent the system using experimental data. The main parameters are lumped inertia, lumped gear efficiency, output shaft compliance and friction coefficient of clutches. Using experimental data makes it easy to estimate parameters accurately that is hard to measure. First, a method for estimating lumped inertia and lumped gear efficiency is proposed using LSE when gear is engaged. Second, resonance frequency of the system is obtained from the lock-up oscillation data occurring at the end of the gear shifting. The output shaft compliance is calculated by analyzing resonance frequency of the system. Third, the slip and friction coefficient of the clutch over time are calculated in the inertia phase. Using those data, the relationship between the slip of the wet clutch and the dynamic friction coefficients can be obtained. Finally, a simulation is constructed to verify the accuracy of the proposed model and the estimated system parameters. Simulation result is compared with experimental data.