METHOD FOR MEASUREMENT BY MEANS OF ULTRASOUND, PARTICULARLY AS A PARKING AID FOR VEHICLES, AND ULTRASONIC MEASUREMENT SYSTEMS

摘要

The method for measurement by means of ultrasound, particularly as a parking aid for vehicles, involves an electro-acoustic ultrasonic transducer (12), which has an oscillating element (14) and is operated without a voltage converter (54, 56) at its input, being actuated with an, in particular pulse-train, actuation signal for the duration of a transmission interval in order to produce ultrasound waves. When the actuation of the ultrasonic transducer (12) is terminated, the transmission interval is followed by a reception interval, with the oscillating element (14) of the ultrasonic transducer (12) swinging out during a decay phase that begins with termination of the transmission interval. The ultrasonic transducer (12) is connected up to at least one damping resistor (50) no later than from the beginning of the decay phase in order to shorten the latter. The connection between the ultrasonic transducer (12) and the damping resistor (50) is terminated when the output signal from the ultrasonic transducer (12) or the output signal from a measuring amplifier (58) connected to the ultrasonic transducer (12) or from a circuit (70) downstream of said measuring amplifier is below a prescribable deactivation threshold. During the reception interval, it is then possible for at least one echo from an ultrasound wave emitted in the preceding transmission interval or another ultrasound wave to be detected. The ultrasonic transducer (12) is connected up to the damping resistor (50) only when the transmission interval is terminated and/or when the reception interval begins.