| 摘要 |
PURPOSE:To detect face information extending to the circumferential edge part of an object, by deciding a detecting distance on the basis of a zero crossing point of an ultrasonic receiving signal having no influence on a condition of a propagation path and a reflection factor of the object. CONSTITUTION:A reflected ultrasonic wave from an object 6 by an ultrasonic transmitter and receiver 1 is received, and an amplitude value of a receiving carrier 15 is written in a memory 24 through a CPU19 by an address corresponding to the time which makes transmission of a transmitting wave 14 a start point. On the basis of this stored contents, the CPU19 decides a zero crossing point 17 having no influence on a condition of an ultrasonic propagation path of the carrier 15 and a reflection factor of the object, and counts back and decides an address number of a receiving time point 18 corresponding to a distance to the object 6 by a fixed value M stored in the CPU19 from the point 17. Accordingly, a scattered ultrasonic wave from the circumferential edge part of the object 6 can also be utilized for deciding a distance of its circumferential edge part, face information extending to the circumferential edge part of the object is detected, and a robot, etc. can be controlled exactly. |
