Merging Subject Matter Expertise and Deep Convolutional Neural Network for State-Based Online Machine-Part Interaction Classification

TL;DR

This paper presents a deep CNN framework for classifying machine-part interactions in smart manufacturing, integrating subject matter expertise to improve accuracy and reduce misclassifications, with successful case study results.

Contribution

It introduces a SME-guided deep CNN framework with a finite state machine for enhanced classification and deployment in cyber-physical systems.

Findings

Achieved an average F1-Score of 0.946 on testing data.

Reduced misclassifications through SME integration.

Demonstrated real-time performance with 0.24s delay.

Abstract

Machine-part interaction classification is a key capability required by Cyber-Physical Systems (CPS), a pivotal enabler of Smart Manufacturing (SM). While previous relevant studies on the subject have primarily focused on time series classification, change point detection is equally important because it provides temporal information on changes in behavior of the machine. In this work, we address point detection and time series classification for machine-part interactions with a deep Convolutional Neural Network (CNN) based framework. The CNN in this framework utilizes a two-stage encoder-classifier structure for efficient feature representation and convenient deployment customization for CPS. Though data-driven, the design and optimization of the framework are Subject Matter Expertise (SME) guided. An SME defined Finite State Machine (FSM) is incorporated into the framework to prohibit intermittent misclassifications. In the case study, we implement the framework to perform machine-part interaction classification on a milling machine, and the performance is evaluated using a testing dataset and deployment simulations. The implementation achieved an average F1-Score of 0.946 across classes on the testing dataset and an average delay of 0.24 seconds on the deployment simulations.