Method for determining at least one temperature compensation parameter for compensating for temperature influences on measured values ​​of a sensor system

Abstract

The invention relates to a method for determining temperature compensation parameters for compensating temperature influences on measured values ​​of a sensor system, the sensor system comprising a sensor unit, a temperature sensor unit, a signal processing unit, determining temperature compensation parameters and compensating temperature influences on measured values ​​of the sensor unit. The method comprises monitoring a measurement situation of the sensor unit and determining whether a current measurement situation corresponds to a reference measurement situation; monitoring the temperature of the sensor unit and determining whether the current temperature is within a predetermined temperature range; detecting at least two different temperature values ​​within the predetermined temperature range and, if the current measurement situation corresponds to the reference measurement situation, detecting the respective associated measurement values ​​of the sensor measurement variable; determining at least one temperature compensation parameter based on at least one reference measurement value of the sensor measurement variable X, at least two different temperature values ​​and the associated measurement value of the sensor measurement variable X. The invention relates to a sensor system.

Description

Technical Field

[0001] The invention relates to a method for determining at least one temperature compensation parameter for compensating for temperature influences on measured values ​​of a sensor system and also to a MEMS sensor system which is designed to carry out the method. Background Art

[0002] The continuous miniaturization of the sensor surfaces of known sensor systems, in particular MEMS sensor systems, leads to technical challenges such as the integration of microcontrollers into sensor systems for covering different application scenarios or the component-specific correction of temperature-dependent offsets and sensitivity inaccuracies of sensor measurement results.

[0003] Temperature influences of the sensor units can lead to inaccuracies in the temperature definition of the measurement results of the sensor units. Currently, such inaccuracies can be corrected by adjusting the measurement results of the corresponding sensor system for the individual temperature support points using the measurement results of a suitable reference sensor system, which serves as a reference value. Such an adjustment using a reference sensor system, however, ignores the influence of individual factors, such as individual characteristics of the individual sensor systems defined by the manufacturer, which can lead to additional measurement inaccuracies.

[0004] Cost-effectively, measurements that are currently used to correct measurement inaccuracies in the temperature definition can only be performed for individual temperature support points during production in the factory. However, such measurements for only individual temperature support points are not sufficient to achieve a comprehensive correction.

[0005] Therefore, there is a need for an individual correction of the temperature-limited measuring inaccuracy that can be adapted to the respective system, which meets the requirements of current sensor systems based on individual factors and consideration of a large number of temperature support points. Summary of the invention

[0006] The object on which the present invention is based can be seen as providing an efficient method for adaptively compensating for temperature influences on measured values ​​of a sensor system and a corresponding sensor system which is designed to carry out such a method.

[0007] This object is achieved by means of the corresponding contents of the technical solution according to the present invention. Advantageous embodiments of the present invention are the contents of the respective preferred embodiments.

[0008] According to a first aspect of the present invention, a method for determining at least one temperature compensation parameter for compensating for temperature influences on measured values ​​of a sensor system is provided, wherein the sensor system comprises at least:

[0009] a. a sensor unit for detecting a measured value of a sensor measurement parameter;

[0010] b. a temperature sensor unit for detecting the temperature of the sensor unit;

[0011] c. a signal processing unit for determining at least one temperature compensation parameter and for compensating for temperature influences on the measured values ​​of the sensor unit;

[0012] Among them, the method includes:

[0013] o monitoring a measurement situation of the sensor unit and determining whether the current measurement situation corresponds to a reference measurement situation for which at least one reference measurement value of the sensor measurement variable is known;

[0014] oMonitoring the temperature of the sensor unit and determining whether the current temperature is within a predetermined temperature range;

[0015] o detecting at least two different temperature values ​​within a predetermined temperature range and, if the current measurement situation corresponds to a reference measurement situation, detecting the associated corresponding measured value of the sensor measurement variable;

[0016] o Determining at least one temperature compensation parameter based on at least one reference measured value of the sensor measurement variable, at least two different temperature values, and the associated measured value of the sensor measurement variable.

[0017] The method according to the invention makes it possible to determine component-specific temperature compensation parameters in continuous operation, that is, in the application, and to update them again if desired. Based on these temperature compensation parameters, a compensation for temperature influences on the measured values ​​can then be carried out, which takes into account both component-specific properties and changes over the service life. The method according to the invention is then an alternative or at least a supplement to factory calibration of the sensor system.

[0018] In this way, it is also possible to carry out an adaptation of initial temperature compensation parameters of the sensor system which are determined at the factory, ie before the sensor system is put into operation in the application.

[0019] A high measurement accuracy of the sensor system can be achieved by repeated calibration and adaptation of the temperature compensation parameters of the sensor units of the sensor system. For example, changes in the temperature characteristics of the sensor system over time can be adjusted by repeated calibration and adaptation of the temperature compensation parameters. Thus, conditions in the overall system can change over a period of time, for example due to mechanical stresses in the structure of the sensor system, which can lead to changing temperature characteristics.

[0020] In addition, if the sensor system has been installed at its determined position, the method for determining the temperature compensation parameters for the sensor system can be implemented by the sensor system itself. Because the influence of assembly and ambient conditions is also considered here, a better compensation for the temperature influence on the measured value can be achieved based on the temperature compensation parameters compared to the temperature compensation parameters determined in the factory. In addition, the factory determination of the temperature compensation parameters sets limits for time and cost reasons, so that only the temperature characteristics of the sensor units of the reference group are always considered here, but the individual temperature characteristics of each sensor unit are not considered. Although the factory-side and individual calibration of each sensor system on the corresponding test bench can be achieved technically at present. However, based on the high cost, such a time-intensive step will lead to this high cost after the manufacture of the corresponding sensor system is completed, this is not an economical solution. Therefore, at present, the sensor system is calibrated only based on the results of the corresponding reference measurement sequence, which is implemented on the representative sensor system of the reference group, in the following way: the parameters obtained for the reference group are only passed to the sensor system to be calibrated. However, individual factors that may affect the measurement characteristics of the sensor system are not considered.

