Multi-Pulse Rocket Ignition Safety Control for Flight Profiles

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Solution Overview

Problem

Existing missile ignition systems for multi-pulse or multi-stage rocket motors lack the ability to selectively control the ignition sequence and timing of multiple rocket motor pulses or stages based on flight profile modes, leading to suboptimal propulsion performance and safety concerns.

Innovation Solution

A modular ignition safety device (ISD) that includes logic circuitry to control the sequential activation of energetic initiators based on flight profile mode selection, allowing for either simultaneous or delayed ignition of rocket motor pulses or stages, with optional inhibition of subsequent ignitions under unstable conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If independent ignition systems are employed for each pulse or stage, then each rocket motor can be ignited independently, but the system complexity increases and selective control capability is reduced

Engineering Contradiction:
Improveselective control capabilityVSAvoidsystem complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines multiple ignition control functions into a single integrated ignition safety device that can control multiple rocket motors. The device uses a unified control architecture with mode selection circuitry that manages all ignition events through one system, reducing overall complexity while maintaining full selective control capability across all pulses or stages.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The ignition safety device is designed as a universal controller that can manage different ignition sequences (simultaneous, sequential, delayed) for multiple rocket motors. The single device performs multiple functions including mode selection, timing control, and safety monitoring for all ignition events, eliminating the need for separate independent systems while preserving adaptability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Productivity

If fixed ignition sequence is used, then system design is simplified, but propulsion performance optimization is limited

Engineering Contradiction:
Improvepropulsion performanceVSAvoidignition control complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The ignition safety device implements dynamic control capability that allows the ignition sequence to be adjusted based on selected flight profile modes. The system can switch between different ignition patterns (simultaneous, sequential, delayed) depending on operational requirements, enabling propulsion performance optimization without requiring multiple fixed systems. The mode selection circuitry provides dynamic adaptability while maintaining a unified control structure.

Inventive Principle:
Principle #15Dynamics

3Power

If simultaneous ignition of all pulses is implemented, then maximum thrust is achieved, but safety risk increases under unstable flight conditions

Engineering Contradiction:
ImprovethrustVSAvoidignition safety
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The ignition safety device incorporates safety monitoring circuitry that can detect unstable flight conditions and provide feedback to the control logic. When instability is detected, the system automatically inhibits subsequent ignition events even if simultaneous ignition was selected, preventing unsafe operation. This feedback mechanism allows the system to maintain high thrust capability under normal conditions while ensuring safety under abnormal conditions.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The device implements preliminary safety checks and inhibition capability before allowing ignition sequences to proceed. The control logic is designed to prevent ignition under unstable conditions by detecting potential hazards in advance and blocking the ignition signal, thereby counteracting the safety risk before it can manifest. This preliminary protective action allows simultaneous ignition to proceed when safe while preventing it when dangerous.

Inventive Principle:
Principle #9Preliminary anti-action

Data Source

PatentEP4248167B1Ignition safety device for a multi-pulse or multi-stage rocket motor system
Publication Date: 2025.10.01 RAYTHEON CO
  • EP4248167B1 patent drawingFigure 1~2
  • EP4248167B1 patent drawingFigure 3~5
  • EP4248167B1 patent drawingFigure 4

AI summary

An ignition safety device (ISD) used in an ignition system of a missile is configured to selectively control the ignition of two or more pulses or stages of a rocket motor propulsion system, based on a flight profile mode selection of a flight velocity mode, in which the missile is configured to travel at an optimized flight velocity, or a flight distance mode, in which the missile is configured to travel an optimized flight distance. The ISD is configured to selectively ignite the pulses or stages substantially simultaneously upon selection of the flight velocity mode, or in a delayed sequential manner upon selection of the flight distance mode. The ISD is also configured to selectively inhibit the delayed sequential ignition of the pulses or stages in the event of incidental ground or water impact of the missile after ignition of the primary pulse or stage.