Remote health check for machine tools
Machine tools are expensive investments that need frequent preventive maintenance. EU-funded researchers have devised new methods to keep them in peak condition through remote monitoring, cutting maintenance costs. Commercial prospects for the new technology are strong thanks to the industrial partners in the project.
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The purchase of machine tools – such as lathes, grinding and milling machines – is a major investment for any manufacturing company. With tools costing up to €1 million and with a productive life of 15 years or more, owners want to minimise time out of service. The usual approach is a scheme of planned preventive maintenance to ensure that the machine is kept in good condition to forestall unnecessary breakdowns. Corrective maintenance is then applied when unexpected failures occur.
“Normally, preventive maintenance is too conservative,” says Aitor Alzaga, coordinator of the EU-funded POWER-OM project. “For example, you may be recommended to change the oil in your car after 10 000 kilometres or one year, but that doesn’t consider the way you have been driving the car.”
Alzaga’s research centre, IK4-Tekniker, led a consortium of five industrial partners that were supported by Luleå University of Technology in a three-year quest to find ways of optimising the maintenance of machine tools by taking account of how they are actually used. The aim was to eliminate unnecessary maintenance while avoiding breakdowns.
The key is to monitor the performance of a machine in real time. By measuring its electrical energy consumption it is possible to detect when its condition is beginning to deteriorate and use this information to make a more considered decision about when maintenance is required.
The POWER-OM partners devised data-loggers that can be embedded in new machines or fitted to existing ones to track the condition of rotating spindles and linear slides, the most critical components of most machine tools.
“We analyse this signal and compare the features when the machine is in good health and not such good health,” Alzaga explains. “We combine this information with data coming from other sensors, such as vibration and especially temperature.”
As well as the end-users being able to monitor their machines, the manufacturer of the machine can also collect the data in real time through the internet to monitor the machines of all its customers and schedule maintenance accordingly. Maintenance costs could be cut by half and productive time increased.
The project finished in the summer of 2015 and one of the partners, Goratu – a maker of machine tools – aims to sell around 10 machines in 2016 with this monitoring technology built-in.
Three other industrial partners – Artis, Predict and Monition – are exploring the possibility of marketing the POWER-OM data-logger along with Predict’s existing e-maintenance platform. The data-logger is already being used in a test installation with a major German car builder.
Artis, which makes machine monitoring systems, has an installed base of 20 000 units which could be fitted with the data-logger if customers so choose. Another partner, Fagor, sells more than 5 000 computerised control units a year, offering a further potential market.
The technology developed in POWER-OM is also being applied in another EU-funded project, T-REX, to monitor the condition of fork-lift trucks and industrial robots. Both are examples of an increasingly popular business model where machines are rented, rather than purchased, and the manufacturer assumes responsibility for continued maintenance for the life of the machine.
Alzaga sees these developments as part of a wider cultural trend to foster cooperation between manufacturer and customer well beyond the traditional warranty period, and to the benefit of both.