A maintenance terminal in your pocket?

Mark Willliamson

A futuristic way of improving maintenance effectiveness and cost is on the doorstep. Wireless portability and cloud data analysis are the keys.

A European technology review magazine called Pan European Networks has recently reported on an intriguing new mobile maintenance application that makes mechanical equipment and valve condition monitoring more comprehensive, less-time consuming and lower cost. This article explains that Metso is developing and field testing a new mobile condition analysis and maintenance application based on commonly used smartphones as portable user interfaces. Dr. Mika Karaila, director of research for Metso,says, "It will be very cost effective, scalable and will fulfill our customers' maintenance routines with wireless condition monitoring measurements. And this is just the beginning; we will have more ideas coming." What he says is all very futuristic sounding stuff, but closer than we think.

The mobile application makes the best use of a number of enabling technologies and standards including magnetic navigation technology, low power micro-electromechanical (MEMS) machinery condition sensors, low power wireless Bluetooth communications and cloud computing access via a Wi-Fi connection to the Internet. The new portable user interface goes beyond the reach of hard-wired systems (that are usually comprised of a few hundred monitored points) to thousands of accessible points. The sensors can be placed during a scheduled maintenance round and can be relocated at a later time. The new application supports the goal to make maintenance activities more effective and lower cost by utilizing intelligent products, tools and services.

Early detection

To achieve high equipment availability, it is vital to detect faults early, schedule maintenance and carry out repairs before production is impacted. Maintenance staff therefore will need intelligent and timely information about the condition of the process equipment. However, there is a lot of walking for maintenance people in a pulp and paper mill and few, if any, know how to find every component that may or may not need repair. There is no easy-to-use or reliable roadmap to all process components and the current condition or history of each point is not known on the spot. Some process- critical components may be hardwired into a centralized analysis system that warns of impending failure patterns. That technology is well established and used where the cost of failure is high, but it is just too costly to equip all moving machinery with sensors and wires. Enter the portable concept.

Extending monitoring capability

The concept of the smartphone interface is easy to understand. A maintenance worker will be given a daily maintenance task list determined by a computerized maintenance management system (CMMS). The user interface then guides the worker through the complex plant to the device to be inspected. The phone can be used to select necessary sensor measurements directly by a Bluetooth wireless connection. The sensor sends data using Bluetooth to a Wi-Fi gateway into the cloud service. The phone shows condition monitoring measurement trends from the cloud from previously –installed condition monitoring sensors or a portable sensor temporarily installed on the casing of the pump, motor, bearing or other component. This portability is a low cost way of extending the monitoring capability within a plant. Monitoring and fault detection can now be done on demand and there is no need to go to a computer terminal since the handset with all the necessary service tasks and communications channels is in your pocket.

The smartphone handset guides a maintenance technician through a complicated plant layout to a point where a service action is required.
The sensor signal analyses in the cloud computing network include sophisticated mathematical techniques like spectral analysis. The device or mechanical component is given a clean bill of health or a specific fault is identified and a service task is initiated. The task can be initiated by a maintenance worker, if a sensor analysis is abnormal or if the cloud determines that a service interval is due. The analysis data is passed along to the cloud for archiving and time trending to see if a problem is getting worse and may need attention in the future. After the action is complete, the worker passes the smartphone past a near field communication (NFC) tag on the portable sensor module. Alternately, a QR code can be read. When the action is complete it is captured in a cloud-based maintenance task database along with a photo, if needed. Subsequent inspections can be scheduled and displayed on the handset when it is due.

Magnetic signature navigation

How does the smartphone guide the worker through the complicated plant maze? Global positioning systems (GPS) don't work well indoors because of the interfering effects of the building structure. Instead, the new navigation technology used in Metso's application is based on reading a magnetic signature that is unique to a building's structure. The smartphone comes equipped with the necessary magnetometers. The principle is similar to a natural phenomenon whereby sea turtles and lobsters use magnetic pattern recognition to navigate their way in the ocean. The technology developed by a Finnish company called Indoor Atlas has been applied to navigate around industrial plants, power plants and mining operations. The magnetic signature of the plant interiors can locate a serviceable monitoring point with good precision. There is no more hunting around and wasting time. It also benefits newly hired technicians and third-party maintenance contractors who may not know the plant's complex layout so well.
Sensor intelligence in the cloud
Portable and low-energy mechanical condition sensing is also a cornerstone of the new mobile maintenance application. These miniscule sensors are based on emerging micro electromechanical (MEMS) technology. One such device application uses acoustic emission techniques developed by Finland's VTT research and development organization. The MEMS sensor analyzes transient elastic waves created by sudden redistribution of stress in a material. This is a result of vibration stress patterns. Typically, a condition monitoring point includes vibration and temperature measurements. This capability can be extended to include miniaturized measurements of acoustics (for leak detection) light emissions, humidity, pressure, magnetic and gyroscopic fluctuations. These capabilities can be turned on and off as needed. The power consumption of these sensors is low so the battery life of MEMS sensors can be up to one year. The handset senses battery strength and can alert the worker if it should be changed. These communications are based on standard Bluetooth profiles.

MEMS condition monitoring sensors have been miniaturized. Source: VTT Finland
The transmission of measured data to the handset is based on low-power Bluetooth wireless communications. The intelligence derived from the raw sensor signals comes from the cloud computing network where the signal spectra and other condition monitoring techniques like envelope analysis are performed. That analysis turns a raw signal into intelligent information that can be used to make decisive corrective actions. As an example of cloud computing power, you may have seen advertisements that the Lotus Formula 1 racing team is using Microsoft cloud –based software to monitor and analyze the signals from over 200 wireless sensors in its race cars. The objective is to make fast and sure adjustments to win races. On the other hand a pulp mill maintenance department wants to increase process uptime. That's a worthy objective as well.

This mobile condition monitoring application promises to extend a plant maintenance department's analysis and service task capability to include many process equipment points that were not feasible before because of the high cost. It also streamlines the management of the regular maintenance route by quickly directing a worker to a maintenance task point and making an intelligent assessment of the component's condition. The application is now being tested at a mine site and a power plant in Finland.

Metso says more details of how the product works will be revealed as it develops. Furthermore, the smartphone application may not be the only user interface. There is talk of using "smart glasses" if the cost is reasonable. Integration of infrared camera heat pattern recognition is also on the table. Stay tuned.