Rotation rate offset compensation

Abstract

Measurements of the rate of rotation (10) obtained with a rate of rotation sensor (150) on the vehicle (200) are corrected by a temperature-dependent offset (25). The offset (25) is provided by the table (20). If the vehicle (200) is stationary, the table (20) may be updated by determining the temperature (15) and determining the rate of rotation (10) from the rate of rotation sensor (150). In addition, aging of the rotation rate sensor (150) is taken into account. A corrected total error (31) in the rotation rate (30) may also be provided.

Description

Technical Field

[0001] The present invention relates to compensating for the offset of a rotational rate sensor on a vehicle. Background Art

[0002] In the automotive industry, there is an increasing trend towards vehicle autonomy, which concept includes fully autonomous vehicles and vehicles with the ability to autonomously perform some driving functions, such as emergency braking or adaptive cruise control. Whether the vehicle is fully or partially autonomous, the driving functions require not only accurate information about the vehicle's position, but also accurate information about the vehicle's motion state, which is defined by the speed of the vehicle's center of mass and the rotation of the vehicle, for example, about each of three orthogonal axes passing through the center of mass. The rotation can be determined by a rotational rate sensor, which is typically part of a larger sensor system similar to an inertial measurement unit (IMU). This is an electronic sensor (or group of sensors) that measures the acceleration, rotational rate of the vehicle, and in some cases also the orientation of the vehicle. The IMU is used, for example, in so-called advanced driver assistance systems (ADAS) or also in restraint control systems (RCS). Obviously, for these applications, the sensor output must be reliable and accurate and remain so over time.

[0003] The published German patent application DE 10 2008 041 451 A1 relates to the calibration of a measuring device in a vehicle, in particular the calibration of a rotational rate sensor. The offset for the measured rotational rate is obtained from a table in which the offset is stored depending on the temperature of the rotational rate sensor and the operating time. The statistical error of each offset is also stored. If the vehicle is stationary, the table can be updated. The updated value of the offset for a specific temperature and normal operating time is a weighted average of the current value of the offset and the newly measured rotational rate, where the weights are given by the new rotational rate and the statistical error of the stored offset, respectively. The statistical error of the stored offset can increase with the time elapsed since the last update.

[0004] U.S. Patent US 5 297 028 discloses a temperature-dependent correction of the measured rotational rate of a vehicle using an offset from a table. In the table, the offset values are stored in association with temperature values. The table can be updated when the vehicle is stationary. U.S. Patent US6 738 721 B1 describes a method according to which, first, an overall measurement of an inertial measurement system is performed in a test device in a calibration operation. The resulting compensation values are used to improve the accuracy of the system during operation.

[0005] It is known that the offset of the rotational rate of a rotational rate sensor is compensated for when cruise starts while the vehicle is still stationary or during cruise. There are problems with both known methods. During cruise, as the cruise duration increases, the offset estimation tends to become erroneous. The determination of the offset at the start of cruise does not address the effects of the offset that only occur later during cruise; in fact, it has been found that temperature is the main influencing factor here, and the temperature typically changes during cruise.

[0006] A further effect on sensor performance is the lifespan of the sensor. Additionally, it would be desirable to estimate the remaining error after offset compensation. Summary of the Invention

[0007] Accordingly, an object of the present invention is to provide a method for compensating the offset of a rotational rate sensor on a vehicle, which method solves at least some of the above problems. This object is achieved by the method according to claim 1. Claim 11 relates to a corresponding system, and claim 12 relates to a corresponding vehicle.

[0008] The method according to the present invention is for compensating the offset of a rotational rate sensor on a vehicle. According to the method, the rotational rate of the vehicle is measured using the rotational rate sensor. The measured rotational rate is corrected by subtracting the offset from the measured rotational rate, and the thus corrected rotational rate is then output.

[0009] The offset is provided from a table that correlates temperature values with offset values. The temperature for the rotational rate sensor is determined, and the offset value associated with the determined temperature from the table is used to correct the measured rotational rate.

