Control device for automatic transmission

A power transfer device comprising:

• an automatic transmission that includes a plurality of engagement elements and a speed change gear mechanism capable of establishing a multiplicity of shift speeds by changing a power transfer path by engaging or disengaging the engagement elements;
• and
• a control device that is configured to control the automatic transmission, wherein:
• the speed change gear mechanism includes a plurality of combinations of engagement elements to be engaged in order to establish an identical predetermined shift speed;
• when shifting is made to the predetermined shift speed by the control device controlling the automatic transmission, a change is made among the combinations of engagement elements for the predetermined shift speed in accordance with a pre-shifting shift speed;
• the speed change gear mechanism includes first to fourth planetary gears, an input member, and an output member,
• the engagement elements includes first to fourth clutches and first and second brakes;
• the first planetary gear has a first sun gear, a first carrier coupled to the input member, and a first ring gear;
• the second planetary gear has a second sun gear, a second carrier coupled to the output member, and a second ring gear;
• the fourth clutch is coupled to any one of the first sun gear, the first carrier, and the first ring gear;
• the second brake is coupled to the second ring gear,
• the first clutch, the second clutch, and the third clutch can transfer power between the first planetary gear and the second planetary gear and the third planetary gear and the fourth planetary gear;
• and
• the first brake is coupled to a rotary element of any one of the third planetary gear and the fourth planetary gear.