Rotation Rate Sensor Structural Deviation Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Micromechanical rotation rate sensors in motor vehicles face issues with undesirable oscillations and changing measurement sensitivity due to manufacturing tolerances and temperature-induced deformations, leading to corrupted measurement results and sensitivity drift.
Innovation Solution
A micromechanical rotation rate sensor design that includes a substrate, seismic mass, drive means for periodic movement, force detection means for Coriolis force measurement, and measurement means to detect structural deviations, producing a test signal independent of structural deviations for improved sensitivity measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If manufacturing tolerances are present in the rotation rate sensor structure, then the sensor can be produced with standard precision, but undesirable oscillations and quadrature signals occur that corrupt measurement results
Solution Approach 1:
The patent introduces measurement means that continuously monitor structural deviations in the spring-mass system and feed this information back to the evaluation means. The evaluation means then compensates for the effects of manufacturing tolerances by adjusting the measurement signal based on the detected structural deviations, thereby eliminating corrupted quadrature signals while maintaining standard manufacturing precision.
Solution Approach 2:
The patent introduces an intermediary measurement system that detects structural deviations as a separate parameter. This intermediary measurement means acts as a mediator between the physical structure and the final measurement output, allowing the system to distinguish between true Coriolis effects and artifacts caused by manufacturing tolerances, thereby improving measurement accuracy without requiring higher manufacturing precision.
2Adaptability or versatility
If temperature changes occur in the ambient environment, then the sensor operates under varying conditions, but deformations of the measurement structure occur that cause measurement sensitivity to drift by up to 10%
Solution Approach 1:
The measurement means continuously monitor structural deviations caused by temperature changes and feed this information back to the evaluation means. The evaluation means then compensates for temperature-induced sensitivity drift by adjusting the measurement signal based on the detected structural deviations, maintaining measurement precision across varying temperature conditions.
Solution Approach 2:
The patent changes the parameter being measured from direct Coriolis force to a corrected measurement signal that accounts for structural deviations. By introducing a correction factor based on detected structural deviations, the system maintains measurement sensitivity despite temperature-induced changes in the physical structure.
3Measurement precision
If the seismic mass is driven periodically to produce Coriolis force for measurement, then the rotation rate can be detected, but undesirable oscillations occur that corrupt the measurement results
Solution Approach 1:
The measurement means detect the oscillations generated by the drive system and feed this information back to the evaluation means. The evaluation means then separates the useful Coriolis signal from the harmful drive-induced oscillations by using the feedback information to identify and filter out the oscillation components, thereby improving rotation rate detection precision.
Solution Approach 2:
The measurement means act as an intermediary that detects both the Coriolis effect and the drive-induced oscillations as separate parameters. This intermediary detection allows the evaluation means to distinguish between the useful measurement signal and the harmful oscillations, enabling accurate rotation rate detection despite the presence of drive-induced vibrations.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Reliably identifies and compensates for structural changes, such as substrate deformations, allowing for accurate measurement sensitivity evaluation and reduced sensitivity drift, enhancing the reliability and stability of rotation rate sensor measurements.
Implementation Method 1
A reaction of the seismic mass to a rotary movement is in this case used to detect the rotary movement. For example, in the case of a rotation rate sensor whose detection of the rotation rate is based on the Coriolis effect, the seismic mass is deflected at right angles to the rotation axis. The radial movement of the seismic mass results in a change in the rotating system to the path velocity thereof, which leads to a corresponding Coriolis force on the seismic mass.
Implementation Method 2
In order to measure the Coriolis force, a defined movement of the seismic mass is first of all necessary. For this purpose, a periodic movement of the seismic mass is produced, for example, by means of a capacitive drive.
Implementation Method 3
the measurement means are designed for measurement of structural deviations of the rotation rate sensor
Data Source
AI summary
A micromechanical rotation rate sensor, in particular for use in motor vehicles, includes a substrate, at least one seismic mass, which is arranged in a sprung manner on the substrate, drive means for production of a periodic movement of the seismic mass, force detection means for detection of a Coriolis force, which acts on the seismic mass as a result of rotation about a rotation axis which is at right angles to the excitation direction, and measurement means, wherein the measurement means are designed for measurement of structural deviations of the rotation rate sensor.