Sensor having a resonance structure, especially an acceleration or rotation rate sensor, and a device for carrying out a self-test

A sensor, comprising:

• a resonant structure configured to detect a measured quantity in accordance with a first periodic vibration of the resonant structure;
• a first arrangement configured to generate an output signal in accordance with the measured quantity;
• a second arrangement configured to at least one of determine and isolate a test signal component from the output signal, the test signal being generated by a second periodic vibration of the resonant structure superposed on the first periodic vibration;
• an actuation unit configured to excite the resonant structure to the first periodic vibration;
• and
• a third arrangement configured to excite the resonant structure to the second periodic vibration that is superposed on the first periodic vibration;
• wherein the third arrangement includes a mechanical unbalance of the resonant structure.

A device for self-testing a sensor, the sensor determining a measured quantity using a resonant structure and generating a periodic output signal in accordance with the measured quantity, comprising:

• an isolation device configured to isolate a test signal component that is superposed on a useful signal component from the periodic output signal of the sensor;
• a comparator device configured to compare the test signal component with one of a predefined value and an adjustable test signal sent to the sensor;
• an actuation unit configured to excite the resonant structure to a first periodic vibration, the sensor determining the measured quantity in accordance with the first periodic vibration;
• and
• a first arrangement configured to excite the resonant structure to a second periodic vibration that is superposed on the first periodic vibration.

A device for self-testing a sensor, the sensor determining a measured quantity using a resonant structure and generating a periodic output signal in accordance with the measured quantity, comprising:

• an isolation device configured to isolate a test signal component that is superposed on a useful signal component from the periodic output signal of the sensor;
• a comparator device configured to compare the test signal component with one of a predefined value and a test signal sent to the sensor;
• an actuation unit configured to excite the resonant structure to a first periodic vibration, the sensor determining the measured quantity in accordance with the first periodic vibration;
• and
• a first arrangement configured to excite the resonant structure to a second periodic vibration that is superposed on the first periodic vibration;
• wherein the first arrangement includes a mechanical unbalance on the resonant structure.

A method for self-testing a sensor having a resonant structure, comprising the steps of:

• exciting the resonant structure by an actuation unit to generate a first periodic vibration and a second periodic vibration including an adjustable test signal;
• superposing the second periodic vibration onto the first periodic vibration of the structure;
• detecting an output signal, the output signal including information relating to a measured quantity coupled to the resonant structure;
• and
• monitoring a test signal component of the output signal, the test signal component being generated by the second periodic vibration of the structure;
• wherein the second periodic vibration is superposed onto the first periodic vibration to permit simultaneous detection of the measured quantity and monitoring of the test signal component.

A method for self-testing a sensor having a resonant structure, comprising the steps of:

• exciting the resonant structure by an actuation unit to generate a first periodic vibration and a second periodic vibration;
• superposing the second periodic vibration onto the first periodic vibration of the structure;
• detecting an output signal, the output signal including information relating to a measured quantity coupled to the resonant structure;
• and
• monitoring a test signal component of the output signal, the test signal component being generated by the second periodic vibration of the structure;
• wherein the second periodic vibration is superposed onto the first periodic vibration to permit simultaneous detection of the measured quantity and monitoring of the test signal component;
• and
• wherein the second periodic vibration of the structure is excited by one of a mechanical coupling and a mechanical crosstalk of the sensor.

An acceleration sensor, comprising:

• a resonant structure, including:
• a resonator;
• and
• a resonant mass coupled to the resonator, a resonance frequency of the resonator changing in accordance with a displacement of the resonant mass;
• an actuation unit configured to excite the resonator;
• a detector configured to generate an output signal in accordance with the resonance frequency of the resonator;
• a control unit configured to generate an excitation signal, the excitation signal including at least two frequencies to simultaneously excite the resonator and the resonant mass to vibrate in different modes;
• and
• an evaluation unit configured to separate a vibration mode of the resonant mass as an adjustable test signal component from the output signal.

An acceleration sensor, comprising:

• a resonant structure, including:
• a resonator;
• and
• a resonant mass coupled to the resonator, a resonance frequency of the resonator changing in accordance with a displacement of the resonant mass;
• an actuation unit configured to excite the resonator;
• a detector configured to generate an output signal in accordance with the resonance frequency of the resonator;
• a control unit configured to generate an excitation signal, the excitation signal including at least two frequencies to simultaneously excite the resonator and the resonant mass to vibrate in different modes;
• and
• an evaluation unit configured to separate the vibration mode of the resonant mass as a test signal from the output signal;
• a self-testing device, the self-testing device including:
• an isolation device configured to isolate the test signal component that is superposed on a useful signal component from the output signal;
• and
• a comparator device configured to compare the test signal component with one of a predefined value and a test signal sent to the sensor;
• wherein the actuation unit is configured to excite the resonant structure to a first periodic vibration mode, the sensor determining the measured quantity in accordance with the first periodic vibration mode;
• wherein the self-testing device further includes a first arrangement configured to excite the resonant structure to a second vibration mode that is superposed on the first periodic vibration mode;
• and
• wherein the first arrangement includes a mechanical unbalance on the resonant structure.