Hierarchical Event-triggered Learning for Cyclically Excited Systems with Application to Wireless Sensor Networks

Fuente: arXiv
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Main Authors: Beuchert, Jonas, Solowjow, Friedrich, Raisch, Jörg, Trimpe, Sebastian, Seel, Thomas
Format: Preprint
Published: 2019
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author Beuchert, Jonas
Solowjow, Friedrich
Raisch, Jörg
Trimpe, Sebastian
Seel, Thomas
author_facet Beuchert, Jonas
Solowjow, Friedrich
Raisch, Jörg
Trimpe, Sebastian
Seel, Thomas
contents Communication load is a limiting factor in many real-time systems. Event-triggered state estimation and event-triggered learning methods reduce network communication by sending information only when it cannot be adequately predicted based on previously transmitted data. This paper proposes an event-triggered learning approach for nonlinear discrete-time systems with cyclic excitation. The method automatically recognizes cyclic patterns in data - even when they change repeatedly - and reduces communication load whenever the current data can be accurately predicted from previous cycles. Nonetheless, a bounded error between original and received signal is guaranteed. The cyclic excitation model, which is used for predictions, is updated hierarchically, i.e., a full model update is only performed if updating a small number of model parameters is not sufficient. A nonparametric statistical test enforces that model updates happen only if the cyclic excitation changed with high probability. The effectiveness of the proposed methods is demonstrated using the application example of wireless real-time pitch angle measurements of a human foot in a feedback-controlled neuroprosthesis. The experimental results show that communication load can be reduced by 70 % while the root-mean-square error between measured and received angle is less than 1°.
format Preprint
id arxiv_https___arxiv_org_abs_1906_03211
institution arXiv
publishDate 2019
record_format arxiv
spellingShingle Hierarchical Event-triggered Learning for Cyclically Excited Systems with Application to Wireless Sensor Networks
Beuchert, Jonas
Solowjow, Friedrich
Raisch, Jörg
Trimpe, Sebastian
Seel, Thomas
Systems and Control
Signal Processing
Communication load is a limiting factor in many real-time systems. Event-triggered state estimation and event-triggered learning methods reduce network communication by sending information only when it cannot be adequately predicted based on previously transmitted data. This paper proposes an event-triggered learning approach for nonlinear discrete-time systems with cyclic excitation. The method automatically recognizes cyclic patterns in data - even when they change repeatedly - and reduces communication load whenever the current data can be accurately predicted from previous cycles. Nonetheless, a bounded error between original and received signal is guaranteed. The cyclic excitation model, which is used for predictions, is updated hierarchically, i.e., a full model update is only performed if updating a small number of model parameters is not sufficient. A nonparametric statistical test enforces that model updates happen only if the cyclic excitation changed with high probability. The effectiveness of the proposed methods is demonstrated using the application example of wireless real-time pitch angle measurements of a human foot in a feedback-controlled neuroprosthesis. The experimental results show that communication load can be reduced by 70 % while the root-mean-square error between measured and received angle is less than 1°.
title Hierarchical Event-triggered Learning for Cyclically Excited Systems with Application to Wireless Sensor Networks
topic Systems and Control
Signal Processing
url https://arxiv.org/abs/1906.03211