JPS57168178A - Peripheral monitor for vehicle - Google Patents

Abstract

PURPOSE:To detect a short-range obstacle at a high accuracy by transmitting or receiving an ultrasonic pulses through a precession movement of a transmitting/ receiving section having a directivity provided on a vehicle to correctively calculate the distnce betweenthe vehicle and the obstacle from the angle of rotation and the propagation time of the section. CONSTITUTION:A transmitting/receiving section 4 is mounted and formed almost at the center toward the rear of a vehicle in such a manner as to oscillate. It comprises a transmitter 41 and a receiver 42. When the transmitting/ receiving section 4 is operated and starts precession, an angle detection signal is output from an angle detecting section 50 to an up/down counter 20 of a scan direction signal output section 60. An angle detection signal is input into a scan signal circuit 70 to trigger an oscillator 25. An ultrasonic signal output from the oscillator 25 is output to the perimeter of a vehicle with a transmitter 41 while a reflected wave from an obstacle is input into a receiver 42 and returned to the circuit 70. A detection signal is input into an FF28 and a terminal Q gains a time difference signal. Then, a range computing section 80 corrects a counted value B of pulses of a reference oscillator 30 with a correction signal A corresponding to the angle of rotation of the transmitting/receiving section 4.