Control apparatus for power train including continuously variable transmission

A control apparatus for a power train including a continuously variable transmission and a clutch that is arranged in series with the continuously variable transmission, comprising:

• an engaging pressure reducing unit that reduces an engaging pressure of the clutch that is in a fully engaged state until a slip of the clutch occurs;
• a re-engaging unit that increases the engaging pressure of the clutch after detection of the slip so as to re-engage the clutch;
• a pressure calculating unit that calculates an engaging pressure of the clutch by giving a predetermined excess pressure to the engaging pressure at which the clutch is re-engaged, such that an excess amount of a transmitted torque of the clutch over a transmitted torque with which a slip occurs in the clutch is set smaller than an excess amount of a transmitted torque of the continuously variable transmission over a transmitted torque with which a slip occurs in the transmission;
• a termination determining unit that determines whether a control termination condition is satisfied, the control termination condition being provided for terminating control for engaging the clutch with the engaging pressure obtained by giving the predetermined excess pressure to the engaging pressure at which the clutch is re-engaged;
• and
• a pressure increasing unit that increases the engaging pressure of the clutch so as to prevent a slip of the clutch after increasing a torque capacity of the continuously variable transmission, when the termination determining unit determines that the control termination condition is satisfied.

A control apparatus for a power train including a continuously variable transmission and a clutch that is arranged in series with the continuously variable transmission, comprising:

• an engaging pressure reducing unit that reduces an engaging pressure of the clutch that is in a fully engaged state until a slip of the clutch occurs;
• a re-engaging unit that increases the engaging pressure of the clutch after detection of the slip so as to re-engage the clutch;
• a pressure calculating unit that calculates an engaging pressure of the clutch by giving a predetermined excess pressure to the engaging pressure at which the clutch is re-engaged, such that an excess amount of a transmitted torque of the clutch over a transmitted torque with which a slip occurs in the clutch is set smaller than an excess amount of a transmitted torque of the continuously variable transmission over a transmitted torque with which a slip occurs in the transmission;
• and
• a clutch engaging pressure setting unit that sets the engaging pressure of the clutch based on a difference between a coefficient of friction of the clutch measured upon re-engagement of the clutch and a coefficient of friction of the clutch measured upon full engagement of the clutch with no slip.

A control apparatus for a power train including a continuously variable transmission and a clutch that is arranged in series with the continuously variable transmission, comprising:

• an engaging pressure reducing unit that reduces an engaging pressure of the clutch that is in a fully engaged state until a slip of the clutch occurs;
• a re-engaging unit that increases the engaging pressure of the clutch after detection of the slip so as to re-engage the clutch;
• a pressure calculating unit that calculates an engaging pressure of the clutch by giving a predetermined excess pressure to the engaging pressure at which the clutch is re-engaged, such that an excess amount of a transmitted torque of the clutch over a transmitted torque with which a slip occurs in the clutch is set smaller than an excess amount of a transmitted torque of the continuously variable transmission over a transmitted torque with which a slip occurs in the transmission;
• and
• a start condition setting unit that sets a control start condition associated with an oil temperature, which condition is provided for starting control for setting the engaging pressure of the clutch to a pressure level obtained by giving the predetermined excess pressure to the engaging pressure at which the clutch is re-engaged, such that the control start condition is different between a case where the engaging pressure calculated by giving the predetermined excess pressure to the engaging pressure at which the clutch is re-engaged has already been obtained, and a case where the engaging pressure has not been obtained.