[0021] The method for determining temperature compensation parameters for the measured values ​​of the sensor system can be implemented by the user at an individually determined time, or automatically according to a predetermined schedule (Zeitplan) stored in the signal processing unit. For example, the method can be implemented when the sensor system is installed for the first time at the target position of the system. Alternatively, the method can also be repeatedly implemented according to a predetermined schedule throughout the service life of the sensor system. Alternatively, the method can also be implemented after a predetermined condition occurs. For example, the calibration of the sensor system can be implemented with the help of a method for determining temperature compensation parameters after exceeding an upper temperature limit or falling below a lower temperature limit. In addition to the temperature limits, other parameters with corresponding limit values ​​can also be considered, which reach or exceed the automatic implementation of the triggering method. Alternatively, the method can be implemented in each startup process of the sensor system, in which the sensor system starts from a static state to an operating state.

[0022] For this purpose, the measuring situation of the sensor unit is monitored and a check is performed to determine whether the current measuring situation of the sensor unit corresponds to a reference measuring situation of the sensor unit.

[0023] The measurement situation of a sensor unit describes the state that the sensor unit is in. In the case of an inertial sensor, the measurement situation may include, for example, whether the sensor unit is at rest or experiencing an acceleration. In the case of other types of sensor units, the corresponding measurement situation may vary accordingly.

[0024] A reference measurement situation of a sensor unit describes a reference state of sensor units of the same type, wherein for the reference state or reference measurement situation a measured value of a sensor measurement variable for sensor units of the same type is known as a reference value.

[0025] Furthermore, the temperature of the sensor unit is monitored and it is determined whether the temperature of the sensor unit is within a predetermined temperature range, i.e., in particular, within the temperature range for which the determination of the temperature compensation parameter is to be carried out. The predetermined temperature range may depend on the type of the respective sensor unit and on the respective intended use of the sensor unit.

[0026] If the measurement situation of the sensor unit corresponds to the reference measurement situation and the temperature of the sensor unit is within a predetermined temperature range, the temperature sensor unit detects the temperature value and the sensor unit detects the associated measured value. If the sensor unit is in the reference measurement situation, i.e. at a different temperature, this temperature and measured value detection must be performed at least twice so that at least two measured values ​​of the sensor unit are in the reference measurement situation but at different temperatures.

[0027] At least one temperature compensation parameter is determined based on at least two detected temperature values, at least two detected measured values ​​of the sensor measurement variable and at least one reference value of the sensor measurement variable for a reference measurement case.

[0028] The temperature compensation parameter may be, for example, a parameter of a model or a mathematical function, by means of which the temperature curve of the sensor measurement variable can be described. For example, the temperature compensation parameter may be the slope or intercept of a linear function, by means of which the linear temperature curve of the sensor measurement variable can be described. Alternatively, the temperature compensation parameter may be a coefficient of a polynomial function, by means of which the nonlinear temperature curve of the sensor measurement variable can be described. Alternatively, the temperature compensation parameter may be a parameter or coefficient of a more complex model, by means of which the temperature curve of the sensor measurement variable can be described. Therefore, the method according to the invention for determining the temperature compensation parameter enables individual adaptation of the model for the temperature curve of the sensor measurement variable to the corresponding sensor unit.

[0029] Based on this individualized model, a temperature compensation of the measured values ​​of the sensor unit recorded during operation of the sensor system can be carried out in the following, i.e. in the entire predetermined temperature range and for any measured values. This temperature compensation is based on the assumption that the sensor unit has the same temperature behavior in any arbitrary measurement case as in the reference measurement case.

[0030] A sensor measurement variable is a physical variable which can be detected by means of a corresponding sensor unit of a sensor system. This can be, for example, a rotational speed, an acceleration or a pressure. Alternatively, the measurement variable can also include another physical variable.

[0031] In the following, a reference value is a comparison value for a measured value of a sensor measurement variable of a sensor unit of a sensor system. The reference value serves as a comparison value for determining a temperature compensation parameter and indicates an expected value of the corresponding measurement variable, which is expected for the corresponding sensor unit and the corresponding temperature value in the case of an optimized calibration of the sensor unit. One or more reference values ​​can be ascertained with the aid of previously carried out comparative measurements of comparable sensor units or identical sensor units and stored in a signal processing unit or in a signal processing unit external to the sensor system. The reference value can be a numerical value of a measured value of a sensor measurement variable.

[0032] According to a further embodiment, the measurement situation is monitored by means of at least one further sensor component and / or using a circuit arrangement which is a component of the sensor system or of a device with which the sensor system is installed.

[0033] This achieves the technical advantage that a precise determination of the measurement situation is possible.

[0034] According to a further specific embodiment, the difference between at least two different temperature values ​​is greater than a predefined threshold value.

[0035] This achieves the technical advantage that a precise determination of the temperature compensation parameter is achieved. The threshold value ensures a clear separation of the temperature value from the associated measured value of the sensor unit.

[0036] According to another embodiment, at least one temperature compensation parameter is determined as a model parameter of a model for describing the temperature influence on the sensor measurement variable, so that based on the model, for any temperature value, a temperature compensation variable for the measurement value detected at this temperature value can be determined. The temperature compensation variable is usually a correction factor for the measurement value or a correction value added to the measurement value.

[0037] This achieves the technical advantage that, based on the model, a temperature compensation variable can be determined for any temperature within the temperature range covered by the model without having to record a reference measured value of the sensor measurement variable for this temperature.

[0038] According to another embodiment, at least one temperature compensation parameter is determined as a coefficient and / or a constant of a function that describes the functional relationship between temperature and a sensor measurement variable under reference measurement conditions within a predetermined temperature range, so that based on this function, a temperature compensation parameter for a measurement value detected at this temperature value can be determined for any temperature value.

