Redundant Electronic Acceleration Switch for Missile Arming

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Solution Overview

Problem

Mechanical acceleration monitors used in vehicles and missiles are large, heavy, and prone to single-point failures due to poor electrical properties, making them unreliable for safety-critical applications.

Innovation Solution

An electronic acceleration switch with redundant power sources, sensors, channels, controllers, and a voting logic system is implemented to prevent single-point failures, ensuring high reliability and accuracy by using multiple accelerometers and controllers to validate acceleration data before triggering responses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If mechanical acceleration monitors are used, then reliability is improved, but device complexity and weight increase

Engineering Contradiction:

ImprovereliabilityVSAvoiddevice complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces mechanical acceleration monitors with electronic accelerometers and voting logic circuits. The electronic system uses multiple accelerometers feeding into voting logic that determines when acceleration thresholds are exceeded, eliminating the need for complex mechanical lever systems while maintaining or improving reliability through redundancy.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent divides the acceleration monitoring function into multiple independent channels, each with its own accelerometer and voting logic. This segmentation allows the system to tolerate failures in individual channels while maintaining overall functionality, thereby improving reliability without requiring a single complex mechanical system.

Inventive Principle:

Principle #1Segmentation

2Reliability

If mechanical acceleration monitors are used, then reliability is improved, but weight increases

Engineering Contradiction:

ImprovereliabilityVSAvoidweight

Core Design Contradiction:

ReliabilityVSWeight of stationary object

Solution Approach 1:

The patent replaces heavy mechanical components with lightweight electronic accelerometers and circuitry. The electronic voting logic system weighs far less than mechanical lever systems while providing equivalent or superior reliability through redundant sensing channels and electronic voting mechanisms.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Device complexity

If electronic acceleration monitors are used, then device complexity is reduced, but reliability deteriorates due to single point failure

Engineering Contradiction:

Improvedevice complexityVSAvoidreliability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent segments the electronic monitoring system into multiple independent channels, each with its own accelerometer and voting logic. This segmentation creates redundancy so that if one channel fails, others can continue to provide accurate acceleration monitoring, thereby improving reliability while maintaining electronic simplicity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent incorporates redundant accelerometers and voting logic that are designed to compensate for potential failures before they occur. The voting logic is pre-configured to require agreement from multiple channels before triggering an event, providing a buffer against single-point failures and ensuring continued reliable operation even when components fail.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

4Ease of manufacture

If mechanical contacts are used, then ease of manufacture is improved, but electrical properties deteriorate due to chatter and signal integrity issues

Engineering Contradiction:

Improveease of manufactureVSAvoidelectrical properties

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent eliminates mechanical contacts entirely by using electronic accelerometers that output electrical signals directly. The voting logic is implemented using electronic circuits or software that process these signals without requiring physical contact, thereby eliminating chatter and signal integrity problems while maintaining ease of manufacture through standard electronic components.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS8412482B2Multi channel electronic acceleration switch

Publication Date: 2013.04.02 RAYTHEON CO

AI summary

An electronic acceleration switch, such as for arming and firing a squib, for instance used in arming a warhead, safe missile air, ground and sea launch separation arming, includes multiple redundancies to provide a fail-safe system that does not have a single-point failure. The switch includes different channels, each of which includes a power subsystem, multiple accelerometers, a pair of controllers, and a switching circuit. The power subsystems of the two channels provide power to multiple accelerometers of each channel. The accelerometers of each channel may include a mix of digital and analog accelerometers. The acceleration sensors can be either one-axis or three-axis sensors. The accelerometers are connected to the controllers of both channels. The controllers provide redundancy for each channel. In addition, the controllers include voting logic that receives inputs from the accelerometers, and determines whether to send arm and enable signals to the multiple squib drivers.