The ‘SAE J2263 Coastdown’ test is a test plugin for the VBOX Test Suite software.
The test itself allows the user to complete a coastdown test to the SAE J2263 specification. Using wind speed and direction inputs, the software will automatically apply the required equations to produce a road load curve.
The SAE J2263 Coastdown test has a unique 'Test Setup' ribbon bar, from which the test and test area can be configured.
Note: Ribbon bar icons may move/ resize dependent on the Software window size.
The 'Configure' button displays a pop up window whereby the parameters of the test can be defined.
The 'Report' button creates a report from the current test results.
Allows the user to create unique maths channels. For more information on maths channels, please see the ‘Maths Channels’ section.
The 'Save Settings' button will save this individual test setup and will appear in the ‘Saved Settings’ area of the ‘Add Test’ window.
This test will also be added to the list of SAE J2263 Coastdown tests under the 'Coastdown' icon on the 'Home' tab for easy switching of the current test.
The 'Export' button displays a drop down menu which allows the user to export either the selected results or line results to either a .csv or .txt file. It is also possible to export the data to a .vbo file for later analysis without the need to take the file from the VBOX's compact flash card. This can also be accessed by using the keyboard shortcut 'Ctrl+E'.
Add Gate (space)
Pressing the ‘Add Gate’ button will add a virtual gate to the chart and map area at the point of the cursor, indicated by green coloured lines. The currently selected gate is indicated by a dark blue coloured line. Once a gate has been added, the gate width can be specified. A gate can also be added by using the keyboard space button.
IMPORTANT - When adding a gate, the vehicle must be travelling greater than 0.8 km/h in order to ascertain the heading of the gate.
Allows the user to rename the currently selected gate line (start/finish, end of bath, etc.).
Deletes the currently selected gate.
Allows the user to either export the created gate(s) as a .spl file for reusing at a later date or using with another VBOX product, or import a previously saved or provided .spl gates file. When imported, gates will be added in the order in which they were saved within the .spl file.
The 'Add' button adds a column to the test results area. Selecting this button will bring up a drop down window where the user can select a channel to display in the test results window.
Sort Ascending/Sort Descending
The 'Sort Ascending/Descending Buttons' will sort the values based on the currently selected column in the results area.
Select All (Ctrl+A)
The 'Select All' button allows the user to tick every run in the results area at once. This can also be accessed by using the keyboard shortcut 'Ctrl+A'.
Deselect All (Ctrl+E)
The 'Deselect All' button allows the user to de select every run in the results area at once. This can also be accessed by using the keyboard shortcut 'Ctrl+E'.
The 'Edit Data' button allows the user to enter session specific data such as driver name, track facility and weather data.
Pressing this 'Help' button will automatically open an internet browsing window and load the relevant section of the Racelogic Support Centre. This page will only be displayed if there is a valid internet connection. If there is no valid internet connection, a cached version of the relevant section (from the last software update) will be presented in PDF form. This can also be accessed by using the keyboard shortcut 'F1'.
Selecting the 'Configure' button will display a pop up window where the user can define the parameters of the test. These include the start and end conditions as well as Calibration requirements.
Use the up and down buttons to the right of the parameters to Expand and Collapse the parameter headings.
Relative Wind Speed
For a successful test, the user must specify which CAN channel relates to the Relative wind speed parameter, typically an Analogue channel from an anemometer.
Relative Wind Direction
For a successful test, the user must specify which CAN channel relates to the Relative wind direction parameter, again typically an Analogue channel from an anemometer.
To stop the software reading false coastdowns (i.e. braking into a turn around point), the user can select the ‘Requires Trigger’ option. When this option is ticked, the software will not record a coastdown result unless the trigger is active. Releasing the trigger at any time during a coastdown will invalidate that run.
Enabling legacy mode will force the software to use an older routine in the final calculations. This feature has been included to allow the results to be compared to the lower resolution VB6 program developed by the EPA.
Ticking this option allows the user to enter a known Drag coefficient (Cd) into the session information which will be then be used in the subsequent equation of motion. If this option is not selected, the Software will automatically calculate the drag coefficient.
The constrained analysis option can yield better results in certain circumstances when the Drag coefficient is known.