[0010] In this way, the temperature dependence of the offset is taken into account when compensating the offset of the rotational rate sensor. Consequently, the compensation of the offset is more accurate.

[0011] It should be noted here that the measurement of the rotational rate using the rotational rate sensor can be achieved by reading a single rotational rate value from the rotational rate sensor, which is then corrected as just described. Alternatively, measuring the rotational rate using the rotational rate sensor can include reading multiple rotational rate values, averaging the multiple rotational rate values, and using the resulting average as the measured rotational rate, which is then corrected as described above. In either case, reading one or more rotational rate values can include, for example, filtering the raw sensor output through a low-pass filter. Any other known way of obtaining a rotational rate reading from the rotational rate sensor can also be suitable. The determination of the temperature of the rotational rate sensor can be achieved by any means known in the art and can include, for example, measuring the temperature of the rotational rate sensor using a temperature sensor, but can also include, for example, measuring one or more temperature values near the rotational rate sensor and inferring the temperature of the rotational rate sensor therefrom. For example, the temperature of the rotational rate sensor can be derived from one or more temperature values measured near the rotational rate sensor through a certain model; or, for the purposes of the present invention, the average of one temperature value or multiple temperature values measured near the rotational rate sensor can be used as the temperature of the rotational rate sensor. Outputting the corrected rotational rate can include providing the corrected rotational rate to other systems and / or functions of the vehicle and can also include displaying the corrected rotational rate to a user, such as a driver.

[0012] The table is updated via the following steps: Determine whether the vehicle is stationary. The reason is that when stationary, the actual rotational rate is zero. Then determine the rotational rate from the rotational rate sensor to provide an offset of the rotational rate sensor. More precisely, if it is determined that the vehicle is stationary, then determine the temperature of the rotational rate sensor and determine the rotational speed from the rotational rate sensor. Determining the temperature can be done as discussed above for the case of providing an offset for correcting the measured rotational rate. Determining the rotational rate can include reading a single rotational rate value from the rotational rate sensor or can include reading multiple rotational rate values and using the average of the multiple rotational rate values as the determined rotational rate. Reading one or more rotational rate values can include, for example, filtering the raw sensor output through a low-pass filter. Subsequently, update the table using the temperature and the associated offset. Determining the offset associated with the temperature involves the determined rotational rate.

[0013] To determine whether a vehicle is stationary, various methods can be applied. For example, signals from various sensors that are obtainable via a vehicle bus can be evaluated. These signals can include, but are not limited to, signals indicating the speed of the vehicle, the acceleration of the vehicle, the rotation of the vehicle, the position of the brake pedal, the position of the accelerator pedal, the state of the reverse gear, the locked state of the steering wheel, the on / off state of the vehicle engine. The speed, acceleration, rotation or their variations obtainable via these signals can be compared with a threshold value in order to determine that the vehicle is stationary.

[0014] In an example that is not part of the claimed invention, the determined rotation rate is used as an offset for the corresponding temperature. In another embodiment that is not part of the claimed invention, the offset for the corresponding temperature is determined by an averaging process of the previously determined rotation rate when the vehicle was stationary for the corresponding temperature and the currently determined rotation rate when the vehicle is stationary. For this purpose, the previously determined rotation rate can be stored in association with the corresponding temperature; for example, a certain number of previously determined rotation rates, such as five, ten or twenty, can be stored for the corresponding temperature. In a specific variant of this example, the averaging process of the rotation rates is a weighted average, where the weight of the rotation rate decreases as the age of the rotation rate increases. For this purpose, when updating the table, together with the temperature for the rotation rate sensor and the rotational speed determined at the time of the update, the date of the update is stored, so that the age of each rotation rate can be inferred for the purpose of weighting. As an alternative variant, instead of storing the date of the update and deriving the weight therefrom, the weight can be stored together with the rotation rate determined at the time of the update. The weight decreases over time.

