Speed change control method for setting a gearshift position of an automatic transmission for vehicles based upon driver acceleration intention and external variables

A speed change control method for setting the gearshift position of an automatic transmission of a vehicle, which has a plurality of gearshift positions, to a position selected in accordance with a preset control mode, comprising the steps of:

• (a) judging whether the vehicle is traveling on a descending slope;
• (b) detecting an intention of the driver of a vehicle, of accelerating the vehicle when the vehicle has been judged as traveling on the descending slope;
• (c) selecting a gearshift position that matches the detected intention, of the driver, of accelerating the vehicle;
• and
• (d) setting the gearshift position of the automatic transmission to the selected gearshift position, wherein said plurality of gearshift positions include a low-speed gearshift position preferable for engine brake application, the step (c) further including the substeps of,
• (1) determining whether the gearshift position of the automatic transmission is set to said low-speed gearshift position based upon a magnitude comparison between a threshold value and a value of at least one parameter for judging whether said low-speed gearshift position is selected,
• (2) detecting at least one parameter value related to frictional resistance of the road surface on which the vehicle is traveling, and
• (3) changing said threshold value to a value that causes said low-speed gearshift position to be selected if the frictional resistance of the road surface is judged to be low in accordance with the detected at least one parameter value related to frictional resistance of the road.

A speed change control method for setting the gearshift position of an automatic transmission of a vehicle, which has a plurality of gearshift positions, to a position selected in accordance with a preset control mode, comprising the steps of:

• (a) judging whether the vehicle is traveling on a descending slope;
• (b) detecting an intention, of the driver of a vehicle, of accelerating the vehicle when the vehicle has been judged as traveling on the descending slope;
• (c) selecting a gearshift position that matches the detected intention, of the driver, of accelerating the vehicle;
• and
• (d) setting the gearshift position of the automatic transmission to the selected gearshift position, wherein said plurality of gearshift positions include a low-speed gearshift position preferable for engine brake application, the step (c) further including the substeps of,
• (1) determining whether the gearshift position of the automatic transmission is set to said low-speed gearshift position based upon a magnitude comparison between a threshold value and a value of at least one parameter for judging whether said low-speed gearshift position is selected, and
• (2) setting said threshold value to a value in accordance with conditions of a road on which the vehicle is traveling, said threshold value being set to a value corresponding to a degree of gradient of the road.

A speed change control method for setting the gearshift position of an automatic transmission of a vehicle, which has a plurality of gearshift positions, to a position selected in accordance with a preset control mode, comprising the steps of:

• (a) judging whether the vehicle is traveling on a descending slope;
• (b) detecting an intention, of the driver of a vehicle, of accelerating the vehicle when the vehicle has been judged as traveling on the descending slope;
• (c) selecting a gearshift position that matches the detected intention, of the driver, of accelerating the vehicle;
• and
• (d) setting the gearshift position of the automatic transmission to the selected gearshift position, wherein said plurality of gearshift positions include a low-speed gearshift position preferable for engine brake application, the step (c) further including the substep of,
• (1) determining whether the gearshift position of the automatic transmission is set to said low-speed gearshift position based upon a magnitude comparison between a threshold value and a value of at least one parameter for judging whether said low-speed gearshift position is selected, and
• (2) setting said threshold value to a value in accordance with conditions of a road on which the vehicle is traveling, said threshold value being set to a value corresponding to a degree of winding of a road on which the vehicle is traveling.

A speed change control method for setting the gearshift position of an automatic transmission of a vehicle, which has a plurality of gearshift positions, to a position selected in accordance with a preset control mode, comprising the steps of:

• (a) judging whether the vehicle is traveling on a descending slope;
• (b detecting an intention, of the driver of a vehicle, of accelerating the vehicle when the vehicle has been judged as traveling on the descending slope;
• (c) selecting a gearshift position that matches the detected intention, of the driver, of accelerating the vehicle;
• and
• d) setting the gearshift position of the automatic transmission to the selected gearshift position, wherein said plurality of gearshift positions include a low-speed gearshift position preferable for engine brake application, the step (c) further including the substeps of,
• (1) determining whether the gearshift position of the automatic transmission is set to said low-speed gearshift position based upon a magnitude comparison between a threshold value and a value of at least one parameter for judging whether said low-speed gearshift position is selected, and
• (2) setting said threshold value to a value in accordance with conditions of a road on which the vehicle is traveling,
• (3) detecting an operating amount of braking by a driver of the vehicle,
• (4) comparing the detected operating amount of braking with a predetermined standard value, and
• (5) changing said threshold value to a value that causes said low-speed gearshift position to be selected if the detected operating amount of braking exceeds the predetermined standard value.