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CN-114234950-B - Sensor system, method for operating a sensor system

CN114234950BCN 114234950 BCN114234950 BCN 114234950BCN-114234950-B

Abstract

A sensor system with a MEMS gyroscope and a method for operating the same are claimed, which sensor system comprises at least a seismic mass which can be excited to oscillate, a drive circuit for detecting a measuring signal, for exciting and maintaining a defined oscillating movement of the seismic mass, a detection circuit for reading out and demodulating the measuring signal, thereby generating a rotational speed signal and a quadrature signal which is phase-shifted with respect to the rotational speed signal, a digital processing circuit for compensating for a shift of the digitized rotational speed signal using the digitized quadrature signal, wherein the detection circuit and the digital processing circuit comprise rotational speed circuit means for generating and processing the rotational speed signal and quadrature circuit means for generating and processing the quadrature signal and for generating a compensation signal for a shift compensation of the digitized rotational speed signal, characterized in that at least a part of the quadrature circuit means can be operated independently of the mode of operation of the rotational speed circuit means in at least one mode of operation which differs from the rotational speed circuit means.

Inventors

  • F deazi
  • R. Halliulin
  • A. Visconti

Assignees

  • 罗伯特·博世有限公司

Dates

Publication Date
20260505
Application Date
20210909
Priority Date
20200909

Claims (10)

  1. 1. A sensor system (100) with a MEMS gyroscope (1), the sensor system comprising at least: a seismic mass (21) which can be excited to oscillate for detecting a measurement signal (200), A drive circuit (10) for exciting and maintaining a defined oscillating movement of the seismic mass (21), A detection circuit (20) for reading out the measurement signal (200) and demodulating the measurement signal (200), thereby generating a rotational speed signal (210) and a quadrature signal (211) phase shifted with respect to the rotational speed signal (210), A digital processing circuit (50) for compensating for an offset of the digitized rotational speed signal using the digitized quadrature signal, Wherein the detection circuit (20) and the digital processing circuit (50) comprise rotational speed circuit means (30, 31, 32) for generating and processing the rotational speed signal and comprise quadrature circuit means (41, 42, 43) for generating and processing the quadrature signal and for generating a compensation signal (212) for offset compensation of the digitized rotational speed signal; Characterized in that at least a part of the quadrature circuit arrangement (41, 42, 43) can be operated independently of the operating mode of the speed circuit arrangement (30, 31, 32) in at least one operating mode which differs from the speed circuit arrangement (30, 31, 32), Wherein the rotational speed circuit arrangement (30, 31, 32) is operated in a measuring mode of operation in which the rotational speed signal is provided at a first data rate and the quadrature circuit arrangement (41, 42, 43) is operated in a first energy saving mode in which the quadrature signal is provided at a second data rate, wherein the second data rate is smaller than the first data rate.
  2. 2. Sensor system (100) according to claim 1, characterized in that the rotation speed circuit arrangement comprises demodulation means (30) and/or an analog-to-digital converter (31) as components of the detection circuit (20) and/or at least one digital filter (32) as components of the digital processing circuit (50).
  3. 3. Sensor system (100) according to any of claims 1 or 2, characterized in that the quadrature circuit arrangement comprises demodulation means (41) and/or an analog-to-digital converter (42) as components of the detection circuit (20) and/or at least one digital filter (43) as components of the digital processing circuit (50).
  4. 4. A sensor system (100) according to any one of claims 1 to 3, having at least one temperature sensor (60) for detecting a temperature signal and having temperature circuit means (61,62,63,63 ',63 ") for processing the temperature signal and for generating the compensation signal, wherein the digital processing circuit (50) is designed for generating the compensation signal on the basis of the digitized quadrature signal and the digitized temperature signal, characterized in that at least a part of the temperature circuit means (61,62,63,63', 63") is operable independently of an operating mode of the speed circuit means (30, 31, 32) in at least one operating mode different from the speed circuit means (30, 31, 32).
  5. 5. The sensor system (100) according to claim 4, characterized in that the temperature circuit arrangement comprises an analog-to-digital converter (61) and/or at least one digital filter (62) and/or at least one adder (63') and/or multiplier (63, 63 ").
  6. 6. Sensor system (100) according to any of the preceding claims 1 to 5, characterized by an operating mode control means for predefining a current operating mode for the rotational speed circuit means (30, 31, 32) and/or for the quadrature circuit means (41, 42, 43) and/or for the temperature circuit means (61,62,63,63', 63 ").
  7. 7. A method for operating a sensor system (100) according to any of the preceding claims, characterized in that the rotation speed circuit arrangement (30, 31, 32) is operated in a measurement operation mode in which the rotation speed signal is provided at a first data rate and the quadrature circuit arrangement (41, 42, 43) is operated in a first energy saving mode in which the quadrature signal is provided at a second data rate, wherein the second data rate is smaller than the first data rate.
  8. 8. Method according to claim 7, characterized in that in the first energy saving mode at least part of the quadrature circuit means (41, 42, 43) is periodically activated and deactivated at predetermined time intervals.
  9. 9. The method according to any one of claims 7 or 8, wherein the sensor system (100) comprises at least one temperature sensor (60) and temperature circuit means (61,62,63,63 ',63 "), characterized in that the temperature circuit means (61,62,63,63', 63") are operated in a second energy saving mode in which a temperature signal is provided at a data rate that is smaller than the first data rate.
  10. 10. The method according to claim 9, characterized in that the quadrature circuit arrangement (41, 42, 43) and the temperature circuit arrangement (61,62,63,63', 63 ") are operated in the same power saving mode, so that the quadrature signal and the temperature signal are provided at the same data rate.

