Capacitive Oil Level Sensor in Vehicle Oil Pan

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Solution Overview

Problem

Conventional methods for monitoring oil levels in motor vehicle oil pans are manual and inefficient, requiring a removable dipstick, which is not always accurate and requires frequent manual checks.

Innovation Solution

An integrated capacitive sensor system within the oil pan that uses multiple sensors to measure oil levels, communicating with a vehicle's computer system via wireless technology, providing accurate readings regardless of the vehicle's orientation and automating oil level monitoring.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If manual dipstick monitoring is used, then device complexity is reduced, but measurement precision and reliability are degraded

Engineering Contradiction:
Improveoil level measurement accuracyVSAvoidsensor system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical dipstick system with an electrical capacitive sensor system. The capacitive sensor detects oil level by measuring changes in capacitance as the oil level rises or falls, eliminating the need for manual mechanical measurement while significantly improving measurement precision and enabling automated monitoring.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The capacitive sensor system operates autonomously without requiring manual intervention. The sensor continuously monitors oil level and automatically transmits data to the vehicle's computer system, allowing the system to self-monitor and provide continuous feedback without human involvement, thereby improving both precision and reliability.

Inventive Principle:
Principle #25Self-service

2Productivity

If manual dipstick monitoring is used, then ease of operation is maintained, but productivity is degraded

Engineering Contradiction:
Improveoil level monitoring efficiencyVSAvoidsystem operation simplicity
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The capacitive sensor provides continuous oil level monitoring rather than periodic manual checks. The sensor continuously measures the oil level and maintains constant communication with the vehicle's computer system, ensuring uninterrupted monitoring that significantly improves productivity and monitoring efficiency.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The manual mechanical dipstick operation is replaced with an automated electrical sensing system that continuously operates without requiring user action, thereby dramatically improving monitoring efficiency while the simple wireless communication interface maintains ease of operation.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Loss of time

If conventional dipstick method is used, then device complexity is minimized, but loss of time is increased

Engineering Contradiction:
Improvetime for oil level checksVSAvoidintegrated sensor system
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The capacitive sensor is pre-installed and continuously ready to measure oil level without requiring any preparatory actions by the user. The system is already in position and actively monitoring, eliminating the time required for manual dipstick insertion, removal, and reading interpretation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The time-consuming manual mechanical process of inserting, removing, and reading the dipstick is replaced by an instantaneous electrical capacitance measurement that occurs automatically and continuously, reducing the time for oil level assessment from multiple seconds or minutes to essentially zero.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Extent of automation

If automated sensor system is implemented, then extent of automation is improved, but device complexity increases

Engineering Contradiction:
Improveoil level monitoring automationVSAvoidsensor and communication system
Core Design Contradiction:
Extent of automationVSDevice complexity

Solution Approach 1:

The manual mechanical monitoring system is replaced with an automated electrical sensing and communication system. The capacitive sensor automatically detects oil level changes and the wireless communication module automatically transmits data to the vehicle's computer, achieving high automation through electrical systems that, while more complex mechanically, simplify the overall operational complexity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The capacitive sensor serves multiple functions: it measures oil level, provides continuous monitoring, and communicates with the vehicle's existing computer system through standard wireless protocols. This multi-functionality justifies the increased device complexity by delivering comprehensive automated monitoring capabilities that integrate with the vehicle's existing infrastructure.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

The system provides accurate, automated, and continuous monitoring of oil levels, reducing maintenance needs and ensuring optimal oil levels are maintained, enhancing vehicle performance and longevity.

Implementation Method 1

the sensor plate is exposed to the reservoir and the capacitance of the sensor plate is measured

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

the capacitance of the sensor plate is measured to determine an oil level in the oil pan

Methodology Applied
Scientific EffectDielectric: Dielectric

Data Source

PatentEP3256823B1Oil pan with integrated capacitive sensor for measuring oil level
Publication Date: 2022.08.17 FLEXTRONICS AP LLC
  • EP3256823B1 patent drawingFigure 1
  • EP3256823B1 patent drawingFigure 2
  • EP3256823B1 patent drawingFigure 3

AI summary

Embodiments provide an oil pan that includes an oil pan having a reservoir configured to hold oil and defined by one or more oil pan walls and an oil pan bottom. The oil pan includes one or more capacitance sensors coupled to a portion of the oil pan walls and configured to sense a capacitance. The oil pan includes a capacitance measuring unit electrically connected to the one or more sensors via one or more conductors and configured to receive each of the sensed capacitances via the one or more conductors and determine capacitance values for each of the sensed capacitances. The oil pan also includes a processor configured to receive the capacitance values and determine the oil level in the oil pan based on the capacitance values.