CN-121994287-A - Method for operating a MEMS sensor and MEMS sensor

Abstract

A MEMS sensor operating method and a MEMS sensor, in which unadjusted sensor raw data are generated, on the basis of unadjusted sensor raw data, adjusted first sensor output data are generated before updating the operating method according to a defined first compensation rule, which is provided in a first output register for transmission to an external, in particular external, control device, the first compensation rule being determined on the basis of first compensation parameters stored in a MEMS sensor non-volatile first memory, second compensation parameters are transmitted from an external data processing device to the MEMS sensor in an operating method updating step and stored in a MEMS sensor second memory, a second compensation rule is determined on the basis of the second compensation parameters, and, on the basis of unadjusted sensor raw data, adjusted second sensor output data are generated in its operation after updating the operating method according to the second compensation rule, which is provided in a second output register for transmission to the external, in particular external, control device.

Inventors

• T. Shearer
• L. Brecher
• M. Vujadinovic

Assignees

• 罗伯特·博世有限公司

Dates

Publication Date

20260508

Application Date

20251107

Priority Date

20241107

Claims (11)

1. 1. Method for operating a MEMS sensor (10), wherein unadjusted sensor raw data (SR) are generated during the operation of the MEMS sensor (10), wherein, prior to an update of the operating method, adjusted first sensor output data (SA 1) are generated on the basis of the unadjusted sensor raw data (SR) according to a defined first compensation rule, wherein the first sensor output data (SA 1) are provided in a first output register (35) for transmission to the outside, in particular to an external control device (100), Wherein the first compensation rule is determined on the basis of a first compensation parameter (KP 1) which is stored in a non-volatile first memory (34) of the MEMS sensor (10), Wherein in an updating step (A1) of the operating method, a second compensation parameter (KP 2) is transmitted from an external data processing device (110) to the MEMS sensor (10) and stored in a second memory (37) of the MEMS sensor (10), wherein a second compensation rule is determined on the basis of the second compensation parameter (KP 2), Wherein, after updating the operating method, in operation of the MEMS sensor (10), adjusted second sensor output data (SA 2) is generated on the basis of the unadjusted sensor raw data (SR) according to the second compensation rule, wherein the second sensor output data (SA 2) is provided in a second output register (39) for transmission outwards, in particular to the external control device (100).
2. 2. Method according to claim 1, wherein, after updating the operating method, in operation of the MEMS sensor (10), first sensor output data (SA 1) generated according to the first compensation rule is still provided in the first output register (35) for transmission outwards, in particular to the external control device (100).
3. 3. Method according to claim 1 or 2, wherein the second memory (37) is a one-time writable OTP memory, which is first written in the updating step (A1).
4. 4. Method according to any of the preceding claims, wherein in the updating step (A1) the second compensation parameter (KP 2) is transmitted to the MEMS sensor (10) in an encrypted manner and decrypted on the sensor side.
5. 5. The method according to any of the preceding claims, wherein generating the first sensor output data (SA 1) according to the first compensation rule is performed by means of a first microcontroller (33) of the MEMS sensor (10), in the updating step a second microcontroller (36) of the MEMS sensor (10) is initialized for generating the second sensor output data (SA 2) according to the second compensation rule.
6. 6. The method according to any of the preceding claims, wherein the second compensation parameter (KP 2) transmitted in the updating step (A1) is wirelessly transmitted to the MEMS sensor (10).
7. 7. The method according to any of the preceding claims, wherein the first sensor output data (SA 1) and/or the second sensor output data (SA 2) comprise internal sensor parameters (SI 1, SI 2), which internal sensor parameters (SI 1, SI 2) are transmitted from the MEMS sensor (10) to the external data processing device (110) in an encrypted manner.
8. 8. A MEMS sensor (10) configured to operate in accordance with the method of any one of the preceding claims.
9. 9. The MEMS sensor (10) according to claim 8, having a first microcontroller (33) for generating adjusted first sensor output data (SA 1) based on unadjusted sensor raw data (SR) according to a first compensation rule, a first output register (35) for providing the first sensor output data (SA 1) outwards, a non-volatile first memory (34) for storing first compensation parameters (KP 1) determining the first compensation rule, a second microcontroller (36) for generating adjusted second sensor output data (SA 2) based on the unadjusted sensor raw data (SR) according to a second compensation rule, a second output register (39) for providing the second sensor output data (SA 2) outwards, and a second memory (37) for storing second compensation parameters (KP 2) determining the second compensation rule.
10. 10. MEMS sensor (10) according to claim 8 or 9 having a cryptographic module (38) for encrypting and decrypting data stored in the second output register (39) or to be stored in the second output register (39), in particular data comprising the second compensation parameter (KP 2).
11. 11. MEMS sensor (10) according to any one of the preceding claims, comprising a wireless module (40) for wireless transmission of data stored in the second output register (39) or to be stored in the second output register (39), in particular data comprising the second compensation parameter (KP 2).

