Sensing system detects abnormal sounds at industrial facilities
Toppan in Japan has developed a sensing system for remotely monitoring abnormal sounds, such as metal on metal impacts and friction that do not occur during normal operation at factories and facilities.
The system consists of sound sensors and a data browsing application and is provided exclusively as a tool for e-Platch, Toppan’s equipment inspection system. It can detect abnormal sounds from equipment and distinguish them from the normal background noise, trigger alerts, and output reports of abnormalities detected.
e-Platch is an integrated monitoring system that can enhance overall risk management at manufacturing plants by automatically collecting environmental data, such as effluent water level and hydrogen ion concentration.
It uses the Zeta Low Power Wide Area (LPWA) network protocol developed in Cambridge, UK, to send data from sensor devices to the monitoring system.
It was originally envisaged that e-Platch would collect information on items for which only a low volume of data, in the range of several to tens of bytes, needs to be sent from machinery to the browsing application. This includes temperature, illuminance, water level, and gas concentration.
The use of Zeta communication to handle sound and other large-volume data was therefore considered challenging. However using circuit design technology developed in its semiconductor design business and data processing expertise from its cloud-based solutions has enabled the handling of sound data efficiently in a Zeta network.
The system records sounds, partitions the data into 21 groups based on bands from 160 to 16,000 hertz, obtains sound intensity data for each frequency band, and sends the data to the browsing application after compressing and dividing it using an original method. The application plots the decibel values of the data in each frequency band, makes sound trends visible on a graph, and sends out an alert if values exceed thresholds set by the user.
Toppan’s solution uses waterproof microphones and takes advantage of Zeta’s Ultra Narrow Band (UNB) multichannel communication, distributed access with intelligent mesh topology, and bi-directional low-power communication. It can therefore be deployed on the roofs of factories and facilities or in underground locations with complex layouts, making it possible to predict equipment failures and implement countermeasures to noise in such locations.
Adding sound sensors to the lineup of devices compatible with e-Platch can drive greater efficiency for maintenance and inspection work by promptly identifying equipment abnormalities and indicating when machinery parts need to be replaced.
The sounds of machinery in operation and work being performed can constantly be heard in factories and facilities, where multiple pieces of equipment run at the same time. Facility managers have had to identify abnormalities by visiting locations several times a day and using their experience to filter out background noise and listen out for signs of machinery problems, such as the sound of loose bolts or friction caused by degraded parts.
Using Zeta allows Toppan to provide the system at less than half the price of existing solutions by shifting functions such as alert activation and abnormality definition/detection from the sensor side to the application side. This makes more detailed monitoring possible, such as by deploying more than double the number of sensors within a budget of the same scale.
Many manufacturing plants have areas with complex structures that inhibit signal transmission or locations at which it is difficult to secure a power source. Appropriate positioning of battery-operated intermediate nodes, known as motes, makes it possible to put in place a wireless network without blind spots.
The Zetabox data converter makes it possible to digitize data output from measurement instruments and send it to a Zeta network. Because existing measurement instruments can be used, initial costs are reduced, and data collection does not necessitate changes to the way maintenance and related tasks are performed.
The data collected by sensors is managed on the cloud-based Zetadrive platform. The dedicated e-Platch monitoring application creates graphs, sends out alerts, generates reports, and provides various other functions to facilitate comprehensive visibility for environmental data at factories and facilities.
“The new sound sensing function adds another dimension to our solution for remote equipment monitoring,” said Masaharu Sadaya, marketing manager in Toppan’s Electronics Division. “We will drive expanded sales of e-Platch, offering a range of sensors, including multi-sensors that measure temperature, humidity, illuminance, and carbon dioxide concentration, as we aim to have the system installed at more than 650 customer facilities by fiscal 2025. This will not only reduce the workload for equipment inspection and alleviate the problem of labour shortages, but also reduce the risk of accidents and contribute to safer, more efficient manufacturing operations.”