Engine Camshaft Sensor Random Current Phase Detection
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Solution Overview
Problem
Existing methods for determining the precise position of pistons in an internal combustion engine cycle are inadequate, particularly for engines with multiple camshafts and variable valve timing, as they struggle to differentiate between the intake and exhaust phases without ambiguity, leading to uncertainty in valve control and emission management.
Innovation Solution
A device comprising two current source sensors coupled in parallel, with an embedded intelligence module and random-number generation module, which generates a random number and modifies current levels to differentiate sensor outputs, allowing precise detection of piston positions and phases through a countdown and interrupt signal mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If multiple current source sensors are coupled in parallel to reduce wiring complexity, then the wiring complexity is reduced, but it becomes difficult to differentiate between sensor outputs due to coincident current levels
Solution Approach 1:
Each sensor is assigned a unique random current level modification pattern, creating local differentiation in an otherwise identical parallel sensor configuration. This allows each sensor to maintain its unique identity and output characteristics while sharing common wiring infrastructure.
Solution Approach 2:
The patent dynamically changes the current level parameter for each sensor by adding random modifications to their respective output levels. This parameter variation ensures that even when sensors are coupled in parallel, their outputs remain distinguishable through their unique current level signatures.
2Measurement precision
If identification elements on a crankshaft target are used to detect piston position, then basic position detection is achieved, but precise determination of cylinder phase (intake vs exhaust) remains ambiguous
Solution Approach 1:
The camshaft sensor system serves multiple functions: it detects camshaft position, determines cylinder phase (intake or exhaust), and provides synchronization information for variable valve timing control. This multi-functionality resolves the information loss by making a single sensor system capable of providing all necessary phase information.
Solution Approach 2:
The patent introduces an intermediary reduction gear between the crankshaft and camshaft, with a specific gear ratio (1/2). This mechanical intermediary creates a predictable relationship between crankshaft and camshaft rotations, allowing the system to deduce cylinder phase information from camshaft position measurements.
3Measurement precision
If camshaft sensors are added to determine precise cylinder phase information, then phase detection accuracy is improved, but the number of sensors and wiring increases
Solution Approach 1:
The patent merges multiple sensor functions into a unified camshaft sensor system that simultaneously provides position detection, phase determination, and synchronization information. By combining these functions into a single sensor location and signal source, the system achieves precise phase detection without proportionally increasing sensor quantity or wiring complexity.
Data Source
AI summary
Sensor delivering detection information in the form of a variation of a current, including a sensitive portion adapted to detecting the passage of a mobile target, an electronic module able to control and shape signals coming from the sensitive portion, an embedded intelligence module adapted, inter alia, to receive information from an electronic computer and to process and generate information intended for the electronic computer, characterized in that the sensor includes a random-number generation module able to generate a random number.