Patent ID: 6928357

Claim:
A slip control system of an automatic transmission with a torque converter, comprising: a lockup clutch, which is disposed between input and output elements of the torque converter, and whose engagement capacity is changeable for adjusting an actual slip-rotation speed between the input and output elements; and a control unit that feedback-controls the engagement capacity, the control unit comprising: (a) a target slip-rotation speed calculation section that estimates a target slip-rotation speed based on engine-and-vehicle operating conditions; (b) a pre-compensating section that pre-compensates for the target slip-rotation speed to produce a target slip-rotation speed correction value; (c) a slip-rotation speed deviation calculation section that calculates a slip-rotation speed deviation between the target slip-rotation speed correction value and the actual slip-rotation speed; (d) a feedback compensating section that feedback-controls the engagement capacity based on the slip-rotation speed deviation to bring the actual slip-rotation speed closer to the target slip-rotation speed; and (e) a dead-time processing section that compensates for the target slip-rotation speed correction value, considering a dead time of dynamic characteristics peculiar to the slip control system in the target slip-rotation speed correction value, to supply a dead-time compensated output to the feedback compensating section.