Cruise control apparatus and control method thereof

1. A cruise control apparatus, comprising:

a communication unit to receive road information from a navigation device; and

a controller that confirms whether or not deceleration information is present in the road information, confirms a speed corresponding to the deceleration information if the deceleration information is present, compares the confirmed speed with a current speed, and controls a speed of a vehicle to the confirmed speed if the confirmed speed is greater than the current speed; and

a speed input unit to receive a speed of the vehicle from a driver,

wherein the deceleration information present in the road information received from the navigation device includes at least one of a position of a curve, a turning radius of the vehicle at a curve, and a speed limit,

wherein the deceleration information indicates the position of a bump, and the controller controls the speed of the vehicle based on the information on the position of the bump to set the speed of the vehicle to a predetermined constant speed while passing the position of the bump,

wherein the controller confirms the highest speed limit if the deceleration information indicates the speed limit, and controls the speed of the vehicle to the highest speed limit, and

wherein when the speed of the vehicle from the driver is received, the controller compares the driver input speed with the highest speed limit, and controls the vehicle to a lower speed among the driver input speed and the highest speed limit based on a comparison result.

2. The cruise control apparatus according to claim 1 , further comprising a wheel speed detecting unit to detect a speed of each of a plurality of wheels provided at the vehicle,

wherein the controller calculates the vehicle speed based on the speeds of the plurality of wheels if the deceleration information indicates the presence of a curve, calculates an allowable vehicle speed based on the vehicle speed and the turning radius of the vehicle at the curve, and controls the speed of the vehicle to the allowable vehicle speed at the position of the curve.

3. The cruise control apparatus according to claim 2 ,

wherein the controller compares the driver input speed with the allowable vehicle speed, and controls the speed of the vehicle to a lower speed among the driver input speed and the allowable vehicle speed based on a comparison result.

4. A cruise control method, comprising:

traveling a vehicle at a speed input by a driver;

receiving road information from a navigation device;

confirming whether or not deceleration information is present in the road information;

confirming a speed corresponding to the deceleration information if the deceleration information is present; and

controlling a speed of the vehicle to the confirmed speed if the confirmed speed is greater than the input speed based on a comparison result of the confirmed speed and the input speed,

wherein the deceleration information present in the road information received from the navigation device includes a position of a bump, and

wherein the controlling the speed of the vehicle includes:

detecting a speed of each of a plurality of wheels provided at the vehicle if the position of the curve and the turning radius are present in the deceleration information;

calculating the vehicle speed based on the speed of the plurality of wheels;

calculating a lateral acceleration based on the vehicle speed and the turning radius of the vehicle at the curve;

calculating an allowable vehicle speed based on the lateral acceleration;

controlling the speed of the vehicle to the allowable vehicle speed at the position of the curve;

comparing the input speed with the allowable vehicle speed; and

controlling the speed of the vehicle to a lower speed among the input speed and the allowable vehicle speed when the speed of the vehicle from the driver is received.

5. The cruise control method according to claim 4 , wherein the confirming whether or not deceleration information is present includes confirming whether or not at least one of a position of a curve, a turning radius of the vehicle at a curve, and a speed limit is present in the road information.

6. The cruise control method according to claim 5 , wherein the controlling the speed of the vehicle includes controlling the speed of the vehicle based on the information on the position of the bump to set the speed of the vehicle to a predetermined constant speed if the position of the bump is present in the deceleration information.

7. The cruise control method according to claim 5 , wherein the controlling the speed of the vehicle includes:

confirming the highest speed limit if the speed limit is present in the deceleration information; and

controlling the speed of the vehicle to the highest speed limit.

8. The cruise control method according to claim 7 , wherein the input speed is compared with the highest speed limit so that the speed of the vehicle is controlled to a lower speed among the input speed and the highest speed limit.

9. The cruise control apparatus according to claim 1 , wherein the controller further controls the speed of the vehicle to the confirmed speed after the vehicle has passed the position of the bump.

10. The cruise control apparatus according to claim 2 , wherein the controller calculates the current speed of the vehicle based on a slower wheel speed among the speeds of each of the plurality of wheels.

11. The cruise control apparatus according to claim 2 , wherein the controller further calculates a yaw rate of front wheels of the vehicle and a yaw rate of rear wheels of the vehicle based on the speeds of each of the plurality of wheels of the vehicle and on a distance between left and right wheels of the vehicle.

12. The cruise control method according to claim 4 , wherein the controlling the speed of the vehicle comprises controlling the speed of the vehicle to the confirmed speed after the vehicle has passed the position of the bump.

13. The cruise control method according to claim 4 , wherein the calculating the vehicle speed comprises calculated the vehicle speed based on a slower wheel speed among the speeds of each of the plurality of wheels.

14. The cruise control method according to claim 4 , further comprising calculating a yaw rate of front wheels of the vehicle and a yaw rate of rear wheels of the vehicle based on the speeds of each of the plurality of wheels of the vehicle and on a distance between left and right wheels of the vehicle.