In the final report, a table of speed vs Road load is produced. The ‘Report Every’ field allows the user to specify the intervals at which these road loads are reported.
i.e. if the user enters ‘10’, then the road load figures will be reported at 10, 20, 30, 40, 50 etc.
The minimum number of complete sets (1 set = 1 run in both directions) required before the statistical accuracy will start to calculate.
The SAE J2263 Coastdown software will automatically calibrate the wind speed and wind direction and will not produce test results until the user has completed the calibration procedures. By selecting the ‘Omit Wind Direction’ or ‘Omit Wind Speed’ boxes, it is possible for the user to complete the test without needing to complete the calibration procedure.
It is possible to set the speed at which one coastdown run will start and end. It is also possible to add extra test intervals by pressing the ‘+’ button, allowing the full coastdown test to be broken into more manageable segments.
Split runs will display within the results area as separate tabs, the colour of the tab is dependent on the number of valid runs within the speed range; red = no runs, orange = 0 –10 runs in each direction, green = >10 runs in each direction.
This option allows the user to enter criteria that will quickly identify whether there has been a ‘Speed Jump’ during the coastdown run. If selected, a PASS/FAIL column for the speed quality appears in the Results Table to indicate if the criteria has been met after each run. A gauge is also available for selection on the Dashboard.
VBOX Test Suite allows the user to specify a channel that can be used to easily identify if certain parameters have exceeded a set threshold, and as such will highlight the run red to mark it as ‘Failed’. The pass conditions can be set so that the run fails whenever the threshold is exceeded, either at the start of the test, at the end of the test, anytime during the test or averaged during the test.
To do this, the user must select a channel from the drop down list and specify a low and high threshold value. More channels can be added by selecting the ‘+’ button.
Completing a Test
To start an online test, the user must first select the correct COM port from the ‘Online’ drop down menu in home tab. Once connected to a VBOX, the dashboard will change to show the 'START', 'STOP' and 'RESET' buttons.
Starting, Stopping and Resetting a Test
By pressing the 'START' button, the software will add a tab to the Test Results area ready to be populated with results once the start and end criteria have been met. The 'START' button will also change to a 'PAUSE' button, allowing the user to pause the test. To resume the test, simply press the 'RESUME' button.
To finish a test, simply press the 'STOP' button. This will stop all open tests. Once the stop button has be pressed, future results cannot be added to that results tab. Pressing the 'START' button will open up a new results tab, however once the stop button has been pressed, the user will be required to undergo the calibration process again before a new test can be started.
If, for any reason, a mistake has been made during the test, it is possible to restart the test by pressing the 'RESET' button and again this will require a calibration of the wind speed and direction.
Calibrating the Wind Direction and Wind Speed Channels
When the user first presses the 'START' button, a dialogue window will appear that contains the calibration instructions.
Firstly the user must remain stationary for 5 seconds with the anemometer pointing directly in line with the vehicles body. Usually it is a good idea to secure the wind vane in the required direction BEFORE pressing the start button. The software will then average the value over the 5 second period to create a bias offset that can be compensated for.
It is then required that the user complete 5 passes in each direction at a steady 50 mph. This allows the software to correct any errors in the anemometer measurement by comparing them to the reference GPS speed.
IMPORTANT - Unless the ‘Omit Calibrations’ options are selected within the Test Configuration, the calibration period is also required when in ‘Offline’ mode, so it is extremely important that the unit is logging before the calibration procedure is carried out, otherwise the software will not produce any test results.
Performing a Coastdown Test
Once the calibration procedure has been completed, the user can then commence the coastdown test.
As per the SAE J2263 spec, the software requires the runs to be completed in pairs of differing directions. For example, a coastdown run of 115-15 in the North direction, followed by a 115-15 in the South direction would constitute one pair of runs. Once a pair has been completed, the user can then repeat the test the required number of times.
Runs will be paired regardless of which order they are done in, for example, if the second direction/run is aborted, VBOX Test Suite will create a pair of runs using the first direction/run and a later second direction/run.