[0039] This achieves the technical advantage that, based on the function, a temperature compensation variable can be determined for any temperature in the temperature range covered by the function, without having to record a reference measured value of the sensor measurement variable for the temperature.

[0040] According to another embodiment, the signal processing unit and / or at least one other component of the sensor system is purposefully controlled in order to heat and / or cool the sensor unit to at least one first temperature value and / or at least one second temperature value within a predetermined temperature range and to detect the corresponding measured value of the sensor measurement variable.

[0041] In this way, the sensor unit can be actively brought to two different suitable temperature values ​​within a predetermined temperature range, wherein the measured values ​​of the sensor unit are then also detected in each case in order to subsequently determine at least one temperature compensation parameter according to the invention. This can accelerate the determination of the temperature compensation parameter.

[0042] According to a further embodiment, the method is carried out during installation and / or during a startup phase of the sensor system and / or repeatedly, at regular time intervals and / or automatically, event-controlled and / or user-initiated.

[0043] The technical advantage of a high measurement accuracy of the sensor system is thereby achieved. Depending on the requirements for the measurement accuracy of the sensor system, the sensor system can be calibrated as often as desired during the operation of the sensor system. For relatively low requirements for the measurement accuracy of the sensor system, the sensor system can be calibrated once when the sensor system is installed. For relatively high requirements for the measurement accuracy of the sensor system, the sensor system can be calibrated at any variable time intervals. In the case of high requirements for the measurement accuracy, the calibration can alternatively be carried out during each startup phase of the sensor system, in which the sensor system is started from a stationary state into an operating state.

[0044] According to a further specific embodiment, temperature-defined deviations of the sensor measurement variable and / or temperature dependencies of the response behavior of the sensor unit are compensated based on at least one temperature compensation parameter.

[0045] This achieves the technical advantage of a broad range of applications for the method.

[0046] In the following, the deviation is the initial value that the sensor unit displays if it is in an inactive state in which it is not subject to external excitation and therefore must display the value zero. The sensitivity or response characteristic of a sensor unit is hereinafter the measurement accuracy for measured values ​​not equal to zero, which is determined by the deviation of the sensor unit for a predetermined external excitation. Both the deviation and the sensitivity of the sensor unit can be temperature-defined.

[0047] By controlling the different system components of the sensor system, these system components generate heat corresponding to the operation by the operation corresponding to the control. In the following, the sensor unit and in particular the sensor system are heated corresponding to the heat by thermal contact. By the controlled operation of the individual system components, the sensor system can thus reach a desired temperature value. For example, the signal processing unit can be controlled to perform a computing operation so that the sensor unit reaches a temperature value based on the implementation of the corresponding operation. Alternatively, an external signal processing unit can also be controlled in order to implement the corresponding operation. It is also possible, for example, to operate a display of the overall system, which includes the sensor system, so that the heat generated by the operation of the display causes the sensor system and in particular the sensor unit of the sensor system to heat up.

[0048] According to one specific embodiment, the determination of the temperature compensation parameter can also be carried out based on a predetermined temperature compensation parameter, wherein the temperature compensation parameter is an adaptation of the predetermined temperature compensation parameter.

[0049] This achieves the technical advantage that a predetermined value can already be taken into account for determining the temperature compensation variable, so that the determined temperature compensation variable is achieved by modifying the predetermined temperature compensation parameter.

[0050] The predetermined temperature compensation parameter may be a temperature compensation parameter that is determined at the factory for the same type of sensor system, for example, with a reference measurement sequence and used as a non-individualized parameter for temperature compensation or calibration of the sensor system. Alternatively, the predetermined temperature compensation parameter may be a temperature compensation parameter that has been determined at an earlier time according to the method according to the invention. In the case where the temperature compensation parameter is a non-individualized parameter determined at the factory, the method according to the invention may be used to individualize and match the predetermined temperature compensation parameter to the corresponding sensor system. In the case where the temperature compensation parameter is a temperature compensation parameter determined at an earlier time using the method according to the invention, it may be possible to match the temperature compensation parameter determined at an earlier time to the state of the corresponding sensor system at the time when the method is repeatedly implemented by re-implementing the method according to the invention at a later time.

[0051] This allows a systematic temperature compensation and calibration that is precisely and individually coordinated to the respective sensor system to be achieved, wherein the state of the respective sensor system that it has at the time of carrying out the method can be taken into account.

[0052] According to one embodiment, the reference value and / or the temperature compensation parameter are stored in the signal processing unit and / or in an external storage unit.

[0053] This achieves the technical advantage that the determination of the temperature compensation parameter can be reproducible. To determine the temperature compensation parameter, not only reference values ​​can be used which have already been created at the factory for the purpose of concluding the manufacturing method of the sensor system with the aid of a corresponding measurement sequence. Alternatively, reference values ​​can also be used which have already been created during the operation of the sensor system with the aid of a corresponding measurement sequence. Older reference values ​​can be replaced by newer reference values.

[0054] The temperature compensation parameters determined according to the invention are likewise storable. This allows a comparison of the temperature compensation parameters determined at different times. If the test result is such that the temperature compensation parameters determined until the test correspond to the temperature compensation parameters determined at an earlier time, this in turn allows the method to be terminated prematurely. This can thus avoid the need to recalibrate the sensor system if the sensor system has already been calibrated based on an earlier calibration.

[0055] According to a second aspect of the present invention, there is provided a sensor system, which at least comprises:

[0056] A sensor unit for detecting a measured value of a sensor measurement variable;

[0057] a temperature sensor unit for detecting a temperature value of the sensor system; and

[0058] A signal processing unit configured to:

[0059] monitoring a measurement situation of the sensor unit and determining whether the current measurement situation corresponds to a reference measurement situation for which at least one reference measurement value of the sensor measurement variable is known;

[0060] The temperature of the sensor unit is monitored and it is determined whether the current temperature is within a predetermined temperature range; the sensor unit and the temperature sensor unit are controlled so that if the current measurement situation corresponds to the reference measurement situation, at least two different temperature values ​​within the predetermined temperature range are detected together with the corresponding measurement values ​​of the sensor measurement variable; at least one temperature compensation parameter is determined based on at least one reference measurement value of the sensor measurement variable, at least two different temperature values ​​and the measurement values ​​of the sensor measurement variable.

