Pressure Regulator Control Using Solenoid Current Waveform

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Solution Overview

Problem

Existing pressure regulators face challenges in rapidly and effectively responding to variations in inlet pressure without using an inlet pressure sensor, leading to increased complexity, dimensions, and costs.

Innovation Solution

The pressure regulator employs an engaging current analysis circuit to detect variations in the solenoid current waveform of the electromagnetic valve, allowing for real-time monitoring of inlet pressure changes and providing modulation signals to the control circuit to stabilize outlet pressure, thereby eliminating the need for an inlet pressure sensor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an inlet pressure sensor is added to detect inlet pressure variations, then the response speed and stability to inlet pressure fluctuations is improved, but the device complexity, dimensions, and costs increase

Engineering Contradiction:
Improvestability of outlet pressureVSAvoidcomplexity of pressure regulator
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses the solenoid current waveform as an intermediary signal that indirectly reflects inlet pressure variations. Instead of directly measuring inlet pressure with a sensor, the system monitors changes in the solenoid's engaging current waveform, which are caused by inlet pressure fluctuations affecting the magnetic field and core movement. This intermediary approach provides inlet pressure information without adding a dedicated pressure sensor.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system uses its own existing components (solenoid, current waveform) to detect inlet pressure variations. The solenoid's operational characteristics naturally change with inlet pressure, and these changes are captured by monitoring the current waveform. This self-service approach eliminates the need for external inlet pressure sensing equipment.

Inventive Principle:
Principle #25Self-service

2Device complexity

If traditional feedback control is used with outlet pressure sensor only, then the device structure is simple, but the response to inlet pressure variations is delayed and causes oscillations

Engineering Contradiction:
Improvesimplicity of regulator structureVSAvoiddelay in control response
Core Design Contradiction:
Device complexityVSLoss of time

Solution Approach 1:

The system performs preliminary detection of inlet pressure variations by monitoring the solenoid current waveform before these variations fully manifest as outlet pressure deviations. By detecting the changes in the engaging current waveform early in the process, the control system can anticipate and respond to inlet pressure fluctuations before they cause significant outlet pressure errors, reducing control delays and oscillations.

Inventive Principle:
Principle #10Preliminary action

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 approach enables the pressure regulator to respond quickly and stably to inlet pressure fluctuations, reducing oscillations and delays in control, while maintaining proportional outlet pressure without the added complexity and cost of an inlet pressure sensor.

Implementation Method 1

an electromagnetic valve (18), in particular the loading electromagnetic valve, comprises an electromagnet formed by a solenoid

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

an engaging current analysis circuit (40) configured to: detect and store reference characteristics of the waveform of the engaging current Is of the solenoid

Methodology Applied
Scientific EffectElectrical resistance measurement: Electrical Resistance

Data Source

PatentEP3775643B1Pressure regulator
Publication Date: 2022.05.04 CAMOZZI AUTOMATION SPA
  • EP3775643B1 patent drawingFigure 1~3
  • EP3775643B1 patent drawingFigure 2~1a
  • EP3775643B1 patent drawingFigure 4

AI summary

A pressure regulator comprises an outlet pressure sensor (16), a loading electromagnetic valve (18), an unloading electromagnetic valve (20) and a regulator control circuit (30) operatively connected to the loading electromagnetic valve (18) and to the unloading electromagnetic valve (20) and configured to pilot the loading electromagnetic valve (18) and the unloading electromagnetic valve (20) so as to cancel an error signal given by the difference between an inlet signal corresponding to the desired outlet pressure and a feedback signal provided by the outlet pressure sensor. The regulator further comprises an engaging current analysis circuit configured to: a) detect and store reference characteristics of the waveform of the engaging current of the solenoid of the loading electromagnetic valve in a stable inlet pressure condition; b) monitor, during the operation of the regulator, the waveform of said engaging current so as to detect any variations of its characteristics with respect to the corresponding reference characteristics; c) in the event of variation, provide a pilot modulation signal to the loading electromagnetic valve (18) and/or the unloading electromagnetic valve (20) and/or a pressure variation signal to the control circuit (30).