CPC G01S 7/52004 (2013.01) [G01S 15/931 (2013.01)] | 18 Claims |
1. A method for determining a functional status of an ultrasonic sensor of an ultrasonic sensor device for a motor vehicle, comprising:
applying, in a normal mode during a driven operation of the motor vehicle, an excitation signal to the ultrasonic sensor to emit an ultrasonic signal into an environment of the motor vehicle and to receive an echo signal of the ultrasonic signal;
generating, in a diagnostic mode during the driven operation of the motor vehicle, an electrical test signal, which has a smaller amplitude than an amplitude of the excitation signal and differs in its signal properties from the excitation signal, wherein the electrical test signal is applied to excite the ultrasonic sensor without transmitting said ultrasonic signal into the environment of the motor vehicle;
evaluating, in the diagnostic mode during the driven operation of the motor vehicle, at least one electrical characteristic parameter of the ultrasonic sensor affected by the electrical test signal and independent of receiving any echo signal;
determining a transfer function of the ultrasonic sensor, wherein the transfer function comprises a relationship between the electrical test signal and the at least one electrical characteristic parameter that are applied and evaluated, respectively, independent of any echo signal and not distorted by any environmental effect; and
comparing the transfer function with a reference transfer function to determine the functional status of the ultrasonic sensor.
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