A control apparatus for a power train including a continuously variable transmission and a clutch that is arranged in series with the continuously variable transmission, comprising:

• an engaging pressure reducing unit that reduces an engaging pressure of the clutch that is in a fully engaged state until a slip of the clutch occurs;
• a re-engaging unit that increases the engaging pressure of the clutch after detection of the slip so as to re-engage the clutch;
• a pressure calculating unit that calculates an engaging pressure of the clutch by giving a predetermined excess pressure to the engaging pressure at which the clutch is re-engaged, such that an excess amount of a transmitted torque of the clutch over a transmitted torque with which a slip occurs in the clutch is set smaller than an excess amount of a transmitted torque of the continuously variable transmission over a transmitted torque with which a slip occurs in the transmission;
• a judder history determining unit that determines whether the clutch has experienced judder;
• and
• a clutch engaging pressure control inhibiting unit that inhibits control for setting the engaging pressure of the clutch to a pressure level calculated by giving the predetermined excess pressure to the engaging pressure at which the clutch is re-engaged, when the judder history determining unit determines that the clutch has experienced the judder.

A control apparatus for a power train including a continuously variable transmission and a clutch that is arranged in series with the continuously variable transmission, comprising:

• an engaging pressure reducing unit that reduces an engaging pressure of the clutch that is in a fully engaged state until a slip of the clutch occurs;
• a re-engaging unit that increases the engaging pressure of the clutch after detection of the slip so as to re-engage the clutch;
• a pressure calculating unit that calculates an engaging pressure of the clutch by giving a predetermined excess pressure to the engaging pressure at which the clutch is re-engaged, such that an excess amount of a transmitted torque of the clutch over a transmitted torque with which a slip occurs in the clutch is set smaller than an excess amount of a transmitted torque of the continuously variable transmission over a transmitted torque with which a slip occurs in the transmission;
• a judder history determining unit that determines whether the clutch has experienced judder;
• and
• an engaging pressure control unit that inhibits control for calculating the engaging pressure of the clutch by giving the predetermined excess pressure to the engaging pressure at which the clutch is re-engaged when the judder history determining unit determines that the clutch has experienced the judder, wherein
• when the engaging pressure calculated by giving the predetermined excess pressure to the engaging pressure at which the clutch is re-engaged has already been obtained, the engaging pressure control unit executes control for engaging the clutch with the engaging pressure that has already been obtained.

A control apparatus for a power train including a continuously variable transmission and a clutch that is arranged in series with the continuously variable transmission, comprising:

• an engaging pressure reducing unit that reduces an engaging pressure of the clutch that is in a fully engaged state until a slip of the clutch occurs;
• a re-engaging unit that increases the engaging pressure of the clutch after detection of the slip so as to re-engage the clutch;
• a pressure calculating unit that calculates an engaging pressure of the clutch by giving a predetermined excess pressure to the engaging pressure at which the clutch is re-engaged, such that an excess amount of a transmitted torque of the clutch over a transmitted torque with which a slip occurs in the clutch is set smaller than an excess amount of a transmitted torque of the continuously variable transmission over a transmitted torque with which a slip occurs in the transmission;
• a judder history determining unit that determines whether the clutch has experienced judder;
• and
• an engaging pressure change rate setting unit that sets a first rate of change of the engaging pressure of the clutch in a case where the judder history determining unit determines that the clutch has experienced the judder, to be larger than a second rate of change of the engaging pressure in a case where the judder history determining unit determines that the clutch has experienced no judder.

A control apparatus for a power train including a continuously variable transmission and a clutch that is arranged in series with the continuously variable transmission in a direction of transmission of a torque, wherein an excess amount of a transmitted torque of the clutch over a transmitted torque with which a slip occurs in the clutch is set smaller than an excess amount of a transmitted torque of the continuously variable transmission over a transmitted torque with which a slip occurs in the transmission, comprising:

• an engaging pressure reducing unit that reduces an engaging pressure of the clutch that is in an engaged state until a slip of the clutch occurs;
• a re-engaging unit that increases the engaging pressure of the clutch after detection of the slip so as to re-engage the clutch;
• and
• an engaging pressure setting unit that sets the engaging pressure of the clutch to a pressure level obtained by adding a predetermined value that provides the excess amount of the transmitted torque of the clutch, to the engaging pressure at which the clutch is re-engaged.

