Measurement Node Selection for Dynamic Network State Tracking

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Solution Overview

Problem

Existing state estimation systems are slow and prone to noise, making them ineffective for real-time selection of measurement nodes and full-state reconstruction in dynamic systems, especially in the presence of noisy measurements and process noise.

Innovation Solution

A system that represents a distributed physical system as a multi-layer network, models network dynamics using hybrid partial differential equations, and determines a minimal set of measurement nodes for full-state observability, allowing for real-time reconstruction and tracking of system states using a Kalman filter.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If existing state estimation systems are used, then system state can be estimated, but the system is slow and subject to noise

Engineering Contradiction:
Improvestate estimation accuracyVSAvoidreal-time processing capability
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system segments the state estimation process into distinct phases: measurement node selection based on observability analysis, initial state reconstruction using selected nodes, and subsequent state tracking using Kalman filtering. This segmentation allows each component to be optimized independently, achieving both accuracy and real-time performance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system performs preliminary measurement node selection and initial state reconstruction before actual tracking begins. By pre-identifying the minimal set of measurement nodes that provide full-state observability, the system avoids computational delays during real-time operation, enabling fast state tracking.

Inventive Principle:
Principle #10Preliminary action

2Loss of information

If measurement nodes are selected for full-state observability, then complete system state can be reconstructed, but the system is subject to noisy measurements and process noise

Engineering Contradiction:
Improvefull-state reconstruction capabilityVSAvoidrobustness to noise
Core Design Contradiction:
Loss of informationVSReliability

Solution Approach 1:

The system implements feedback through the Kalman filter, which continuously compares predicted states with actual measurements and adjusts estimates accordingly. This feedback mechanism allows the system to maintain full-state reconstruction capability while filtering out noise and adapting to process disturbances in real-time.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts estimation parameters through the Kalman filter, including the Kalman gain which balances trust between predictions and measurements. By adapting these parameters based on noise characteristics and system dynamics, the system maintains reliability in noisy environments while preserving full-state observability.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS11200354B1System and method for selecting measurement nodes to estimate and track state in dynamic networks
Publication Date: 2021.12.14 HRL LAB
  • US11200354B1 patent drawing
  • US11200354B1 patent drawing
  • US11200354B1 patent drawing

AI summary

Described is a system for selecting measurement nodes in a distributed physical system of agents. In operation, the distributed physical system is represented as a multi-layer network having a communication layer and an agent layer. The communication layer represents the amount of collective communication activities between any pair of areas and the agent layer represents movement of agents within the distributed physical system such that the communication layer and agent layer collectively generate network dynamics. The network dynamics are modeled as hybrid partial differential equations (PDEs) with measurable interconnected states in the communication layer. Notably, placement of a minimum set of measurement nodes is determined within the distributed physical system to provide full-state observability of the distributed physical system. The system can then track the full system state and apply compensation to one or more agents in the distributed physical system based on tracking the full system state.