Method of determining a default transmission input speed
First Claim
1. A default method of operation for a motor vehicle powertrain including an engine, an automatic shift power transmission, engine speed measuring apparatus, transmission input speed measuring apparatus, and transmission output speed measuring apparatus, the method comprising the step of:
- detecting a malfunction of the transmission input speed measuring apparatus;
in response to a detected malfunction of the transmission input speed measuring apparatus, determining a default transmission input speed value based on an output speed signal produced by the transmission output speed measuring apparatus during a non-shifting mode of operation of said power transmission, and based on an engine speed signal produced by the engine speed measuring apparatus during a shifting mode of operation of said power transmission; and
substituting said default transmission input speed value for an input speed signal produced by said transmission input speed measuring apparatus so long as a malfunction of said transmission input speed measuring apparatus is detected.
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0 Petitions
Accused Products
Abstract
A default value of transmission input speed in a motor vehicle powertrain having an automatic-shift multi-gear ratio power transmission is continuously updated based on a measured value of the input speed and other reliable speed data including transmission output speed and engine speed. The default value is substituted for the measured input speed when a malfunction of the input speed sensor is detected, and transitions back to the measured input speed when the input speed sensor malfunction is no longer present.
20 Citations
10 Claims
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1. A default method of operation for a motor vehicle powertrain including an engine, an automatic shift power transmission, engine speed measuring apparatus, transmission input speed measuring apparatus, and transmission output speed measuring apparatus, the method comprising the step of:
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detecting a malfunction of the transmission input speed measuring apparatus; in response to a detected malfunction of the transmission input speed measuring apparatus, determining a default transmission input speed value based on an output speed signal produced by the transmission output speed measuring apparatus during a non-shifting mode of operation of said power transmission, and based on an engine speed signal produced by the engine speed measuring apparatus during a shifting mode of operation of said power transmission; and substituting said default transmission input speed value for an input speed signal produced by said transmission input speed measuring apparatus so long as a malfunction of said transmission input speed measuring apparatus is detected. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification