Vehicle powertrain shift control method

A vehicle powertrain shift control method comprising:

• calculating, by a controller configured to divide a shift process into a series of shift phases and perform shift control based on the series of shift phases, a control hydraulic pressure basic calculated value for implementing a necessary torque of a control target shift element according to the series of shift phases by using a control matrix generated from a vehicle powertrain model;
• calculating a control hydraulic pressure corrected calculated value by correcting the control hydraulic pressure basic calculated value with a correction value comprising a learning value regarding the shift element;
• and
• controlling the control target shift element according to the control hydraulic pressure corrected calculated value;
• wherein, after calculating the control hydraulic pressure corrected calculated value, and before controlling the control target shift element, the vehicle powertrain shift control method further comprises:
• determining to which of four types of divided hydraulic pressure difference areas a main hydraulic pressure difference belongs, by the controller, the main hydraulic pressure difference being a value obtained by subtracting a coupling-side preparatory hydraulic pressure from a coupling-side preliminary target pressure;
• and
• limiting an inclination of the control hydraulic pressure corrected calculated value of a first shift initiation phase or a second shift initiation phase so as not to deviate from predetermined limit values, by the controller, when corresponding to an area in which the main hydraulic pressure difference is equal to or less than a predetermined positive first reference value, and an area in which the main hydraulic pressure difference is equal to or larger than a predetermined negative second reference value, respectively, among the four types of hydraulic pressure difference areas.