Patent ID: 8182398

Claim:
A control apparatus for an automatic transmission where a gear of a first gear ratio is implemented by engaging a first friction element and engaging a second friction element, and a gear of a second gear ratio is implemented by engaging a third friction element and engaging a fourth friction element both different from said first friction element and said second friction element, said automatic transmission including a fluid coupling with an input shaft coupled to a power source and a transmission mechanism connected to an output shaft of said fluid coupling, said control apparatus comprising: a first disengagement controller to lower engagement force of said first friction element so as to disengage said first friction element at the time of a shift from said gear of said first gear ratio to said gear of said second gear ratio; a half-engagement controller to lower engagement force of said second friction element to preliminarily fixed engagement force with the disengagement of said first friction element; a first engagement controller to increase engagement force of said third friction element at a first time point after starting said shift; a second disengagement controller to further lower the engagement force of said second friction element so as to disengage said second friction element with the engagement of said third friction element; and a second engagement controller to increase engagement force of said fourth friction element at a second time point later than said first time point; a first detector to detect an input shaft revolution speed of said fluid coupling; a second detector to detect an output shaft revolution speed of said fluid coupling; and a learning unit to learn said first time point based on said input shaft revolution speed and said output shaft revolution speed.