Backup Controller Switching for Real-Time Failure Recovery

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing control systems face challenges in ensuring real-time recovery when a failure occurs, as data compatibility issues between different systems hinder immediate switching to backup control software, compromising the real-time property of the system.

Innovation Solution

A controller that backs up state values and necessary input values in a time series, allowing for quick recovery by using these backed-up values to restore the backup control software, ensuring the system's availability and safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If data are saved in backup before failure and copied to newly activated system, then recovery speed is improved, but real-time property cannot be guaranteed due to data incompatibility and initialization time

Engineering Contradiction:
Improverecovery timeVSAvoidreal-time property
Core Design Contradiction:
Loss of timeVSReliability

Solution Approach 1:

The patent applies preliminary action by pre-initializing required data in the backup control system before failure occurs. The backup ECU pre-loads and initializes control data, state variables, and parameters during normal operation, so that when switching occurs, the backup system is already prepared and can immediately take over without requiring time-consuming initialization processes, thus ensuring real-time recovery property

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses copying by transferring pre-initialized control data from the active ECU to the backup ECU during normal operation. The backup system maintains a synchronized copy of essential data including control parameters, state variables, and operational data, enabling immediate takeover without data incompatibility issues or re-initialization delays

Inventive Principle:
Principle #26Copying

2Reliability

If all data are backed up for recovery, then recovery completeness is improved, but data compatibility issues between different control systems prevent successful recovery

Engineering Contradiction:
Improverecovery completenessVSAvoiddata compatibility
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent applies local quality by selectively backing up only the specific control data and parameters that are essential for recovery, rather than all system data. The backup ECU stores pre-initialized data in the same formats and structures as the active ECU, ensuring compatibility. This targeted approach to data selection and formatting ensures that the backed-up data can be directly used by the backup control system without compatibility issues

Inventive Principle:
Principle #3Local quality

3Measurement precision

If deficient data are gradually initialized by applying calculation results, then data accuracy is improved, but recovery time increases and real-time property is compromised

Engineering Contradiction:
Improvedata accuracyVSAvoidinitialization time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies preliminary action by pre-calculating and pre-initializing all required control data during normal operation before failure occurs. The active ECU continuously updates and maintains accurate control data including state variables, parameters, and calculation results in the backup ECU during normal operation. When failure occurs, this pre-initialized accurate data is immediately available, eliminating the need for time-consuming gradual initialization after failure

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3614216B1controller
Publication Date: 2022.11.23 HITACHI LTD
  • EP3614216B1 patent drawingFigure 1~2
  • EP3614216B1 patent drawingFigure 3
  • EP3614216B1 patent drawingFigure 4~5

AI summary

Fail operational that can guarantee stability of control while suppressing cost increase is difficult. A control controller according to the present invention stores information necessary for recovery in a normal travel mode in time series in a backup, and thus control software can be recovered from the backup in real time if a failure occurs in the system.