Reductant Delivery Diagnostic System for Exhaust Aftertreatment
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Solution Overview
Problem
Conventional systems for determining reductant delivery performance in exhaust aftertreatment systems are inaccurate due to sensitivity to vehicle operation cycles, installation variations, and manufacturing tolerances, leading to unreliable diagnostic separation between healthy and failed systems.
Innovation Solution
A system and method that utilize signal processing to interpret pump parameters and dosing parameters at multiple positions, allowing for a more accurate determination of reductant delivery performance by distinguishing between under-restricted and over-restricted delivery mechanisms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional systems are used to determine reductant delivery performance, then the system is simpler to implement, but the measurement precision is poor due to sensitivity to vehicle operation cycles, installation variations, and manufacturing tolerances
Solution Approach 1:
The patent segments the reductant delivery system into multiple measurement positions along the delivery path. By measuring at multiple positions and processing the signals from each position, the system achieves more accurate delivery performance determination while compensating for variations and tolerances in the system components.
Solution Approach 2:
The patent transitions from single-point measurement to multi-position measurement along the reductant delivery path. This dimensional expansion from one position to multiple positions enables more comprehensive signal processing and more accurate determination of delivery performance, reducing sensitivity to local variations.
2Reliability
If multiple measurement positions are used to improve diagnostic accuracy, then the measurement precision improves, but the device complexity increases
Solution Approach 1:
The patent divides the measurement system into multiple segments corresponding to different positions in the reductant delivery path. Each position has its own measurement capability, and the combined signals from all segments provide more reliable diagnostic information about system health and performance.
Solution Approach 2:
The patent implements signal processing that compares measured values from multiple positions against expected values or thresholds. This feedback mechanism enables the system to reliably diagnose delivery mechanism status and alert operators to potential issues, improving overall diagnostic reliability.
Data Source
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AI summary
An apparatus includes a pump, a delivery mechanism in fluid communication with the pump, and a controller communicatively coupled to the pump and the delivery mechanism. The controller is structured to interpret, via a pump diagnostic circuit, first and second pump parameters indicative of first and second pump rates, interpret, via a dosing diagnostic circuit, first and second dosing parameters indicative of at least one of (i) first and second reductant flows or (ii) first and second injector characteristics, determine, via a delivery diagnostic circuit, a delivery status based, at least in part, on the interpretation of the first and second pump parameters and the first and second dosing parameters, and generate, via the delivery diagnostic circuit, a status command indicative at least one of an under-restricted delivery mechanism or an over-restricted delivery mechanism in response to the determination of the delivery status.