System and method for adaptive lock-up control

Claim 1

A system for an adaptive control of a lock-up clutch in a hydrokinetic torque transmitting unit including a pump impeller coupled with an engine, and a turbine runner, the lock-up clutch being engageable to connect the turbine runner to the pump impeller, the system comprising: means for generating an operating signal, said operating signal including an initial value and a term related to a difference between an actual slip in the hydrokinetic torque transmitting unit and a target slip; means, including an electric actuator, for controlling engagement of the lock-up clutch in response to said operating signal, wherein, during occurrence of engagement of the lock-up clutch, an actual lag before initial engagement of the lock-up clutch is determined, and a deviation of said actual lag from a target time interval is determined, said initial value being modified in response to said deviation in such a direction so that a subsequent occurrence of engagement of the lock-up clutch using a modified initial value results in a reduction in said deviation.

Claim 2

A system for an adaptive control of a lock-up clutch in a hydrokinetic torque transmitting unit including a pump impeller coupled with an engine, and a turbine runner, the lock-up clutch being engageable to connect the turbine runner to the pump impeller, the system comprising: means for generating an operating signal, said operating signal including an initial value and a term related to a difference between an actual slip in the hydrokinetic torque transmitting unit and a target slip; means, including an electric actuator, for controlling engagement of the lock-up clutch in response to said operating signal, wherein, during occurrence of engagement of the lock-up clutch, an actual lag before initial engagement of the lock-up clutch is determined, and a deviation of said actual lag from a target time interval is determined, said initial value being modified in response to said deviation in such a direction so that a subsequent occurrence of engagement of the lock-up clutch using a modified initial value results in a reduction in said deviation.

Claim 6

A method for an adaptive control of a lock-up clutch in a hydrokinetic torque transmitting unit including a pump impeller coupled with an engine, and a turbine runner, the lock-up clutch being engageable to connect the turbine runner to the pump impeller, the method comprising the steps of: controlling engagement of the lock-up clutch in response to an operating signal; determining an actual slip in the hydrokinetic torque transmitting unit; generating said operating signal, said operating signal including an initial value and a term related to a difference between said actual slip and a target slip; determining a target time interval; determining an actual time interval from a first instant when said generating step starts generating said operating signal to a second instant when said actual slip starts changing during occurrence of engagement of the lock-up clutch; calculating a deviation of said actual time interval from said target time interval; and modifying said initial value in response to said deviation in such a direction so that a subsequent occurrence of engagement of the lock-up clutch using a modified initial value results in a reduction in said deviation.

Claim 7

A method for an adaptive control of a lock-up clutch in a hydrokinetic torque transmitting unit including a pump impeller coupled with an engine, and a turbine runner, the lock-up clutch being engageable to connect the turbine runner to the pump impeller, the method comprising the steps of: controlling engagement of the lock-up clutch in response to an operating signal; determining an actual slip in the hydrokinetic torque transmitting unit; generating said operating signal, said operating signal including an initial value and a term related to a difference between said actual slip and a target slip; determining a target time interval; determining an actual time interval from a first instant when said generating step starts generating said operating signal to a second instant when said actual slip starts changing during occurrence of engagement of the lock-up clutch; calculating a deviation of said actual time interval from said target time interval; and modifying said initial value in response to said deviation in such a direction so that a subsequent occurrence of engagement of the lock-up clutch using a modified initial value results in a reduction in said deviation.

Claim 8

A system for an adaptive control of a lock-up clutch in a hydrokinetic torque transmitting unit including a pump impeller coupled with an engine of a motor vehicle, and a turbine runner, the lock-up clutch being engageable to connect the turbine runner to the pump impeller, the system comprising: means for detecting a revolution speed of the engine and generating an engine revolution speed indicative signal indicative of said revolution speed of the engine detected; means for detecting a revolution speed of the turbine runner and generating a turbine revolution speed indicative signal indicative of said revolution speed of the turbine runner detected; means for detecting a vehicle speed of the motor vehicle and generating a vehicle speed indicative signal indicative of said vehicle speed detected; a control unit including, means for deriving an actual slip from said engine revolution speed indicative signal and said turbine revolution speed indicative signal and generating an actual slip indicative signal indicative of said actual slip derived; means for generating an operating signal, said operating signal including an initial value and a term related to a difference between said actual slip indicative signal and a target slip value, said operation signal being generated after said vehicle speed indicative signal has exceeded a predetermined lock-up vehicle speed value; means for calculating a first time derivative of said actual slip indicative signal and generating a first time derivative indicative signal indicative of said first time derivative calculated; means for determining whether said first time derivative indicative signal fulfills a predetermined condition; means for counting a time elapsed after said vehicle speed indicative signal has exceeded said predetermined lock-up vehicle speed value until determination that said first time derivative indicative signal fulfills said predetermined condition and generating a time interval indicative signal indicative of said time counted; means for calculating a deviation of said time interval indicative signal from a target time interval and generating a deviation indicative signal indicative of said deviation calculated; and means for updating said initial value in response to said deviation indicative signal whereby said operating signal generated thereafter is modified; and means for controlling engagement of the lock-up clutch in response to said operating signal.

