Method for assessing the state of a sensor as well as sensor system and method for operating the sensor system

A method for assessing a state of a sensor, the sensor including a deflectable micromechanical sensor structure configured to detect a physical input variable and to convert the physical input variable into an electrical sensor signal, wherein a medium surrounding the sensor acts directly or indirectly on the micromechanical sensor structure, and wherein the micromechanical sensor structure is deflectable using an excitation signal, the method comprising the following steps:

• generating the excitation signal using a driver unit, wherein the excitation signal exhibits at least an amplitude change;
• outputting the excitation signal to the micromechanical sensor structure;
• deflecting the micromechanical sensor structure using the excitation signal;
• detecting a response behavior of the micromechanical sensor structure in response to the excitation signal;
• comparing the response behavior to a reference behavior to determine a measure of deviation for the response behavior in relation to the reference behavior;
• and
• assessing, based on the measure of deviation, the state of the sensor with respect to presence of a deposit.

A sensor system, comprising:

• a sensor having a deflectable micromechanical sensor structure configured to detect a physical input variable and to convert the physical input variable into an electrical sensor signal, wherein a medium surrounds the sensor and directly or indirectly acts on the micromechanical sensor structure, and wherein the micromechanical sensor structure is deflectable using an excitation signal;
• a driver unit configured to generate and output the excitation signal, the excitation signal exhibiting at least an amplitude change;
• an evaluation unit configured to determine a response behavior of the micromechanical sensor structure in response to the excitation signal, and to form a measure of deviation based on a comparison of the response behavior with a reference behavior;
• and
• an assessment unit configured to assess a state of the sensor with respect to presence of a deposit, based on the measure of deviation.

A method for operating a sensor system, the sensor system including:

• (i) a sensor having a deflectable micromechanical sensor structure configured to detect a physical input variable and to convert the physical input variable into an electrical sensor signal, wherein a medium surrounds the sensor and directly or indirectly acts on the micromechanical sensor structure, and wherein the micromechanical sensor structure is deflectable using an excitation signal;
• (ii) a driver unit configured to generate and output an excitation signal, the excitation signal exhibiting at least an amplitude change;
• (iii) an evaluation unit configured to determine a response behavior of the micromechanical sensor structure in response to the excitation signal, and to form a measure of deviation based on a comparison of the response behavior with a reference behavior;
• and (iv) an assessment unit configured to assess a state of the sensor with respect to presence of a deposit, based on the measure of deviation, the method comprising the following steps:
• detecting, using the sensor system, a physical input variable, and converting, using the sensor system, the detected physical input variable into an electrical sensor signal;
• and
• performing, automatically at regular intervals and/or in an event-initiated manner and/or as initiated by a host system:
• generating the excitation signal using the driver unit,
• outputting the excitation signal to the micromechanical sensor structure,
• deflecting the micromechanical sensor structure using the excitation signal,
• detecting the response behavior of the micromechanical sensor structure in response to the excitation signal,
• comparing the response behavior to the reference behavior to determine the measure of deviation for the response behavior in relation to the reference behavior, and
• assessing, based on the measure of deviation, the state of the sensor with respect to the presence of the deposit.