The method can bs used to extract segments of data based on global positioning satellite data (GPS/GNSS) position from a recording. This could be used to identify specific road surfaces, separate laps on a circular track, and more. Example extraction shown in Figure 1 below:
Figure 1: Left – Original GPS measurement (red line), Middle – Example of two separate extracted segments (red and green line), Right – Two consecutively extracted segments (red and green line)
The following examples for segmenting data based on global positioning satellite data are covered in this article. The first example is covered in detail. Subsequent examples focus on the triggers needed for each scenario. 1. Getting Started 2. Single Segment 2.1 Export GPS Measurement to Google Earth 2.2 Import GPS Measurement to Google Earth 2.3 Create Trigger Locations in Google Earth 2.4 Export Triggers from Google Earth to KML File 2.5 Use Triggers KML File with “Spilt by Position” in Simcenter Testlab Neo 3. Circular Track 4. Multiple Separate Segments 5. Multiple Consecutive Segments 6. Results
1. Getting Started
To make the “Split by Position” method available in the Method Library of Simcenter Testlab Process Designer, go to “File -> Add-ins” and turn on “Trackside Validation” add-in (17 tokens). The “Split by Position” will be available as shown in Figure 2.
Figure 2: The “Split by Position” method can extract segments based on GPS/GNSS location. Turn on the “Track-side Validation” add-in to make it available in the Method Library.
The following steps are needed to use the “Split by Position” method:
Create triggers: Triggers (each trigger is a line defined by two points) need to be defined. Triggers can be created in Google Earth (either online version or downloaded version).
Names: The triggers created in Google Earth need to have names that follow a certain convention:
The name consists of three parts (Beginning, middle, end) separated by a colon symbol. In the last two parts only numbers (negative or positive) or the wild card * symbol are valid. For example “Name:*:1” or “Name:1:-1”.
Beginning: Name is a free field. This will be used as the extracted segment run name in Simcenter Testlab Neo after running the process with “Split by Position” method.
Middle:
If a sequence of triggers is desired, the middle number is the identifier number of the preceding trigger. Data will be recorded from the preceding trigger only.
Using the wildcard symbol * means no data from a previous trigger is needed to detect the current trigger. For example, this might be useful for a start trigger condition.
End: The last number is the identifier number assigned to the trigger. A positive number means the data after the trigger is to be stored. A negative number means data after the trigger is not to be stored. Any negative number can be used.
Export the triggers to KML (Keyhole Markup Language) format from Google Earth.
Import the KML file with triggers in the “Split by Position” method within Simcenter Testlab Neo.
Run: Run the process to extract the segments. Additional methods can be connected to the “Split by position” to process data (Spectrums, overall levels, etc) from the extracted segments.
Multiple scenarios are covered in the rest of the article. The "Single Segment" example is highly detailed. The other examples have less detail and focus mainly on the triggers that need to be defined for each specific scenario.
In this example, a shorter segment is trimmed from a longer recording:
Two Triggers: Start and End
Example Applications: Extract Rough Road Surface or Smooth Road Surface from Track
In Figure 3 below the measurement (red line) contains a specific section (yellow bracket) of road desired for analysis.
Figure 3: With a Google Earth plug-in in Simcenter Testlab Neo, the GPS location (red line) of the acquired data is shown. The yellow indicates the desired road segment to be analyzed. Right click in the map to switch from Satellite to Map view.
Click on either the Latitude or Longitude channel in the throughput file in Simcenter Testlab Neo to show the GPS measurement.
Note that Simcenter Testlab Neo does not have the Google Earth display active by default (due to export restrictions). Contact your Siemens sales or support contact to request a license to add the capability at no cost if in an eligible country.
2.1 Export GPS Measurement to Google Earth
Triggers to identify the desired road surface are created in Google Earth by creating a KML (Keyhole Markup Language) file of the measured GPS data. Right click on the throughput file in the navigation tree and choose ”Export…” as shown in Figure 4 below.
Figure 4: To create a KML file from the measurement, right click on the throughput file and choose “Export…”. When selecting KML as the export format, only GPS location data will be exported.
