Rotation Rate Sensor Offset Compensation for Thermal Aging
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Solution Overview
Problem
Existing methods for compensating rotation rate sensor offsets in vehicles fail to account for temperature changes and sensor aging, leading to inaccurate offset estimations during vehicle operation.
Innovation Solution
A method that updates a temperature-dependent offset table by measuring the vehicle's rest state to determine and correct rotation rates, incorporating temperature and age factors, using a weighted average to ensure accurate offset compensation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If offset compensation is performed using a fixed table lookup method, then the device complexity is reduced, but the measurement precision deteriorates due to temperature changes and sensor aging
Solution Approach 1:
The offset compensation method transitions from static (fixed table lookup) to dynamic (continuous updating based on temperature and time). The system now adapts the offset values dynamically according to changing temperature conditions and sensor aging, thereby maintaining measurement precision without significantly increasing device complexity.
Solution Approach 2:
The invention changes the parameters used for offset compensation from simple temperature-based lookup to a more sophisticated model that incorporates both temperature and time (sensor aging) parameters. This allows the system to account for both thermal effects and degradation over time, improving measurement precision while keeping the compensation mechanism relatively simple.
2Productivity
If offset is determined at the beginning of cruise, then the productivity is improved, but the reliability deteriorates because temperature changes during cruise are not accounted for
Solution Approach 1:
The system performs preliminary offset determination at the beginning of cruise to quickly establish an initial compensation value, maintaining productivity. Simultaneously, it prepares for subsequent adjustments by implementing a mechanism to update the offset during cruise based on temperature changes, thereby maintaining reliability throughout the operation.
Solution Approach 2:
The invention introduces feedback by continuously monitoring temperature during cruise and using this information to adjust the offset values. This feedback loop ensures that the offset remains accurate despite temperature changes, resolving the reliability issue while maintaining the initial productivity benefit of quick offset determination.
3Measurement precision
If temperature-dependent offset correction is implemented, then the measurement precision is improved, but the device complexity increases due to additional temperature monitoring and table update mechanisms
Solution Approach 1:
The system achieves universality by making the offset compensation table serve multiple functions: it stores both the base offset values and the temperature correction data. The same table structure is used for both initial offset determination and temperature-dependent correction, reducing the need for separate data structures and reducing overall device complexity.
Solution Approach 2:
The invention merges the temperature monitoring and offset correction mechanisms into a unified process. The temperature data is integrated with the offset lookup process, and the table update mechanism handles both base offset calibration and temperature-dependent corrections in a single system, thereby improving measurement precision without proportionally increasing device complexity.
Data Source
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AI summary
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) may be taken into account. A total error (31) of the corrected rotation rate (30) may also be provided.