[0061] The following technical advantages are thereby achieved, and a sensor system is provided: it is possible to automatically determine at least one temperature compensation parameter, on which the compensation of the temperature influence on the measured values ​​of the sensor unit of the sensor system is based. The determination of one or more temperature compensation parameters can be carried out during the operation of the sensor system, if the sensor system is already installed at its target location. It is thus possible to carry out temperature compensation based on temperature compensation parameters determined for different temperature values ​​within a predetermined temperature range and for different measurement situations during the entire life of the sensor system. It is thus possible to achieve an increase in the measurement accuracy of the MEMS sensor system. In addition, it is possible to achieve an individual temperature compensation of the measured values ​​of the sensor unit of the sensor system that is better coordinated with the corresponding sensor system and its application, in that if the sensor system is already installed at its application location, the temperature compensation parameters are determined individually for the sensor unit or the sensor system.

[0062] According to one specific embodiment, the sensor system comprises at least one further sensor component and / or circuit arrangement for monitoring the measurement situation of the sensor unit.

[0063] This achieves the technical advantage that the measurement situation can be determined precisely.

[0064] According to one embodiment, the sensor system comprises at least one data memory for at least two different detected temperature values ​​and the associated corresponding measured value of the sensor measurement variable and / or for at least one temperature compensation parameter and / or for a predefined threshold value ΔT for the difference between at least two different temperature values.

[0065] This achieves the technical advantage that the determined variables and parameters can be stored.

[0066] According to one specific embodiment, the sensor system comprises at least one further component which is controllable by the signal processing unit for selectively influencing the temperature of the sensor unit.

[0067] This achieves the technical advantage that the sensor system can actively be brought to different temperatures in order to determine at least one temperature compensation parameter.

[0068] According to one specific embodiment, the signal processing unit is designed to correct a measured value of the sensor measurement variable detected during a measuring operation of the sensor system using a corresponding temperature compensation variable and to output a temperature-corrected measured value of the sensor measurement variable.

[0069] This achieves the technical advantage that a sensor system with increased measurement accuracy is provided. After successful determination of the temperature compensation parameters and the associated calibration of the sensor system, the sensor system can output temperature-corrected measured values ​​of the sensor measurement variable during measurement operation.

[0070] According to one embodiment, the sensor unit is a MEMS rotational speed sensor unit, a MEMS acceleration sensor unit, a magnetic sensor unit or a MEMS pressure sensor unit.

[0071] This makes it possible to achieve the technical advantage that the sensor system has a wide range of applications.

[0072] According to one specific embodiment, the reference value is stored in the signal processing unit or in an external storage unit or can be ascertained with the aid of another reference sensor unit.

[0073] The following technical advantages are achieved in this way: For determining the temperature compensation parameter, a reference value determined at the factory can be used, which is generated after the manufacturing process has been completed with the aid of a corresponding measurement sequence. Alternatively, a reference value generated during the operation of the sensor system can also be used. Furthermore, a corresponding measurement sequence can be implemented by the sensor system. Alternatively, a corresponding measurement sequence can be implemented by an additional reference sensor unit. The reference sensor unit can be a system component of the sensor system or be designed as an external sensor unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] Embodiments of the present invention are shown in the drawings and further explained in the following description.

[0075] Figure 1 : Flowchart of a method for determining at least one temperature compensation parameter for compensating for temperature influences on measured values ​​of a sensor system according to one embodiment;

[0076] Figure 2 : Two possibilities for describing the temperature dependency of the sensor measurement variable of the sensor unit in a reference measurement situation by means of a functional relationship between the sensor measurement variable and the temperature;

[0077] Figure 3 : The advantages of the sensor unit according to the invention in that the temperature compensation parameters for a selected temperature range are determined individually in comparison with conventional methods for describing the relationship between temperature and sensitivity of individual sensor units;

[0078] Figure 4 : Flow chart of a first variant of the method according to the invention for determining temperature compensation parameters for the sensor unit 803 without active temperature regulation;

[0079] Figure 5 : Flow chart of a second variant of the method according to the invention for determining temperature compensation parameters for the sensor unit 803 with active temperature control;

[0080] Figure 6: A schematic diagram of a sensor system according to an embodiment of the present invention;

[0081] Figure 7 :exist Figure 6 Schematic diagram of internal heat generation of the sensor system in FIG.

[0082] Figure 8 :exist Figure 6 Schematic diagram of external heat generation of the sensor system in FIG.

[0083] Fig. 9 : Schematic flow chart of the use of different sets of temperature compensation parameters for the sensor unit 803 depending on the required measurement accuracy or quality of the measurement data.

[0084] The same reference numerals may be used hereinafter for the same features. DETAILED DESCRIPTION

[0085] Figure 1 A flow chart of a method 100 for determining at least one temperature compensation parameter for compensating for temperature influences on a measured value XV of a sensor system 800 according to an embodiment of the present invention is shown. Figures 7 to 9 The method 100 describes the structure of a sensor system 800. The sensor system 800 comprises a sensor unit 803 for detecting a measured value XV of a sensor measurement variable X, a temperature sensor unit 805 for monitoring the temperature of the sensor unit 803 and for detecting a corresponding temperature value TV, and a signal processing unit 807 for determining a temperature compensation parameter TC.

[0086] According to Figure 1 According to the method 100 of the invention shown in , the measurement situation of the sensor unit 803 is continuously monitored in order to determine whether the current measurement situation corresponds to the following reference measurement situation: for which at least one reference measurement value of the sensor measurement variable X is known. In parallel, the temperature TV of the sensor unit 803 is continuously monitored. The monitoring of the measurement situation and the monitoring of the temperature of the sensor unit are realized in method step 101.