Description

Method for operating a MEMS sensor and MEMS sensor Technical Field The invention relates to a method for producing a MEMS sensor with a microelectromechanical system, and to a MEMS sensor produced according to the method, which can be designed, for example, as a pressure sensor, an ultrasonic sensor or, particularly preferably, as an inertial sensor. Background Inertial sensors, in particular rotational speed sensors and/or acceleration sensors, based on microelectromechanical systems (MEMS) belong to the standard equipment of common road vehicles. Typically, such MEMS sensors are used to implement functions of a driving assistance system, such as an airbag function, an electronic stabilization procedure, or a start assist (especially hill start assist). Other applications involve navigation, typically used with satellite-based global navigation systems (GNSS). In highly automated driving, MEMS sensors are used, for example, to perform emergency stops in which the vehicle is brought into a parked state in a controlled manner. In the field, the MEMS sensor is subjected to certain disturbances of its output signal, in particular disturbances caused by external influences, such as temperature and/or humidity changes, mechanical stresses (e.g. bending of the circuit board to which the MEMS sensor is soldered), aging effects, coupling in of linear accelerations and angular accelerations or vibrations and/or electromagnetic disturbances in the environment or in the supply voltage. These effects are disturbance variables that may cause variations such as offset, sensitivity, lateral Sensitivity (also known as "Cross-Axis Sensitivity"), or signal noise. Known MEMS sensors are designed to compensate for such environmental effects to a certain extent to achieve the above-mentioned applications. However, the ever-increasing demands, especially in terms of as small a structural size as possible and reduced test costs, represent a challenge for development. Disclosure of Invention Against this background, the invention proposes a method for operating a MEMS sensor, which is suitable for compensating for the disturbing influences occurring during the operation of the MEMS sensor. The above-mentioned object is achieved by a method according to the invention for operating a MEMS sensor and a MEMS sensor according to the invention. Advantageous configurations of the invention are given below. According to one aspect of the invention, it is proposed to obtain knowledge for development from field data that can be generated by the MEMS sensor in use, in particular with regard to improving error correction and/or improving compensation for disturbance variables that occur only during operation. According to another aspect of the present invention, a MEMS sensor is provided that is configured to implement a compensation method for subsequent matching. This matched compensation method can be applied in particular as an update to already operating MEMS sensors. A MEMS sensor within the scope of the present disclosure is a semiconductor structural element having a microelectromechanical system (MEMS) and an integrated circuit (ASIC) configured for component-specific manipulation and analysis processing of the MEMS. The microelectromechanical system includes a movable structure that is typically integrated in the layer structure of the MEMS sensor. In order to protect the movable structure, the MEMS sensor may optionally comprise a cover, which may likewise be formed in the layer structure of the semiconductor construction element. The microelectromechanical system is a physical implementation of the MEMS sensor device, that is to say, in a configuration variant, the MEMS sensor can be, for example, a pressure sensor, an ultrasonic sensor or, in particular, an inertial sensor. In operation of such MEMS sensors in the field, unregulated (unbereinigte) sensor raw data is detected, for example, in the form of unregulated analog sensor signals. The adjusted first sensor output data is generated based on the unadjusted sensor raw data according to a prescribed first compensation rule. The first compensation rule is determined as a function of a first compensation parameter, which is determined, for example, at the end of the production chain in a measurement and trimming step and is stored in a nonvolatile first memory of the MEMS sensor, which is in particular not writable many times. The first sensor output data generated according to the first compensation rule is provided in a first output register of the MEMS sensor for transmission outwards, in particular to an external control device. In this way, it is ensured in particular that the first compensation rule defined by the first compensation parameter meets a predetermined safety requirement. In particular, MEMS sensors which are provided for use in safety-critical applications in the automotive field (e.g. vehicle dynamics control and/or airbag systems) have correspondingly high d