Guided Projectile Maneuver Envelopes for Range Cross-Range Control

Solution Overview

Problem

Guided projectiles face challenges in optimizing corrective maneuvers for range and cross-range movements, as these actions often come at the expense of the other direction's control authority, due to complex relationships between ground impact points and control actions during flight.

Innovation Solution

The use of maneuver envelopes that describe control actions versus time allows for optimal timing of corrective maneuvers, enabling efficient use of limited control authority by predicting impact points and determining maneuver commands based on launch velocity and quadrant elevation, thereby optimizing range and cross-range corrections without compromising the other direction's control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If corrective maneuvers are performed to effect changes in range or cross-range, then the impact point accuracy is improved, but the control authority in the other direction is compromised

Engineering Contradiction:

Improveimpact point accuracyVSAvoidcontrol authority

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent applies dynamics by making the control system adaptive through maneuver envelopes that are updated in real-time based on current flight conditions. The control authority is dynamically adjusted according to the projectile's state, allowing optimal control decisions that account for changing aerodynamic characteristics and remaining flight time, thereby resolving the contradiction between maintaining impact accuracy and preserving control authority.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes parameters by using maneuver envelopes that incorporate current flight conditions (velocity, altitude, time-to-go) to determine optimal control actions. By continuously updating the control parameters based on the projectile's state and the maneuver envelope data, the system can make corrective maneuvers that maintain both impact point accuracy and control authority throughout the flight trajectory.

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If control commands are generated to correct cross-range errors, then cross-range accuracy is improved, but range control authority deteriorates

Engineering Contradiction:

Improvecross-range accuracyVSAvoidrange control authority

Core Design Contradiction:

Measurement precisionVSManufacturing precision

Solution Approach 1:

The patent segments the control problem into independent range and cross-range components by using maneuver envelopes that separately characterize control effectiveness in each direction. This allows the control system to evaluate and execute corrections in one direction without adversely affecting the other, as each direction's control authority is independently assessed and optimized through the segmented maneuver envelope approach.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies dynamics by making the control system adaptive through maneuver envelopes that are updated in real-time based on current flight conditions. The control authority is dynamically adjusted according to the projectile's state, allowing optimal control decisions that account for changing aerodynamic characteristics and remaining flight time, thereby resolving the contradiction between maintaining impact accuracy and preserving control authority.

Inventive Principle:

Principle #15Dynamics

3Measurement precision

If corrective maneuvers are performed early in flight, then impact point correction capability is improved, but control authority for subsequent maneuvers is reduced

Engineering Contradiction:

Improveimpact point correction capabilityVSAvoidcontrol authority duration

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies preliminary action by using maneuver envelopes that are pre-computed for different flight conditions and times-to-go. The control system uses these pre-prepared envelopes to determine the optimal timing and magnitude of corrective maneuvers, ensuring that actions are taken at the most effective moments without depleting control authority prematurely, thus balancing early correction capability with sustained control authority.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent applies dynamics by making the control system adaptive through maneuver envelopes that are updated in real-time based on current flight conditions. The control authority is dynamically adjusted according to the projectile's state, allowing optimal control decisions that account for changing aerodynamic characteristics and remaining flight time, thereby resolving the contradiction between maintaining impact accuracy and preserving control authority.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS11555680B2Method for controlling a projectile with maneuver envelopes

Publication Date: 2023.01.17 BAE SYSTEMS INFORMATION ANDELECTRONIC SYSTEMS INTEGRATION INC

AI summary

A guided projectile including a precision guidance munition assembly utilizes at least one maneuver envelope to optimally control movement of at least one canard to steer the guided projectile during flight. The maneuver envelopes optimize movements of the at least one canard that effectuate movement in either the range direction or the cross-range direction, or both. The maneuver envelope enables optimal timing such that maneuvering in one direction does not come at the expense of maneuver authority in the other direction.