Data Acquisition - Layer 1: Functionality

About

Data Acquisition acquires and stores data from different sensors plugged into channels.  The DA unit has a timer and methods for determining good data from bad in some cases but not all.  You will become familiar with the major functions of the sensors commonly used in karting, along with the overall operation of the storage unit.

DA Models & Track Mapping Features

Those with Track Mapping Features

Those without Track Mapping Features

Track Mapping requires a type of sensor called an Accelerometer to measure left & right turn forces.  Together with a Axle Rev Counter, Beacon Pickup, and System Clock, the analysis software can calculate the shape of the track and create a Track Map.  Obviously the extra features of Track Mapping cost more money then the more simple systems.

Using the Race Studio software, a Track Map is actually a separate file that is created from the data identified above, and it's a separate step - the user has to select the "Create a Track Map" function.  That Track Map can be used by others even those whose Mychron is not equipped with Track Mapping Functions.

Functional Product Documentation along with Analysis Software cane be downloaded from the respective manufacturers. 

Links to DA Supplier Websites:

• Mychron
• Alfano
• PI Research
• Digitron

Hardware & Components

Analog Channel is one or more of the Data Logger Unit connection ports that takes a variable voltage input and measures it for data storage.  Most Karting systems like the EVO 3 have 2 Analog Channels. 

Digital Channel is one or more of the Data Logger Unit connection ports that simply looks for a change in voltage on the sensor connected, and stores those counts.  Don't confuse these Digital Channels with something like a PC Serial Port or anything else on a PC for that matter.  Its simply a counter.

Batteries are important - without them charged the DA system becomes a DOA system.  Some DA's use 9V dry cells some have rechargeables.   Some DA systems record and store battery voltage levels which can be helpful in determining when they need charging.

Temperature Sensors can generally measure about any temp from sub-freezing to 1600° F.  They may vary in mounting configuration depending on how they are to used.  A Cylinder Head Temp (CHT) probe may be a ring shape to fit on the Spark Plug, where an Exhaust Gas Temp (EGT) or Water Temp (WT) probe are the same threaded types.  Each probe plugs into an Analog Channel.

Axle Rev Counter counts the number of revolutions an axle makes and can convert that into both speed and distance.  As this sensor just counts pulses, it uses a Digital Channel.

RPM Counter counts Spark Plug firing and uses a Digital Channel.

System Clock is a timer that starts when the system is turned on to keep track of all the data that gets stored.  Each data element has a time stamp when it gets stored so the system knows when everything was logged.  The System Clock is contained in the Data Logger Unit.

Beacon Pickup senses the Beacon signal on the track and sets a point on the timer so the data is displayed according to lap.

Accelerometers measure the G-Forces in a given axis - some units measure on the left-right axis only (turns) some left - right, forward-back (braking/acceleration).  The only axis really needed for a kart is left-right, as the Axle Rev Counter can determine accel/decel rates.

Display connects to the Data Logger Unit to give the driver some feedback on track.  data provided varies from one model to another, as do features like backlighting and various warning lights.

Download Accessories connect between the Data Logger Unit and a PC to download the session data to a PC for analysis.

Data

The following table provides a list of data that is measured and stored by various Data Logger products;

Depending on the unit, some of the data can be played back on the display such as best lap time, RPM, and temperature, and some units will even play back these data measurements in real time through a chosen lap.  That may be handy for a quick glimpse, but is very limited in what it tells the tuner the kart is doing.

Data storage is also based on sampling rates.  At any given instant a sample of the data may be taken, and how often those samples are taken may be configured by the user.  There is a default setting for these sampling rates that probably works best, although in later sections we will discuss the benefits of configuration changes.  For now, just be aware that the more frequent a sample rate is set the more quickly unit memory is depleted.

For those lacking strong PC skills, don't be intimidated by the list of data above.  The traditional form of stopwatch, seat of the pants, and Peak RPM all relies on one or more of the data elements above.  Where some tuners processed data with a notepad or even in their head they may not have gone to the extent of breaking down each crucial measurable element and then assembled it in a presentation quite the way an analysis program does.  It takes a little learning, but the payoff is pretty good.  It is difficult to run at the front of a pack without data analysis when others are using it.

Lap Counter is the lap of the downloaded session it's the start/stop of each lap.  Note that the Data Logger Unit is matching several data fields to within a specific lap and time.  If the kart comes to a stop and the Axle Rev Counter or the Tachometer counts fall below a certain number it sets a "condition flag" for the Analysis software to treat that lap as "incomplete"  Say for example the driver spins on a lap and shuts off the motor - in the analysis screen that might show as a really fast lap or be mixed in with other laps if the flag wasn't set.