Method for determining a function state of an ultrasonic sensor for a vehicle

A device for determining a functional state of an ultrasonic sensor for a vehicle having the device,

• the device comprising:
• an excitation unit for applying an electrical test signal to the ultrasonic sensor;
• a detection unit for detecting an electrical response signal from the ultrasonic sensor;
• a determining unit for determining a phase-frequency response,
• wherein the phase-frequency response comprises the phase angle of the detected response signal for the applied test signal as a function of an excitation frequency of the applied test signal;
• a comparison unit for comparing at least a first phase angle below and a second phase angle above a resonant frequency in the determined phase-frequency response with a respective expected phase angle;
• a correction unit for correcting the determined phase-frequency response using the comparison;
• and
• a determining unit for determining the functional state on the basis of the corrected phase-frequency response and a detected temperature of the ultrasonic sensor or a vehicle environment,
• wherein the ultrasonic sensor is operated in accordance with the determined functional state, and
• wherein the applying, the detecting the electrical response signal, the determining the phase-frequency response, the comparing, the correcting and the determining the functional state are carried out at an end of a production line in which the vehicle comprising the ultrasonic sensor is manufactured, and at or immediately after each starting of the vehicle.

A non-transitory computer readable medium storing instructions on a memory coupled to a processor, the instructions comprising functionality for:

• applying an electrical test signal to the ultrasonic sensor;
• detecting an electrical response signal from the ultrasonic sensor;
• determining a phase-frequency response comprising the phase angle of the detected response signal for the applied test signal as a function of an excitation frequency of the applied test signal;
• comparing at least a first phase angle below and a second phase angle above a resonant frequency in the determined phase-frequency response with a respective expected phase angle;
• correcting the determined phase-frequency response on the basis of the comparison;
• and
• determining the functional state on the basis of the corrected phase-frequency response and a detected temperature of the ultrasonic sensor or a vehicle environment,
• wherein the ultrasonic sensor is operated in accordance with the determined functional state, and
• wherein the instructions are configured to be carried out at an end of a production line in which the vehicle comprising the ultrasonic sensor is manufactured, and at or immediately after each starting of the vehicle.