[0015] In the method according to the invention, the offset for a specific temperature in the table is updated as follows. The new, updated offset value for the specific temperature is the weighted average of the previous offset in the table for that specific temperature, i.e., the offset before the update, and the currently determined rotation rate when the vehicle is stationary for that temperature. The older the previous offset in the table, i.e., the longer the time that has passed since that previous offset was calculated, the smaller the weight of that previous offset. In a variant outside the scope of the invention, the date of the most recent update is stored together with the offset. According to the invention, instead of storing the date of the most recent update, the weight of the updated offset is stored, and the weight decreases over time. At the next update, the weight of the offset in the table is directly available as a stored value and does not need to be derived from the date of the previous update.

[0016] More precisely, according to the invention, at the time of the update, the updated offset receives a predefined initial weight represented by the value of a counter. The counter is decremented at fixed time intervals. The weight of the currently determined rotation rate in the weighted average is equal to the predefined initial weight.

[0017] In an embodiment, an update of a table at a specific temperature is performed only if a predefined minimum amount of time has elapsed since the last update at that specific temperature.

[0018] By the above update of the table, the aging of the rotational rate sensor is taken into account. Thus, the offsets stored in the tables of the various embodiments can change over time as the rotational rate sensor undergoes changes over time. In this way, it is ensured that when a correction of the measured rotational rate is required, the relatively most recent offset is included in the table.

[0019] In an embodiment, determining the rotational rate when the vehicle is stationary includes reading a plurality of rotational rate values from the rotational rate sensor and calculating the average of the plurality of rotational rate values. In this embodiment, a measured value of the fluctuation of the plurality of rotational rate values is additionally calculated and stored in association with the corresponding temperature. Such a measured value of the fluctuation can be considered an estimate of the statistical error of the determined rotational rate. The measured value of the fluctuation can be, for example, a plurality of standard deviations of the plurality of rotational rate values, such as one, two, or three standard deviations; the measured value of the fluctuation can also be, for example, the maximum deviation of the values in the plurality of rotational rate values from the average of the plurality of rotational rate values, i.e., the maximum deviation from the determined rotational rate.

[0020] In an embodiment, an estimate of the total error of the corrected rotational rate is output together with the output of the corrected rotational rate, the total error including at least the measured value of the fluctuation of the rotational rate values for the corresponding temperature; the measured value of the fluctuation represents the statistical error of the corrected rotational rate due to the fluctuation of the rotational rate during the determination of the offset, i.e., due to the statistical error of the offset.

[0021] In a variant of this embodiment, the total error includes an error due to the rate of change of temperature. The reason here is that although the offsets determined for various temperatures as described above can be used to correct the rotational rate obtained from the rotational rate sensor, such compensation may be unreliable if the temperature of the rotational rate sensor is not well defined. In particular, if the temperature of the rotational rate sensor or its environment is changing, the rotational rate sensor may not be operating in a thermally stable state, resulting in additional errors in the values of the rotational rate provided by the sensor. The estimate of this error is included in the total error. One way to achieve this is to rely on a sensor data sheet provided by the manufacturer of the specific rotational rate sensor used, which gives an estimate of this error depending on the rate of change of temperature.

[0022] As described above, the table associating temperature with offset can be updated. Nevertheless, it may happen that when the offset for a particular temperature is needed, the last update of the offset at that particular temperature was some time ago; in the meantime, the offset may have changed. To account for this, in another variant, the total error includes the error resulting from the age of the offset used to correct the rotation rate. One way to obtain this error is from a sensor data sheet provided by the manufacturer of the sensor, which states the drift rate of the rotation rate output from the sensor with sensor age or the maximum drift of the sensor over the specified lifetime of the sensor. In a simple example, the drift rate can be obtained as such maximum drift divided by the specified lifetime. Thus, an estimate of the error due to the age of the offset used for correction can be obtained as that drift rate multiplied by the time elapsed since the offset was calculated in the update of the table.

[0023] The total error including one or more of the contributions as described above can cause the correct rotation rate of the vehicle to lie within a range specified by the total error around the corrected rotation rate with a specified probability, such as 95% or 99%, and these percentages are not limitations of the present invention.

