To realize acceleration and deceleration without sense of incongruity at the time of traveling on a descending road.
When it is detected to travel on a descending road with comparatively large gradient, a traveling speed upper limit value Vcmax larger than a setting traveling speed Vc and a traveling speed lower limit value Vcmin smaller than the traveling speed upper limit value Vcmax and larger than the setting traveling speed Vc are set. When its own vehicle traveling speed V becomes over the traveling speed upper limit value Vcmax, rapid braking with comparatively large deceleration is performed, and when the vehicle traveling speed V becomes lower than the traveling speed lower limit value Vcmin, braking is released and canceled, so that pumping brake is realized in an area with a traveling speed larger than the setting traveling speed Vc. Thus, the speed is matched to a driving sense or a traveling sense of a driver.
Yoshiaki Naito
Cui Shu Tetsu