Fluid Quantity Estimation Using Sliding Average During Vehicle Stops

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Solution Overview

Problem

Existing methods for estimating the quantity of consumable fluids in vehicle tanks face inaccuracies due to vehicle dynamics and positioning, leading to unreliable measurements and potential false alarms, especially when the vehicle is stationary but not horizontal.

Innovation Solution

A method that takes multiple measurements during successive vehicle stoppages, uses a sliding average to stabilize values, and discards non-relevant measurements, leveraging existing gauge-type measuring means and engine control system data without additional devices, to improve measurement reliability and accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If gauge-type measuring means are used to measure fluid level in the reservoir, then the measurement can be performed continuously, but the measurement precision deteriorates due to vehicle dynamics and positioning variations

Engineering Contradiction:
Improvecontinuous measurement capabilityVSAvoidfluid level measurement accuracy
Core Design Contradiction:
Duration of action of moving objectVSMeasurement precision

Solution Approach 1:

The system performs preliminary actions by collecting multiple fluid level measurements during successive vehicle stoppages before making a final assessment. Instead of relying on a single measurement during vehicle operation, the system accumulates data points during stationary periods when the vehicle is stopped, ensuring measurements are taken when fluid motion is minimized.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system implements feedback by using the control unit to process multiple measurements and determine when the fluid level has stabilized within a predetermined range. The control unit continuously monitors measurements and provides feedback on whether the fluid level assessment should be accepted or if further measurements are needed, adjusting the assessment process based on the stability of consecutive readings.

Inventive Principle:
Principle #23Feedback

2Reliability

If multiple measurements are taken during vehicle stoppages to improve accuracy, then the measurement reliability is improved, but the time required for assessment increases

Engineering Contradiction:
Improvemeasurement reliabilityVSAvoidtime for fluid level assessment
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system applies periodic action by taking measurements at regular intervals during vehicle stoppages rather than continuously. The control unit is configured to take a predetermined number of measurements during each stop period, then assess whether the fluid level has stabilized. This periodic sampling approach balances the need for reliable data with time efficiency.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system changes parameters by adjusting the assessment criteria based on the stability of measurements. The control unit monitors whether consecutive measurements fall within a predetermined range and adjusts the number of measurements required and the timing of assessments based on the observed fluid level stability, optimizing the balance between reliability and time consumption.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If measurements are taken when the vehicle is stationary, then the impact of vehicle motion on measurement accuracy is reduced, but the system cannot account for fluid dynamics that occur during vehicle movement

Engineering Contradiction:
Improvemeasurement accuracy during stationary phaseVSAvoidfluid dynamics information during vehicle operation
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The system extracts the measurement process from the vehicle motion context by specifically performing measurements during vehicle stoppages. The control unit identifies when the vehicle is stationary and isolates these time periods for measurement, separating the measurement function from the dynamic vehicle operation to eliminate motion-induced measurement errors.

Inventive Principle:
Principle #2Taking out (Extraction)

4Measurement precision

If additional sensors or devices are added to measure vehicle horizontality and correct measurements, then the measurement accuracy is improved, but the device complexity increases

Engineering Contradiction:
Improvemeasurement accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system applies self-service by using the vehicle's existing stoppage detection capabilities and control unit to perform the measurement stabilization assessment. The control unit that already manages vehicle operations is leveraged to also handle the fluid level measurement logic, eliminating the need for separate dedicated hardware for stop detection and measurement control.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP2834605B1Method of estimating fluid quantity of a consumable fluid reservoir of a motor vehicle
Publication Date: 2020.03.11 PSA AUTOMOBILES SA
  • EP2834605B1 patent drawingFigure 1A~2

AI summary

The invention relates to a method of estimating the quantity of fluid in a consumable-fluid reservoir of a motor vehicle, which reservoir is equipped with at least one means for measuring said quantity, in particular of the gauge type, such that it comprises establishing a sliding average on fluid quantity measurements by said means during a plurality of successive vehicle stopping phases.