Video
from Contour Camera. Data from AIM EVO 4. Data display by Race Renderer
3.
The
track map is in the upper left hand corner. It is created from the
GPS data. The timing line is not at the same place as the official
Start/Finish line, so lap times differ slightly from official times.
Next
to the track map is the G-force display. This is the lateral and
longitudinal forces acting on the car as it turns, accelerates and
brakes.
Upper
right corner includes a Speedometer from GPS data. The lap count
and time is for the current lap but displays for 10 seconds after
the end of the lap for easy reading.
The
two numbers display under lap time are the results for the current
lap. In the race, the driver can not see these figures until the
end of the lap when they are calculated. For the video, we are displaying
this information during the lap to help the viewer understand whether
it is an effective lap or not.
The
'Miles' number is the number of miles the race vehicle would cover
if every lap was driven exactly the same as the current lap. This
is calculated against both the 60 minute limit and the battery capacity
limit. This gives the driver a way to compare a slower lap that
uses less energy and a faster lap that uses more energy against
the ultimate goal of covering as much distance as possible in the
time allotted.
The
'Whrs' number is the average Watt Hours used this lap. The battery
pack capacity is 945 Watt hours. Any lap under that amount, the
driver is not using as much energy as available. Any lap over that,
the driver is using more energy than the pack can sustain for an
hour.
The
driver sees these numbers on the Driver Displays Unit (DDU) while
racing. The DDU also tracks energy remaining and calculates whether
there is enough energy to finish the race based on the speed and
power usage of the last lap. This check is displayed as a simple
green, yellow, red background color.
The
displays on the bottom of the screen are, on the right, Watt hours
going from battery pack to motor. On the left, Watt hours being
consumed overcoming aero drag and rolling resistance and motor inefficiencies.
This is calculated by looking at changes in kinetic energy. This
information helps display how driving technique influences power
usage. You might also notice that the uphill sections consume more
energy than the downhill.
At
the end of lap 12, the chain from motor to rear wheel comes off.
We are running a 114 tooth gear to keep RPM high where it is most
efficient on this motor. The large diameter of the gear and the
lateral loads created too much movement. We remounted the chain
and ran another 15 laps before it came off again.
For
the second race, we used a smaller 77 tooth gear and completed 66
laps before the rear tire wore through. The camera mount glue melted
in the Florida sun, so we were unable to collect video.