SCADA helps keep road tunnel traffic safe and free flowing
27 November 2012
Traffic flow and safety have been enhanced in one of Italy’s most important motorway tunnels by the commissioning of a new control system based on Products4Automation’s Movicon 11 SCADA technology.
Because of the country’s mountainous landscape, road tunnels are an important part of Italy’s transport infrastructure. Each tunnel has its own unique traffic management system to handle the safety and security requirements involved with their operation. Because of the ever growing usage volumes as the number of cars on the road increase each system needs to be regularly maintained and developed. Bespoke control solutions are usually specified for each tunnel; programmed for the unique challenges each one presents.
When engineers for the Spogliamonaco Tunnel on the Lauria–Lagonegro motorway in Basilicata were looking to renew their control system, they wanted to develop a system which allowed for both local, on-site control and remote control from head office. They identified a bus architecture and SCADA software as the optimum solution and also wanted an open system so that they could mix and match hardware from different manufacturers – a critical requirement for a system that could be operating for decades.
The architecture the engineers developed consisted of a central PC acting as the overall supervision and control unit. The decision was made early on to design out other local controllers such as PLCs or CPUs, as the simplicity of the system would help contain initial costs and ensure maintenance was straightforward. Instead they ran a single bus the whole 1500m length of the tunnel, with all the I/O nodes distributed along it.
When it came to selecting the SCADA (supervisory control and data acquisition) software many options were considered before eventually deciding that the Movicon 11 system was most appropriate to their needs. Movicon 11 is XML-based and combines SCADA with an HMI (human machine interface), which means it offers an all-in-one development environment for managing HMI, SCADA, soft-logic and analysis of operating data. It is also open and highly flexible, and attractive feature in an application where constant design evolution is to be expected.
The I/O control is based on Windows XP, which is freely available, well supported and low cost. Windows XP is not deterministic (able to absolutely guarantee the sequence and speed of signal processing); but this is not a requirement in tunnel control systems, as no instructions are completely time critical. Instead a LonWorks card fitted in the PC handles all the data traffic from the 110 I/O nodes on the bus.
LonWorks is an open networking platform that is used worldwide in a range of automation applications, including many in building automation and HVAC environments, as well as in other tunnel control systems. There are a great many brands and models of hardware products available that are compatible with LonWorks including high power lamps, emergency lighting, ventilation fans and water pumps.
In the Spogliamonaco Tunnel installation, the Movicon SCADA system constantly monitors all the data produced on the bus for alarms, such as failed lamps, and trending towards critical conditions such as rising carbon dioxide levels. It is also able to monitor other parameters such as dangerous vibrations (e.g. earthquakes and rock falls), reduced visibility due to excessive exhaust, wind speed and direction, ventilation extraction rate, CCTV and several other functions.
Many functions are automated by the Movicon system, freeing the staff in the control room from routine duties so that they can concentrate on higher level activities. From the supervision stations, situated both in the local control stations and in the main control centre, operators can monitor the full length of the tunnel as well as facilities at each end, using screen pages that display both current and logged data.
All the commands can be easily and intuitively set by mouse-clicking on the on-screen graphics. For example, the traffic lights that control vehicle movements are normally run automatically by the Movicon logic control function, but users can assume manual override should the situation require it. The same is true of the ventilators and other critical equipment.
All operating data is logged by the SCADA software, and can be analysed for alarms, trends etc. This leads to optimisation of operations and helps to maintain efficiency and smooth traffic flow.
The engineers have also programmed the Movicon SCADA to provide enhanced management of the maintenance programmes. Optimising the work schedules for the maintenance technicians can be complicated because some equipment - such as the lamps - is maintained to regular time schedules while other equipment – such as the fan – is maintained based on usage. Added to this there is the need to attend failures and breakdowns. By working this out automatically equipment is better maintained and people’s time and resources are used to the best advantage.
The Spogliamonaco Tunnel has always been fitted with landline telephones, giving personnel a straightforward and effective means of communication. These landlines have been integrated into the SCADA system so that their use is logged alongside the rest of the operating data. The SCADA also has the capacity to send text messages and pre-recorded mobile phone messages to staff who are ‘on-call’.
In summary, Movicon has provided an innovative tunnel control solution that facilitates rapid development at low cost, yet which still functions at a high level and with simplicity.
For further information, please contact Paul Hurst:
Products4Automation, 4th Floor, Patrick House, 5 Maney Corner, Sutton Coldfield, B72 1QL Tel: +44 (0)845 077 3858 Email: firstname.lastname@example.org Web: www.products4automation.com