After selecting “Export…”, choose “KML” as the export file format. Only the GPS location data will be exported. All other channels (acceleration, strain, etc) are not exported.
2.2 Import GPS Measurement to Google Earth
Go to Google Earth (either web version at https://earth.google.com/ or the downloaded application). Open the KML file exported from Simcenter Testlab Neo to make it easier to identify triggers.
Create a new “Project” within Google Earth and import the KML file that was exported from Simcenter Testlab (Figure 5). Importing the original measurement will make it easier to select appropriate triggers in Google Earth.
Figure 5: Open a new project in Google earth and import the KML file (Open local KML file).
The GPS positions corresponding to the Simcenter Testlab recording are now shown in Google Earth (Figure 6):
Figure 6: The location of the vehicle during the measurement is shown in Google Earth.
Now trigger locations can be identified to trim the measurement to the desired road segment.
2.3 Create Trigger Locations in Google Earth
Now click on the “Add path or polygon” icon. Define a start trigger by clicking on two points in Google Earth as shown in Figure 7.
Figure 7: Click on two points that cross the GPS path in Google Earth to define a single start trigger.
To be used by the “Split by GPS Postion” method in Simcenter Testlab Neo, the trigger needs a very specific name (see below for guidance). Repeat the operation again for the end trigger (Figure 8):
Figure 8: A start (light blue) and end trigger (light green) defined in Google Earth.
In Google Earth, give the start and end trigger specific names.
The start trigger is called “Euclid_Road_North:*:1”. It has a beginning, middle, and end separated by the “:” symbol:
Beginning: Euclid_Road_North is the name of the trigger and will be the name of the run corresponding to extracted data in Simcenter Testlab Neo.
Middle: The * symbol means the trigger will be activated by crossing it. The * is a like a wild card, the trigger will always be activated.
End: The number 1 is an identifier number to the trigger. Assigning a positive number means the data after the trigger is to be stored.
The end trigger is called “Euclid_Road_North:1:-1”
Beginning: Euclid_Road_North is the name of the trigger and will be the name of the run corresponding to extracted data in Simcenter Testlab Neo.
Middle: The number 1 means that data starting with trigger identifier 1 is to be saved. It only works if the start trigger with identifier 1 was the previous trigger that was activated. Any other triggers are ignored. In this case, the data will only be segmented when traveling from the south to the north. The start trigger must be passed over for the end trigger to be active.
End: The number -1 means no data after this trigger is to be saved. The negative number effectively makes this the end trigger. Any negative number can be used in this manner, but for easier book keeping the number -1 was used.
2.4 Export Triggers from Google Earth to KML File
Export the triggers to a KML file from Google Earth. Be sure not to include the original GPS recording in the exported KML. To be used in Simcenter Testlab Neo, the KML trigger file must only contain the trigger information, not the original GPS data.
In Google Earth, delete the “GPS Points” and “GPS Track” as shown in Figure 9.
Figure 9: Delete both “Gps Points” and “Gps track” before exporting the triggers to a KML to be used in Simcenter Testlab Neo.
With the deletions completed, choose “File -> Export as KML file” in Google Earth to export the triggers as shown in Figure 10.
Figure 10: From Google Earth, choose “File -> Export as KML file” for use in the “Split by Position” method in Simcenter Testlab Neo Process Designer.
The newly created KML trigger file can be used in Simcenter Testlab Neo.
2.5 Use Triggers KML File with “Spilt by Position” in Simcenter Testlab Neo
In Simcenter Testlab Neo Process Designer, double click on the “Split by position” method in Simcenter Testlab Process Designer to set the Properties.
In the Properties dialog, select the KML trigger file in the “Track Definition” parameter (Figure 11):
Figure 11: In the Properties of the “Split by Position” method select the KML file under “Track Definition”.
Note: The “Export Track Definition” is only used to transfer the KML (perhaps it was lost) to another process or project.
In this example, multiple laps of a circular track were driven. Each lap of the track is to be separated.