Description

Sensor system, method for operating a sensor system Technical Field The invention is based on a sensor system with a MEMS gyroscope. Background Gyroscopes for measuring rotational speed are well known and are used, for example, as microelectromechanical systems (MEMS) in a wide variety of devices and applications. In practice, for example in consumer electronics, a decisive characteristic variable of such a sensor is the current consumption or the energy consumption of the sensor. Although current consumption of active gyroscopes has been reduced in the past, there is a further need for savings in a large number of applications (e.g., in wearable devices and IOT devices). However, the pursuit of reducing the consumed power is often contradictory to the goal of improving the signal quality of the output sensor signal. Thus, careful trade-offs are often required in power optimization in order to be able to achieve, on the one hand, a power-saving sensor system and, on the other hand, as accurate and low-noise rotational speed measurements as possible. Disclosure of Invention The object of the present invention is to provide a power-saving sensor system with a MEMS gyroscope, by means of which rotational speed measurement can preferably still be achieved with a relatively high signal quality. The sensor system according to the invention comprises at least a seismic mass which can be excited to oscillate for detecting the measuring signal, a drive circuit for exciting and maintaining a defined oscillating movement of the seismic mass, a detection circuit for reading out the measuring signal and demodulating the measuring signal, thereby generating a rotational speed signal and a quadrature signal which is phase-shifted with respect to the rotational speed signal, a digital processing circuit for compensating for an offset of the digitized rotational speed signal using the digitized quadrature signal, wherein the detection circuit and the digital processing circuit comprise rotational speed circuit means for generating and processing the rotational speed signal and comprise quadrature circuit means for generating and processing the quadrature signal and for generating a compensation signal for offset compensation of the digitized rotational speed signal, wherein at least a part of the quadrature circuit means can be operated independently of the mode of operation of the rotational speed circuit means in at least one mode of operation which differs from the rotational speed circuit means. The sensor system according to the invention has the advantage over the prior art that at least a part of the quadrature circuit arrangement can be operated independently of the operating mode of the speed circuit arrangement in at least one operating mode which differs from the speed circuit arrangement. The quadrature circuit arrangement can therefore preferably be operated at least partially in an operating mode in which the quadrature circuit arrangement has a lower power consumption than in its operation in the operating mode of the rotational speed circuit arrangement. In this way, a large number of individual reductions in the current consumption can be achieved, wherein a rotational speed signal with a relatively high quality can still be output. It is thus possible to adapt particularly individually to the specific requirements imposed on the sensor system in the determination application. In a gyro system, in order to correct offset drift of a rotation speed signal, a quadrature signal of a gyro is generally used, and is generally used together with temperature information. However, in gyroscopes, the use of simple Duty-Cycle-TECHNIKEN is limited by the desired signal quality, since the data path for the rotational speed signal should be run continuously in order to efficiently filter noise and disturbances caused by external influences, such as vibrations. According to the invention, it is advantageously possible to operate at least one part of the quadrature circuit arrangement independently of the operating mode of the speed circuit arrangement in at least one operating mode different from the speed circuit arrangement. Offset variations in the tacho signal caused by quadrature effects and/or temperature effects advantageously typically occur at a lower frequency than the output of the tacho signal. Thus, according to the invention, it is possible to achieve a current saving by operation of at least a part of the quadrature circuit arrangement in the other operating mode without the signal quality of the rotational speed signal being (significantly) negatively affected. Advantageous configurations and embodiments of the invention emerge from the following description. According to one embodiment of the invention, the rotational speed circuit arrangement comprises demodulation means and/or an analog-to-digital converter as components of the detection circuit and/or at least one digital filter as components of the dig