Development of New Sports Shift Control System for Toyota's Automatic Transmission

Kobayashi, Norimasa; Tokura, Takaaki; Shiiba, Kazuyuki; Fukumasu, Toshihiro; Asami, Tomohiro; Yoshimura, Atsushi

doi:10.4271/2008-01-0535

Cited by 7 publications

(2 citation statements)

References 3 publications

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“…To facilitate faster inertia phase time when the amount of engine torque reduction available is limited by spark, airflow or cam phasing actuators is to turn off the fuel flow to the engine as mentioned by [11]. Cutting fuel to the engine momentarily places it in a motoring condition.…”

Section: Oncoming Clutch Cumulative Energymentioning

confidence: 98%

“…This approach greatly simplifies the required calculations to synthesize the performance attributes of a given transmission design during a shift event when compared to other methods presented by [8,9,10,11,12]. The equations of motion for the free body diagram contained in Figure 4 are summarized in the following two sections.…”

Section: Simplified Automatic Transmission Modelmentioning

confidence: 98%

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Performance Characterization of Automatic Transmission Upshifts with Reduced Shift Times

Robinette

Gibson

Szpara

et al. 2015

SAE Int. J. Engines

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As the number of fixed gear ratios in automatic transmissions continues to increase in the pursuit of powertrain system efficiency, particular consideration must continue to be focused on optimizing the design for shifting performance. This investigation focuses on the effect of shift time on the performance attributes of shift quality, durability, on schedule fuel consumption and enablers to further reduce shift time. A review of fundamental design features that enable reduced shift times in both planetary and dual clutch transmissions is presented along with key operating features of both the transmission and engine/prime mover. A lumped parameter metric is proposed to assess and compare the upshift controllability of new transmission architectures and powerflows using simple analysis. The durability of fast shift times during performance maneuvers are quantified through calculation of shifting clutch energy and power from analysis and form measurements on a powertrain dynamometer. In addition to perceived powertrain performance, powertrain dynamometer measurements running the FTP test schedules fuel consumption trends with respect to inertia phase shift time and can provide upwards of 1.25% by optimization of shift times depending on powertrain details. The paper concludes with vehicle measurements comparing part and wide-open throttle shift times for 6 and 8 speed planetary automatics transmissions.

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Section: Oncoming Clutch Cumulative Energymentioning

confidence: 98%