Method and apparatus for alleviating transmission shift shocks
AssigneeNissan Motor Co., Ltd.
InventorHitoshi Takeda
Life of this patent
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Abstract
In order to alleviate shocks occurring when an automatic transmission driven by an engine shifts between reduction ratios, the engine is caused to change its output torque by an amount indicated by a target torque variation. The target torque variation is set in response to an estimated engine revolution speed variation before and after the shifting operation.
Claims10
A method of alleviating shocks occurring when a transmission shifts from one reduction ratio to another reduction ratio, the transmission having an output shaft and being driven by an engine, said method comprising the steps of:
- detecting a shift command occurring in the transmission from the one reduction ratio to the other reduction ratio and generating a shift command signal;
- estimating responsive to said shift command signal and engine revolution speed variation during actual shifting operation in the transmission which is caused by the occurrence of said shift command and generating an estimated engine revolution speed variation signal indicative of the engine revolution speed variation estimated;
- and
- controlling the engine such that the output torque of the engine is subjected to a temporary change
- that is variable in response to said estimated engine revolution speed variation signal so as to alleviate shocks occurring during the shifting operation.
An apparatus for alleviating shocks occurring when a transmission shifts from one reduction ratio to another reduction ratio, the transmission having an output shaft and being driven by an engine, said apparatus comprising:
- means for detecting a shift command occurring in the transmission from the one reduction ratio to the other reduction ratio and generating a shift command signal;
- means for estimating responsive to said shift command signal an engine revolution speed variation during actual shifting operation in the transmission which is caused by the occurrence of said shift command and generating an estimated engine revolution speed variation signal indicative of the engine revolution speed variation estimated;
- and
- means for controlling the engine such that the output torque of the engine is subjected to a temporary change that is variable in response to said estimated engine revolution speed variation signal so as to alleviate shocks occurring during the shifting operation.
Dependencies are inferred from the claim text.