Virtual Field Device Control With Consensus Failover

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Solution Overview

Problem

Existing industrial control systems face challenges in achieving high reliability and zero downtime in virtualized and containerized IT/OT converged infrastructure due to software failures and lack of effective reliability mechanisms, leading to potential factory downtime and operational disruptions.

Innovation Solution

A system with a server pool operating multiple instances of virtual control applications in parallel, utilizing a network proxy device to replicate status update messages, perform consensus-based decision-making, and ensure consistent control data transmission to field devices, thereby enhancing reliability and availability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If virtual control applications are deployed on general-purpose hardware, then flexibility and scalability are improved, but reliability deteriorates due to software failures and virtualization layer issues

Engineering Contradiction:

ImproveflexibilityVSAvoidreliability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The system segments the control application into multiple independent virtual instances (vPLCs) that can run in parallel on the same hardware platform. Each instance is isolated and can fail independently without affecting others, allowing the system to maintain flexibility while improving reliability through redundancy.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system pre-configures multiple standby virtual control instances before failures occur. When a failure is detected, a standby instance is already ready to take over immediately, eliminating downtime and ensuring continuous operation without requiring reactive reconfiguration.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If multiple replicas of virtual control applications are run simultaneously, then high-availability is improved, but device complexity increases

Engineering Contradiction:

Improvehigh-availabilityVSAvoiddevice complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The system uses a universal hardware platform that can host multiple virtual control instances simultaneously. This multi-functional approach allows the same physical infrastructure to provide both redundancy and scalability, managing complexity through virtualization rather than requiring separate dedicated hardware for each control instance.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system creates virtual copies of the control application that can be deployed rapidly across the server pool. These copies are lightweight representations that consume minimal additional resources, enabling high-availability without proportionally increasing hardware complexity or cost.

Inventive Principle:

Principle #26Copying

3Reliability

If reactive failover mechanisms are used, then reliability is improved, but downtime occurs during migration process

Engineering Contradiction:

ImprovereliabilityVSAvoiddowntime

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The system pre-configures standby virtual instances with all necessary control logic and state information before failures occur. This preliminary preparation ensures that when a failure is detected, the takeover is immediate and seamless, eliminating the migration downtime that plagues reactive approaches.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system maintains continuous control operation by having standby instances ready to execute immediately upon failure detection. The transition from active to standby instance is designed to be seamless, ensuring that the useful action of controlling field devices continues without interruption or downtime.

Inventive Principle:

Principle #20Continuity of useful action

4Reliability

If consensus-based decision-making is implemented among multiple instances, then reliability is improved, but communication overhead and processing time increase

Engineering Contradiction:

ImprovereliabilityVSAvoidprocessing time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The system implements a simplified consensus mechanism where only a majority vote is required rather than full agreement from all instances. This partial action approach provides sufficient reliability through majority decision-making while significantly reducing the communication overhead and processing time compared to requiring unanimous consensus.

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentEP4647913A1System for controlling a field device, method to operate a system for controlling a field device and method to configure a system for controlling a field device

Publication Date: 2025.11.12 SIEMENS AG

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AI summary

The invention relates to a system (1) for controlling a field device (2), wherein the system (1) comprises a server pool (6) comprising servers for operating instances of a virtual control application; the system (1) comprises a network proxy device (23), configured to receive a status update message from the field device (2), comprising status data, and to send replicated status update messages comprising the status data to each instance of the virtual control application assigned to the field device (2); the network proxy device (23) is configured to receive respective control response messages of each of the instances of the virtual control application and to perform a consensus-based decision making procedure to evaluate consensus control data based on the control data provided by the instances of the virtual control application and to send a control response message comprising the consensus control data to the field device (2).