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Control Strategy and Energy Recovery Potential for P2 Parallel Hybrid Step Gear Automatic Transmissions

Journal Article
2019-01-1302
ISSN: 2641-9645, e-ISSN: 2641-9645
Published April 02, 2019 by SAE International in United States
Control Strategy and Energy Recovery Potential for P2 Parallel Hybrid Step Gear Automatic Transmissions
Sector:
Citation: Robinette, D. and Orlando, J., "Control Strategy and Energy Recovery Potential for P2 Parallel Hybrid Step Gear Automatic Transmissions," SAE Int. J. Adv. & Curr. Prac. in Mobility 1(3):1364-1382, 2019, https://doi.org/10.4271/2019-01-1302.
Language: English

Abstract:

The purpose of this investigation is to present a control strategy and energy recovery potential for P2 parallel hybrid step gear automatic transmissions. The automatic transmission types considered for the investigation are rear wheel drive 8 speed dual clutch transmission and 8 speed planetary automatic equipped each equipped with an electric motor between the engine and transmission. The governing equations of clutch-to-clutch upshift controls are presented and are identical for each transmission type. Various strategies are explored for executing the upshift under a range of input torques, shift times and engine torque management approaches. The differences in energy recovery potential based upon control strategy is explored piecewise as well as through a DFSS study. On a comprehensive drive cycle consisting of FTP 75, US06 and HWFET test cycles, it is shown that upshift regen torque management can be equivalent to approximately 0.8% of the total fuel energy used. Additionally, it is shown that the utilization of the P2 electric motor is a further enabler to reduced shift times and improved shift quality at part throttle without compromise to net battery energy or fuel consumption.