[0024] It may happen that the measured rotation rate needs to be corrected and the temperature of the rotation rate sensor when the rotation rate was measured is not included in the table. One method is to select the offset in the table for the temperature closest to the temperature at which the rotation rate was measured. Another method is to calculate the offset for that temperature by interpolating the values included in the table. The interpolation can be, for example, linear interpolation or cubic spline interpolation, and the present invention is not limited thereto.

[0025] Regarding the temperature and offset values stored in the table, the following further explanations are as follows: If the table is updated when the vehicle is stationary, the temperature of the rotational rate sensor that is not yet included in the table is determined, and this temperature together with the correspondingly determined offset can be included in the table. For a temperature that was not previously included in the table, the offset determined in the case of first including the temperature-offset pair in the table can be the rotational rate determined when the vehicle is stationary at this temperature. This also applies to the case where the table is completely empty, for example, for a brand-new vehicle or rotational rate sensor, or after a reset. The limited precision and resolution of temperature determination, for example, the temperature sensor used for this purpose will have limited resolution and precision, can lead to the coarsening of the temperature values stored in the table. Such coarsening can also be introduced by the design of the table. For example, the table can only hold temperature values spaced at minimum degrees, such as one, two, or five degrees Celsius intervals. During an update, the determined rotational rate can be used to update the following entry of the table, the corresponding temperature of which is closest to the temperature first found during the update, that is, the average of one or more temperatures measured at or near the rotational rate sensor. Each temperature included in the table can be considered as an effective temperature, and in this case, for the purpose of update, the temperature of the rotational rate sensor is this effective temperature. The method can be refined by estimating the offset for the effective temperature, for example, by linear approximation. A further improvement is that in addition to updating the entry of the table for the effective temperature, the table is also updated at adjacent entries, that is, the entries corresponding to another one of the temperatures held in the table, such that the temperature of the rotational rate sensor first found is between the effective temperature and the temperature corresponding to the adjacent entry. The corresponding offsets for the adjacent entries can be estimated, for example, by linear approximation.

[0026] In an embodiment, when determining the temperature of the rotational rate sensor for the update of the table, the rate of change of the temperature of the rotational rate sensor is also determined. The update of the table is only performed when this rate of change is lower than a predefined threshold. The higher the rate of change of the temperature, the lower the thermal stability of the rotational rate sensor, and the more unreliable its rotational rate output becomes. By restricting the update of the table to the case when the rate of change of the temperature is lower than a predefined threshold, it can be ensured that the data in the table remains reliable to an acceptable degree during the update process. In the case as described above, where the temperature of the rotational rate sensor is the effective temperature, the rate of change of the temperature before transitioning to the effective temperature should be considered here, that is, one or more temperatures measured at or near the rotational rate sensor.

[0027] Generally, the method according to the present invention can be performed by a data processing unit on the vehicle in cooperation with the rotational rate sensor. The rotational rate sensor can be implemented in an inertial measurement unit. The table holding the temperature and offset values and other values to be stored according to the method can be stored in the data processing unit in one or more known and suitable data structures.

[0028] The system according to the invention comprises a data processing unit and a rotational rate sensor, and is configured to perform the method according to the invention, as described above. The vehicle according to the invention comprises the aforementioned system according to the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Hereinafter, the invention and its advantages will be described with reference to the drawings.

[0030] Figure 1 Illustrates the dependence of the rotational rate offset on temperature.

[0031] Figure 2 Is the principle of rotational rate compensation.

[0032] Figure 3 Shows three graphs showing quantities related to temperature.

[0033] Figure 4 Shows an example of an update of the temperature-offset table.

[0034] Figure 5 Shows an example of rotational rate compensation.

[0035] Figure 6 Shows a vehicle according to the invention.

