Home > VBOX Motorsport > Performance meters > PerformanceTools / DriftTools > PT / DT User Guide > 06 - PT / DT Analysing Lap Timing

06 - PT / DT Analysing Lap Timing

Pressing the Lap timing button in the Toolbar causes the software to scan the loaded file and apply loaded split file information to produce a table of Lap times, with a V Max for each lap and with the fastest lap highlighted.

 

This facility also allows individual laps from the loaded file to be loaded and compared in the main Graph window. In addition a circuit overlay can be loaded into the Graph:Map window to aid with drive-line analysis.

 

pt17.png

 

Start / Finish Lines and Splits

Before you can carry out any lap time analysis you must set a start / finish line in the file you have loaded. The information pertaining to these points can be saved to start / finish files for later use with new data from the same circuit, or for sharing with other PerformanceBox / DriftBox users.

Defining start / finish lines and splits

To define a start / finish line, move the cursor in the Graph window to the desired point, then press the spacebar to mark a start / finish point, or press the Set Start / Finish button in the Toolbar.

 

When the cursor is moved in the Graph window the cursor in the Map window follows this movement so you can see where the cursor point relates to on the track. After setting a start / finish line a green dot will then appear in the Map window at the corresponding cursor position.

 

In addition to the start / finish, up to 20 split points can also be set in the software. However if you save the start / finish and splits to a file for use in a PerformanceBox or DriftBox, only the first six will be saved and used by the unit. To ensure that only the maximum amount of splits that can be accepted by the PerformanceBox / DriftBox are created, an option to set this maximum is in the ‘Start, Finish & Splits’ menu.

pt18.png

 

To define the split points, press the ‘S’ key at the desired cursor location or select the ‘Set Split’ option from the ‘Start / Finish & Splits’ drop down menu.

 

A separate finish line can be placed when the start line is not also the finish line. This is used in situations such as hill climbs, or for data analysis along a stretch of track that does not end where it starts - such as “Bridge to Gantry” at the Nordschleife in Germany.

 

pt19.png

 

Create a finish line by holding Shift + Spacebar at the desired cursor location or by selecting the ‘Set finish’ button from the ‘start / finish & splits’ menu.

Note: It is important to try to place the start / finish line at a fast part of the circuit to reduce the effects of positional error and to get the best lap timing accuracy.

 

 

Loading and Saving start / finish line and split data

Click on the ‘Save’ option from the start/finish drop down menu to save to the start / finish and split line information created in the Graph screen to a ‘.dsf’ file. If you want to save more than six splits for software use only then choose the file type ‘.spl’ instead which is only compatible with the software and not PerformanceBox or DriftBox units.

 

Click on the ‘Load‘ button in the Start/finish drop down menu to load in a ‘.dsf’ or ‘.spl’ file. The .dsf file must be copied into the DATA directory of the SD card being used. 

 

If you have multiple .dsf files from various tracks, it is advisable to keep them stored on the PC in directories named after the track – then the DBOX.dsf file can be loaded into the unit prior to going to the circuit.

 

Clearing start / finish line and split data

If the current start / finish and split file information needs to be cleared from the PerformanceTools / DriftTools background memory and display screens, select ‘Clear All’ from the ‘Start / Finish & Splits’ menu in the Graph screen toolbar, or from the main ‘Tools’ menu.

Moving Splits

Splits can be moved by pressing ‘M’ in the Graph window and entering the number of the split to be moved, or by selecting ‘Move split’ from the menu.

 

Show Split Info on Graph Chart

The start / finish and split lines can be hidden from view by selecting the Show Split Info on Graph Chart option. This is available either by right-clicking on any of the three main windows to bring up the context menu, or from the Graph Setup button on the Toolbar. If you choose to hide the start / finish and split lines they will still remain active – the software will still generate lap time data even if the lines are not visible.

pt20.png

Gate Width

The width of the split gate can be set from the ‘Start, Finish & Splits’ menu.

 

If you intend to create a .dsf file for use at a circuit, where split points are placed on areas of track which pass very close to each other, it may be necessary to reduce the gate width accordingly: this will ensure that you do not inadvertently drive back through a split point even though you are on a different section of the track. See the example below.

 

pt21.png

 

 

The circled area circled in green shows two sections of track passing by each other by only approximately 20m. If a split point is set on this section, and the virtual gate has been set too wide, the split point could be registered by the PerformanceBox / DriftBox as it passes by in the opposite direction.

pt22.png

 

 

 

 

 

 

 

 

 

Track proximity can be checked in Google EarthTM using the measurement tool if you are in doubt as to how wide the split points should be created.

 

Split Names

Split points can be named from the option in the ‘Start, Finish & Splits’ menu. When the Lap Timing – Split Line option is chosen to display lap times (assuming that split points have been created) an extra column will display the split names.

