METHOD FOR CONTROLLING SPEED CHANGE OF CONTINUOUSLY VARIABLE TRANSMISSION

摘要

PURPOSE:To carry out not only a proportional process but a required integral process by allowing the integral process of errors between a target value and an actual engine speed when an actual speed change ratio in the vicinity of a limit value is moved to an intermediate speed change ratio area side. CONSTITUTION:Errors EOR between a target engine speed NESPR calculated by a throttle opening and a vehicle speed and an actual engine speed NE are manupulated to carry out speed change control for a continuously variable transmission in ratio solenoid duty OPWRAT in a manner that a first error E1R is calculated due to a proportional gain 200 and a second error E2R is calculated by finding an integral value X1IR due to an integral gain 204 and an integral 206 and the second error is subtracted from a ratio solenoid null value. When an actual ratio moves in the vicinity of an overdrive line and a full low line in an intermediate area, a switching portion 202 is switched to a YES side to prohibit the integral process, and when moving to the interme diate ratio area side, the switching portion is switched to a NO side to allow it. Thus, the integral value is avoided to become an abnormal value.