Magnetic marker and magnetic marker detection system
Provided are a magnetic marker and a magnetic marker detection system with a reduced magnetic force. The magnetic marker detection system ( 1 S) in which magnetism generated from the magnetic marker ( 1 ) laid on a road surface ( 53 ) is detected by a magnetic sensor ( 2 ) attached to a vehicle's body floor ( 50 ) of a vehicle ( 5 ) is a system with the magnetic marker ( 1 ) and the magnetic sensor ( 2 ) in combination, the magnetic marker having a magnetism reach ratio Gh/Gs, which is a ratio of a magnetic flux density Gh at a position at a height of 250 mm with respect to a magnetic flux density Gs of a surface, being equal to or larger than 0.5% and the magnetic sensor using a magneto-impedance element including a magneto-sensitive body with impedance changing in accordance with an external magnetic field.
1. A magnetic marker, wherein
the magnetic marker is configured to be detectable by a magnetic sensor attached to a bottom surface side of a vehicle to achieve driving support control on a vehicle side for supporting driving of a driver when the magnetic marker is laid on a road surface,
the magnetic marker has a diameter equal to or larger than 80 mm,
the magnetic marker has a magnet, and
the magnet has a surface taken as a reference height, and a magnetism reach ratio Gh/Gs, which is a ratio of a magnetic flux density Gh at a position at a height of 250 mm with respect to a magnetic flux density Gs at a position at a height of 0 mm, is equal to or larger than 0.5%.
2. The magnetic marker according to claim 1 , wherein
the magnetic flux density Gh is equal to or larger than 0.5 μT and equal to or smaller than 20 μT (equal to or larger than 5 mG and equal to or smaller than 200 mG).
3. The magnetic marker according to claim 2 , wherein
the magnetism read ratio Gh/Gs is equal to or larger than 1.0%.
4. A magnetic marker detection system in which magnetism generated from a magnetic marker laid on a road surface is detected by a magnetic sensor attached to a bottom surface of a vehicle to achieve driving support control of the vehicle, wherein
the magnetic marker is the magnetic marker according to claim 3 .
5. The magnetic marker according to claim 3 , wherein
a coating or a resin mold having a waterproof and wear-resistant effect is applied to the surface.
6. The magnetic marker according to claim 3 , wherein
the magnetic marker has a thickness within 5 mm and can be laid on the road surface without boring a recessed accommodation hole.
7. A magnetic marker detection system in which magnetism generated from a magnetic marker laid on a road surface is detected by a magnetic sensor attached to a bottom surface of a vehicle to achieve driving support control of the vehicle, wherein
the magnetic marker is the magnetic marker according to claim 2 .
8. The magnet marker according to claim 2 , wherein
the magnetic marker has a circular shape and the diameter equal is equal to or smaller than 100 mm.
9. The magnetic marker according to claim 2 , wherein
a coating or a resin mold having a waterproof and wear-resistant effect is applied to the surface.
10. The magnetic marker according to claim 2 , wherein
the magnetic marker has a thickness within 5 mm and can be laid on the road surface without boring a recessed accommodation hole.
11. The magnetic marker according to claim 1 , wherein
the magnetism reach ratio Gh/Gs is equal to or larger than 1.0%.
12. A magnetic marker detection system in which magnetism generated from a magnetic marker laid on a road surface is detected by a magnetic sensor attached to a bottom surface of a vehicle to achieve driving support control of the vehicle, wherein
the magnetic marker is the magnetic marker according to claim 11 .
13. The magnetic marker according to claim 11 , wherein
a coating or a resin mold having a waterproof and wear-resistant effect is applied to the surface.
14. The magnetic marker according to claim 11 , wherein
the magnetic marker has a thickness within 5 mm and can be laid on the road surface without boring a recessed accommodation hole.
15. The magnetic marker according to claim 1 , wherein
a coating or a resin mold having a waterproof and wear-resistant effect is applied to the surface.
16. The magnetic marker according to claim 15 , wherein
the magnetic marker has a thickness within 5 mm and can be laid on the road surface without boring a recessed accommodation hole.
17. The magnetic marker according to claim 1 , wherein
the magnetic marker has a thickness within 5 mm and can be laid on the road surface without boring a recessed accommodation hole.
18. A magnetic marker detection system in which magnetism generated from a magnetic marker laid on a road surface is detected by a magnetic sensor attached to a bottom surface of a vehicle to achieve driving support control of the vehicle, wherein
the magnetic marker is the magnetic marker according to claim 1 .
19. The magnetic marker detection system according to claim 18 , wherein
as the magnetic sensor, at least one type among a magneto-impedance sensor, a fluxgate sensor, and a Tunneling Magento Resistive sensor is used.
20. The magnet marker according to claim 1 , wherein
the magnetic marker has a circular shape and the diameter equal is equal to or smaller than 100 mm.