Displaying Lap Times

Load the .dbn data file into the software, then define a start / finish line (along with split points and a separate finish line if required) in the manner described above, or by loading a .dsf or .spl file.

 

pt24.png

 

Press the Lap Timing button on the Toolbar. The software scans the currently loaded file, extracts lap times and Vmax for each logged lap, and displays the data in a results window.

 

pt23.png

 

Note: The fastest lap in the results table will be highlighted for quick and easy recognition.

 

 

 

Including Split times

If you have set up split points in addition to the start / finish and wish to see the split times displayed, click on the right hand arrow on the Lap timing button, then from the drop down menu select ‘Lap Timing – Split Line’. The results table will show the split times as well as the Lap times in the file.

 

Naming the split files (see ‘Split Names’ above) from the option in the ‘Start, Finish & Splits’ menu will result in the split names being displayed when the ‘Lap Timing – Split Line’ option is chosen – see the example on the next page, which shows the split points that have been set on corners at Silverstone Circuit and named accordingly.

 

 

Exporting Lap Time Results

The generated results can be exported into other software as a variety of document types by clicking the Export Results button on the Toolbar and selecting the required file type.

Clearing Lap Time Results

To clear all the results in the results window, click the ‘Clear Results’ button on the Toolbar.

Lap Highlight

With lap data being displayed in the ‘Report Generator – Circuit Test’ window, individual laps are highlighted in the main Graph screen by clicking on any of the values at the bottom of individual lap/split data tables:

pt25.png

pt26.png

 

Loading and comparing individual laps from the same file

Individual laps from the loaded file can be compared to each other in the main Graph and Graph:Map windows. Each lap shown in the Lap timing table has a Graph Icon associated with it in the right hand column. Clicking one of these buttons allows that lap to be individually graphed:

pt27.png

 

 

You will now have one individual lap displayed in the Graph window, and one corresponding column in the Graph:Data window. From the results window, select a compare lap by clicking a different Graph Icon, in this example the next fastest lap:

 

pt28.png

 

Result in the Graph window:

pt29.png

 

The main run is in red, the compare run in blue. In this instance the two laps have been performed very consistently: the peaks and troughs, which indicate the braking and acceleration points, sit on top of each other almost every time.

 

Note that the Graph window’s X axis is set to distance – this makes direct comparison of braking and acceleration points possible as the distance covered on each lap will be virtually identical. If comparison laps are loaded when the Graph window’s X axis is set to time, the data is very much more difficult to analyse.

 

Result in the Graph:Map window:

pt30.png

Note how in this instance, the driver’s lines have barely deviated between the two laps – the main run in red is only just visible below the compare run in blue.

 

Three compare laps can be loaded in total, allowing for comparison of four laps at once (the main run plus compare runs 1, 2, and 3.) Each compare lap will have corresponding data displayed in an individual column in the Graph:Data window. To change the colours of each run, open the Channel Setup window and pick the colours required from the Run x columns.

 

 

 

 

 

 

 

Loading and comparing individual laps from different files

Lap data created by individual users, and therefore not logged in one .dbn file, can also be loaded and compared:

 

  • Load the first file containing the lap data, set the start / finish line, and click the lap timing button. The laps will appear in the results window.
  • Load the next file to be analysed – ensure that the results from the first file have not been cleared, and do not load the second file as a compare file.
  • Click the laptiming button again and the second set of lap times will appear in the results window.
  • The individual laps can now be chosen as Main and Compare files in the same manner as before:

 

pt31.png

In this example, the main run chosen is lap 8 from the first set of times (the same fastest lap from the previous example.) The Compare Run 1 is lap 8 from another file, which is again the fastest lap. See below to view the differences in performance as shown in the Graph window

 

Result in the Graph window:

pt32.png

 

The main run (1:30.70 – the fastest lap from the previous example) is in red, the compare run (1:26.10) in blue. Note in this instance how there are differences in the peaks and troughs of the speed plots, indicating that the faster driver carried more speed before braking, and accelerated harder.

 

Replaying Laps (Drift Tools Only)

If you have recorded laps loaded into the software you can replay them, by clicking on the Replay button. 

pt33.png

By default the cursor will move through the Graph window and round the path in the Graph:Map window at the same speed at which the file was recorded. 

However by clicking on the arrow to the right of the button a faster replay speed can be chosen.

When the Replay button is pressed the Drift Meter and Sector windows will also appear, but these can be closed if not required.

 

Whilst the file is being replayed the cursor in the Graph:Map will move around the path taken. If more than one lap is currently being viewed there will be a cursor for each run, and these will move around the circuit in a manner according to how the graph window x axis has been set: if the Graph window is displaying speed over distance, the cursors will move around the circuit together, as the distance covered during each lap will be virtually identical. However, if the Graph window is set to speed over time then the cursors will travel according to the actual lap times.