A method of controlling a power train including a continuously variable transmission and a clutch that is arranged in series with the continuously variable transmission, comprising the steps of:

• reducing an engaging pressure of the clutch that is in a fully engaged state until a slip of the clutch occurs;
• re-engaging the clutch by increasing the engaging pressure of the clutch after detection of the slip;
• calculating an engaging pressure of the clutch by giving a predetermined excess pressure to the engaging pressure at which the clutch is re-engaged, such that an excess amount of a transmitted torque of the clutch over a transmitted torque with which a slip occurs in the clutch is set smaller than an excess amount of a transmitted torque of the continuously variable transmission over a transmitted torque with which a slip occurs in the transmission;
• and
• determining a learned value as a correction value of the engaging pressure that is set in advance in accordance with an input torque applied to the clutch, based on the engaging pressure calculated by giving the predetermined excess pressure to the engaging pressure at which the clutch is re-engaged.

A method of controlling a power train including a continuously variable transmission and a clutch that is arranged in series with the continuously variable transmission, comprising the steps of:

• reducing an engaging pressure of the clutch that is in a fully engaged state until a slip of the clutch occurs;
• re-engaging the clutch by increasing the engaging pressure of the clutch after detection of the slip;
• calculating an engaging pressure of the clutch by giving a predetermined excess pressure to the engaging pressure at which the clutch is re-engaged, such that an excess amount of a transmitted torque of the clutch over a transmitted torque with which a slip occurs in the clutch is set smaller than an excess amount of a transmitted torque of the continuously variable transmission over a transmitted torque with which a slip occurs in the transmission;
• determining whether a control termination condition is satisfied, the control termination condition being provided for terminating control for engaging the clutch with the engaging pressure obtained by giving the predetermined excess pressure to the engaging pressure at which the clutch is re-engaged;
• and
• increasing the engaging pressure of the clutch so as to prevent a slip of the clutch after increasing a torque capacity of the continuously variable transmission, when it is determined that the control termination condition is satisfied.

A method of controlling a power train including a continuously variable transmission and a clutch that is arranged in series with the continuously variable transmission, comprising the steps of:

• reducing an engaging pressure of the clutch that is in a fully engaged state until a slip of the clutch occurs;
• re-engaging the clutch by increasing the engaging pressure of the clutch after detection of the slip;
• calculating an engaging pressure of the clutch by giving a predetermined excess pressure to the engaging pressure at which the clutch is re-engaged, such that an excess amount of a transmitted torque of the clutch over a transmitted torque with which a slip occurs in the clutch is set smaller than an excess amount of a transmitted torque of the continuously variable transmission over a transmitted torque with which a slip occurs in the transmission;
• and
• setting the engaging pressure of the clutch based on a difference between a coefficient of friction of the clutch measured upon re-engagement of the clutch and a coefficient of friction of the clutch measured upon full engagement of the clutch with no slip.

A method of controlling a power train including a continuously variable transmission and a clutch that is arranged in series with the continuously variable transmission, comprising the steps of:

• reducing an engaging pressure of the clutch that is in a fully engaged state until a slip of the clutch occurs;
• re-engaging the clutch by increasing the engaging pressure of the clutch after detection of the slip;
• calculating an engaging pressure of the clutch by giving a predetermined excess pressure to the engaging pressure at which the clutch is re-engaged, such that an excess amount of a transmitted torque of the clutch over a transmitted torque with which a slip occurs in the clutch is set smaller than an excess amount of a transmitted torque of the continuously variable transmission over a transmitted torque with which a slip occurs in the transmission;
• and
• setting a control start condition associated with an oil temperature, which condition is provided for starting control for setting the engaging pressure of the clutch to a pressure level obtained by giving the predetermined excess pressure to the engaging pressure at which the clutch is re-engaged, such that the control start condition is different between a case where the engaging pressure calculated by giving the predetermined excess pressure to the engaging pressure at which the clutch is re-engaged has already been obtained, and a case where the engaging pressure has not been obtained.

