Using Vibration sensing in Condition Monitoring

A key driver behind the adoption of Industry 4.0 is to improve productivity and efficiency. By offering increased interoperability and information transparency a more holistic view can be obtained of industrial equipment.

The ability to continuously monitor and collate data not only gives a perspective on how the equipment is performing but also early warning of potential equipment inefficiencies or early indicators of wear which can result in an equipment fail and downtime. Having this more proactive approach not only improves efficiency and reliability of the operations but also offers cost benefits, helping a business to grow.

Predictive Maintenance is enabled through increased use of IIoT enabled pieces of equipment. It enables the scheduling of maintenance whilst the machine is still in working order to avoid a major fault resulting in downtime. Conditioning Monitoring is a key aspect of Predictive Maintenance. Condition monitoring includes the ongoing collection of data outlining the current status of the monitored equipment. Conditioning Monitoring drives the maintenance work based on the condition of the equipment and how it is performing. This enables an organisation to use their maintenance resources to focus on the pieces of equipment that need to be looked at first, offering prioritisation based on critical nature to the business and the current condition. Condition Monitoring is estimated to provide up to 15% (Source: Mordor Intelligence, March 2018) cost saving over Predictive Maintenance alone.

Motors of different sizes, shapes and powers are central to automated equipment and found in numerous places in industry. A failing or badly performing motor can not only put wear on the motor itself but also the equipment it powers. Being able to easily monitor the condition of a wide range of motors is an increasing challenge for industry. Motors all create some form of vibration as a result of their movement. The vibration and sound the motor makes are key aspects experienced maintenance people use to evaluate if a motor is performing as expected.  So being able to remotely measure the vibration profile of motors that are in unmanned remote locations, or difficult to reach pieces of equipment offers visibility on how the motors are working. A profile based on the motor working efficiently can be obtained on install and this can be compared to the current motor performance. Differences between these two profiles will flag up potential condition concerns.

8power utilises vibration not only to sense the vibration status but also to power the sensing beacon. This brings a robust solution tailored to the demanding needs of the industrial space – the ability to safely operate in high and low temperatures, a self-powered design which requires minimal maintenance. 8power offer scalable solutions that can be easily and quickly installed on motors no matter their age, brand or location – bringing an easy way of monitoring the condition of a wide range of equipment from one centralised point.

Battery Blues

To date primary cell batteries have been the most popular way to power low cost devices. However, they have limitations that have required the battery industry to look at more innovative ways of powering devices. One of the key market areas that are helping to drive small battery innovation forward is the Internet of Things (IoT).

Current battery trends in rechargeable cells require batteries to have a lower discharge rate for several reasons; to increase the length of time the charge can be held but also the ability to be trickle charged by the range of energy harvesting chargers now available.  Energy harvesting is an exciting prospect to obtain energy from the environment. This can be from solar, heat or from the device itself, through vibration. Conversely, often fast discharge functionality is also needed to support the very high currents for pulse type communications typically found in older cellular systems.

Industrial IoT (IIoT) brings it with several additional challenges. The battery technology needs to be low cost, a small physical footprint and able to operate across a range of environments. Industrial rated batteries are required operate over wide temperature ranges both high and low and typical electronics specs for the industrial space quote temperature ranges of -40°C up to 100 or 150°C. So the chosen battery technology needs support these ranges. But industrial locations also often have high humidity, a variety of vibrations and some are in total darkness, if they are unmanned. These all put pressures on the Lithium based batteries which are at risk of becoming flammable in some instances.

Lithium-ion batteries have been the main workhorse of battery technologies over recent years – however they are now experiencing additional pressures from external influences. As the number of battery powered devices increases, the issue of disposal of the batteries is becoming more of a concern. It has been recognised the current issues of disposal around plastics will soon be followed on by safe battery disposal as a key concern as more devices such as mobile phones and cars continue to increase their battery usage. Many products have benefitted from the advancement in smaller, lower-power battery technologies, as seen in the mobile phone space, but the trend here is for larger batteries to support the increased range of activities, whilst being able to maintain a day long charge.

