Dynamic shift control for an automatic transmission
First Claim
1. In a motor vehicle automatic transmission including gear elements defining a plurality of forward speed ratios and control elements for shifting between speed ratios in response to predefined shift control parameters, first look-up means for storing a first set of shift control parameters for use by said control elements during normal operation of said vehicle, and second look-up means for storing a second set of shift control parameters for use by said control elements during performance-oriented operation of said vehicle, a method of operation comprising the steps of:
- periodically measuring longitudinal acceleration values of said vehicle;
identifying peak acceleration values measured in each of a series of successive time intervals during the operation of said vehicle;
accumulating said peak acceleration values to form an average peak acceleration value;
looking up first and second shift control parameters from said first and second look-up means; and
ratiometrically determining shift control parameters for said control elements intermediate said first and second shift control parameters based on said average peak acceleration value, thereby to define a continuum of shift control parameters based on the operation of said vehicle.
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Accused Products
Abstract
An improved control, which dynamically adjusts the shift control parameters in response to the driving habits of the operator, as judged by an indication of the average peak acceleration during specified operation of the vehicle. To determine the indication of average peak acceleration, the longitudinal acceleration of the vehicle is continuously determined in the course of vehicle operation. The peak acceleration values occurring in successive ratio-dependent time intervals are identified and accumulated to form cumulative and average peak acceleration terms. The average peak acceleration term is used to form a dynamic shift factor which is used to ratiometrically schedule the shift pattern, line pressure and desired shift time between predefined Normal and Performance values to provide a continum of shift control parameters uniquely suited to the driving style of the operator of the vehicle.
31 Citations
8 Claims
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1. In a motor vehicle automatic transmission including gear elements defining a plurality of forward speed ratios and control elements for shifting between speed ratios in response to predefined shift control parameters, first look-up means for storing a first set of shift control parameters for use by said control elements during normal operation of said vehicle, and second look-up means for storing a second set of shift control parameters for use by said control elements during performance-oriented operation of said vehicle, a method of operation comprising the steps of:
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periodically measuring longitudinal acceleration values of said vehicle; identifying peak acceleration values measured in each of a series of successive time intervals during the operation of said vehicle; accumulating said peak acceleration values to form an average peak acceleration value; looking up first and second shift control parameters from said first and second look-up means; and ratiometrically determining shift control parameters for said control elements intermediate said first and second shift control parameters based on said average peak acceleration value, thereby to define a continuum of shift control parameters based on the operation of said vehicle. - View Dependent Claims (2, 3, 4, 5, 6)
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7. In a motor vehicle automatic transmission including gear elements defining a plurality of forward speed ratios, a source of fluid pressure, and fluid pressure operated control elements for shifting between speed ratios, first look-up means for storing a first desired pressure to be supplied to said control elements by said source during normal operation of said vehicle, and second look-up means for storing a second desired pressure to be supplied to said control elements by said source during performance-oriented operation of said vehicle, a method of operation comprising the steps of:
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periodically measuring longitudinal acceleration values of said vehicle; identifying peak acceleration values measured in each of a series of successive time intervals during the operation of said vehicle; accumulating said peak acceleration values to form an average peak acceleration value; looking up first and second desired pressure values from said first and second look-up means; and ratiometrically determining a desired pressure to be supplied to said control elements by said source intermediate said first and second desired pressures based on said average peak acceleration value, thereby to define a continuum of desired pressure values based on the operation of said vehicle. - View Dependent Claims (8)
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Specification