Configuring the BRAKEBOX
The configuration menu allows you to set up all aspects of the behaviour and operation of the BRAKEBOX. All configuration options are persistent, hence there is a slight pause when setting an option as the new value is written into the unit's flash memory. An option exists to reset the unit to the factory defaults if required. Each of the available options is discussed below. The full configuration menu structure is shown in figure 3, in which the factory defaults are indicated by being underlined.
This option allows the units for the display and printing of speed, distance and acceleration to be set. The units of speed can be set to miles per hour (mph), kilometres per hour (kph) or metres per second (m/s). The units of distance can be set to be feet (ft) or metres (m). Acceleration can be set to g (defined internally as 9.81m/s2) or m/s2.
This sets the language for the menus and options.
These options configure the behaviour of the actual brake test, and control the measurement that is taken.
Trigger Mode. This sets whether the brake test starts on a speed threshold or an electrical pulse, typically from a brake pedal input or possibly an optical barrier.
End Trigger Mode. This sets whether the brake test is ended by a speed threshold or an electrical pulse, typically from an optical barrier.
Start Speed. If the trigger mode is set to “Trigger on Speed” then you have the option of setting the speed at which the braking distance measurement will start. The units of the speed threshold are as set in the configuration menu.
End Speed. If the end trigger mode is set to “Trigger on Speed” this sets the speed at which the brake test finishes. Typically this is set to zero (0 MPH) meaning that the brake test completes once the car is stationary, however you can set a higher speed if required.
Use 2D or 3D Speeds. The BRAKEBOX can use either 2D or 3D velocity to calculate the braking distances. In theory 3D velocity is more accurate as it includes any inclines of the road, however in practice using 2D velocity can give more repeatable results as the effects of small pot-holes and other minor road surface imperfections are reduced. Most competitor brake measurement systems use 2D velocity, however in practice the velocities are so accurate from the BRAKEBOX that both modes will give very similar results.
Set MFDD Thresholds. MFDD (Mean fully-developed deceleration) is the average deceleration recorded between two user-settable proportions of the test start speed, by default 80 – 10%. These values can both be set by the user, with the limitation that the lower threshold must remain lower than the upper threshold. It is necessary to press SET at the upper threshold screen to progress to the lower threshold screen.
Set Start Exceed. When the BRAKEBOX is configured to start the brake test at a given speed (“Trigger on Speed”), this speed must initially be exceeded by a certain margin before the BRAKEBOX will arm, to ensure that the test is not started by noise on the speed signal whilst accelerating upwards through the start speed. This margin is set here. The units are as set in the configuration menu, and in common with other user-set speeds, the value will not be changed when the units are changed.
The BRAKEBOX can generate a number of tables following a brake test. The following options control whether or not tables are printed at the end of a test, and if so which tables are generated, and the intervals used.
Print Results. This first option allows you to set if the results of the brake test are printed through the serial connection labelled “printer” once the test has completed. You can set the system to always print the results, never print the results, or prompt the user to see if results should be printed. If a serial printer is not available, the results tables can be viewed by connecting the “printer” serial connection to a PC, and using Hyperterminal to view the results, set to connect at a baud rate of 9600.
Speed Table, Path Distance Table, Time Table. The tables generated have one independent variable down the left hand side with the values spaced at regular intervals and then up to three additional dependant variables. The three independent variables that can be used in the tables are speed, path distance and time. Each of these can set activated as required:
- Calc Speed Table. This option enables the braking results to be tabulated as a function of speeds.
- Calc Path Distance Table. The option enables the braking results to be tabulated as a function of distance.
- Calc Time Table. This option enables the braking results to be tabulated as a function of time.
When you activate a table, then you are prompted to enter the interval for the table.
Whilst speed, path distance and time results are always shown, there are also another six variables that are optional:
- Forward distance. This is the distance that the vehicle has travelled during the test in the direction of the initial heading.
- Deviation distance. This is the deviation laterally from a straight line in the direction of the initial heading. Note that this is the deviation at the end of the test, NOT the maximum deviation recorded. Deviation during the test may be seen using the tables. The sign convention is that deviation to the right is positive, and to the left is negative.
- Direct Distance. This is the distance directly from the start point of the test to the end point of the test.
- Average Acceleration. The sign convention used is that acceleration is positive, and deceleration is negative.
- MFDD (Mean fully-developed deceleration). This is the average deceleration recorded between two user-settable proportions of the test start speed, by default 80 – 10%.
- Initial Heading. This is the heading recorded at the start of the test.
Each of these variables can be used or hidden. If they are used then they will be displayed on the screen immediately following a braking test and included in the printed tables of results, if printing is enabled. A more detailed explanation of the various distance metrics used can be found in the “Explanation of Results” section later in the manual.
This option allows you to set if the results of the brake test are stored to internal memory once the test has completed. If enabled, the unit stores the complete set of raw data recorded during the test, and so the full set of available parameters can be viewed at a later date. For instance, even if the unit is set to not display forward and deviation distance at the end of a test, these parameters can still be viewed later if the data is stored, simply by changing the configuration to display these parameters, and recalling the results.
The system can be configured to always store the results, never store the results, or prompt the user to see if results should be stored. Once the results are stored they will be retained until the memory is cleared. If there is insufficient space to store the results at the end of a run, the user will be offered the option of clearing the memory of existing results, or discarding the current data. Note that selecting the clear memory option clears the memory of all saved results, and is irreversible.
To identify the test files, you can set a name for them to be stored under. This is used as a basis for the internal “file name” and can be up to 5 characters long. The characters are typically the initials of the test driver or car registration code. A 3 digit number is automatically appended to the name by the BRAKEBOX when saving the run in order to differentiate separate runs. This starts at 001, and automatically increments each time another run with the same name is saved.
This clears the entire internal memory. This is 100% permanent; once the memory has been cleared there is no way to recall the data.
This screen allows the user to set the LED brightness, to a value between 1 and 8. All of the LEDs are lit whilst adjusting the brightness to show the brightness selected.
This resets all configuration options to the factory defaults, except for the language option which will remain in the language selected by the user.
The firmware version is displayed here.