One Trigger
Example Applications: Race tracks, loops, any circular track where separate laps are of interest
See previous section for detailed instructions, this section only outlines what triggers are needed for the circular track scenario.
The original measurement GPS is shown in Figure 12 below:
Figure 12: Measurement of three laps of circular path.
The measurement consists of three laps of a circular track. After exporting to a KML file and importing it to Google Earth, a single trigger needs to be defined to separate laps as shown in Figure 13:
Figure 13: A single trigger can be defined to extract multiple laps from the circular laps.
The single trigger consists of the following:
The start trigger is called “lap:*:1”
It has a beginning, middle, and end separated by the “:” symbol:
Beginning: “lap” is the name of the trigger and will be the name of the run corresponding to extracted data in Simcenter Testlab Neo.
Middle: The * symbol means the trigger will be activated by crossing it. The * is a like a wild card, the trigger will always be activated.
End: The number 1 is an identifier number to the trigger. Assigning a positive number means the data after the trigger is to be stored.
After importing the trigger only KML into Simcenter Testlab Neo Process Designer, the results of the “Split by Position” method are shown in Figure 14:
Figure 14: Results of lap-by-lap extraction. Each lap has separate color red, green, and blue.
The three laps are shown above. They are colored red, green, and blue. It is easy to see that the green lap was not consistent with the rest of the laps. It has an extra detour in the lower left.
4. Multiple Separate Segments
In this example, two separate segments will be extracted from the track.
Four Triggers: Start and end on two different but separate segments
Example Applications: On a proving grounds, two separate road tracks can be extracted in a row
Consider the route shown in Figure 15 below:
Figure 15: In the route (red) line, two segments are desired (Loop and Elbow).
In this case, two segments (“Loop” and “Elbow”) are to be extracted separately from the overall route.
Four triggers (Figure 16) are setup in Google Earth to extract these two separate segments:
Figure 16: Four triggers define the two segments to be extracted.
The trigger names for the first extracted segment called “CCWiseLoop” consist of the following:
The start trigger (light blue in picture above) is called “CCWiseLoop:*:1”. It has a beginning, middle, and end separated by the “:” symbol:
Beginning: “CCWiseLoop” is the name of the trigger and will be the name of the run corresponding to extracted data in Simcenter Testlab Neo.
Middle: The * symbol means the trigger will be activated by crossing it. The * is a like a wild card, the trigger will always be activated.
End: The number 1 is an identifier number to the trigger. Assigning a positive number means the data after the trigger is to be stored.
The end trigger (light green in picture above) is called “CCWiseLoop:1:-1”
Beginning: “CCWiseLoop” is the name of the trigger and will be the name of the run corresponding to extracted data in Simcenter Testlab Neo.
Middle: The number 1 means that data starting with trigger identifier 1 is to be saved. It only works if the start trigger with identifier 1 was the previous trigger that was activated. Any other triggers are ignored.
End: The number -1 means no data after this trigger is to be saved. The negative number effectively makes this the end trigger. Any negative number can be used in this manner, but for easier bookkeeping the number -1 was used.
The trigger names for the second extracted segmenet called “Elbow” consist of the following:
The second start trigger (red in picture above) is called “Elbow:*:2”. It has a beginning, middle, and end separated by the “:” symbol:
Beginning: “Elbow” is the name of the trigger and will be the name of the run corresponding to extracted data in Simcenter Testlab Neo.
Middle: The * symbol means the trigger will be activated by crossing it. The * is a like a wild card, the trigger will always be activated.
End: The number 1 is an identifier number to the trigger. Assigning a positive number means the data after the trigger is to be stored.
The second end trigger (yellow in picture above) is called “Elbow:2:-2”
Beginning: “Elbow” is the name of the trigger and will be the name of the run corresponding to extracted data in Simcenter Testlab Neo.
Middle: The number 2 means that data starting with trigger identifier 2 is to be saved. It only works if the start trigger with identifier 2 was the previous trigger that was activated. Any other triggers are ignored.