[0087] If the sensor unit 803 is in the reference measurement situation, then in method step 103 a check is performed to determine whether the current temperature of the sensor unit 803 is within the predetermined temperature range TR2 and whether the current temperature of the sensor unit 803 is relevant for redetermining or updating the temperature compensation parameters. If this is the case, then in method step 105 the currently measured temperature value TV of the sensor unit 803 and the associated measured value XV are detected.

[0088] Method steps 101 to 105 are run through until at least two measured values ​​XV1 and XV2 are detected for different temperature values ​​TV1, TV2 for a reference measurement case. Only in that case, at least one temperature compensation parameter TC, i.e. a reference measured value based on the sensor measurement variable X, is determined in method step 107 from the measured values ​​XV1, XV2 and the associated temperature values ​​TV1, TV2.

[0089] The measurement situation of the sensor unit 803 is determined in the context of the present invention by a measurement variable. In this way, the measurement situation is described by a variable of the acceleration acting on the sensor unit in the case of an acceleration sensor, and by a variable of the rotational speed acting on the sensor unit in the case of a rotational speed sensor. As a reference measurement situation, the following measurement situation is represented here: the measurement variable to be detected for this measurement situation is known. In the case of an inertial sensor, a stationary situation is provided as a reference measurement situation, because no force acts on the sensor unit except the earth's gravity. In the case of a rotational speed sensor, the reference measurement value is then equal to zero in the stationary situation. Another reference measurement situation can also be selected within the scope of the present invention, as long as the corresponding reference measurement value for this reference measurement situation is known. Such a reference measurement value can be obtained, for example, within the scope of a factory-side calibration method.

[0090] As described above, in step 103 it is determined whether the temperature of the sensor unit 803 is within the predetermined temperature range TR2 and whether the current temperature of the sensor unit 803 is relevant for redetermining or updating the temperature compensation parameters.

[0091] The predetermined temperature range TR2 can simply be the entire temperature range for which the sensor unit 803 is designed at the factory. Depending on the type of intended application of the sensor unit 803, it can also be advantageous to determine the temperature compensation parameters only for a partial range of the temperature range if the sensor unit is preferably operated in a sub-range of the temperature range. The determination of the temperature compensation parameters is based on at least two measurements / measurement values ​​XV1 and XV2 of the sensor unit at different temperatures TV1 and TV2 in the case of a reference measurement. In order to ensure that the temperature compensation parameters describe the temperature curve of the sensor unit as realistically as possible, these temperatures TV1 and TV2 should be significantly different. Advantageously, the difference between TV1 and TV2 is used as a criterion for selecting the measurements XV1 and XV2.

[0092] The method according to the invention is based on the assumption that the temperature influence on the measured value of the sensor unit can be described by a model in a predetermined temperature range. The temperature compensation parameters determined according to the invention are model parameters for the model. With the help of the method according to the invention, individual model parameters can be determined for the sensor unit in the continuous operation of the sensor unit, and the temperature influence on the measured value of the individual sensor unit can be described by means of the individual model parameters. In addition, the invention is based on the assumption that the sensor unit has essentially the same temperature characteristics throughout the entire measuring range, that is, for all measuring situations. It is therefore considered sufficient to determine the individual temperature compensation parameters of the sensor unit for a reference measuring situation. Based on such an individualized model, a temperature compensation variable for compensating for the temperature influence on the measured value can be determined for each measured value of the sensor unit and each temperature in a predetermined temperature range.

[0093] For example, the temperature compensation parameter may be a parameter of a mathematical function, with the aid of which one or more parameters the temperature curve of the sensor measurement variable X can be described. For example, the temperature parameter may be a slope or an intercept of a straight line equation, with the aid of which a linear temperature curve of the sensor measurement variable can be described. Alternatively, the temperature compensation parameter TC may be a coefficient of a polynomial equation, with the aid of which a nonlinear temperature curve of the sensor measurement variable can be described. Alternatively, the temperature compensation parameter TC may be a parameter or coefficient of a more complex model, with the aid of which the temperature curve of the sensor measurement variable X can be described.

[0094] Insofar as the temperature compensation parameter TC is determined as a model parameter or a function parameter of a mathematical function which describes the temperature influence on the sensor measurement variable X, the temperature compensation parameter TC is varied as a variable parameter of the model or the mathematical function in such a way that the temperature curve of the recorded measured values ​​XV of the sensor measurement variable X is described as well as possible by the model or the mathematical function. Thus, for example, under the assumption of a linear curve of the temperature behavior, the slope and the deviation of the linear function can be determined as temperature compensation parameters from at least two measured values ​​XV1 and XV2 in the case of TV1 and TV2.

[0095] With the aid of a corresponding model or a corresponding mathematical function, a temperature compensation of the measured values ​​of the sensor unit recorded during operation of the sensor unit 803 can be implemented below. Based on the model or the mathematical function, which each covers the entire predetermined temperature range, a flawless temperature compensation can be achieved for any temperatures and measured values ​​within the predetermined temperature range, without having to determine corresponding measured values ​​XV of the sensor measurement variable X and temperature compensation parameters TC for these temperatures according to the method according to the invention.

[0096] According to the invention, a temperature compensation parameter ascertained for a reference measurement situation and a model based thereon or a mathematical function associated therewith are used to describe the temperature profile of the sensor measurement variable for any measurement situation of the sensor system.

[0097] Figure 2 A schematic diagram showing determination of a temperature compensation parameter TC according to method 100 is shown.

[0098] The simplified diagram a) shows the temperature profile of a sensor measurement variable X of a sensor unit 803 of a sensor system 800, i.e. a plurality of measured values ​​XV recorded at different temperatures TV of the sensor unit 803. The measured values ​​XV were each acquired in a reference measurement situation of the sensor unit 803, which is characterized by a reference measured value RV. The measured values ​​XV of the sensor measurement variable show a pronounced temperature behavior and describe a non-constant temperature profile.

