An Adaptable and Unsupervised TinyML Anomaly Detection System for Extreme Industrial Environments

Sensors (Basel). 2023 Feb 20;23(4):2344. doi: 10.3390/s23042344.

Abstract

Industrial assets often feature multiple sensing devices to keep track of their status by monitoring certain physical parameters. These readings can be analyzed with machine learning (ML) tools to identify potential failures through anomaly detection, allowing operators to take appropriate corrective actions. Typically, these analyses are conducted on servers located in data centers or the cloud. However, this approach increases system complexity and is susceptible to failure in cases where connectivity is unavailable. Furthermore, this communication restriction limits the approach's applicability in extreme industrial environments where operating conditions affect communication and access to the system. This paper proposes and evaluates an end-to-end adaptable and configurable anomaly detection system that uses the Internet of Things (IoT), edge computing, and Tiny-MLOps methodologies in an extreme industrial environment such as submersible pumps. The system runs on an IoT sensing Kit, based on an ESP32 microcontroller and MicroPython firmware, located near the data source. The processing pipeline on the sensing device collects data, trains an anomaly detection model, and alerts an external gateway in the event of an anomaly. The anomaly detection model uses the isolation forest algorithm, which can be trained on the microcontroller in just 1.2 to 6.4 s and detect an anomaly in less than 16 milliseconds with an ensemble of 50 trees and 80 KB of RAM. Additionally, the system employs blockchain technology to provide a transparent and irrefutable repository of anomalies.

Keywords: Internet of Things; Tiny-MLOps; TinyML; anomaly detection; blockchain; machine learning.

Grants and funding

This study was partially supported by “Legge provinciale 6/99 sugli incentivi alle imprese” (L.P. 6/99) della Provincia Autonoma di Trento through the “EdgeMetrix 5Gi4.0” project. Moreover, it was partially carried out within the Interconnected Nord-Est Innovation Ecosystem (iNEST) and received funding from the European Union Next-GenerationEU (PIANO NAZIONALE DI RIPRESA E RESILIENZA (PNRR)—MISSIONE 4 COMPONENTE 2, INVESTIMENTO 1.5—D.D. 1058 23/06/2022, ECS00000043). This manuscript reflects only the authors’ views and opinions, neither the European Union nor the European Commission can be considered responsible for them.