[0036] The drawings are used to illustrate the invention and relate to embodiments of the invention. These drawings should not be considered as limiting the invention to these embodiments. DETAILED DESCRIPTION

[0037] Figure 1 Is an example of a graph showing the rotational rate determined using the rotational rate sensor on the vehicle at rest versus temperature. Thus, this graph shows the rotational rate offset that depends on temperature. Although this dependence will be different for different types or models of rotational rate sensors, a typical rotational rate sensor has an offset that varies in the range of about 0.5 degrees per second over a temperature range from about -20 degrees Celsius to 100 degrees Celsius. If reliable autonomous driving functions are to be achieved, this variation in offset is too large to be ignored; in particular, it is not sufficient to determine the offset only once while the vehicle is still at rest before cruising, because the temperature usually changes during cruising.

[0038] Figure 2Illustrates the principle of rotational rate compensation. The rotational rate 10 is measured using a rotational rate sensor 150. The temperature 15 of the rotational rate sensor 150 is determined. The temperature 15 is referenced to Table 20, which holds temperature values associated with rotational rate offsets. This reference results in an offset 25 for the temperature 15. The offset 25 is subtracted from the measured rotational rate 10 to obtain a corrected rotational rate 30. If the temperature 15 is found in Table 20, the associated offset is the resulting offset 25. If the temperature 15 is not found in Table 20, the offset associated with the temperature in Table 20 that is closest to the temperature 15 can be the resulting offset 25. Another possibility is to find the resulting offset 25 from an interpolation of the temperature-offset pairs in Table 20.

[0039] Figure 3 Includes three graphs with a common abscissa that represents the temperature T of the rotational rate sensor. The top graph shows the temperature-dependent offsets stored in a table. The temperature values contained in the table are represented by line 56. The rotational rate sensor has an operating temperature range 54, and in the example shown, only the offsets for the temperatures within a smaller range 52 contained within the operating range 54 are determined and updated in the table. For temperatures within the range 54 but outside the range 52, the offset for the closest temperature within the range 52 is used. It can be seen that in this example, the temperature values stored in the table are not equidistantly spaced.

[0040] The middle graph represents the statistical error of the offsets determined within the range 52. Outside the range 52, the maximum rotational rate error of the operating life of the rotational rate sensor is used as the offset error. This maximum rotational rate error can be obtained, for example, from a data sheet provided by the manufacturer of the rotational rate sensor for a specific rotational rate sensor.

[0041] The bottom graph shows the weights of the offsets for the various temperatures stored in the table. The weights shown apply to a given point in time because the weights decrease as the age of the offset increases, i.e., as the time since the last update for the corresponding temperature increases. At the time of update, the offset always receives a predefined initial weight represented by the value of a counter. At fixed time intervals, e.g., every 10 seconds, the counter is decremented by one. At the time of update, the new offset is calculated as a weighted average of the rotational rate determined at the time of update and the offset already stored in the table for the corresponding temperature. The weight of the stored offset is the value that the counter has reached at the time of update, and the weight of the rotational rate determined at the time of update is equal to the predefined initial weight. The new offset starts with the predefined initial weight.

