Master-Slave Valve Positioning via Digital Network

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing systems face challenges in achieving near simultaneous operation of master and slave valves due to high response times and noise susceptibility in analog communication methods, leading to mechanical vibrations and pressure control instability.

Innovation Solution

Implementing a digital network to couple master and slave valves, where the master valve broadcasts a digital position setpoint over a dedicated network, allowing each slave valve to position itself with minimal time delay and eliminating noise, thereby achieving precise and stable valve control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If analog communication is used between master and slave valves, then communication speed is fast, but noise susceptibility increases leading to reduced accuracy

Engineering Contradiction:

Improvecommunication speedVSAvoidposition accuracy

Core Design Contradiction:

SpeedVSMeasurement precision

Solution Approach 1:

The patent replaces the analog communication system with a digital communication system. Instead of using analog voltage signals (0-10V) that are susceptible to noise, the system uses digital signals transmitted through a communication interface. This substitution eliminates noise interference while maintaining fast communication speed, as digital signals can be cleanly regenerated and are immune to analog noise accumulation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the communication parameter from analog voltage levels to digital signal levels. By converting the position setpoint into digital form and transmitting it through a communication protocol, the system achieves both fast communication (maintaining the speed advantage) and high accuracy (eliminating noise susceptibility). The digital representation allows for precise position commands without the degradation inherent in analog systems.

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If low-pass filters are used to reduce noise in analog signals, then accuracy improves, but response time increases

Engineering Contradiction:

Improvesignal accuracyVSAvoidresponse time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent eliminates the need for low-pass filters by replacing the analog communication path with a digital communication path. Since digital signals are inherently noise-resistant and can be cleanly transmitted without filtering, the system achieves high accuracy without the time delay introduced by filtering operations. The digital communication interface directly transmits position commands without requiring signal conditioning that would slow down the response.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If analog-to-digital conversion is performed at slave valve, then digital processing is enabled, but noise digitization causes jittering of slave valve position

Engineering Contradiction:

Improvedigital processing capabilityVSAvoidvalve position stability

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

Instead of converting analog signals to digital at the slave valve (which digitizes noise and causes jitter), the patent inverts the approach by transmitting digital signals directly to the slave valve. The master valve generates digital position setpoints and transmits them through a digital communication interface, eliminating the A/D conversion step at the slave valve entirely. This inversion prevents noise digitization while maintaining digital processing capabilities.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent replaces the analog A/D conversion process with a digital communication system. By using a digital interface to transmit position commands directly, the system eliminates the need for analog-to-digital conversion at the slave valve. This substitution prevents the digitization of noise and the resulting position jitter, while still enabling full digital processing and control at the slave valve.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Productivity

If multiple slave valves are controlled simultaneously, then system capability increases, but mechanical vibrations and pressure control instability increase

Engineering Contradiction:

Improvesystem capabilityVSAvoidpressure control stability

Core Design Contradiction:

ProductivityVSStability of the object's composition

Solution Approach 1:

The patent replaces the analog communication system with a digital communication system to control multiple slave valves. The digital transmission of position setpoints ensures that each slave valve receives clean, noise-free commands simultaneously. This eliminates the mechanical vibrations caused by noisy analog signals and the resulting pressure control instability, while maintaining the ability to control multiple valves in parallel. The digital communication ensures synchronized and stable operation of all slave valves.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS7643909B2Highly responsive master-slave valve positioning

Publication Date: 2010.01.05 MKS INSTR INC

AI summary

A master valve and at least one slave valve are connected via a network, wherein upon broadcast of a position setpoint of the master valve the at least one slave valve achieves a corresponding position within a shortened period of time, such network being a dedicated network or high speed shared network with position setpoint priority.