Back to results
US 8,078,381 B2Granted
Vehicle speed control apparatus in accordance with curvature of vehicle trajectory
AssigneeHitachi, Ltd.
InventorsMakoto Yamakado, Atsushi Yokoyama, Masato Abe
Life of this patent
Estimating the term…
Abstract
In order to fit a driver's driving feeling, a vehicle speed control system includes a unit that calculates the instantaneous curvature and a unit that controls vehicle speed. The system reduces the vehicle speed when the instantaneous curvature tends to increase, and enhances it when the instantaneous curvature tends to decrease.
Claims9
A vehicle speed control system comprising:
- means for calculating instantaneous curvature;
- and
- means for controlling a vehicle speed;
- wherein,
- a vehicle is controlled to reduce the vehicle speed when the instantaneous curvature tends to increase and to enhance the vehicle speed when the instantaneous curvature tends to decrease;
- the means for calculating instantaneous curvature includes means for instantaneously detecting a positional coordinate (x(t), y(t)) of the vehicle in a plane defined by at least two axes perpendicular to each other;
- and
- the instantaneous curvature (κ(t)) is calculated on the basis of the following expression;
- κ
-
- (
- t
- )
- =
- x
- .
-
- (
- t
- )
-
- y
- ¨
-
- (
- t
- )
- -
- x
- ¨
-
- (
- t
- )
-
- y
- .
-
- (
- t
- )
- (
- x
- .
-
- (
- t
- )
- 2
- +
- y
- .
-
- (
- t
- )
- 2
- )
- 3
- 2
- .
58 more elements
Dependencies are inferred from the claim text.