Three-MEMS Pressure Sensor for Signal Rationality Diagnosis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing pressure sensors in vehicles are unable to diagnose the rationality of pressure signals, leading to potential inaccuracies and faults such as zero point shifts or abnormal slopes, which affect the reliability of particulate filter monitoring.
Innovation Solution
A pressure sensor with a detection unit comprising three MEMS sensing elements and a processing unit that diagnoses the rationality of pressure signals by comparing measured pressures and differences, outputting diagnostic information if abnormalities are detected.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pressure sensors are used to measure pressure difference and absolute pressure in particulate filter monitoring, then pressure measurement capability is achieved, but the ability to diagnose signal rationality is lacking
Solution Approach 1:
The patent implements a feedback mechanism where the processing unit continuously monitors pressure signals from multiple sensing elements, compares them against expected physical relationships, and generates diagnostic information when anomalies are detected. This closed-loop feedback system enables real-time validation of pressure signal rationality, transforming the open-loop measurement system into a self-diagnosing system that actively identifies faults such as zero-point shifts and abnormal slopes.
Solution Approach 2:
The processing unit serves as an intermediary between the pressure sensing elements and the output system. It receives raw pressure signals, performs rationality checks by comparing differential pressure measurements with calculated pressure differences from absolute pressure sensors, and either outputs valid pressure information or generates abnormal diagnostic information. This intermediary layer filters out unreliable data before it reaches the output, preventing propagation of erroneous measurements.
2Reliability
If multiple pressure sensing elements are used to enable signal rationality diagnosis, then diagnostic capability is improved, but device complexity increases
Solution Approach 1:
The patent employs multiple pressure sensing elements that serve dual functions: the first and second sensing elements provide both absolute pressure measurements and participate in differential pressure validation. The processing unit uses these same elements for both normal pressure measurement operations and for rationality diagnosis, eliminating the need for separate dedicated diagnostic sensors. This multi-functional approach enables signal validation without proportionally increasing device complexity.
Solution Approach 2:
The patent merges the measurement and diagnosis functions into a single integrated system. The processing unit combines data from multiple pressure sensing elements, merging absolute pressure measurements with differential pressure measurements to perform rationality checks. By combining these functions in one processing unit rather than using separate measurement and diagnosis systems, the patent achieves diagnostic capability while controlling overall device complexity.
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
Enhances the reliability and accuracy of pressure measurement by identifying and correcting faults, ensuring compliance with stringent emission regulations and reducing particulate emissions.
Implementation Method 1
the detection unit comprises three MEMS sensing elements that are a first MEMS sensing element, a second MEMS sensing element and a third MEMS sensing element
Data Source
Figure 1a
Figure 1b
Figure 2~3
AI summary
A pressure sensor (100) includes a pressure measuring device (120) including: a circuit board (121); and a processing unit (122) and a detection unit, both provided on the circuit board (121); the detection unit includes first, second and third MEMS sensing elements (123, 124, 125); the first MEMS sensing element (123) is configured to sense a first pressure (PI) at a first target position; the second MEMS sensing element (124) is configured to sense a second pressure (P2) at a second target position, and the third MEMS sensing element (125) is configured to sense a pressure difference (ΔP) between the first and second target positions; the processing unit (122) is configured to determine whether the three MEMS sensing elements (123, 124, 125) are abnormal based on the first and second pressures and on the pressure difference; if it is determined that at least one of the three MEMS sensing elements is abnormal, the processing unit (122) outputs abnormal diagnostic information; if it is determined that none of the three MEMS sensing elements is abnormal, the processing unit (122) outputs information about the pressure(s) at the first and/or second target position(s) and the pressure difference; thus rationality diagnosis of the pressure signals is achieved, resulting in increased reliability and accuracy in pressure measurement.