| 摘要 |
PROBLEM TO BE SOLVED: To enable a driver to drive without a sense of incongruity by computing reference vehicle speed in a present position on the basis of the detected recommended vehicle speed, and the distance and a road gradient from the present position to a specific spot, and regulating a change gear ratio within a predetermined range at the time of the present vehicle speed exceeding the reference vehicle speed. SOLUTION: A navigation system 10 computes road curvature of a specified block every node point on the road and retrieves recommended vehicle speed. After computing a road gradient from a present position to a specific node point, deceleration/acceleration G3 and deceleration/acceleration G2 taking account of G3 are set, and vehicle speed V4-3, 3-2 are computed from the block distance and the deceleration/acceleration G3, G2 on the basis of the recommended vehicle speed. In case of the vehicle speed V4-3 being lower than the present vehicle speed, fourth gear speed is made an optimum shift stage. In case of the vehicle speed V4-3 being the present vehicle speed or lower, and the vehicle speed V3-2 being higher than the present vehicle speed, third gear speed is made an optimum shift stage. In case of the vehicle speed V4-3, 3-2 being the present vehicle speed or lower, second gear speed is made an optimum shift stage. At the time of selecting third gear speed as the optimum shift stage, the upper limit command value of fourth gear speed is set as long as there is no brake pedal action, and the upper limit command value of third gear speed is set when there is brake pedal action. Automatic shift control conformed to a driver's intention can therefore be performed. |
