MEM Sensor Signal Correction via Nonlinear Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Nonlinearity in the force feedback of microelectromechanical sensors (MEM sensors) reduces noise performance and limits feedback quantization, especially when using pulse width modulation (PWM) feedback, which requires high frequencies and restricts resolution.
Innovation Solution
A device and method for correcting sensor signals using a nonlinear processing rule, applied in a feedback unit and a signal correction unit, which processes and corrects sensor signals to compensate for nonlinearity, allowing for high resolution without high frequencies and low power loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If PWM feedback is used to avoid nonlinearity, then linearity is improved, but feedback quantization is limited to a few bits due to high frequency requirements
Solution Approach 1:
The feedback signal is segmented into multiple levels (e.g., 6-10 bits quantization) and processed through separate processing paths. The signal is divided into coarse and fine components that can be handled at different resolution levels, enabling high-precision feedback without requiring uniformly high-frequency operation across the entire signal range.
Solution Approach 2:
The system dynamically adjusts processing parameters based on signal characteristics. The feedback mechanism transitions between different operational modes (PWM and voltage feedback) depending on the required precision and frequency conditions, optimizing performance for each operating regime rather than using a fixed approach.
2Manufacturing precision
If high frequency PWM is used for high quantization, then feedback resolution is improved, but power loss increases and technology becomes impractical
Solution Approach 1:
The system applies partial PWM action combined with voltage feedback. Instead of using full PWM for all quantization levels, the invention uses PWM for coarse quantization (lower frequency, less power) and supplements it with voltage feedback for fine quantization, achieving high overall resolution without the power penalty of high-frequency PWM across the entire range.
Solution Approach 2:
The system changes operational parameters dynamically, switching between PWM mode and voltage feedback mode based on the required feedback precision. This allows the feedback mechanism to operate at lower frequencies when high precision is not required, significantly reducing power consumption while maintaining the capability for high-resolution feedback when needed.
3Manufacturing precision
If voltage feedback with multiple voltage values is used, then feedback resolution is improved, but nonlinearity is introduced reducing noise performance
Solution Approach 1:
The invention introduces a nonlinear processing unit as an intermediary between the voltage feedback signal and the sensor. This processing unit applies a nonlinear transformation that compensates for the nonlinearity introduced by the voltage feedback mechanism, effectively linearizing the overall feedback path and restoring noise performance while maintaining high feedback resolution.
Solution Approach 2:
The system replaces direct voltage feedback with a processed feedback signal that has been transformed through a nonlinear processing unit. This substitution allows the system to use voltage feedback (which offers high resolution) while compensating for its nonlinearity through signal processing, thereby maintaining both resolution and noise performance.
Data Source
AI summary
A device for correcting a sensor signal, includes a sensor interface, a signal processing unit, a feedback unit, and a signal correction unit. The sensor interface is configured to read in a sensor signal which represents a physical variable. The signal processing unit is configured to determine a processing signal by using the sensor signal. The feedback unit is configured to output a feedback signal to the sensor and to provide the feedback signal on the basis of a nonlinear processing rule and the processing signal. The signal correction unit is configured to determine a corrected signal by using the processing signal, and to determine the corrected signal by using the nonlinear processing rule or a processing rule derived from the nonlinear processing rule.