The current poor environmental footprint of batteries, with respect to the levels of toxic metals and chemicals, is becoming more of a focus for EU regulations with more emphasis on safe disposal. More responsibility is being put back onto the battery manufacturers who are having to finance the cost of collecting, treating and recycling all collected batteries, which will ultimately put additional pricing costs on the batteries themselves. The cost of the underlying metals used are also increasing due to the rising demand from electrical and hybrid cars. A very worrying trend is the cost of Lithium itself is expected to increase x4 in the next 5 years according to the EU.

As these increasing pressures are being applied to Lithium based batteries, more companies are looking at how they can either reduce the size, or in some cases remove the battery completely from their small devices. Harvesting energy is key to turning this into a reality. There are a wide range of energy harvesting options including thermal, solar and vibration. All these aspects could be leveraged in an industrial location as more of an energy source than a hindrance. 8power is looking at how tailored solutions can be incorporated into sensing devices to maximise the power that can be harvested from the environment. Some instances such as for outside plant equipment monitoring, a small photovoltaic cell can power a wireless sensor; whereas a larger piece of rotating plant equipment can create enough vibration to power more sophisticated and much higher power systems.

There is an abundance of energy in the environment and we need to have solutions that take advantage of this. At 8power we believe that our energy harvesting eliminates the need for battery replacement and recharging. This not only makes great economic sense, it also helps the environment by reducing the cycle of metal mining and disposal. It is a true “win-win”. The

Transforming water plant equipment maintenance through condition-based monitoring

Wastewater and water treatment equipment is susceptible to failure for many reasons. Equipment networks are dispersed across a wide range of locations, most are unmanned which means many of the assets tend to receive limited, structured maintenance. There are many incidents when maintenance is reactive only when a failure is reported which is always costly. Having the ability to easily monitor a wide range of industrial equipment and detect the early onset of problems increases operational efficiency and maximises the effectiveness of maintenance resources.

In water operations and particularly in wastewater, many of the remote assets such as pumps and motors are often the root cause of problems – however the problem can be identified further through the system. This can make troubleshooting difficult, costly and time consuming. Added to this, the unpredictable nature of the external environment caused by elements such as rainfall levels, debris and sewage levels can further complicate plant management. The current estimate for the cost of maintenance of wastewater treatment plants is between 15-25% of total operational costs (Source: Hamburg Public Sewage). This is dependent on the age and historical maintenance levels of the plant equipment. We have seen figures that suggest reactive maintenance is the most expensive with the cost currently estimated at £5M-£15M per annum for a UK WASC to maintain a large sewage pumping station. These figures show there is a clear need to balance the visibility of the condition of the wastewater equipment and costs of monitoring.

Normally vibration is seen as a bad thing in plant equipment and something that engineers try to remove, but it can hold a vital clue on the condition of motors, pumps and other equipment. Vibration can be utilised to give an easy to monitor source of information. Using one of the new generation of low power, multi-axis accelerometers to monitor an asset’s health via vibration you can yield lots of useful information. Just from vibration alone it is possible to record an asset’s start and stop times, its total duty cycle and its energy usage. By simple analysis of the vibration traces you can detect if the asset has been set up correctly for time of day operation. Further analysis can also show if there are signs of blockages, bearing wear, chipped gears, shaft misalignment or surface degradation. Currently it is estimated that 30% of all sewage pumping stations contain at least one blocked or restricted element of functionality creating inefficiency and excess energy usage. Being able to easily monitor the health of these remote stations will enable a more effective maintenance approach by highlighting when assets need attention. This allows asset managers and operators to prioritise and allocate maintenance resources to the most affected sites with the target to reduce reactive maintenance costs and minimize asset downtime.

8power have engineered a small footprint, self-powered, scalable, solution that enables remote condition monitoring across a fleet of water industry assets. We use vibration to power our retrofittable, wireless sensor system. Without the constraints of battery power our devices can perform much of the vibration analysis locally on the sensor using the high-performance embedded ARM processor.

We are seeing that condition monitoring of all assets is becoming a critical business need for water treatment and wastewater processing.

Currently 8power are conducting remote condition monitoring pilot programs with water companies in the UK and Europe and will be publishing the results of these later in the year.