Smart Machines & Factories
Optimising safety
Published:  16 May, 2017

Industry 4.0 conjures up images of a highly dynamic working environment, able to respond almost immediately to shifts in customer requirements through rapid reorganisation and reconfiguration of manufacturing processes. In this scenario, individual production lines and cells can transform their operations and output almost at will, based on information garnered and analysed in real time. Mike Lomax, head of product management UK, Bosch Rexroth, reports.

While Industry 4.0 is almost invariably associated with ever-increasing levels of automation, the role of people in the production environment must never be forgotten. Indeed, one of the primary tenets of Industry 4.0 is that people should be key players – and that the connectivity between production staff and machinery is just as fundamental to the success of the operation as the connections and interaction between individual machines and components.

In a ‘traditional’ production environment, with lines or cells frequently geared to the manufacture of a single product, the safety of those working in the facility is generally straightforward to monitor. A risk assessment of all aspects of the operation, from individual components through to operator ‘touch points’ with equipment, will create a guide which in theory should remain valid until the use of that line changes or alterations are made to the equipment within it. Immediate hazards can be minimised and risks to operator safety averted, as long as correct procedures are followed.

However, a plant operating under Industry 4.0 principles potentially presents a very different and more intricate set of challenges. Reconfiguration of production areas at short notice, involving the rapid changes of tooling and even the physical movement of equipment, can pose a range of safety challenges, while the sheer number of configurations achievable to meet potential requirements may entail a separate risk assessment for each. Yet, with another of the key features of Industry 4.0 being the safety of personnel and data under a secure value-creation network, these considerations cannot be ignored if compliance with local, national and international regulations is to be maintained.

Fortunately there are a variety of technologies available to counter these issues – and it is no exaggeration to say that Industry 4.0 offers the opportunity to increase safety further due to the ability to gather data in real time and then act upon it before a potential hazard becomes a real one.

For example, a range of devices can be fitted onto equipment capable of detecting and reporting operator behaviour which may pose a risk to safety. This equipment can take a number of forms; among the most common are intelligent cameras which gather digital images or footage and pass these to a central control point, automatically highlighting any abnormal behaviours such as entry into a restricted area. Many systems designers also opt to equip their machines with safety sensing devices which can immediately sense if a human operator has moved into an unsafe area or positioned themselves too close to a particular piece of plant. In such instances, the default response is usually to power down the machine or, in the case of a collaborative robot, to slow down to a safe speed, allowing the individual time to move away from the hazard. The decision on which device to use depends primarily on the level of risk involved. This type of feature is also beneficial when equipment has to be moved, for example, previously a machine would need to have all its guards in place and be completely switched off before any action could be taken. Given that there will always be a desire to avoid switching off machines completely to avoid additional warm-up times and quality issues with first-off components, this is a major advantage in the dynamic production environments associated with Industry 4.0.

Meanwhile, many Industry 4.0-compatible technologies now have additional safety features built into them, rather than having to be added afterwards. One example is Industry 4.0 compatible drives which can be used to create a machine protocol with a unique number, highlighting immediately a potential safety issue if a different protocol is used.

A further technology which has become commonplace in Industry 4.0 environments is the dedicated safety protocol. There are a number of these on the market – openSAFETY, SERCOS and ProfiNet to name but a few – with all common bus systems now having a safety version. All have been designed as an advance on older wire-based systems for powering down and enable a greater flow of information to ensure uptime is maximised and that equipment only powers down as a last resort. An alternative to these is a safety zone module which continuously check wires and negates the need to invest in a separate safety bus system in certain applications.

While these features are beneficial, it must be remembered that the basic tenets of sound health & safety practice must still be adhered to. A risk assessment of every scenario likely to be encountered (effectively, any machine configuration which can be selected) must be undertaken, with operatives receiving the necessary training to work effectively in this more dynamic environment. Applications which have always needed physical guards around them will continue to need the same level of protection – the most unpredictable and vulnerable aspect of any manufacturing environment has always been and remains the individual people working within it and no effort should be spared in protecting them irrespective of the manufacturing processes adopted.

To emphasise this, while individual system components may be considered to be ‘safe’, it is their use in combination which must be considered when it comes to creating, and then justifying, a safety factor, as part of a risk assessment. One example in an Industry 4.0 environment might be the need to programme alternative routes for autonomous loading/unloading or robotic equipment which encounters an unanticipated obstacle on its route around the facility. This is the sort of consideration which could be said to go beyond those associated with more traditional production environments. It highlights the need for health & safety personnel responsible for due diligence to receive the necessary training to truly understand the ethos and capabilities of Industry 4.0 – and the availability and capability of safety technologies specifically designed to complement and operate in an Industry 4.0 environment. Working alongside component suppliers with safety-qualified engineers, a truly safe Industry 4.0 compliant production environment is more than readily achievable.

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