If the full coastdown cannot be completed in a continuous run, then it is possible to use the ‘Split Run’ option as detailed in the test configuration section above. In a split run, data is first collected for the ‘high speed’ portion (125 km/h to ‘X’ km/h) in each direction (i.e. both North and South Runs) before then collecting data from the ‘Low Speed’ portion (‘X’ km/h to 15 km/h) in both directions. The process is then repeated the required amount of times and once finished, the software will automatically combine the high and low speed portions into one complete coastdown run.
Test Results Area
The test results area is the area that displays all of the results from the current test. Within this area it is possible to include/exclude results from the chart area, display the average/max/min values and also easily identify any runs which have not met the pass criteria.
Every time a new test is started (via the 'START' button on the dashboard), or a new file is loaded, a new tab will be added to the test results area, allowing the user to switch between separate tests or files and compare runs from each. A session can be removed from the results area by pressing the ‘x’ icon on the tab.
It is possible to rename the session tab by double clicking on the tab header. Changing the session tab within the software will automatically change the name of the locally saved .vbo file.
By pressing the 'Edit Data' button next to the name of the file/session or in the ‘Test Setup' ribbon bar , a new window will be displayed as below, whereby the user can add various different pieces of vehicle and test information.
The software requires that the user enters the frontal area, rolling weight, temperature and pressure information before the final equations can be completed. If the user has selected constrained analysis, it is also required that the Aerodynamic drag coefficient be entered.
When in 'Offline' mode, this information will be saved into the .vbo file meaning that this information will be recalled every time the file is loaded into VBOX Test Suite.
When in 'Online' mode, a newly-created session will be populated with session data from the previous session.
This information will be included in the test report to allow the user to understand under what conditions the test was conducted.
To save time, it is possible for the user to import and export the session information for use in other sessions (the entire range of data is exported not just the visible screen).
Once the session information has been completed, it is possible to export the data to a .vbses file. This file will contain all the session information that can then be imported into the open session information field.
Along the top of the Test results area are some default columns. These columns are:-
- Run – Indicates which run number the results relate to, with run one being the first run completed. There is also a selection box that, when ticked, includes that run in the graph and into the Average/Max/Min/Standard Deviation calculations. Once selected, a coloured square will appear to indicate which colour this run is displayed as on the graph.
A directional arrow will also be present next to the run number to indicate which direction the run was completed.
Note: If you are loading a file offline, all valid runs are ticked automatically.
- Time – The total time the run has taken.
- Distance – The total distance travelled in that run.
- Wind Speed (avg) – The average wind speed during the run. This will highlight red when the average wind speed exceeds 35 km/h as per the regulations.
- Wind Speed (max) – The maximum wind speed during the run. This will highlight red when the max wind speed exceeds 50 km/h as per the regulations.
- Cross Wind Speed (avg) – The average cross wind speed during the run.
- Speed Quality (if speed quality check has been ticked) – A PASS/FAIL indication of whether the Speed Quality criteria has been met. If failed, this column will be highlighted deep red and the whole run will be highlighted light red.
Adding a Column
It is possible to add columns to the test results area by selecting the ‘Add’ button on the ‘Test Setup' tab in the ribbon bar. Selecting this button will display a drop down list of all available channels which the user can select to display as a results column. By default, this value is displayed as an ‘At End’ value, whereby the column will display the value of that parameter at the end of the run.
It is also possible to right click anywhere in the test results area and select the ‘Add’ option from the dropdown menu.
To remove a column, simply select the ‘x’ icon that appears when you hover over the column title. If a column has been removed, it can be added again by selecting the ‘Add’ button and choosing the desired channel.
Adding a Note
Notes can be added to the ‘Notes’ column of the results area. This is done by double clicking inside the column for the required run. This will then change that column to a text box and you can enter a note against that run. This note will then be included in the report and the exported .csv file.
Editing a Column
As default, a column is added as an ‘At End’ condition. It is possible to change this by selecting the column title you wish to edit (once selected, the column will be highlighted in yellow) and changing the condition in the ‘data column’ area in the ‘Test Setup’ tab of the ribbon bar.
It is possible to choose the following conditions for the main results:-
- Avg – The mean average of the parameter during the run.
- Max – The maximum value of the parameter during the run.
