Gas Sensor Control Apparatus Switching Noise Reduction
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Solution Overview
Problem
Existing gas sensor control systems face challenges in accurately detecting element resistance due to switching noise generated during heater energization, particularly when the detection period overlaps with the switching timing, leading to complex control requirements and potential inaccuracies in resistance measurement.
Innovation Solution
A gas sensor control apparatus that includes change amount detection means, element resistance detection means, and heater energization control means, where the instruction signal for detecting response change amounts is output at a predetermined wait time after the energization state switching, preventing overlap and thus minimizing the impact of switching noise on resistance detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the detection period and heater switching timing are forcedly shifted to prevent overlap, then switching noise interference is reduced, but control complexity increases due to continuous monitoring and adjustment requirements
Solution Approach 1:
The patent applies preliminary action by setting a fixed wait time between the heater switching timing and the detection period start. This predetermined time interval is established in advance to ensure that switching noise has decayed before detection begins, eliminating the need for continuous monitoring and dynamic adjustment while maintaining detection accuracy.
Solution Approach 2:
The patent implements periodic action by establishing a regular, fixed-period timing relationship between heater switching and detection operations. The detection period is scheduled at predetermined intervals with a fixed wait time following each heater switch, creating a rhythmic, predictable operation pattern that simplifies control logic while ensuring noise-free measurements.
2Measurement precision
If the detection period is extended to avoid overlap with switching timing, then switching noise interference is reduced, but detection response time increases
Solution Approach 1:
The patent applies parameter changes by optimizing the wait time parameter to a specific fixed value that balances noise suppression and response time. Rather than extending the detection period unnecessarily, the invention adjusts the wait time parameter to achieve the optimal point where switching noise has sufficiently decayed while maintaining fast detection response.
3Measurement precision
If continuous monitoring of detection period and switching timing is implemented to prevent overlap, then detection accuracy is maintained, but control system complexity and computational load increase
Solution Approach 1:
The patent eliminates continuous monitoring by implementing preliminary action - a fixed wait time is set in advance before each detection operation. This predetermined timing relationship is established once and executed automatically without requiring real-time monitoring or dynamic decision-making, greatly simplifying the control system while ensuring detection accuracy.
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
This configuration allows for accurate detection of element resistance without interference from switching noise, simplifying the control process and ensuring reliable measurements, even under changing pulse width conditions.
Implementation Method 1
a heater section for heating the sensor element section is provided so as to heat the sensor element section to an activation temperature at which the sensor element section becomes active
Implementation Method 2
detecting the element resistance of the sensor element section regularly... temporarily changing the voltage between the electrodes of the sensor element section or the current flowing between the electrodes, detecting the change in voltage or current in response to the temporal change
Data Source
AI summary
A gas sensor control apparatus (1) for controlling a gas sensor (2) includes a change amount detection means (40); an element resistance detection means for detecting the element resistance Rpvs of a sensor element section (3) on the basis of the response change amount ΔVs; a heater energization control section for on-off controlling the supply of electric current to a heater section (4) by pluses PS having a fixed period T; and an instruction signal output section for instructing the change amount detection section (40) to detect the response change amount ΔVs at a third timing t3 which comes after elapse of a predetermined wait time TW from a second timing t2 (heater energization off) which changes in accordance with the pulse width PSW.