Shifting control apparatus for vehicular automatic transmission

A shifting control apparatus for a vehicular automatic transmission having (a) an electrically controlled continuously variable transmission portion configured to transmit a rotary motion of a drive power source to an intermediate power transmitting member such that a speed ratio of an operating speed of the drive power source to a rotating speed of the intermediate power transmitting member is continuously varied with a torque control by a differential motor/generator, and (b) a mechanically operated step-variable transmission portion which is disposed between the intermediate power transmitting member and drive wheels of a vehicle, and which has a plurality of mechanically established gear positions having respective different ratios of the rotating speed of the intermediate power transmitting member to an output speed of the step-variable transmission portion, the shifting control apparatus comprising:

• an overall-speed-position shifting control portion configured to control the electrically controlled continuously variable transmission portion, so as to establish a plurality of overall speed positions of the vehicular automatic transmission having respective different values of a speed ratio which is a ratio of the operating speed of the drive power source to an output speed of the mechanically operated step-variable transmission portion,
• wherein the overall-speed-position shifting control portion includes:
• a multiple-step shifting control portion configured to command the vehicular automatic transmission to be shifted up to at least one intermediate overall speed position intermediate between a present one of the plurality of overall speed positions and a target overall speed position of the plurality of overall speed positions;
• and
• a synchronous shifting control portion configured to implement a synchronous control of a shifting action of the vehicular automatic transmission from the at least one intermediate overall speed position to the target overall speed position and a shifting action of the mechanically operated step-variable transmission portion to a target gear position of the plurality of gear positions, such that a moment of generation of a command to establish the target overall speed position is delayed with respect to a moment of generation of a command to establish the target gear position, so that the shifting actions of the vehicular automatic transmission and the mechanically operated step-variable transmission portion take place in synchronization with each other, irrespective of different control response times of the shifting actions.