[0099] In the diagram b), two functions y1 and y2 are shown, which are proposed for describing the detected temperature curve of the sensor measurement variable X:

[0100] Y1=ax+b describes the linear curve of the sensor measurement parameter X and temperature, where "a" describes the slope and "b" describes the intercept.

[0101] Y2=ax2+bx+c describes the quadratic curve of the sensor measurement variable X and temperature. "a, b, c" here describe the polynomial coefficients.

[0102] These function parameters a, b and c can be determined as temperature compensation parameters by means of the method according to the invention. Depending on the choice of the function for describing the temperature curve of the sensor measurement variable X over temperature, at least two measured values ​​XV1 and XV2 at temperatures TV1 and TV2 are required for a linear relationship between the sensor measurement variable and temperature, or at least three measured values ​​MV1 to MV3 at temperatures TV1 to TV3 are required for a quadratic relationship between the sensor measurement variable and temperature.

[0103] exist Figure 2 The linear and quadratic models shown in are merely examples for a mathematical description of the temperature curve of a sensor measurement variable X. Figure 3 Show according to Figure 1 Schematic diagram of the model development in Method 100d.

[0104] In the diagrams a) and b), the sensitivity ascertained by measurement or the response characteristic of the individual sensor unit 803 is respectively plotted over the temperature T, ie in the form of a solid line.

[0105] In the simplified diagram a), a first overall linear model (dashed line) for describing the temperature curve of the sensitivity of the sensor unit 803 is also shown, which is created based on a comparative measurement sequence of comparable sensor units of a reference group. This model only describes the actual temperature curve of the sensitivity of the sensor unit 803 very inadequately. In the simplified diagram a), another linear model (dotted line) for describing the temperature curve of the sensitivity of the sensor unit 803 is also shown, which is determined individually for the sensor unit 803, that is, for the entire temperature range of the simplified diagram a). Accordingly, although the individual linear model is generally better than the overall linear model, in the preferred middle temperature range - which is the part surrounded by a circle here - the individual linear model is also significantly different from the actual temperature curve of the sensitivity of the sensor unit 803.

[0106] In the simplified diagram b), the linear model of the individual from the simplified diagram a) and the linear model optimized according to the invention for the temperature range TR1 are shown for the same temperature curve (individual) of the sensitivity of the sensor unit 803. For the optimized linear model, the temperature compensation parameters of the model are adapted to the individual characteristics of the sensor unit in a certain measurement situation by the method 100. For this purpose, according to the method 100, the measured values ​​XV of the sensor measurement variable X are respectively detected in the reference measurement situation for a plurality of temperatures within the temperature range TR1 and the temperature compensation parameters TC are determined based on this, which describe the optimized straight line. In this way, for example, the slope of the straight line and / or the intercept of the linear model can be determined by means of the method according to the invention. The optimization range TR1 is selected because the sensor unit 803 is preferably operated in this temperature range. The simplified diagram b) illustrates that the linear model obtained in this way is optimized only for the temperature range TR1, so it describes the temperature curve of the sensitivity of the sensor unit 803 in this temperature range very well, which does not necessarily apply outside the temperature range TR1.

[0107] Figure 4 The flow chart of a first variant of the method according to the invention for determining temperature compensation parameters for sensor unit 803 without active temperature control is shown. That is, the method 100 according to the invention is run in a passive mode, wherein the temperature value TV for which the measured value XV of the sensor measurement variable X is to be detected is not actively controlled. Instead, the temperature value TV of sensor unit 803 corresponds to the temperature prevailing at the location of sensor unit 803 within sensor system 800. As soon as this temperature assumes the temperature value TV for which the measured value XV of the sensor measurement variable X is to be detected, sensor unit 803 detects the measured value XV of the sensor measurement variable X, which is as follows according to Figure 4 Further clarification.

[0108] After the method according to the invention is started in step 401, the measurement situation of the sensor unit 803 is continuously monitored in order to determine whether the current measurement situation corresponds to a reference measurement situation for which at least one reference measurement value of the sensor measurement variable X is known. Figure 1 Detailed explanation. In parallel, the temperature TV of the sensor unit 803 is continuously monitored. The monitoring of the measurement situation and the monitoring of the temperature of the sensor unit are implemented in method step 402. If the sensor unit 803 is in the reference measurement situation, then in method step 403, it is checked whether the current temperature of the sensor unit 803 is within the predetermined temperature range TR2 and whether the current temperature of the sensor unit 803 is relevant for the redetermination or updating of the temperature compensation parameters. Here, for example, already detected measured value pairs (XV, TV) can also be taken into account in order to ensure a certain distribution of the detected measured value pairs over the predetermined temperature range. If the current temperature of the sensor unit meets all the criteria for the measurement value detection, then in method step 404, the currently measured temperature value TV and the associated measurement value XV of the sensor unit 803 are detected. Method steps 401 to 404 are traversed until at least two measurement values ​​XV1 and XV2 for different temperature values ​​TV1, TV2 are detected for the reference measurement situation. This is ensured by branching back to method step 402 from method steps 403 and 404. Only in that case is at least one temperature compensation parameter TC determined in a further method step (not shown here) from the measured values ​​XV1 , XV2 detected in the reference measurement and the associated temperature values ​​TV1 , TV2 .

[0109] Figure 5 A flow chart of a second variant of the method according to the invention for determining temperature compensation parameters for sensor unit 803 with active temperature control is shown. That is, in this method variant, a temperature value TV is actively introduced for which measured value XV is to be detected by actively heating or cooling sensor unit 803.

[0110] exist Figure 5 For combination Figure 4 Already explained method steps are given the same reference numerals. The following explanation is limited to the same Figure 4 The differences in the method variants are shown.

