Actuator Controller Flow Sensor Placement

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing actuator controllers face challenges in ensuring a simple structure and reliable movement control for fluidically operable actuators, particularly due to the high pressure levels in feed lines which complicate flow sensor design and accuracy.

Innovation Solution

A flow sensor is placed between the discharge line valve and the fluid outlet, allowing for a lower pressure environment that simplifies the sensor's construction and enhances measurement accuracy, while a control device uses flow signals to manage valve activations for precise movement control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the flow sensor is installed in the feed line, then the measurement can be performed at the source, but the high pressure level complicates the sensor construction and reduces measurement accuracy

Engineering Contradiction:

Improveflow measurement accuracyVSAvoidsensor construction complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

Instead of placing the flow sensor in the high-pressure feed line (conventional approach), the patent inverts the placement to the low-pressure discharge line between the discharge line valve and the fluid outlet. This reversal allows the use of simpler, lower-cost sensors while maintaining measurement accuracy, as the working fluid has already discharged and pressure losses are negligible.

Inventive Principle:

Principle #13The other way round (Inversion)

2Measurement precision

If a high-pressure flow sensor is used in the feed line, then accurate measurement is possible, but the sensor cost and complexity increase significantly

Engineering Contradiction:

Improveflow measurement accuracyVSAvoidsensor manufacturing cost

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent changes the pressure parameter of the measurement environment by relocating the flow sensor from the high-pressure feed line to the low-pressure discharge line. This parameter change allows the use of simpler, lower-cost sensor designs that cannot withstand high pressures, thereby reducing manufacturing costs while maintaining measurement functionality.

Inventive Principle:

Principle #35Parameter changes

3Stress or pressure

If the discharge line valve is activated to restrict flow, then the pressure level in the discharge line decreases, but the actuator movement control becomes more challenging

Engineering Contradiction:

Improvepressure level in discharge lineVSAvoidactuator movement control

Core Design Contradiction:

Stress or pressureVSEase of operation

Solution Approach 1:

The patent implements a closed-loop control system where the flow sensor provides real-time feedback on the actual fluid flow rate to the control device. The control device uses this feedback to continuously adjust the discharge line valve activation, optimizing both pressure reduction and actuator movement control. This feedback mechanism resolves the contradiction by dynamically balancing the two opposing requirements.

Inventive Principle:

Principle #23Feedback

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 configuration enables a low-cost, high-accuracy flow measurement system that effectively controls actuator movement by influencing fluid flow rates, suitable for both single-acting and double-acting actuators, with optional pressure sensor integration for enhanced precision.

Implementation Method 1

a flow sensor, which is designed to determine a fluid flow rate in the discharge line and to provide a flow signal

Methodology Applied

Scientific EffectFlow measurement:

Implementation Method 2

the feed line is assigned a feed line valve and the discharge line is assigned a discharge line valve, each of which is designed to influence a fluid flow rate at the actuator port

Methodology Applied

Scientific EffectFluid flow control:

Implementation Method 3

an average pressure of the working fluid flowing through the flow sensor is at a lower level than if the flow sensor were installed into the feed line, where the supply pressure for the pressurised working fluid is applied

Methodology Applied

Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentUS10697476B2Actuator controller and method for regulating the movement of an actuator

Publication Date: 2020.06.30 FESTO AG & CO KG

AI summary

An actuator controller for actuating an actuator which can be operated fluidically, having a feed line for an inflow of the working fluid to an actuator connector and having a discharge line for an outflow of the working fluid to a fluid outlet, wherein the feed line is assigned a feed line valve and the discharge line is assigned a discharge valve, which valves are configured in each case to influence a volumetric fluid flow at the actuator connector, and having a control device for actuation of the feed line valve and the discharge valve. A throughflow sensor is arranged in a line section between the discharge valve and the fluid outlet, which throughflow sensor is configured for determining a volumetric fluid flow in the discharge line and for providing a throughflow signal.