 

Note in this example (below) how the green triangle is behind the red and blue triangles – this is a snapshot of three individual laps being replayed when the Graph screen has been set to speed over time. This feature allows for ‘live’ analysis of where a driver is gaining or losing time, and on which part of the circuit.

pt34.png

 

Set Position Cursor Type

The cursors themselves are configurable: right click on any of the main windows (Graph, Data or Map) to bring up the context menu (or click on the Graph Setup button on the Toolbar.) Select ‘Set Position Cursor Type’ and choose the style and colour required for each cursor. Each run can now display a different shape and colour of position cursor.

 

Circuit Overlays

A circuit overlay is a file created to map the outer and inner bounds of a circuit, and is a useful aid in drive-line analysis - comparison of lines taken by different drivers can help to improve lap times.

NOTE: A circuit overlay is only a feature that can be used in software post-processing – it is not vital that it is created or obtained prior to visiting a circuit unless specific drive line analysis, that requires the track boundaries, is going to be carried out between lap sessions.

Creating a Circuit Overlay

There are two ways that an overlay file can be created: either by driving around the circuit, or by creating a .kml file in Google Earth and importing it into Performance Tools / Drift Tools.

Creating an Overlay File by Driving the Circuit

Note: It is best to use an external antenna to get maximum positional accuracy

  • Power up PerformanceBox / DriftBox and let it acquire satellites for at least 5 minutes.
  • Drive to the left hand side of the start of the circuit.
  • Place the antenna on the left hand side of the roof.
  • Insert the SD card, ready for logging.
  • Drive round the left hand side of the circuit.
  • Stop back at the place you started.
  • Move the antenna from the left hand side of the roof to the right hand side slowly, being careful not to cover the aerial – let it see the sky at all times.
  • Drive at right angles across the track to the opposite side.
  • Drive round the right hand side of the circuit.
  • Load the logged file from the SD card using ‘File’ -> ‘Load All’
  • Save using ‘Save’, select ‘Save as type’ and pick ‘Circuit file’ (‘.cir’).

 

Creating an Overlay File in Google EarthTM

Please refer to the Google Earth help files for instructions on creating paths in the software.

Creating Track Maps in Google Earth

Creating Start/Finish Files in Google Earth

Once you have plotted a path along the inside and outside of your chosen track, it must be saved as a .kml file. This can then be imported into PerformanceTools or DriftTools by clicking on TOOLS>Import  Data

pt36.png

Once the .kml file has been imported, it can be re-saved as a .cir file for later use with lap data from the circuit. 

 

 

 

 

 

 

 

 

 

Loading a Circuit Overlay File

The .cir file can be now be loaded into the Graph screen and viewed in the Map window. To do this, first load a file logged from the circuit in question, and then click on the drop-down arrow next to the Load All button. Select Load Circuit Map, and choose the .cir file you have created:

pt37.png

 

 

If you want to load a .cir file into PerformanceTools on its own, click Load All and then type *.* in the File name field:

pt38.png

 

You can then select the .cir file and it will load like a normal .dbn file.

 

A library of circuit overlay files is available from the VBOX Motorsport website. If you would like to share circuit files you have created please contact us and they will be added to those already available.

Aligning Circuit Overlays and Laps

The standard positional accuracy of PerformanceBox and DriftBox units is 5m 95% CEP for Longitude and Latitude.  CEP = circle error probable.


95% CEP means 95% of the time the position readings will be within a 5m diameter circle of the true position. This error is due to the changing state of the ionosphere, constantly changing the time taken for the satellite signals to reach the earth. This means that overlaid laps may appear to miss the edges of the track, especially if the laps or overlay were logged several hours apart.

 

The Align Circuit Tracks feature allows post-processing analysis to counter some of this positional error, by rearranging the driving lines or circuit overlay in the Graph:Map window. This can be especially useful if the circuit overlay file has been created in Google Earth, which is not always 100% positionally accurate (a good example of this, at the time of going to press, is the Paul Ricard circuit in the south of France – the Google Earth image is approximately 200m adrift of its true position.) It can also help to combat the effects of positional shift that have occurred between sessions at a circuit, such as morning/afternoon or one day to another.

 

In order to be able to view truer drive lines, right-click on the Graph Map - the option to align either the lap data or overlay will appear at the top of the context menu. Having chosen which you wish to move in the “Select run to align” dialogue box, use the keyboard cursor keys to realign either the circuit overlay or lap data. Once you are content that the drive lines resemble the actual lines taken, press return.

 

pt39.png

 

Importing a background image in to the Graph Map

You can import any image of your choosing into the Graph Map by right-clicking on either the Graph:Data, Graph:Map, or Graph windows and selecting the Graph: Map Background Image>Load option:

 

The image will need to be resized and scaled to fit correctly in the Graph:Map window.

 

pt40.png

 

You must to post a comment.
Last modified

Tags

This page has no custom tags.

Classifications

This page has no classifications.
Having trouble finding what you need?