Process heating valves are automated with a number of technologies used to drive the movement of the valve — electric, pneumatic and hydraulic actuation, for instance. These operators normally have both automated and manual modes of operation. When it is necessary for valve or actuator maintenance such as when doing periodic valve calibration, the operations and maintenance team (O&M) must be in close communication to ensure that the valve can be safely moved without harm to the people, equipment and processes that are being controlled.
In the past, this has been done with one operator in the control room looking at the supervisory software (SCADA) screens. He or she would ensure that the reported position of the valve and the position of other interrelated valves are as planned. He or she would also check that temperatures and pressure measurements around the valve are conducive to the intended maintenance procedure. In this environment, communication to the maintenance worker at the valve is often done using radios.
Mobility in today’s world is usually associated with off-the-shelf mobile devices, most notably smart phones and tablets. They are increasingly the preferred way for people such as the maintenance personnel responsible for the heating valves to receive and record their information while on the move. Interaction with mobile devices is, in practice, done differently from the way in which people interact with laptop and desktop computers. Historical approaches to mobility solutions used to monitor, diagnose, maintain and control heating valves are being transformed by advances in contextual mobility.
The rise of smart mobile devices has created an opportunity to improve mobility for maintenance and monitoring of process heating valves. This trend is moving away from managing from a central control room to a distributed model focused on mobility workers. The way in which users interact with their mobile device in comparison to the way in which an operator works in a control room requires a mobility infrastructure to optimize efficiency, safety and security.
Contextual HMI and Proximity Services
Indoor positioning systems (IPS) and the familiar global positioning system (GPS) are standard features found on nearly all modern mobile devices. Using IPS or GPS, it is possible for the mobile device to determine its current location. When combined with the credentials of the user (e.g., login and password), the system is able to determine both the location of the mobile device and the role of the current user. With this information in hand, the mobile device, driven by a server-based contextual logic engine (CLE), is able to deliver information and controls for equipment (HMI), filtered on the context of role and location. The mobility server determines the appropriate actions and distributes information and controls to the mobile worker in the context of the valves the worker is closest to as well as the worker’s responsibilities regarding the nearby equipment. This is known as contextual HMI.
The information may include valve status or the controls necessary to move the process valve. It may suggest additional resources (drawings, schematics, etc.) needed by the worker in the performance of their valve-maintenance duties. Some examples are:
- Graphical human machine interface (HMI) to the valve with current valve position. Also, show the alert status and have the ability to command the valve to change position.
- List of related sensor measurement such as pressures and temperatures.
- Trend chart showing valve position history over time.
- Acknowledge and manage alarms generated by the valve or other process variables.
- The ability to launch a web page, display a document or call up a valve calibration application.
When the CLE determines that conditions require new information and control elements to be provided to the mobile user, they are automatically downloaded to the smart device.
Connectivity. In contextual mobility architecture, the device is connected using wireless networks. Geo-tags — Bluetooth low energy (BLE) beacons, near-field communication tags and QR codes, for instance — are used along with WiFi access-point triangulation and other technologies to determine the specific location of the mobile worker. Because this picture is changing as the worker moves, the server records the movement as appropriate to labor agreements. (If you are thinking that there is no WiFi or Bluetooth beacons in the vicinity of your valves, keep in mind that the cost of deploying beacons or extending networks into equipment tunnels is becoming more affordable as these networks become more pervasive.)
Security. Cybersecurity concerns are paramount in any supervisory control system. It is important to protect the network with the full range of security measures such as firewalls and active user rights management. Additional considerations must be included when deploying a mobility solution. Specific features within the framework of the mobility infrastructure include:
- User sign-on required to use the smart app.
- Re-authenticate before control actions are performed.
- Validation before critical actions are performed.
- Validate proximity of the user to the mobile device with a wearable sensor such as a BLE beacon.
- Confirm validity via a geo-tag attached to the equipment such as a QR code.
Benefits of Contextual HMI for Valve Maintenance
Many benefits are realized with the deployment of an infrastructure for contextual HMI mobility. These include benefits to central management as well as benefits to the mobile worker. There also are benefits for the entire organization in safety, security, comfort and efficiency improvements.
Operations. Operations and maintenance personnel are able to move away from their SCADA system and be near the valves that they manage. This is possible with the ability to see critical information on the mobile device, which is automatically refreshed upon movement. At the same time, it is possible to maintain awareness and receive equipment alarms across all zones. Trends may be viewed, setpoints can be modified and other valve operator actions performed. When out of the zone where the O&M user has responsibility, the controls that allow movement of the valve may be withdrawn and substituted with displays of valve positions without permitting access to control of those valves.
