Write Filter for Solid-State Memory in Control Systems

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

General-purpose operating systems used in control systems face reliability issues due to the sensitivity of hard disks to physical shock and vibration, and the risk of data loss during power shutdowns, making it difficult to achieve a reliable control system.

Innovation Solution

A control system configuration that uses non-volatile solid-state memory as an auxiliary storage device, in conjunction with a magnetic-disk device, to store critical data and programs, with a write-filter mechanism to protect data in the solid-state memory and prevent accidental rewriting, ensuring data integrity and reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a hard disk is used as auxiliary storage device, then storage capacity and cost are improved, but reliability deteriorates due to sensitivity to physical shock and vibration

Engineering Contradiction:

ImprovereliabilityVSAvoidsensitivity to physical shock and vibration

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the mechanical hard disk system with a non-volatile solid-state memory system. This substitution eliminates moving parts and mechanical components that are susceptible to physical shock and vibration, thereby resolving the contradiction between reliability and sensitivity to physical harmful factors.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If a hard disk is used to store control programs and data, then storage capability is improved, but data integrity deteriorates due to file system vulnerability during power shutdown

Engineering Contradiction:

Improvedata integrityVSAvoidfile system vulnerability during power shutdown

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent replaces the hard disk file system with a non-volatile solid-state memory system that does not rely on traditional file systems. This eliminates the vulnerability of file systems during power shutdown events, as the solid-state memory inherently preserves data without requiring file system operations that are susceptible to power interruptions.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent implements a write filter that buffers write operations before they reach the storage medium. This cushioning mechanism prevents direct write operations that could corrupt data during power shutdown, allowing the system to maintain data integrity even when power is interrupted during normal write operations.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Reliability

If non-volatile solid-state memory is used as auxiliary storage device, then reliability is improved, but storage capacity and cost deteriorate

Engineering Contradiction:

ImprovereliabilityVSAvoidstorage capacity

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent segments the storage system into two parts: non-volatile solid-state memory for storing critical control programs and data that require high reliability, and hard disk for storing less critical data with lower reliability requirements. This segmentation allows the system to achieve high reliability for essential functions while maintaining adequate total storage capacity and controlling costs.

Inventive Principle:

Principle #1Segmentation

4Reliability

If non-volatile solid-state memory is used as auxiliary storage device, then data loss is reduced, but system cost deteriorates

Engineering Contradiction:

Improvedata loss preventionVSAvoidsystem cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent segments the storage system to use non-volatile solid-state memory only for critical control programs and data, rather than entirely replacing the hard disk. This selective application reduces the overall system cost while still achieving the primary goal of preventing data loss for essential system components.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies high-reliability non-volatile solid-state memory specifically to the local area where control programs and critical data are stored, rather than uniformly across the entire storage system. This localized application of high-quality storage media achieves data loss prevention for critical functions while controlling overall system cost.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS7478207B2Control system with a write filter for protection of data

Publication Date: 2009.01.13 SEIKO EPSON CORP

AI summary

A control system configured to control a predetermined unit by using a control program running on a general-purpose OS. The control system includes an auxiliary storage device configured to store the general-purpose OS, the control program, and various data items required for the control program to run, and a main storage device on which each of the general-purpose OS and the control program are loaded when they are executed. The entire auxiliary storage device is constituted by a silicon disk, or by a hard disk and the silicon disk.