Control apparatus and method for automatic transmission by oil pressure on clutch

A control apparatus of an automatic transmission having a torque converter for controlling by oil pressure at least one clutch of the automatic transmission which is connected to an engine output to be engaged or disengaged to perform gear shifting comprising:

• engine torque calculating means for calculating an output torque of said engine on a basis of a parameter representing a load of said engine and an engine speed;
• transfer torque calculating means for calculating a transfer torque necessary for said clutch from parameters associated with at least said calculated engine output torque and engine speed;
• command value calculating means for determining a command value relative to an oil pressure acted on said clutch on a basis of said calculated transfer torque;
• means for calculating a pump capacity coefficient of said torque converter on a basis of said engine speed and an output shaft speed of said torque converter;
• means for calculating a second engine output torque on a basis of said pump capacity coefficient and said engine speed;
• means for generating a gear shifting start signal to said automatic transmission;
• and
• means for correcting said engine output torque produced from said engine torque calculating means by a difference between said engine output torque from said engine torque calculating means and said second engine output torque during a period from the generation of said gear shifting start signal to an actual shifting operation.

A control apparatus of an automatic transmission having a torque converter for controlling by oil pressure at least one clutch of the automatic transmission connected to an engine output to be engaged or disengaged to perform gear shifting, comprising:

• engine torque calculating means for calculating an output torque of said engine on a basis of a parameter representing a load of said engine and an engine speed;
• transfer torque calculating means for calculating a transfer torque necessary for said clutch from parameters associated with at least said calculated engine output torque and engine speed;
• command value calculating means for determining a command value relative to an oil pressure acted on said clutch on a basis of said calculated transfer torque;
• means for calculating a torque ratio of said torque converter on the basis of said engine speed and the output shaft speed of said torque converter;
• turbine torque calculating means for calculating an output shaft torque of said torque converter on a basis of said engine output torque and said torque ratio;
• and
• means for calculating said transfer torque necessary for said clutch from at least said output shaft torque and output shaft speed of said torque converter;
• means for calculating a pump capacitance coefficient of said torque converter by use of said engine speed and said output shaft speed of said torque converter;
• means for calculating a second output shaft torque of said torque converter on a basis of said torque ratio, said pump capacity coefficient and said engine speed;
• means for generating a gear shifting start signal to said automatic transmission;
• and
• means for correcting said output shaft torque from said turbine torque calculating means by a difference between said output shaft torque from said turbine torque calculating means and said second output shaft torque during a period from the generation of said shifting start signal to an actual shifting operation.

A control apparatus of an automatic transmission for controlling by oil pressure at least one clutch of the automatic transmission which is connected to an engine output to be engaged or disengaged to perform gear shifting, comprising:

• engine torque calculating means for calculating an output torque of said engine on a basis of a parameter representing a load of said engine and an engine speed;
• transfer torque calculating means for calculating a transfer torque necessary for said clutch from parameters associated with at least said calculated engine output torque and engine speed;
• command value calculating means for determining a command value relative to an oil pressure acted on said clutch on a basis of said calculated transfer torque;
• a data map of the oil pressure command value with respect to said transfer torque, said data map having an oil pressure value changed with a value of friction coefficient of said clutch.

A control apparatus of automatic transmission for controlling by oil pressure at least one clutch of an automatic transmission with a torque converter connected to an engine output to be engaged or disengaged to make gear shifting, comprising:

• means for capturing a signal of said engine speed;
• means for capturing a signal of parameter representative of a load of said engine;
• means for capturing a signal of output shaft speed of said torque converter;
• means for calculating a speed ratio between the input and output shafts of said torque converter on the basis of said engine speed and said output shaft speed of said torque converter;
• and
• command value calculating means for changing a command value of oil pressure acted on said clutch by the parameter representative of a load of said engine and said engine speed, wherein when said parameter representative of a load of said engine is changed, the oil pressure command value calculated according to the order to change the output torque of said engine is changed faster than changing of said speed ratio.

A control apparatus of automatic transmission for controlling by oil pressure at least one clutch of an automatic transmission connected to an engine output to be engaged or disengaged to make gear shifting, comprising:

• means for capturing a signal of engine speed;
• means for capturing a signal of parameter representative of a load of said engine;
• means for capturing a signal of output shaft speed of said automatic transmission;
• means for calculating a speed ratio between the input and output shafts of said automatic transmission on the basis of said engine speed and said output shaft speed of said automatic transmission;
• and
• command value calculating means for changing a command value of oil pressure acted on said clutch by the parameter representative of a load of said engine and said engine speed, wherein when said parameter representative of a load of said engine is changed, the oil pressure command value calculated according to the order to change the output torque of said engine is changed faster than said speed ratio is.

An automatic transmission control method for controlling by an oil pressure at least one clutch of an automatic transmission having a torque converter coupled with an engine output to be engaged or disengaged to perform gear shifting, comprising the steps of:

• calculating an output torque of said engine on a basis of a parameter representative of a load of said engine and an engine speed;
• calculating a transfer torque necessary for said clutch by use of parameters of at least said calculated engine output torque and said engine speed;
• and
• determining a command value of oil pressure acted on said clutch according to said calculated transfer torque
• wherein when the change of the output torque of said engine is indicated, said oil pressure command value is determined faster than is a ratio between an input and output shaft speed of said torque converter.