SMA Valve Positioner Actuation Without a Pneumatic Pilot Stage

Solution Overview

Problem

Conventional pneumatic actuators for industrial applications face inefficiency and high costs due to the need for constant blow-off of pneumatic medium, leading to complex and bulky designs, as they require both high pneumatic pressure and low power consumption, which is achieved through a balanced main stage and controllable pilot stage configuration.

Innovation Solution

The use of a shape memory alloy (SMA) actuation element directly coupled to the valve positioner, allowing for electrical control and reducing the need for pneumatic pressure, thereby eliminating the pilot stage and pressure reducer, resulting in a more efficient and compact system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stress or pressure

If a balanced main stage and controllable pilot stage configuration is used, then high pneumatic pressure operation is achieved, but the system becomes complex and bulky

Engineering Contradiction:

Improvepneumatic pressureVSAvoidsystem complexity

Core Design Contradiction:

Stress or pressureVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the pilot stage from the system, using a shape memory alloy actuator to directly control the main stage. This removes the complex subsystem that was needed to control pneumatic pressure, while still achieving the required high pressure operation through the intelligent material's direct mechanical action.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the pneumatic control system (pilot stage with pneumatic pressure control) with a shape memory alloy actuator that uses thermal-mechanical properties. This substitution eliminates the need for complex pneumatic control mechanisms while maintaining the ability to achieve high pneumatic pressure through direct mechanical actuation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Stress or pressure

If a balanced main stage and controllable pilot stage configuration is used, then high pneumatic pressure operation is achieved, but the system becomes bulky

Engineering Contradiction:

Improvepneumatic pressureVSAvoidsystem volume

Core Design Contradiction:

Stress or pressureVSVolume of moving object

Solution Approach 1:

The patent extracts and eliminates the pilot stage from the system, using a shape memory alloy actuator to directly control the main stage. This removes the complex subsystem that was needed to control pneumatic pressure, while still achieving the required high pressure operation through the intelligent material's direct mechanical action.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the functions of the pilot stage and main stage into a single integrated system controlled by the shape memory alloy actuator. The SMA element directly acts on the diaphragm and valve mechanism, combining what were previously separate control and execution functions into one compact unit.

Inventive Principle:

Principle #5Merging (Combining)

3Use of energy by moving object

If a pilot stage is used to control pneumatic pressure, then low power consumption is achieved, but constant blow-off of pneumatic medium occurs leading to inefficiency

Engineering Contradiction:

Improvepower consumptionVSAvoidpneumatic medium loss

Core Design Contradiction:

Use of energy by moving objectVSLoss of energy

Solution Approach 1:

The patent replaces the pneumatic control system (pilot stage with pneumatic pressure control) with a shape memory alloy actuator that uses thermal-mechanical properties. This substitution eliminates the need for complex pneumatic control mechanisms while maintaining the ability to achieve high pneumatic pressure through direct mechanical actuation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The shape memory alloy actuator operates through periodic heating and cooling cycles to achieve actuation and reset. This periodic thermal action replaces the continuous pneumatic blow-off, allowing the system to consume energy only when position changes are needed, thereby eliminating constant pneumatic medium loss.

Inventive Principle:

Principle #19Periodic 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 solution provides a robust, energy-efficient, and compact pneumatic positioner system that is less sensitive to temperature changes and external vibrations, reducing air consumption and enabling efficient operation with reduced design complexity and cost.

Implementation Method 1

The shape memory alloy actuation element is configured to be controlled by electrical current

Methodology Applied

Scientific EffectResistive heating: Joule Heating

Implementation Method 2

a shape memory alloy (SMA) actuation element, also named 'SMA actuator' for controlling a valve positioner with pneumatic output

Methodology Applied

Scientific EffectShape memory alloy effect: Shape Memory Alloy

Data Source

PatentUS20240318742A1Shape Memory Alloy Actuator for Controlling a Valve Positioner with Pneumatic Output

Publication Date: 2024.09.26 ABB (SCHWEIZ) AG

AI summary

A positioner drive for controlling a pneumatic positioner, is described with a shape memory alloy actuation element, wherein the shape memory alloy actuation element is configured to be mechanically coupled to a valve of the valve positioner with pneumatic output for controlling the pneumatic positioner.