Sensor system for vehicle
A sensor system has object detection sensors 4 which are mounted on door mirrors 2 and have a parking space search mode for searching for an object within ranges extending laterally from a vehicle 14, and a vehicle monitoring mode for searching for an object in rear lateral sides of the vehicle 14 by folding and retracting the door mirrors 2; and a control section 7 for causing the object detection sensors 4 to be driven when the vehicle 14 travels at a speed equal to or less than a prescribed value, and for making a search frequency of the object detection sensors 4 higher in the parking space search mode than in the vehicle monitoring mode.
1. A sensor system for a vehicle comprising:
an object detection sensor which is mounted on a door mirror, and has a first search mode for searching for an object using a range extending laterally from a vehicle as a detection area, and a second search mode for searching for an object using a rear lateral side of the vehicle as a detection area by folding and retracting the door mirror; and
a control section for causing the object detection sensor to be driven when the vehicle travels at a speed equal to or less than a prescribed value, and for making a search frequency of the object detection sensor higher in the first search mode than in the second search mode.
2. The sensor system for a vehicle according to claim 1 , further comprising an object detection deciding section for deciding a parking possible area by detecting an obstacle from search results successively obtained from the object detection sensor in the first search mode.
3. The sensor system for a vehicle according to claim 1 , further comprising a moving obstacle detection deciding section for detecting a moving obstacle from a result of comparing a past search result with a current search result of the object detection sensor in the second search mode.
4. The sensor system for a vehicle according to claim 3 , wherein the control section increases the search frequency of the object detection sensor when the moving obstacle detection deciding section detects the moving obstacle.
5. The sensor system for a vehicle according to claim 3 , wherein
the moving obstacle detection deciding section decides approach of the moving obstacle to the vehicle by comparing previous and current search results obtained by the object detection sensor; and
the control section increases the search frequency of the object detection sensor when the moving obstacle detection deciding section detects the moving obstacle, and decides that the moving obstacle is approaching the vehicle.
6. The sensor system for a vehicle according to claim 3 , wherein
the control section controls whether to issue an alarm or not and controls the search frequency of the object detection sensor in response to the detection result of the moving obstacle by the moving obstacle detection deciding section and in response to proximity of an immobilizer to the vehicle.
7. The sensor system for a vehicle according to claim 1 , wherein
the object detection sensor searches for an object downward from a horizontal plane.
8. The sensor system for a vehicle according to claim 1 , wherein
the object detection sensor searches for an object using a range which faces more frontward than the door mirror and extends obliquely from the vehicle as the detection area in the first search mode.
9. The sensor system for a vehicle according to claim 1 , wherein
the control section alters the search range of the object detection sensor in accordance with a difference in the first and second search modes.
10. The sensor system for a vehicle according to claim 9 , wherein
the control section alters the search range by adjusting directivity of a search signal transmitted from the object detection sensor.
11. The sensor system for a vehicle according to claim 10 , wherein
the control section narrows the directivity in the second search mode than in the first search mode.
12. The sensor system for a vehicle according to claim 10 , wherein
the object detection sensor is a ultrasonic sensor; and
the control section adjusts the directivity of ultrasonic waves transmitted from the ultrasonic sensor in accordance with a transmission frequency of the ultrasonic waves.
13. The sensor system for a vehicle according to claim 10 , wherein
the object detection sensor is a ultrasonic sensor whose horn for emitting the ultrasonic waves has a variable shape; and
the control section adjusts the directivity of the ultrasonic waves transmitted from the ultrasonic sensor by controlling the variable shape of the horn.
14. The sensor system for a vehicle according to claim 9 , wherein
the control section alters the search range by adjusting the detection range of the object detection sensor.
15. The sensor system for a vehicle according to claim 14 , wherein
the control section makes the detection range in the second search mode shorter than that in the first search mode.
16. The sensor system for a vehicle according to claim 14 , wherein
the object detection sensor is a ultrasonic sensor; and
the control section adjusts the detection range of the ultrasonic waves transmitted from the ultrasonic sensor in response to at least one of transmission voltage, transmission frequency and transmission pulse width of the ultrasonic waves.
17. The sensor system for a vehicle according to claim 1 , further comprising a driving command informing section for causing the door mirror to be folded and retracted when detecting that the vehicle is stopped.