[0042] Figure 4An example of updating the temperature-offset table 20 is shown. Vehicle bus data 17 and a rotational rate value 10 are provided to a determination block 40 to determine whether the vehicle is stationary. The vehicle bus data 17 can include, for example, the locked state of the vehicle steering wheel, the positions of the throttle and brake, the state of the gear, the on / off state of the vehicle engine, the speed and acceleration of the vehicle. The rotational rate 10 is obtained from a rotational rate sensor 150 and is shown here as being obtained after passing the raw output from the rotational rate sensor 150 through a low-pass filter 152. If it is found that the vehicle is not stationary, the table 20 is not updated. In a determination block 42, it is determined whether the rate of change 16 of the temperature of the rotational rate sensor 150 over time is below a predefined threshold. If the rate of change 16 is above the threshold, the table 20 is not updated because the rotational rate 10 provided by the rotational rate sensor 150 may have too large an error. If it is determined in the determination block 40 that the vehicle is stationary and it is found in the determination block 42 that the rate of change 16 of the temperature is below the threshold, various quantities are calculated 50. The calculation 50 involves the rotational speed 10, the temperature 15 of the rotational rate sensor 150, the offset 25 currently stored in the table 20 for the temperature 15, and the weight 28 currently stored in the table 20 for the temperature 15. For the temperature 15, an updated value of the offset 25 is calculated as a weighted average of the rotational rate 10 and the offset 25 currently stored in the table 20, and the weighted average requires the weight 28. In addition, an error 26 of the offset is determined; the error includes at least a statistical error. The temperature 15, the updated value 25 of the offset, the determined error 26 of the offset, and the updated weight 28 are stored in the table 20. Determining the statistical error included in the error 26 for updating requires obtaining the rotational rate 10 as an average from a plurality of rotational rate readings from the rotational rate sensor 150 via the low-pass filter 152, and also requires calculating the variation of the values of the plurality of readings around that average, as described above. Similarly, as described above, if the temperature 15 determined for the rotational rate sensor 150 does not match the coarsening of the temperature in the table 20, an appropriately adjusted temperature can alternatively be used.

[0043] Figure 5 An example of rotational rate compensation is shown as being in Figure 2Implementation of the general principles discussed in the case. The rotational speed 10 is measured by the rotational speed sensor 150 via the low-pass filter 152. The measured rotational speed 10, the temperature 15 of the rotational speed sensor 150, and the rate of change 16 of the temperature of the rotational speed sensor 150 are provided to the compensation routine 52. The compensation routine 52 can access the data stored in the table 20, namely the temperature, the corresponding offset, error, and weight, as well as the data 21 on the rotational speed sensor 150, which may be sourced from the manufacturer of the rotational speed sensor 150. According to the data stored in the table 20, the compensation routine 52 obtains an offset to correct the measured rotational speed 10; if the temperature 15 has a value between the temperature values included in the table 20, the offset can be obtained by interpolation. This offset is subtracted from the measured rotational speed 10 to obtain the corrected rotational speed 30. According to the data in the table 20, the compensation routine 52 also obtains the statistical error of the rotational speed, which can also be obtained by interpolation if the temperature 15 has a value between the temperature values included in the table 20. The statistical error is part of the total error 31. According to the data 21, the compensation routine 52 obtains the error of the measured rotational speed caused by the rate of change 16 of the temperature. This error is added to the statistical error. As mentioned above, due to the fact that the most recent update of the data related to the temperature 15 in the table 20 may have been some time ago, a further contribution to the total error 31 is generated. The drift rate of the rotational speed sensor error over time is obtained from the data 21, and the corresponding contribution to the total error 31 is derived from the time since the last update of the relevant data in the table 20. The time since the last update can be directly inferred from the measurement time of the rotational speed 10 to be corrected and the time of the last update (if this time is stored in the table 20), or it can be inferred from the weights stored in the table 20, since the weights decrease from a defined value in a defined manner over time. The corrected rotational speed 30 and the total error 31 are output from the compensation routine 52. Based on the statistical error from the table 20 and the errors related to the rotational speed sensor specifications due to the rate of change of the temperature and the time since the last update, the nature of the total error 31 is such that the correct rotational speed deviates from the corrected rotational speed 30 by at most the total error 31 with a defined probability, such as 95% or 99%.

[0044] Figure 6 Vehicle 200 according to the present invention is schematically shown. Vehicle 200 includes system 100 according to the present invention. System 100 includes a data processing unit 110 and an inertial measurement unit 120, and the inertial measurement unit 120 further includes a rotational speed sensor 150. System 100 is configured to perform the method according to the present invention.

