Continuously variable transmission control method and apparatus

An apparatus for controlling a continuously variable transmission for use with an automotive vehicle including an accelerator pedal, the transmission having an input and output shaft, the transmission being operable at a variable speed ratio for transmitting a drive from the input shaft to the output shaft, comprising:

• means for sensing vehicle operating conditions including vehicle deceleration;
• means for producing a released accelerator pedal indicative signal when the accelerator pedal is released;
• means for calculating a target value for the speed of rotation of the input shaft based on the sensed vehicle operating conditions;
• means for calculating a correction factor per predetermined unit time based on the sensed vehicle deceleration when the sensed vehicle deceleration exceeds a first threshold value in the presence of the released accelerator pedal indicative signal;
• means for subtracting the correction factor from the target input shaft speed value to decrease the target input shaft speed value at intervals of the predetermined unit time;
• and
• means for controlling the speed ratio to bring the input shaft speed into coincidence with the decreased target value.

A method of controlling a continuously variable transmission for use with an automotive vehicle including an accelerator pedal, the transmission having an input and output shaft, the transmission being operable at a variable speed ratio for transmitting a drive from the input shaft to the output shaft, the method comprising the steps of:

• sensing vehicle operating conditions including vehicle acceleration;
• producing a released accelerator pedal indicative signal when the accelerator pedal is released;
• calculating a target value for the speed of rotation of the input shaft based on the sensed vehicle operating conditions;
• calculating a correction factor based on the sensed vehicle acceleration when the sensed vehicle acceleration exceeds a threshold value in the presence of the released accelerator pedal indicative signal;
• adding the correction factor to the target input shaft speed value to correct the target input shaft speed value;
• controlling the speed ratio to bring the input shaft speed into coincidence with the corrected target value;
• and
• continuously repeating the above sequence of steps at uniform intervals of time to effect changes in the target input shaft speed value in response to changes in the vehicle acceleration.

A method of controlling a continuously variable transmission for use with an automotive vehicle including an accelerator pedal, the transmission having an input and output shaft, the transmission being operable at a variable speed ratio for transmitting a drive from the input shaft to the output shaft, the method comprising the steps of:

• sensing vehicle operating conditions including vehicle deceleration;
• producing a released accelerator pedal indicative signal when the accelerator pedal is released;
• calculating a target value for the speed of rotation of the input shaft based on the sensed vehicle operating conditions;
• calculating a correction factor based on the sensed vehicle deceleration when the sensed vehicle acceleration exceeds a first threshold value in the presence of the released accelerator pedal indicative signal;
• subtracting the correction factor to the target input shaft speed value to decrease the target input shaft speed value;
• controlling the speed ratio to bring the input shaft speed into coincidence with the decreased target value;
• and
• continuously repeating the above sequence of steps at uniform intervals of time to effect changes in the target input shaft speed value in response to changes in the vehicle deceleration.

An apparatus for controlling a continuously variable transmission for use with an automotive vehicle including an accelerator pedal, the transmission having an input and output shaft, the transmission being operable at a variable speed ratio for transmitting a drive from the input shaft to the output shaft, comprising:

• means for sensing vehicle operating conditions including vehicle speed;
• means for calculating a target value for the speed of rotation of the input shaft based on the sensed vehicle operating conditions;
• means for producing a released accelerator pedal indicative signal when the accelerator pedal is released;
• means for determining a vehicle acceleration;
• means for calculating a correction factor per predetermined unit time based on the determined vehicle acceleration when the determined vehicle acceleration exceeds a threshold value in the presence of the released accelerator pedal indicative signal;
• means for adding the correcting factor to the target input shaft speed value to correct the target input shaft speed value at intervals of the predetermined unit time;
• and
• means for controlling the speed ratio to bring the input shaft speed into coincidence with the corrected target value.

An apparatus for controlling a continuously variable transmission for use with an automotive vehicle including an accelerator pedal, the transmission having an input and output shaft, the transmission being operable at a variable speed ratio for transmitting a drive from the input shaft to the output shaft, comprising:

• means for sensing vehicle operating conditions including vehicle speed;
• means for calculating a target value for the speed of rotation of the input shaft based on the sensed vehicle operating conditions;
• means for producing a released accelerator pedal indicative signal when the accelerator pedal is released;
• means for determining a vehicle deceleration;
• means for calculating a correction factor per predetermined unit time based on the determined vehicle deceleration when the determined vehicle deceleration exceeds a first threshold value in the presence of the released accelerator pedal indicative signal;
• means for subtracting the correction factor from the target input shaft speed value to decrease the target input shaft speed value at intervals of the predetermined unit time;
• and
• means for controlling the speed ratio to bring the input shaft speed into coincidence with the decreased target value.

A method of controlling a continuously variable transmission for use with an automotive vehicle including an accelerator pedal, the transmission having an input and output shaft, the transmission being operable at a variable speed ratio for transmitting a drive from the input shaft to the output shaft, the method comprising the steps of:

• sensing vehicle operating conditions including vehicle speed;
• calculating a target value for the speed of rotation of the input shaft based on the sensed vehicle operating conditions;
• producing a released accelerator pedal indicative signal when the accelerator pedal is released;
• determining a vehicle acceleration;
• calculating a correction factor based on the determined vehicle acceleration when the determined vehicle acceleration exceeds a threshold value in the presence of the released accelerator pedal indicative signal;
• adding the correction factor to the target input shaft speed value to correct the target input shaft speed value;
• controlling the speed ratio to bring the input shaft speed into coincidence with the corrected target value;
• and
• continuously repeating the above sequence of steps at uniform intervals of time to effect changes in the target input shaft speed value in response to changed in the vehicle acceleration.

A method of controlling a continuously variable transmission for use with an automotive vehicle including an accelerator pedal, the transmission having an input and output shaft, the transmission being operable at a variable speed ratio for transmitting a drive from the input shaft to the output shaft, the method comprising the steps of:

• sensing vehicle operating conditions including vehicle speed;
• calculating a target value for the speed of rotation of the input shaft based on the sensed vehicle operating conditions;
• producing a released accelerator pedal indicative signal when the accelerator pedal is released;
• determining a vehicle deceleration;
• calculating a correction factor based on the determined vehicle deceleration when the determined vehicle deceleration exceeds a first threshold value in the presence of the released accelerator pedal indicative signal;
• subtracting the correction factor to the target input shaft speed value to decrease the target input shaft speed value;
• controlling the speed ratio to bring the input shaft speed into coincidence with the corrected target value;
• and
• continuously repeating the above sequence of steps of uniform intervals of time to effect changes in the target input shaft speed value in response to changes in the vehicle deceleration.