| 摘要 |
<p>PURPOSE: To prevent wrong obstacle detection caused by road surface reflection. CONSTITUTION: Ultrasonic wave is transmitted from a transducer 1, and the wave reflected on an obstacle is received by the transducer 1. The received signal is amplified according to reception time by an amplifier circuit 4. At this time, amplitude factor correction part 11 reduces amplification factor of the signal corresponding to road surface reflection wave. The distance from a vehicle to a point the road surface reflection wave is generated is calculated in advance, with road surface height at an installation place of the transducer 1, inclination angle of a central line of the ultrasonic wave against horizontal plane, and beam width of the ultrasonic wave as parameters, and stored into a storage part 14. The stored data is, when vehicle height is changed from reference height by a vehicle height adjustment device, compensated according to the change amount by a compensation part 15.</p> |
