Abstract
If sufficient time is allowed for detection, the aerial ultrasonic pulsed radar sensor can detect reflecting objects without being unduly subject to the effect of wind. When used for safety assurance like obstacle detection of automated guided vehicles, the pulsed radar sensor must have such fail-safe characteristics that it can monitor an area wilder than that it is originally designed to monitor when it malfunctions and can produce a hazard-signifying output signal when it stops. The ultrasonic pulsed radar sensor discussed here is in its normal operating state when a short-distance transmitter/receiver signal is received as inspection signal for monitoring its operation. The pulse signal reflected from the obstacle in question, operation monitoring signal, and gate signal are added and converted into a ternary signal. The ternary signal is converted into a binary signal that indicates the normal state of the sensor (logic 1) or the faulty state of the sensor or detection of the obstacle (logic 0). A fail-safe pulsed radar can be realized in this way.