[0111] If the result of the check in method step 403 is that the current temperature of the sensor unit does not meet all criteria for measuring the measured value, then in a further check step 405 it is checked whether another measuring value measurement is required at all. If not, the temperature of the sensor unit 803 is monitored further by the method jumping back to method step 402. However, if another measuring value measurement is to be carried out, then in method step 406 the temperature of the sensor unit 803 is actively influenced until the sensor unit 803 has reached a suitable temperature. For this purpose, for example, a heating device of the sensor system 800 can be activated.

[0112] If sensor unit 803 has reached a temperature suitable for measuring the value, then in method step 404 the sensor measured value XV and the associated temperature value are measured.

[0113] Figure 6 A schematic diagram of a sensor system 800 is shown according to one embodiment.

[0114] according to Figure 6 The sensor system 800 includes: a carrier 801 for accommodating components of the sensor system 800; a sensor unit 803 for detecting a measured value XV of a sensor measurement variable X; a temperature sensor unit 805 for monitoring the temperature of the sensor unit 803 and for detecting a temperature value TV of the sensor unit 803; and a signal processing unit 807, which is configured to monitor a measurement condition of the sensor unit 803 and determine whether a current measurement condition corresponds to a reference measurement condition for which at least one reference measurement value of the sensor measurement variable X is known; monitor the temperature TV of the sensor unit 803 and determine whether the current temperature is within a predetermined temperature range TR2; and control the sensor unit 803 and the temperature sensor unit 805 so that if the current measurement condition corresponds to the reference measurement condition, at least two different temperature values ​​TV1, TV2 are detected within the predetermined temperature range TR2 together with the corresponding measured values ​​XV1, XV2 of the sensor measurement variable X. Signal processing unit 807 is furthermore designed to determine at least one temperature compensation parameter TC based on at least one reference measured value of sensor measurement variable X, at least two different temperature values ​​TV1 , TV2 and associated measured values ​​XV1 , XV2 of sensor measurement variable X.

[0115] exist Figure 6 In the embodiment, the sensor unit 803, the temperature sensor unit 805 and the signal processing unit 807 are arranged on the carrier 801 in a stacked manner. Alternatively, the sensor unit 803, the temperature sensor unit 805 and the signal processing unit 807 can be arranged in parallel with each other. In addition, the sensor system 800 can also include additional components, and / or the sensor units can be arranged in a manner different from that in the embodiment. Figure 7 The other sequences shown in FIG. 8 can be stacked on top of each other as long as there is a thermal coupling between the sensor unit 803 and the temperature sensor 805 . The carrier 801 can be a substrate. Alternatively, the carrier 801 can also be formed as a housing part of a housing of the sensor system 800 .

[0116] The sensor unit 803 may be a rotational speed sensor unit, an acceleration sensor unit, a pressure sensor unit, a magnetic sensor unit or a comparable sensor unit. The sensor measurement variable X may be rotational speed, acceleration, pressure, magnetic field strength or another physical variable detectable by means of the sensor unit 803 .

[0117] Different from Figure 6 As shown in FIG, sensor system 800 may also have further components, for example analog components and possibly non-programmable digital components. Figure 6 The components shown in FIG. 1 may be arranged in different arrangements.

[0118] Figure 7 Shown in Figure 6 Schematic diagram of internal heat generation of the sensor system 800. Figure 7 Heat generated by the operation of signal processing unit 807 is conducted from signal processing unit 807 to temperature sensor unit 805 and sensor unit 803 by means of a thermal connection between signal processing unit 807, temperature sensor unit 805 and sensor unit 803. The heat generated by the operation of signal processing unit 807 and the conduction of heat to temperature sensor unit 805 and sensor unit 803 can also be used to heat MEMS sensor system 800 according to control step 111 of method 100 to a temperature value for which a measured value XV of sensor measurement variable X is to be detected.

[0119] Figure 8 Show Figure 6 Schematic diagram of external heat generation of the sensor system 800 in FIG. The operation of the system component 809 is controlled by the control command given to the system component 809 of the sensor system 800 by the signal processing unit 807. The heat generated by the operation of the system component 809 is transmitted to the sensor unit 803 and the temperature sensor unit 805 by means of a thermal connection. This causes the temperature sensor unit 805 and the sensor unit 803 to heat up. As a result, the sensor system 800 can be heated to a temperature value TV according to the control step 111, for which the measured value XV should be detected. The system component 809 can, for example, include a display, which has the following heat generation during operation: it is suitable for heating the sensor system 800 to the corresponding temperature value TV. However, the system component 809 can also include other components, which are suitable for achieving heating of the sensor system 800 by corresponding control.

[0120] Fig. 9 A schematic flow chart showing the determination of a temperature compensation parameter TC according to a method 100 for a sensor system 800 according to different modes.

[0121] At point 1101, the sensor system 800 with the sensor unit 803 is switched on in the start phase. At selection point 1103, the user can select whether the sensor unit 803 should be operated with high measurement accuracy or normal measurement accuracy. If normal measurement accuracy is selected, then at selection point 1105, a check is made as follows: which temperature compensation parameters are available, i.e., only temperature compensation parameters for factory calibration are available, or already individualized temperature compensation parameters that have been determined according to the method of the present invention are available. If only temperature compensation parameters calibrated at the factory are available, then these temperature compensation parameters are used in step 1107 to compensate for the temperature influence on the sensor measurement value until the sensor unit 803 is closed or turned off again in step 1119. Otherwise, the individualized temperature compensation parameters are used in step 1109 until the sensor unit is deactivated in step 1119. In any case, if the sensor unit 803 should be operated with normal data quality, i.e., normal measurement accuracy, then the already existing temperature compensation parameters are used. In this case, the method according to the present invention for determining individualized temperature compensation parameters is not started.

