Sensor Interface Circuit for Diverse Signal-Path Safety Verification
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current sensor interfaces for automotive applications face challenges in achieving cost efficiency while ensuring functional safety, as they often rely on multiple sensors to diagnose health and prevent common mode failures, which can be costly and complex.
Innovation Solution
A sensor interface circuit that calculates one sensor result and outputs it along with characterization data, allowing a further device to verify reliability using different processing means, with options for time multiplexing and separate conversion paths for each signal path, and the ability to store sensor characterization data for external processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple sensors are used to diagnose sensor health and prevent common mode failures, then functional safety is improved, but cost and device complexity increase
Solution Approach 1:
The patent divides the safety verification function into two separate signal paths: one path processes the sensor signal through the sensor interface circuit, while the other path uses a different computation method or alternative sensor. This segmentation allows independent verification of sensor health without requiring a complete redundant sensor system, reducing overall complexity while maintaining functional safety.
Solution Approach 2:
The patent introduces an intermediary evaluation device that receives signals from multiple sensors and performs comparative analysis. This intermediary component coordinates the safety verification process by comparing sensor readings and determining sensor health status, eliminating the need for each sensor to independently implement complex safety logic.
2Reliability
If multiple sensors are used to diagnose sensor health and prevent common mode failures, then functional safety is improved, but cost increases
Solution Approach 1:
The patent makes the sensor interface circuit capable of performing multiple functions: it processes the primary sensor signal and simultaneously provides data for safety verification through alternative computation paths. This multi-functionality eliminates the need for dedicated separate circuits for each safety function, reducing overall component quantity and cost while maintaining functional safety.
Solution Approach 2:
The patent changes the computational parameters or processing methods in alternative signal paths to verify sensor health. By using different computation approaches (e.g., different algorithms, different physical principles) rather than identical redundant sensors, the system achieves functional safety with lower cost components.
3Area of stationary object
If sensor interface is made smaller to reduce silicon area and cost, then cost is reduced, but functionality may be compromised
Solution Approach 1:
The patent merges the safety verification functions directly into the sensor interface circuit itself, combining multiple functions (signal processing, alternative computation, safety evaluation) into a single integrated unit. This integration eliminates the need for separate discrete components, reducing silicon area while preserving full functionality.
Solution Approach 2:
The sensor interface circuit is designed with multi-functionality, capable of performing both primary signal processing and safety verification through alternative computation paths within the same circuit architecture. This universality allows the circuit to maintain comprehensive functionality while occupying minimal silicon area through efficient resource sharing.
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The present invention relates to a sensor interface circuit (120) comprising - an input arranged to receive a sensor signal being an electrical signal representative of an electrical quantity, said electrical quantity being a physical quantity converted in a sensor, - conversion means (123) arranged for converting said sensor signal into a digital signal, - memory (125) to store sensor characterisation data, - signal processing means (128) adapted to obtain a first sensor result by processing said digital signal using said sensor characterisation data, - an output unit (122) arranged to receive and output said first sensor result, said digital signal and said sensor characterisation data. An external control unit (140) is arranged for verifying signals derived from a sensor signal received in the sensor interface circuit (120), the external control unit (140) being adapted - to receive from said sensor interface circuit (120) said first sensor result, said digital signal and said sensor characterisation data, - to determine a second sensor result by processing said digital signal using said sensor characterisation data in a signal processing means of said external control unit, and - to compare said first and said second sensor result.