Maintenance. The mobility server is aware of the location of valve maintenance personnel and is able to intelligently dispatch alarms to the person who is best positioned to respond. The proximity rules enable innovative thinking about organizing a maintenance strategy. New ways to combine proactive and reactive aspects of maintenance based on a real-time assessment of resources and proximity are possible.
The information needed for maintenance resides in the SCADA system, but it can be difficult to access. Also, given the amount and format of some of the technical information, it can be difficult to understand. The promise of mobility to proactively deliver only the needed information in an understandable format and to guide the maintenance worker to solve the problem has been identified as a major benefit of contextual mobility.
As the maintenance worker moves, he or she is provided with an updated view of the valves and related equipment. These views are in the context of the physical orientation (nearby valves, boiler room or across the full facility) and also factored to provide the most useful tools for that user based on training and certifications on file.
For example, a maintenance engineer may be monitoring a valve operator that is suspected or known to have malfunctioned. The component is uniquely identified, its location determined by one or more geo-tags. When approaching the geo-tags, the proximity services app synchronizes with the mobility server, which responds with contextual information and control actions. The information and control actions related to nearby valves include:
- Access to real-time and historical information about the valve history.
- Display of the trend for any parameter such as fluid temperature that may be of interest.
- Access to the valve’s alarm history list.
- Ability to put the valve into maintenance mode.
- Access to technical documentation, including wiring diagrams for the valve.
Commissioning. Commissioning can be labor intensive and time consuming. Typically, one worker located at the control room uses a radio to communicate with a field worker to relay the current position and valve status. The mobile worker is provided with an HMI for operating the valve and access to resources such as commissioning checklists, electrical diagrams and startup procedures. They are automatically delivered to the mobile device as the worker approaches the valve and actuator assembly.
Access Control. The mobility server’s knowledge of workers’ credentials and current locations provides the baseline for access control. When a contractor comes to work as a temporary worker, and they require access to a zone, the request is known to the mobility server based on the person’s proximity to a geo-tag associated to the access point. The mobility server may grant access and verify that the user has, in fact, entered the zone.
Geo-fencing refers to the management of user rights as they move through different zones. The mobility server enforces the geo-fences. The rights of a worker are allowed to change depending upon the current zone. An alarm may be raised when persons are entering or leaving a zone (crossing the virtual fence) without prior authorization.
Safety. The mobility infrastructure also supports life safety. It is able to coordinate and monitor the progress of any required evacuations, including providing information about the best route given the real-time situation. The mobility server is able to monitor workers remaining in danger zones and alert workers moving in an unsafe direction. Safety-related warnings can be directed to the mobility user, and that person will now be accounted for in the case of an emergency.
Management. The top-level view of mobile personnel and assets is extremely valuable for managing maintenance resources.
Maintenance Routes. Tracking changes of location over time is an extension of the proximity services. By monitoring the real-time location of the valve technician, actions that may be configured on the mobility server as a result of tracking location include:
- Raising a security alarm if entering an unsafe or unauthorized area.
- Adjusting environmental controls for temperature, lighting, etc.
Asset Tracking. Geo-tags associated with assets also are registered in the mobility server. The relationship with the position of the asset geo-tag compared to stationary geo-tags associated with zones makes it possible to track mobile assets inside a plant environment. As in previously described cases, the mobility server may react to the repositioning of a moving asset via alarming, visualization or recording (archiving).
The rise of smart mobile devices that are now familiar to almost all workers has created an opportunity to improve mobility for maintenance and monitoring of process heating valves. This trend moves away from managing via a central control room to a distributed model focused on mobility workers. The way in which users interact with their mobile device in comparison to the way in which an operator works in a control room requires a mobility infrastructure to optimize efficiency, safety and security.
With the standardization of geo-location and micro geo-location capability on mobile devices, it is possible to monitor mobile personnel location. Based on that location, the system can drive contextual information and controls to their smart device based on their credentials without requiring specialized equipment.
The mobility infrastructure was born of the desire to make use of the rapid growth and availability of smartphones and tablets. A good mobility strategy will be built on the mobility infrastructure and enabled by a mobile app. This app should incorporate the proximity services required to realize the mobility infrastructure and working in concert with mobility server, enabling world-class mobility solutions for SCADA and building management system projects that use process heating valves.
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