Enhancing safety with mobile devices
The flood of modern production facilities managed by central controls is coming. However, for comprehensive and timely monitoring of processes, data needs to be available closer to the process and more directly – preferably in real time and with low latency.
Modern, intrinsically safe (IS) smartphones and tablets can serve as decentralized mini-data centers or digital gateways – for example in combination with professional software, sensors, beacons or other smart peripheral devices. The accumulated data can be transferred to the mobile device in real time and evaluated there, with the corresponding applications, at any location and at any time. This solution can help improve productivity and also raises employee safety in hazardous areas.
The right safety level
Employees often work alone on the plant floor, outside the range of hearing and vision of their colleagues. They can be exposed to higher risks in their daily work and depend on quick assistance in case of an emergency. If no appropriate safety precautions are taken, injuries, accidents and consequential damage to people and equipment can easily occur. The company must ensure an accident is detected and the rescue chain is set in motion. In case of critical hazards it is mandatory to set up a certified lone-worker protection (LWP) solution.
Programmable 3D motion sensors can trigger an alarm in the event of a hazard, report the exact location of the incident and document the entire process for later investigation.
A typical comprehensive lone worker protection system will consist of personal alarm signal terminals (PAST) just as a mobile phone or wireless device; personal alarm signal system (PASS) (software on server); and connection between the PASS and PAST via telephone or wireless network. For larger scale LWP solutions, mobile devices can be integrated into cloud server systems.
Benefits of LWP
A power plant operator in northern Italy offers a good demonstration of the benefits of an LWP solution consisting of mobile devices and for hazardous areas developed Bluetooth Low Energy (BLE) beacons.
The management was looking for a reliable automated system that would help prevent accidents and reduce the time for a potential rescue to an absolute minimum. With BLE beacons employees can also be located indoors or be warned of possible hazards in advance. They have an interior range of 10 to 30 m and up to 300 m in the open field. The signal from the beacon is received by an application on the Smart-Ex smartphone and the distance to the beacon is calculated.
When the mobile worker enters the working area, the location can be read out accurately – even three-dimensionally, i.e. across floors – and forwarded to the control center’s central navigation system. The user is not dependent on an internet connection, because the mobile devices and applications store the beacon signals locally on the device and send them to update the backend system as soon as access to the company network is available. Compared to other geo-location technologies, this beacon technology offers a high degree of precision and accuracy in all three axes. The position of the mobile worker is stored in the temporary memory of the device and only forwarded to the rescuer in the event of an alarm. It cannot be retrieved either from the device itself or from the outside, from the alarm console in the control center or by subsequent technical analysis. The solution meets all data protection requirements, guarantees the safety of lone workers and, in an emergency, reduces the response times of the rescuers to a minimum.
In another scenario, an oil company commissioned Italian institute L’Istituto di Vigilanza dell’Urbe (IVU) to optimize and secure the refueling of petrol tanks at gas stations. This posed a challenge due to the high safety measures for the refueling process. Delivery and filling, for example, may only be carried out by specialized forwarding agents, under the supervision of a qualified person. The goal was to centralize the monitoring of tank processes in a control center and to implement a comprehensive protection system for lone workers. When selecting and integrating a solution, IVU relied on a specialist systems integrator for radio communication and control rooms.
These mobile devices are equipped with a push-to-talk-over-cellular application. In the event of an accident, rescue workers can be notified via LWP applications. Programmable 3D motion sensors automatically start an SOS request when, for example, the device falls off or no movement is detected. Each work area has been mapped with geofencing so the software detects the GPS position of the worker. This guarantees an accident is always instantly detected. All SOS requests also activate the hands-free function of the smartphone as well as its camera which allows the control center to assess whether the employee is responsive and of what kind the injuries are. Where two people were previously necessary because of safety requirements, one is now sufficient.
The supervisor no longer has to be on site because the devices are monitored continuously and entries and exits in a filling station are automatically noted. The control room supervisor will be able to determine, in seconds, whether an alarm is real. It is also possible to document an emergency situation by using recorded voice communication, video streaming, GPS position and event logs. The documentation of the entire rescue chain makes the process evaluable and provides an effective basis for further optimizing alert processes.
Dietmar Deppisch is business development manager applications, ECOM Instruments at Pepperl + Fuchs. This article originally appeared on Control Engineering Europe’s website. Edited by Chris Vavra, associate editor, Control Engineering, CFE Media, email@example.com.