| 摘要 |
PURPOSE:To prevent retreat of a vehicle on an upgrade slope, excessive creep- torque at the time of idle-up, etc., by controlling speed change gears in response to the grade of a road surface, engine speed, etc., and making it possible to control the speed change gears to creep-torque permitting the vehicle to stop or advance at extremely slow speed always in any condition. CONSTITUTION:Respective output signals from an engine speed sensor 12, a speed sensor 13, a grade sensor 14, and an oil temperature sensor 15 are inputted to the A/T controller 20 of an automatic transmission which provides command signals to solenoids 21 to 24 provided in a hydraulic control device 6 to control the engaging state of a clutch and a brake, and to establish specified speed change gears. Loss torque FL is determined from the map data indicating the relationship between AT oil temperature and the loss torque, necessary torque FN is determined from the map data indicating the relationship between the grade of a road and the necassary loss, and output torque FO is determined from the map data indicating the relationship between engine speed and the output torque of a torque converter. Then, a gear ratio K1 is calculated fron the formula K1=FN/(FO-FL) in order speed change control to be carried out. |
