Ultrasonic distance measuring device

Abstract

Abstract PURPOSE:To improve the precision of distance measurement, by incorporating preliminarily synchronized clock devices in respective devices in the transmission side and the reception side and synchronizing the ultrasonic radiation time and the count start time with each other through these clock devices by radio waves or the like. CONSTITUTION:When a square pulse is outputted from a pulse generator 10 in a transmitting device 1, radio waves B subjected to frequency modulation are radiated during a duration t2 of this pulse, and ultrasonic waves A are radiated from a transmitter 4 by the pulse which is generated from a delay pulse generator 16 after the time t2. In a receiving device 2, radio waves B are received, and a clear signal is generated from a time signal generating circuit 21 on a basis of these radio waves. This signal is generated in accordance with the trailing edge of the pulse from a generator 10 and is given to a counter 23 to determine the start time of counting. The time of generation of the clear signal coincides with the time when ultrasonic waves A are radiated from the transmitter 4 in the transmission side. Thus, counting is started simultaneously with the start of propagation of ultrasonic waves, and the precision of distance measurement is improved.

Inventors

• 👤 Toshihiko Kuroda
• 👤 俊彦 黒田

Bibliographic Details