[0045] List of reference numerals:

[0046] 10 Rotational speed

[0047] 15 Temperature

[0048] 16 Temperature change rate

[0049] 17 Vehicle bus data

[0050] 20 Table

[0051] 21 Sensor data

[0052] 25 Offset

[0053] 26 Offset error

[0054] 28 Weight

[0055] 30 Corrected rotation rate

[0056] 31 Total error

[0057] 40 Decision block

[0058] 42 Decision block

[0059] 50 Calculation

[0060] 52 Compensation routine

[0061] 100 System

[0062] 110 Data processing unit

[0063] 120 Inertial measurement unit

[0064] 150 Rotation rate sensor

[0065] 152 Low-pass filter

[0066] 200 Vehicle.

Claims

1. A method for compensating for the offset of a rotational rate sensor (150) on a vehicle (200), the method comprising: Measuring the rotational rate (10) of the vehicle (200) using the rotational rate sensor (150); Correcting the rotational rate (10) by subtracting the offset (25) from the measured rotational rate (10); Outputting the corrected rotational rate (30); Wherein a temperature (15) is determined for the rotational rate sensor (150), and The offset (25) is provided from a table (20) that correlates temperature values with offset values, Wherein the table is updated by performing the following steps: Determining whether the vehicle (200) is stationary; If it is determined that the vehicle (200) is stationary, then Determining the temperature (15) for the rotational rate sensor (150), Determining the rotational rate (10) from the rotational rate sensor (150), Updating the table (20) using the offset (25) and the temperature (15), wherein a weight (28) for the updated offset (25) is stored when updating the table (20), the offset (25) being calculated as a weighted average of the currently determined rotational rate (10) when the vehicle is stationary and the previous offset (25) for the corresponding temperature (15) included in the table (20), and the weight (28) of the updated offset (25) decreases over time after the update, characterized in that, The weight of the updated offset at the time of update is a predefined initial weight represented by the value of a counter; The counter is decremented at a fixed time interval; The weight of the currently determined rotational rate (10) in the weighted average is equal to the predefined initial weight.

2. The method according to claim 1, wherein, Determining the rotational rate (10) includes reading a plurality of rotational rate values from the rotational rate sensor (150) and calculating an average of the plurality of rotational rate values, and wherein, additionally, a measured value of the fluctuation of the plurality of rotational rate values is calculated and stored in association with the corresponding temperature (15).

3. The method according to claim 2, wherein, Outputting a total error (31) of the corrected rotational rate (30) together with the output of the corrected rotational rate (30), the total error (31) at least including the measured value of the fluctuation of the plurality of rotational rate values for the corresponding temperature (15).

4. The method according to claim 3, wherein The total error (31) includes an error caused by the rate of change of temperature (16) during the measurement of the rotational rate (10).

5. The method according to claim 3 or 4, wherein The total error (31) includes an error caused by the age of the offset (25) used to correct the rotational rate (10).

6. The method according to any one of claims 1 to 5, wherein, Updating of the table (20) when the vehicle is stationary is performed only if the rate of change of the temperature (16) for the rotational rate sensor (150) is below a predefined threshold.

7. The method according to one of claims 1 to 6, wherein The table (20) is designed to hold only specific temperature values, and when updating the table (20), the temperature (15) for the rotational rate sensor (150) is the effective temperature, which is equal to one of the specific temperature values held in the table (20) that is closest to the measured temperature of the rotational rate sensor (150).

8. The method according to claim 7, wherein In addition to updating the table (20) for the effective temperature, the table (20) is also updated for an adjacent one of the specific temperature values held in the table (20), such that the measured temperature of the rotational rate sensor (150) is between the effective temperature and the adjacent one of the specific temperature values held in the table (20).

9. The method according to one of the preceding claims, wherein, If an offset (25) for a temperature (15) not included in the table (20) is required for the correction of the rotational rate (10), the offset (25) is calculated by interpolating the values included in the table (20).

10. The method according to one of the preceding claims, wherein, The method is performed by the data processing unit (110) on the vehicle (200) in cooperation with the rotational rate sensor (150).

11. A system (100) comprising a data processing unit (110) and a rotational rate sensor (150), the system (110) being configured to perform the method according to one of claims 1 to 10.

12. A vehicle (200) comprising the system (100) according to claim 11.

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