| 摘要 |
PROBLEM TO BE SOLVED: To use a MMW(microwave/millimeter wave) for detection by forming a road sign with thermoplastic paint containing a specified amount of metal granular material. SOLUTION: Paint formed of thermoplastic material having preset MMW temperature characteristics and solid granular material having a high dielectric constant including iron globules and titanium oxide is applied onto a road to provide a sign 7. In this case, the volume of the solid granular material is not less than 10% of that of the thermoplastic material. MMW energy λemitted from another planet and an atmosphere is reflected from a road 5 and the sing 7 and received by a horn 2 as an antenna. When a cart 3 is moved forward and the horn 2 senses part of the sign 7, a radiation temperature to be observed is decreased, when the view field of the horn 2 corresponds to the sing 7, the radiation temperature is more decreased and, when that of the horn 2 is beyond the sign 7, the temperature is increased up to a road temperature, originally observed. In this way, the presence of the sign is recognized and an alarm is used to control a vehicle to be located at the center of a lane. |
