Pressure Sensor Testing Circuit Using Transfer Functions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Pressure sensors in automotive applications, such as engine control, degrade due to mechanical and temperature stresses, leading to corrosion and electrical leakage, making it difficult to identify faulty sensors, especially when they provide false information, which can cause more serious issues if left unrepaired.
Innovation Solution
A method involving a pressure sensor system with differential outputs and transfer functions, where a first transfer function is used for normal operation and a second, similar transfer function with different coefficients is used during testing to predict the second differential output, allowing for comparison and identification of sensor failure without requiring multiple pressure tests.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional pressure sensor testing methods are used, then multiple pressure tests are required to identify sensor failures, but this increases testing time and complexity
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing transfer functions that relate the first differential output to the second differential output under various pressure conditions. During testing, these pre-established transfer functions are used to predict expected second differential output values based on measured first differential outputs, eliminating the need for multiple actual pressure tests and enabling rapid sensor failure identification.
2Reliability
If pressure sensors operate under mechanical and temperature stresses, then sensor durability is reduced, but continuous monitoring adds system complexity
Solution Approach 1:
The patent implements self-service by enabling the pressure sensor system to autonomously monitor its own health using its existing differential output signals. The control circuit processes the relationship between the first and second differential outputs through pre-stored transfer functions to detect sensor degradation or failure, allowing the system to self-diagnose without requiring external monitoring equipment or increasing overall system complexity.
Data Source
AI summary
A method for testing a pressure sensor having a first node and a second node includes coupling the first node to a first input of an amplifier and coupling a reference voltage to a second input of the amplifier; applying a transfer function to an output of the amplifier to provide a first output voltage that is based on a difference in voltage between the first node and the reference voltage; coupling the reference voltage to the first input and coupling the second node to the second input; obtaining a second output voltage at the output of the amplifier; and determining, based on the first and second output voltages, whether the pressure sensor passed or failed. During normal operation, the first node is coupled to the first input and the second node to the second input, and a second transfer function is applied to the output of the amplifier.