[0122] If a high measurement accuracy is selected at selection point 1103, then at selection point 1111, a check is also performed as follows: whether only factory-calibrated temperature compensation parameters are available, or whether the already individualized temperature compensation parameters obtained using the method according to the present invention are available. If there are already individualized temperature compensation parameters, then in step 1117, the temperature influence on the sensor measurement value is compensated based on the individualized temperature compensation parameters. If the individualized temperature compensation parameters are not yet available, then in step 1113, the method for determining such individualized temperature compensation parameters according to the present invention is started and the method is implemented in the continuous operation of the sensor unit 803 until the individualized temperature compensation parameters are determined. Subsequently, in step 1115, temperature compensation is implemented based on the individualized temperature compensation parameters, so as to achieve the required high measurement accuracy or data quality. Different from the above-mentioned mode with normal data quality, if there are no such individualized temperature compensation parameters, then the method for determining the individualized temperature compensation parameters is automatically started here.

Claims

1. A method (100) for determining at least one temperature compensation parameter for compensating for temperature influences on measured values ​​of a sensor system (800), wherein: The sensor system (800) comprises at least: a. a sensor unit (803), the sensor unit being used to detect a measured value of a sensor measurement parameter (X); b. a temperature sensor unit (805), wherein the temperature sensor unit is used to detect the temperature of the sensor unit (803); c. a signal processing unit (807) for determining at least one temperature compensation parameter and for compensating for temperature influences on the measured values ​​of the sensor unit (803); Wherein, the method comprises: o monitoring (101) the measurement situation of the sensor unit (803) and determining whether the current measurement situation corresponds to a reference measurement situation for which at least one reference measurement value of the sensor measurement variable (X) is known; o monitoring (103) the temperature of the sensor unit (803) and determining whether the current temperature is within a predetermined temperature range (TR2); o detecting (105) at least two different temperature values ​​within the predetermined temperature range (TR2) and, if the current measurement situation corresponds to a reference measurement situation, detecting the associated corresponding measured value of the sensor measurement variable (X); o determining (107) at least one temperature compensation parameter (TC) based on at least one reference measured value of the sensor measurement variable (X), the at least two different temperature values ​​and the associated measured value of the sensor measurement variable (X).

2. The method according to claim 1, wherein: The measurement situation is monitored by means of at least one further sensor component and / or by means of a circuit arrangement which is part of the sensor system or of a device installed together with the sensor system.

3. The method according to claim 1 or 2, wherein: The difference between the at least two different temperature values ​​is greater than a predefined threshold value ΔT.

4. The method according to claim 1 or 2, wherein: The at least one temperature compensation parameter (TC) is determined as a model parameter of a model for describing the temperature influence on the sensor measurement variable (X), so that based on the model a temperature compensation variable for a measurement value acquired at this temperature value can be determined for any temperature value.

5. The method according to claim 1 or 2, wherein: The at least one temperature compensation parameter (TC) is determined as a coefficient and / or a constant of a function that describes the functional relationship between temperature and the sensor measurement variable (X) in a reference measurement within the predetermined temperature range (TR2), so that based on the function a temperature compensation variable for a measured value detected at the temperature value can be determined for any temperature value.

6. The method (100) according to claim 1 or 2, wherein: The signal processing unit and / or at least one other component of the sensor system is controlled in a targeted manner so as to heat and / or cool the sensor unit (803) to at least one first temperature value and / or at least one second temperature value within the predetermined temperature range (TR2) and to detect the corresponding measured value of the sensor measurement variable (X).

7. The method (100) according to claim 1 or 2, wherein: The method is carried out during installation and / or in a startup phase of the sensor system (800) and / or repeatedly, at regular time intervals and / or automatically, event-controlled and / or user-initiated.

8. The method (100) according to claim 1 or 2, wherein: Based on the at least one temperature compensation parameter (TC), temperature-related deviations of the sensor measurement variable (X) are compensated and / or the temperature dependency of the response characteristic of the sensor unit (803) is compensated.

9. A sensor system (800), the sensor system comprising at least: - a sensor unit (803) for detecting a measured value of a sensor measurement variable (X); - a temperature sensor unit (805), which is used to detect a temperature value of the sensor system (800); - a signal processing unit (807), the signal processing unit being configured to: o monitoring the measurement situation of the sensor unit (803) and determining whether the current measurement situation corresponds to a reference measurement situation for which at least one reference measurement value of the sensor measurement variable (X) is known; o monitoring the temperature of the sensor unit (803) and determining whether the current temperature is within a predetermined temperature range (TR2); o controlling the sensor unit (803) and the temperature sensor unit (805) so that, if the current measurement situation corresponds to a reference measurement situation, at least two different temperature values ​​within the predetermined temperature range (TR2) are detected together with the associated corresponding measured values ​​of the sensor measurement variable (X); o At least one temperature compensation parameter (TC) is determined based on at least one reference measured value of the sensor measurement variable (X), at least two different temperature values ​​and an associated measured value of the sensor measurement variable (X).

10. The sensor system (800) according to claim 9, comprising at least one further sensor component and / or a circuit arrangement, wherein the at least one further sensor component and / or the circuit arrangement is used to monitor the measurement conditions of the sensor unit (803).

11. A sensor system (800) according to claim 9 or 10, wherein the sensor system has at least one data storage device for the at least two different temperature values ​​detected and the corresponding measured values ​​of the sensor measurement variable (X) and / or for at least one temperature compensation parameter (TC) and / or for a predetermined threshold value ΔT for the difference between the at least two different temperature values.

12. The sensor system (800) according to claim 9 or 10, comprising at least one further component which can be controlled by the signal processing unit (807) and is used to influence the temperature of the sensor unit (803) in a targeted manner.

13. The sensor system (800) according to claim 9 or 10, wherein: The signal processing unit (807) is designed to correct a measured value of the sensor measurement variable (X) detected during a measurement operation of the sensor system (800) by means of a corresponding temperature compensation variable (T) and to output a temperature-corrected measured value of the sensor measurement variable (X).

14. The sensor system (800) according to claim 9 or 10, wherein: The sensor unit (803) is a MEMS rotation speed sensor unit, a MEMS acceleration sensor unit, a magnetic sensor unit or a MEMS pressure sensor unit.

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