| 摘要 |
PROBLEM TO BE SOLVED: To provide an ultrasonic sensor which can set a drive frequency capable of compensating variation of a resonant frequency of an ultrasonic element, and can achieve highly convenient calibration without necessity of complicated work or cost increase of devices.SOLUTION: The ultrasonic sensor of the present invention is stored in a housing and includes: an ultrasonic element (12); transmitting means (20, 31) for supplying a transmission signal to the ultrasonic element; receiving means (21, 22, 23, 24, 25, 32) for detecting a received signal supplied from the ultrasonic element; distance calculation means (32); and calibration control means (33). At the time of calibration of a drive frequency of the transmitting means, the calibration control means selectively sets, for the transmitting means, a drive frequency which maximizes the strength of a received signal corresponding to a reflected wave from the housing, among multiple drive frequencies expected as a variation range of a resonant frequency of the ultrasonic element. |