A method of controlling a power train including a continuously variable transmission and a clutch that is arranged in series with the continuously variable transmission, comprising the steps of:

• reducing an engaging pressure of the clutch that is in a fully engaged state until a slip of the clutch occurs;
• re-engaging the clutch by increasing the engaging pressure of the clutch after detection of the slip;
• calculating an engaging pressure of the clutch by giving a predetermined excess pressure to the engaging pressure at which the clutch is re-engaged, such that an excess amount of a transmitted torque of the clutch over a transmitted torque with which a slip occurs in the clutch is set smaller than an excess amount of a transmitted torque of the continuously variable transmission over a transmitted torque with which a slip occurs in the transmission;
• determining whether the clutch has experienced judder;
• and
• inhibiting control for setting the engaging pressure of the clutch to a pressure level calculated by giving the predetermined excess pressure to the engaging pressure at which the clutch is re-engaged, when it is determined that the clutch has experienced the judder.

A method of controlling a power train including a continuously variable transmission and a clutch that is arranged in series with the continuously variable transmission, comprising the steps of:

• reducing an engaging pressure of the clutch that is in a fully engaged state until a slip of the clutch occurs;
• re-engaging the clutch by increasing the engaging pressure of the clutch after detection of the slip;
• calculating an engaging pressure of the clutch by giving a predetermined excess pressure to the engaging pressure at which the clutch is re-engaged, such that an excess amount of a transmitted torque of the clutch over a transmitted torque with which a slip occurs in the clutch is set smaller than an excess amount of a transmitted torque of the continuously variable transmission over a transmitted torque with which a slip occurs in the transmission;
• determining whether the clutch has experienced judder;
• and
• inhibiting control for calculating the engaging pressure of the clutch by giving the predetermined excess pressure to the engaging pressure at which the clutch is re-engaged when it is determined that the clutch has experienced the judder, wherein
• when the engaging pressure calculated by giving the predetermined excess pressure to the engaging pressure at which the clutch is re-engaged has already been obtained, control for engaging the clutch with the engaging pressure that has already been obtained is executed.

A method of controlling a power train including a continuously variable transmission and a clutch that is arranged in series with the continuously variable transmission, comprising the steps of:

• reducing an engaging pressure of the clutch that is in a fully engaged state until a slip of the clutch occurs;
• re-engaging the clutch by increasing the engaging pressure of the clutch after detection of the slip;
• calculating an engaging pressure of the clutch by giving a predetermined excess pressure to the engaging pressure at which the clutch is re-engaged, such that an excess amount of a transmitted torque of the clutch over a transmitted torque with which a slip occurs in the clutch is set smaller than an excess amount of a transmitted torque of the continuously variable transmission over a transmitted torque with which a slip occurs in the transmission;
• determining whether the clutch has experienced judder;
• and
• setting a first rate of change of the engaging pressure of the clutch in a case where it is determined that the clutch has experienced the judder, to be larger than a second rate of change of the engaging pressure in a case where it is determined that the clutch has experienced no judder.

A method of controlling a power train including a continuously variable transmission and a clutch that is arranged in series with the continuously variable transmission in a direction of transmission of a torque, wherein an excess amount of a transmitted torque of the clutch over a transmitted torque with which a slip occurs in the clutch is set smaller than an excess amount of a transmitted torque of the continuously variable transmission over a transmitted torque with which a slip occurs in the transmission, comprising the steps of:

• reducing an engaging pressure of the clutch that is in an engaged state until a slip of the clutch occurs;
• re-engaging the clutch by increasing the engaging pressure of the clutch after detection of the slip;
• and
• setting the engaging pressure of the clutch to a pressure level obtained by adding a predetermined value that provides the excess amount of the transmitted torque of the clutch, to the engaging pressure at which the clutch is re-engaged.