- Min – The minimum value of the parameter during the run.
- Delta – The difference between the start and end value of the parameter.
- Std Dev – The standard deviation of the parameter during the run.
- At Start – The value of the parameter at the start of the run.
- At End – The value of the parameter at the end of the run.
- Gate (if a gate has been added) – The value of the parameter at the crossing of the specified gate line (e.g. Start/Finish).
It is also possible to change the displayed parameter, by using the other drop down menu on the ribbon tab and selecting the desired parameter.
Sorting the Results
It is possible to either sort the result in either ascending or descending order. To do this, first select the desired column and then click either the ‘Sort Ascending’ or ‘Sort Descending’ buttons from the ribbon bar. This action can also be performed by right clicking in the test results area.
It is possible to filter results by right clicking on a value within the cell results table (e.g. Time (s)). You can then choose to include only results with a value equal to the selected value or that have a value that is <= than or >= than the selected value for that channel. Multiple channels can be filtered, a notification bar above the results shows which filters are applied. To remove the filters, click on the 'x' within this bar.
Copying Cells (Ctrl+C), Rows or Columns
Individual results cells can be copied so that they can be pasted into another piece of software. To copy a cell, select the required cell, right click and then select ‘Copy’ or use the keyboard shortcut 'Ctrl+C'. To select multiple cells, either left click with the mouse and drag or hold down the 'Ctrl' when selecting. To select all cells between 2 cells, hold down the 'Shift' key when selecting.
It is also possible to copy an individual row, column or the entire results table. This is achieved by right clicking the required row or column and selecting ‘Copy Row’, ‘Copy column’ or ‘Copy all’.
Renaming a Column (F2)
To rename a column, you can either Double Click on the column title, right click the required column and select ‘Rename Column’ or use the keyboard shortcut 'F2' whilst the column is highlighted. Renamed columns will be included within an exported file and a generated report.
Right clicking anywhere in the test results area and selecting the ‘Export’ option from the dropdown menu will replicate the function of 'Export' within the Ribbon Bar.
Average/Max/Min/Standard Deviation Values
It is possible for the software to automatically calculate the Average/Max/Min/Standard Deviation values of all relevant runs by ticking the selection box next to the relevant run number.
Once more than one result has been selected, the average, maximum and minimum values will be displayed, and once more than two results have been selected, the standard deviation of the selected runs will be also be displayed.
Selecting the tick box next to the ‘Avg’ line will add a moving average ‘best fit’ curve to all of the selected runs.
Along with the usual dashboard functionality, the ‘SAE J2263 Coastdown’ test has some extra options that can be displayed to the user.
By selecting the 'Add Gauge' button from the dashboard tab, a drop down menu will appear whereby the user can select 'Test' and then the desired parameter to be displayed. On selection, a gauge will be automatically added to the dashboard. Any gauges displaying a result of a test, such as an average or maximum value, will have a 'Result' icon to the left of the gauge name to indicate that it is either a result of the previous run if viewing live data, or the currently selected run if viewing a saved file.
All Result Column parameters are also available as a gauge.
Showing Test Results on the Dashboard
It is possible to display the time and distance test results from the last run completed as a gauge on the dashboard.
It is also possible to show the current run number on the dashboard to give an easy, clear indication of the amount of runs completed. An 'OK Runs' gauge can be added to indicate how many runs have met any specified pass conditions.
A 'Speed Quality' gauge is available for use when conducting live testing to show the status of the last completed run with regards to the Speed Quality criteria. It will display as a green 'PASS' when the last run has met the criteria and a red 'FAIL' when the criteria has been exceeded.
A 'Run Status' gauge is available for use when conducting live testing to show the status of the last completed run with regards to the Pass Conditions. It will display as a green 'PASS' when the last run has met all Pass Conditions and a red 'FAIL' when any of the Pass Conditions limits have been exceeded.
Creating a Report
VBOX Test Suite allows the user to turn the results table into a custom report whereby the user can easily compare and display the results from their coastdown test.
This report will include all of the previously entered session data, along with the coefficient results and a table and graph of force vs speed.
The user can then choose to print or save this report. A sample of this report can be seen below.