Sensorless DC Fuel Pump Control via Ripple Extraction

Solution Overview

Problem

Conventional methods for measuring the revolutions per minute (RPM) of a DC motor in a DC fuel pump require complex circuits and current sensors, leading to increased costs and reduced economic efficiency.

Innovation Solution

A sensorless control device that measures and controls the RPM of a DC motor by removing DC and switching components from the input voltage, using a measuring unit, first and second removing units, a delay unit, a square wave generation unit, and a calculation unit to generate a square wave and calculate RPM, eliminating the need for a smoothing circuit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a conventional smoothing circuit and current sensor are used to measure RPM, then the RPM measurement can be achieved, but the device structure becomes complex and costs increase

Engineering Contradiction:

ImproveRPM measurement capabilityVSAvoidcontrol device structure

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts and removes the DC component and switching component from the input voltage signal using removing units, leaving only the ripple component that contains RPM information. This eliminates the need for complex smoothing circuits and current sensors while maintaining RPM measurement capability.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the conventional mechanical/electrical smoothing circuit and current sensor system with an electronic signal processing system that uses removing units, delay units, and square wave generation units to extract RPM information directly from the voltage signal.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If a conventional smoothing circuit and current sensor are used to measure RPM, then the RPM measurement can be achieved, but the manufacturing cost increases

Engineering Contradiction:

ImproveRPM measurement capabilityVSAvoidmanufacturing cost

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent extracts and removes the DC component and switching component from the input voltage signal using removing units, leaving only the ripple component that contains RPM information. This eliminates the need for complex smoothing circuits and current sensors while maintaining RPM measurement capability.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses simple electronic components (removing units, delay units, square wave generation units) that are cheaper and easier to manufacture than conventional current sensors and smoothing circuits, reducing overall manufacturing costs.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Device complexity

If the control device is simplified by removing the smoothing circuit, then the device structure becomes compact and costs decrease, but the RPM measurement must be achieved through alternative methods

Engineering Contradiction:

Improvecontrol device structureVSAvoidRPM measurement difficulty

Core Design Contradiction:

Device complexityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent replaces the conventional mechanical/electrical smoothing circuit and current sensor system with an electronic signal processing system that uses removing units, delay units, and square wave generation units to extract RPM information directly from the voltage signal.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces intermediary processing steps (removing DC component, removing switching component, delaying signal, generating square wave) that transform the raw voltage signal into a form that easily reveals RPM information through counting, simplifying the measurement process.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 solution simplifies the control device structure, reduces costs, and improves economic efficiency by enabling RPM measurement and control without a conventional smoothing circuit, allowing for a downsized control device.

Implementation Method 1

The second removing unit may include a band pass filter or a high pass filter

Methodology Applied

Scientific EffectFiltering: Filter (electronic)

Implementation Method 2

The second removing unit may further include an amplifier disposed at a rear end of the band pass filter or the high pass filter to amplify and output an input signal

Methodology Applied

Scientific EffectAmplification: Magnetic Amplifier

Data Source

PatentUS11326544B2Sensorless control device for DC fuel pump

Publication Date: 2022.05.10 COAVIS

AI summary

Provided is a sensorless control device for a DC fuel pump that may be downsized as compared to a conventional control device for a DC fuel pump and may implement the same operation at a relatively low cost, and the sensorless control device for a DC fuel pump.