Driving support apparatus for vehicle

1. A driving support apparatus for a vehicle, comprising:

a vehicle speed setting unit for setting a set vehicle speed based on an operation state to an operation input unit by a driver;

a constant speed cruise control unit for performing constant cruise control using the set vehicle speed as a target speed;

an imaging unit for capturing an image ahead of a subject vehicle;

a speed limit recognizing unit for recognizing a speed limit displayed on a sign on a road based on the image captured by the imaging unit; and

a vehicle speed switching unit that, when a speed limit different from the set vehicle speed is recognized by the speed limit recognizing unit, temporarily performs a standby mode in which the set vehicle speed can be switched to the recognized speed limit and displays the set vehicle speed and the recognized speed limit so that the speeds can be compared with each other, wherein

the operation input unit includes an up switch for changing a current set vehicle speed to be higher and a down switch for changing a current set vehicle speed to be lower,

during the standby mode entered as a result of recognizing the speed limit higher than the set vehicle speed, the vehicle speed switching unit switches the set vehicle speed to the speed limit when the up switch is operated by the driver and maintains the set vehicle speed when the down switch is operated by the driver, and

during the standby mode entered as a result of recognizing the speed limit lower than the set vehicle speed, the vehicle speed switching unit maintains the set vehicle speed when the up switch is operated by the driver, and switches the set vehicle speed to the speed limit when the down switch is operated by the driver.

2. The driving support apparatus for a vehicle according to claim 1 , wherein

the operation input unit includes a resume switch for returning a current set vehicle speed to a previous set vehicle speed; and

the vehicle speed switching unit maintains the set vehicle speed when the resume switch is operated by the driver during the standby mode, or switches the set vehicle speed to the speed limit when the resume switch is not operated by the driver during the standby mode.

3. The driving support apparatus for a vehicle according to claim 2 , wherein

when a new speed limit is recognized by the speed limit recognizing unit during the standby mode, the vehicle speed switching unit extends a time during which the standby mode is performed.

4. The driving support apparatus for vehicle according to claim 1 , wherein

when neither the up switch nor the down switch is operated by the driver during the standby mode, the vehicle speed switching unit maintains the set vehicle speed.

5. The driving support apparatus for a vehicle according to claim 4 , wherein

when a new speed limit is recognized by the speed limit recognizing unit during the standby mode, the vehicle speed switching unit extends a time during which the standby mode is performed.

6. The driving support apparatus for a vehicle according to claim 1 , wherein

when a new speed limit is recognized by the speed limit recognizing unit during the standby mode, the vehicle speed switching unit extends a time during which the standby mode is performed.

7. The driving support apparatus for a vehicle according to claim 1 , further comprising:

a display device,

wherein during performing the standby mode, the constant speed cruise control unit displays the set vehicle speed and the recognized speed limit on the display device simultaneously.

8. The driving support apparatus for a vehicle according to claim 7 , wherein after the set vehicle speed and the recognized speed limit are displayed, the vehicle speed switching unit prompts the driver to select whether to maintain the set vehicle speed or to change the set vehicle speed to the recognized speed limit.