Rotation rate offset compensation
AssigneeVeoneer Sweden Safety Systems AB
InventorsHela BEN SAID, Aurore LOISY, Yann LEMERRER, Arnaud DEVAVRY
Life of this patent
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Abstract
Measurements of rotation rates (10) obtained with a rotation rate sensor (150) on board of a vehicle (200) are corrected by a temperature dependent offset (25). This offset (25) is provided from a table (20). The table (20) may be updated if the vehicle (200) is at rest by determining a temperature (15) and determining a rotation rate (10) from the rotation rate sensor (150). Additionally, ageing of the rotation rate sensor (150) is taken into account. A total error (31) of the corrected rotation rate (30) may also be provided.
Claims20
A method for offset compensation of a rotation rate sensor on board of a vehicle, the method comprising:
- measuring a rotation rate of the vehicle with the rotation rate sensor;
- correcting the rotation rate by subtracting an offset from the measured rotation rate;
- outputting the corrected rotation rate;
- wherein
- a temperature is determined for the rotation rate sensor, and
- the offset is provided from a table associating temperature values with offset values,
- wherein the table is updated by performing the following steps:
- determining if the vehicle is at rest;
- if it is determined that the vehicle is at rest,
- determining a temperature for the rotation rate sensor, determining a rotation rate from the rotation rate sensor, updating the table with an offset and the temperature, wherein in the updating of the table a weight for the updated offset is stored, the offset is calculated as a weighted average of the currently determined rotation rate at vehicle rest and the previous offset contained in the table for the respective temperature, and the weight of the updated offset is decreased with increasing time after the update,
- wherein
- the weight upon update for the updated offset is a pre-defined initial weight, expressed by a value of a counter;
- the counter is decreased by one at fixed time intervals;
- the weight of the currently determined rotation rate in the weighted average is equal to the pre-defined initial weight.
A system including
- a rotation rate sensor configured to measure a rotation rate of a vehicle;
- one or more data processors;
- and
- memory including instructions that, when executed by the one or more data processors perform to:
- correct the rotation rate by subtracting an offset from the measured rotation rate;
- output the corrected rotation rate;
- determine a temperature for the rotation rate sensor;
- determine the offset from a table associating temperature values with offset values;
- and
- update the table by performing the following:
- determine if the vehicle is at rest;
- if it is determined that the vehicle is at rest, determine a temperature for the rotation rate sensor, determining a rotation rate from the rotation rate sensor, update the table with an offset and the temperature, wherein in the updating of the table a weight for the updated offset is stored, the offset is calculated as a weighted average of the currently determined rotation rate at vehicle rest and the previous offset contained in the table for the respective temperature, and the weight of the updated offset is decreased with increasing time after the update,
- wherein the weight upon update for the updated offset is a pre-defined initial weight, expressed by a value of a counter;
- the counter is decreased by one at fixed time intervals;
- the weight of the currently determined rotation rate in the weighted average is equal to the pre-defined initial weight.
(canceled)
Dependencies are inferred from the claim text.