End: The number -2 means no data after this trigger is to be saved. The negative number effectively makes this the end trigger. Any negative number can be used in this manner, but for easier bookkeeping the number -2 was used.
After exporting the KML file and using it with the “Split by position” method in Simcenter Testlab Neo Process Designer, the result should look like Figure 17 below.
Figure 17: Left: Original measurement GPS route. Right: Extracted segments from “Split by GPS” method in Simcenter Testlab Neo Process Designer.
Two separate segments are now extracted for processing from the original measurement.
5. Multiple Consecutive Segments
In this example, two consecutive segments will be extracted from the track.
Three Triggers: Start, middle, and end to define two consecutive segments
Example Applications: On a proving ground, two consecutive road segments can be extracted in a row
With the same track as the previous example, suppose that the “Elbow” segment should immediately follow the “Loop” segment as shown in Figure 18:
Figure 18: In this case, two consecutive segments are to be extracted from the measurement.
Here three triggers would be needed to extract the two consecutive segments. This is how the three triggers would be defined in Google Earth (Figure 19):
Figure 19: Three triggers are used to extract two consecutive segments.
The trigger names for the “Elbow” and “Loop” consist of the following:
The start trigger (light green in picture above) is called “CCWiseLoop:*:1”. It has a beginning, middle, and end separated by the “:” symbol:
Beginning: “CCWiseLoop” is the name of the trigger and will be the name of the run corresponding to extracted data in Simcenter Testlab Neo.
Middle: The * symbol means the trigger will be activated by crossing it. The * is a like a wild card, the trigger will always be activated.
End: The number 1 is an identifier number to the trigger. Assigning a positive number means the data after the trigger is to be stored.
The middle trigger (red in picture above) is called “Elbow:1:2”. It has a beginning, middle, and end separated by the “:” symbol:
Beginning: “Elbow” is the name of the trigger and will be the name of the run corresponding to extracted data in Simcenter Testlab Neo.
Middle: The number 1 means that data from trigger identifier 1 is to be stored when this trigger is crossed.
End: The number 2 is an identifier number to the trigger. Assigning a positive number means the data after the trigger is to be stored.
The end trigger (yellow in picture above) is called “Elbow:2:-2”
Beginning: “Elbow” is the name of the trigger and will be the name of the run corresponding to extracted data in Simcenter Testlab Neo.
Middle: The number 2 means that data starting with trigger identifier 2 is to be saved. It only works if the start trigger with identifier 2 was the previous trigger that was activated. Any other triggers are ignored.
End: The number -2 means no data after this trigger is to be saved. The negative number effectively makes this the end trigger. Any negative number can be used in this manner, but for easier bookkeeping the number -2 was used.
After exporting the KML file and using it with the “Split by position” method in Simcenter Testlab Neo Process Designer, the result looks like Figure 20 below:
Figure 20: Left: Original measurement GPS route. Right: Consecutive extracted segments from “Split by GPS” method in Simcenter Testlab Neo Process Designer.
Two separate consecutive segments are now extracted for processing from the original measurement.
6. Results
The “Spilt by Position” method outputs a new file containing only a segment of the original file. The typical output results are shown in Figure 21 below:
Figure 21: The output of a segment extraction method is typically a folder called “Process” in a run (top picture). There may be links to the original throughput data as well (bottom picture).
The segment of data extracted is usually stored in a new run called “Process”. Often there is a link to the original data as well, for example a Throughput file. When viewing data, highlighting the run may show both the original data and extracted data in the display. Highlight just the “Process” folder to see only the extracted data.
It is also possible to create a new run that contains only the extracted segment without a link to the original recording. This can be done by changing the “Input Data” setting from “Save time data as link” to “Do not save” in the “Input” method as shown in Figure 22 below:
Figure 22: To see only the extracted segment in the results, change the “Input Data” setting from “Save time data as link” to “Do not save” in the “Input” method properties.
Hope this article helps with using "Split by Position" in Simcenter Testlab Neo! Questions? Email peter.schaldenbrand@siemens.com.
