Anomaly reception with Anomaly Detect Type - Receiver

When Batch Tracking receives a detection signal that is associated with an Anomaly Detect configured as a Receiver, it will behave like a Detector in how it observes the deadband windows. Additionally, the anomaly will be considered received and will automatically be removed from the pipeline.

There are two abnormal alarms that are associated with anomalies that have a designated receiver. The two alarms are:

• Anomaly approaching a segment that does not lead to the designated receiver

• Anomaly entering a segment that does not lead to the designated receiver

The following sections discuss how Batch Tracking checks for the conditions that cause these alarms to be raised.

Anomaly approaching a segment that does not lead to the designated receiver

To enable this type of check, the Controller must specify a positive value in the anomaly's Unexpected Anomaly Detection Volume field.

The purpose of this check is to provide a warning to the Controller if entering the next downstream segment will result in a situation where the anomaly is guaranteed not to arrive at the designated receiver. To make this determination, when an anomaly approaches any node in the pipeline (that is, it is detected to be within the Unexpected Anomaly Detection Volume window), Batch Tracking will perform the following procedure:

1. Retrieve all segments immediately downstream of the node. This can yield no segments if this is the end of the pipeline, a single segment if there is no branching at the node, or multiple segments if there is branching at the node.

2. Filter out segments that are not currently flowing.

3. Filter out segments that are currently flowing but in the opposite direction.

4. If there are no remaining segments, exit the procedure without an alarm.

5. Otherwise, for each remaining segment (flowing in the same direction):

   1. Search downstream for a viable physical path in the pipeline. In this context, a viable path is defined as path that goes to the designated receiver. This search does not take into consideration the flowing conditions of the downstream paths.

   2. If at least one viable path is found, do not raise an alarm. If no viable paths are found, raise an Anomaly Approaching – No Receiver alarm. If the alarm is inhibited, only an event will be raised.

Anomaly entering a segment that does not lead to the designated receiver

The purpose of this check is to alert the Controller of a situation where an anomaly has just entered a segment that does not lead to the designated receiver. If there is no route from this segment to the designated receiver that an Anomaly Entered – No Receiver alarm will be raised. If the alarm is inhibited, only an event will be raised.

Example

In this example, anomaly Pig X is moving with the flow of the pipeline. Arrows indicate direction of flow. Segments in red are not flowing. The designated receiver is at the end of Segment 8. The shaded areas A through D show the Unexpected Anomaly Detection Volume associated with Pig X.

After some time, when Pig X enters the volume window A:

• Retrieve the flowing segments immediately downstream: Segment 2

• Starting with Segment 2, search downstream for viable physical paths. There are multiple physical paths that Pig X can go through:

  • Path 1: Segment 2 -> Segment 3 -> Segment 4 -> Segment 5. This path is not viable because the designated receiver is not down this path.

  • Path 2: Segment 2 -> Segment 7 -> Segment 8. This path is viable as it leads to the receiver. Note that at this point, the fact that these segments are not flowing is not relevant, because flow conditions might change as Pig X continues to move down the pipeline.

• There is at least one viable physical path. Do not raise the Anomaly Approaching – No Receiver alarm.

When Pig X enters Segment 2:

• There is still a viable path to segment 8. Do not raise the Anomaly Entering – No Receiver alarm.

Assuming flowing conditions have not changed, when Pig X enters the volume window B:

• Retrieve the flowing segments immediately downstream: Segment 3 only. Segment 7 is excluded because it is not flowing.

• Starting with Segment 3, search downstream for viable physical paths. There is only one physical path that Pig X can go through:

  • Path 1: Segment 3 -> Segment 4 -> Segment 5. This path is not viable because it does not lead to the designated receiver.

• There is no viable physical path, and an Anomaly Approaching – No Receiver alarm has not been raised previously for this segment. Raise the alarm.

When Pig X enters Segment 3:

• There is no viable path to the receiver. Raise the Anomaly Entering – No Receiver alarm.

Assuming flowing conditions have not changed, and the Controller took no action to relocate the simulated pig, when Pig X enters the volume window C:

• Retrieve the flowing segments immediately downstream: Segment 4

• Starting with Segment 4, search downstream for viable physical paths. There is only one physical path that Pig X can go through:

  • Path 1: Segment 4 -> Segment 5. This path is not viable because the receiver is not down this path.

• There is no viable physical path. Raise the Anomaly Approaching – No Receiver alarm.

When Pig X enters Segment 4:

• There is no viable path to the receiver. Raise the Anomaly Entering – No Receiver alarm.

Assuming flowing conditions have not changed, and the Controller took no action to relocate the simulated pig, when Pig X enters the volume window D:

• Retrieve the flowing segments immediately downstream: Segment 5

• Starting with Segment 5, search downstream for viable physical paths. There is only one physical path that Pig X can go through:

  • Path 1: Segment 5. This path is not viable because the receiver is not down this path.

• There is no viable physical path. Raise the Anomaly Approaching – No Receiver alarm.

When Pig X enters Segment 5:

• There is no viable path to the receiver. Raise the Anomaly Entering – No Receiver alarm.