This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Improving Automatic Transmission Shift Quality by Feedback Control with a Turbine Speed Sensor
Annotation ability available
Sector:
Language:
English
Abstract
Shift quality in automatic transmissions is greatly affected by deterioration and variation of engine torque, hydraulic pressure control valves, friction elements and other factors. This paper presents a new control system that improves shift quality by using a turbine speed sensor to monitor the shift duration, particularly the duration of the inertia phase.
The use of feedback control to vary the line pressure according to the shift duration makes it possible to eliminate the effects of aging and component variability. Other factors affecting shift quality, such as atmospheric pressure, road gradient and additional engine load from the air conditioner and alternator, were also examined, and it was found that their effects can be virtually eliminated through feedback control. The inertia phase usually becomes shorter as the engaging clutch capacity increases. However, an extremely small torque capacity can cause a short inertia phase, resulting in a large torque disturbance. This problem is avoided by measuring the interval from the initiation of the shift command to the completion of the inertia phase, this making it possible to distinguish between small and large torque capacity conditions.
Power-off upshifts, resulting from abrupt throttle closing, can cause shock and chatter. These disturbances are eliminated through synchronized clutch engagement, achieved by sensing the speed ratio between the turbine and output shaft.
Power-on downshifts when going downhill pose a critical condition for clutch slip. Friction elements are protected from damage in this system by controlling the timing and capacity of the engaging and releasing elements.
Recommended Content
Technical Paper | Modeling of Pulse Width Modulation Pressure Control System for Automatic Transmission |
Technical Paper | Development of a New Clutch-to-Clutch Shift Control Technology |
Technical Paper | Enhanced Air Turbine Starter Clutch Design |
Authors
Topic
Citation
Narita, Y., "Improving Automatic Transmission Shift Quality by Feedback Control with a Turbine Speed Sensor," SAE Technical Paper 911938, 1991, https://doi.org/10.4271/911938.Also In
References
- Hiramatsu T. et al “Shift Quality Control of an Electronically Controlled FourSpeed Automatic Transmission,” Paper 865149 , FISITA Congress June 1986
- Schwab M. “Electronic Control of a 4 Speed Automatic Transmission with Lock Up Clutch,” SAE Paper 840448 February 1984
- Haider S.A. et al “Powertrain Torque Management,” SAE Paper 970081
- Leising M.B. et al “The All Adaptive Controls for the Chrysler Ultradrive Transaxle,” SAE Paper 890529
- Ohtsuka K. et al “New Automatic Transmission with Electrohydraulic System,” Journal of the Society of Automotive Engineers of Japan 42 8 August 1988
- Shinohara M. et al “Nissan Electronically Controlled Four Speed Automatic Transmission,” SAE Paper 890530 February 1989