Vehicle lock-up clutch control device and lock-up clutch control method

In a vehicle on which a torque converter having a lock-up clutch is mounted between an engine and a transmission, a lock-up clutch control device of the vehicle comprises:

• a lock-up controller that performs engagement control for the lock-up clutch;
• and
• a meet point learning controller that performs learning control for obtaining a learning value based on information on a meet point at which the lock-up clutch starts torque transmission,
• wherein the meet point learning controller estimates a lock-up transmission torque based on a difference between an engine torque and a torque converter transmission torque when the lock-up clutch moves from a non-engaged state to an engaged state during traveling of the vehicle, and uses, as the meet point information, a meet point detection pressure at a time when the lock-up transmission torque estimated value is determined to have entered an upward trend, and
• wherein the meet point learning controller determines that the lock-up transmission torque estimated value has entered the upward trend, when a variation in the lock-up transmission torque estimated value per unit time exceeds an edge detection threshold value that represents a start of a monotonic increase.

In a vehicle on which a torque converter having a lock-up clutch is mounted between an engine and a transmission, the vehicle equipped with a lock-up controller that performs engagement control for the lock-up clutch, and a meet point learning controller that performs learning control for obtaining a learning value based on information on a meet point at which the lock-up clutch starts torque transmission, a lock-up clutch control method of the vehicle comprises:

• estimating a lock-up transmission torque based on a difference between an engine torque and a torque converter transmission torque when the lock-up clutch moves from a non-engaged state to an engaged state during traveling of the vehicle;
• using, as the meet point information, a meet point detection pressure at a time when the lock-up transmission torque estimated value is determined to have entered an upward trend;
• and
• determining that the lock-up transmission torque estimated value has entered the upward trend, when a variation in the lock-up transmission torque estimated value per unit time exceeds an edge detection threshold value that represents a start of a monotonic increase.