Guidance Controls for Non-Gaussian Target Tracking

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Solution Overview

Problem

Guidance systems face challenges in navigating a pursuer to a target with non-Gaussian statistics, as existing methods struggle to provide optimal control strategies that minimize miss distance and pursuer maneuvering costs while adhering to state constraints, especially when the target location cannot be described using Gaussian probability distributions.

Innovation Solution

A method that involves generating candidate guidance controls, evaluating their costs based on projected pursuer trajectories and miss distances, and iteratively refining these controls using an optimization algorithm, such as a swarm algorithm, to determine the optimal guidance control for navigating the pursuer to a target with non-Gaussian statistics, considering pursuer state constraints and termination conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If Particle Filtering is used to represent non-Gaussian target probability distribution, then target location estimation capability is improved, but guidance control optimization becomes more difficult

Engineering Contradiction:
Improvetarget location estimationVSAvoidguidance control optimization
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The guidance problem is segmented into two independent parts: (1) target state estimation using Particle Filter, and (2) guidance control optimization using swarm algorithms. This segmentation allows each sub-problem to be solved independently with appropriate methods, resolving the complexity issue while maintaining estimation precision.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention introduces an intermediary cost function that bridges the particle filter output and the guidance control optimization. The cost function incorporates both miss distance and control effort, allowing the non-Gaussian target distribution to be translated into a form suitable for swarm-based optimization without direct coupling between the estimation and control modules.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If optimal guidance control is determined by minimizing cost function, then miss distance is reduced, but computational complexity increases

Engineering Contradiction:
Improvemiss distanceVSAvoidcomputational complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The invention replaces traditional analytical or numerical optimization methods with swarm-based optimization algorithms. This substitution allows for parallel computation of multiple candidate controls, reducing the computational burden of finding the optimal control that minimizes the cost function while achieving minimal miss distance.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The swarm algorithm evaluates multiple candidate controls simultaneously, using a population-based approach where not all candidates need to be perfectly optimized. This partial action approach allows the system to find sufficiently good solutions with reduced computational complexity compared to exhaustive optimization methods.

Inventive Principle:
Principle #16Partial or excessive action

3Use of energy by moving object

If guidance law minimizes control effort, then maneuvering cost is reduced, but miss distance may increase

Engineering Contradiction:
Improvecontrol effortVSAvoidmiss distance
Core Design Contradiction:
Use of energy by moving objectVSManufacturing precision

Solution Approach 1:

The cost function uses parameter weighting to balance control effort and miss distance. By adjusting the relative weights of these parameters in the cost function, the system can optimize the trade-off between maneuvering cost and accuracy, finding the optimal guidance control that achieves acceptable miss distance with minimal control effort.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2609475B1Guidance method and apparatus
Publication Date: 2016.01.06 MBDA UK
  • EP2609475B1 patent drawingFigure 1
  • EP2609475B1 patent drawingFigure 2
  • EP2609475B1 patent drawingFigure 3

AI summary

A method of guiding a pursuer to a target is provided, and is of particular use when the possible target location is described by non-Gaussian statistics. Importantly, the method takes into account the fact that different potential target tracks in the future have significantly different times to go. That can give rise to emergent behaviour, in which the guidance method covers several possible outcomes at the same time in an optimal way. An example embodiment of the method combines Particle Filter ideas with Swarm Optimization techniques to form a method for generating guidance commands for systems with non- Gaussian statistics. That example method is then applied to a dynamic mission planning example, to guide an airborne pursuer to a ground target travelling on a network of roads where the pursuer has no-go areas, to avoid collateral damage.