Claim 9

A system for an adaptive control of a lock-up clutch in a hydrokinetic torque transmitting unit including a pump impeller coupled with an engine of a motor vehicle, and a turbine runner, the lock-up clutch being engageable to connect the turbine runner to the pump impeller, the system comprising: means for detecting a revolution speed of the engine and generating an engine revolution speed indicative signal indicative of said revolution speed of the engine detected; means for detecting a revolution speed of the turbine runner and generating a turbine revolution speed indicative signal indicative of said revolution speed of the turbine runner detected; means for detecting a vehicle speed of the motor vehicle and generating a vehicle speed indicative signal indicative of said vehicle speed detected; a control unit including, means for deriving an actual slip from said engine revolution speed indicative signal and said turbine revolution speed indicative signal and generating an actual slip indicative signal indicative of said actual slip derived; means for generating an operating signal, said operating signal including an initial value and a term related to a difference between said actual slip indicative signal and a target slip value, said operation signal being generated after said vehicle speed indicative signal has exceeded a predetermined lock-up vehicle speed value; means for calculating a first time derivative of said actual slip indicative signal and generating a first time derivative indicative signal indicative of said first time derivative calculated; means for determining whether said first time derivative indicative signal fulfills a predetermined condition; means for counting a time elapsed after said vehicle speed indicative signal has exceeded said predetermined lock-up vehicle speed value until determination that said first time derivative indicative signal fulfills said predetermined condition and generating a time interval indicative signal indicative of said time counted; means for calculating a deviation of said time interval indicative signal from a target time interval and generating a deviation indicative signal indicative of said deviation calculated; and means for updating said initial value in response to said deviation indicative signal whereby said operating signal generated thereafter is modified; and means for controlling engagement of the lock-up clutch in response to said operating signal.

Claim 10

A method for an adaptive control of a lock-up clutch in a hydrokinetic torque transmitting unit including a pump impeller coupled with an engine of a motor vehicle, and a turbine runner, the lock-up clutch being engageable to connect the turbine runner to the pump impeller, the method comprising the steps of: detecting a revolution speed of the engine and generating an engine revolution speed indicative signal indicative of said revolution speed of the engine detected; detecting a revolution speed of the turbine runner and generating a turbine revolution speed indicative signal indicative of said revolution speed of the turbine runner detected; detecting a vehicle speed of the motor vehicle and generating a vehicle speed indicative signal indicative of said vehicle speed detected; deriving an actual slip from said engine revolution speed indicative signal and said turbine revolution speed indicative signal and generating an actual slip indicative signal indicative of said actual slip derived; generating an operating signal, said operating signal including an initial value and a term related to a difference between said actual slip indicative signal and a target slip value, the operating signal being generated after said vehicle speed indicative signal has exceeded a predetermined lock-up vehicle speed value; urging the lock-up clutch to engage in response to said operating signal; calculating a first time derivative of said actual slip indicative signal and generating a first time derivative indicative signal indicative of said first time derivative calculated; determining whether said first time derivative indicative signal fulfills a predetermined condition; counting a time elapsed after said vehicle speed indicative signal has exceeded said predetermined lock-up vehicle speed value until determination that said first time derivative indicative signal fulfills said predetermined condition and generating a time interval indicative signal indicative of said time counted; calculating a deviation of said time interval indicative signal from a target time interval and generating a deviation indicative signal indicative of said deviation calculated; and updating said initial value in response to said deviation indicative signal whereby said operating signal generated thereafter is modified.

Claim 11

A method for an adaptive control of a lock-up clutch in a hydrokinetic torque transmitting unit including a pump impeller coupled with an engine of a motor vehicle, and a turbine runner, the lock-up clutch being engageable to connect the turbine runner to the pump impeller, the method comprising the steps of: detecting a revolution speed of the engine and generating an engine revolution speed indicative signal indicative of said revolution speed of the engine detected; detecting a revolution speed of the turbine runner and generating a turbine revolution speed indicative signal indicative of said revolution speed of the turbine runner detected; detecting a vehicle speed of the motor vehicle and generating a vehicle speed indicative signal indicative of said vehicle speed detected; deriving an actual slip from said engine revolution speed indicative signal and said turbine revolution speed indicative signal and generating an actual slip indicative signal indicative of said actual slip derived; generating an operating signal, said operating signal including an initial value and a term related to a difference between said actual slip indicative signal and a target slip value, the operating signal being generated after said vehicle speed indicative signal has exceeded a predetermined lock-up vehicle speed value; urging the lock-up clutch to engage in response to said operating signal; calculating a first time derivative of said actual slip indicative signal and generating a first time derivative indicative signal indicative of said first time derivative calculated; determining whether said first time derivative indicative signal fulfills a predetermined condition; counting a time elapsed after said vehicle speed indicative signal has exceeded said predetermined lock-up vehicle speed value until determination that said first time derivative indicative signal fulfills said predetermined condition and generating a time interval indicative signal indicative of said time counted; calculating a deviation of said time interval indicative signal from a target time interval and generating a deviation indicative signal indicative of said deviation calculated; and updating said initial value in response to said deviation indicative signal whereby said operating signal generated thereafter is modified.