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Rotary Racer - Car Performance
Castle Coombe 2011-10-02
Results
An excellent race. The weather was brilliant, sunny and warm with a reasonably light wind (16 km/h ?). The car
was RR8h. A tail peice befind the rear brake light had been added.
Car Computer Log
This shows the main items measured by the Rotary Racers car computer. They are:
| Item |
Description |
| Throttle |
The position of the twist grip throttle from 0 to 100% |
| MotorCtl |
The
motor power output setting. The Car computer sets the motor power based
on the drivers throttle position, the speed of the car and the current
being used. There is a software algorithm to implement this "drive by
wire" system. The Car computer drives the PWM (Pulse Width Modulation)
Motor Speed controller with a duty cycle proportional to this value. 0
- 100% |
| Speed |
The speed of the car in Km/H calculated from the magnetic read switch pulse generator by the Car Computer. |
| Voltage |
The batteries voltage under load. |
| Current |
The current being taken from the batteries. |
| Charge0 |
The
charge left in the battery pack 0. This is calculated by the car
computer using an algorithm that has been honed to match the battery
discharge curves for the Yuasa batteries. It currently bases its
results on the current being used from the battery. |
| Charge1 |
The
charge left in the battery pack 1. This is calculated by the car
computer using an algorithm that has been honed to match the battery
discharge curves for the Yuasa batteries. It currently bases its
results on the current being used from the battery. |
| Charge2 |
The charge left in the battery pack 2. This is calculated by the car
computer using an algorithm that has been honed to match the battery
discharge curves for the Yuasa batteries. It currently bases its
results on the current being used from the battery. |
| BatPack |
The
battery pack in use (0, 1 or 2), the turbo button (4) and the Pitstop
warning (8) . We generally change the battery pack with each driver
change. |
| Temp |
The Temperature of the motors casing in degrees C. |
| GPS |
GPS position, speed and time together with lap position information |
| Misc |
Other items describing the operation of the control system |
The graphs show the overall data, the actual ASCII data log files
are also available, from the links below, for detailed analysis.
Practice Laps Data
Notes
- The
Car was RR8h. This was the cars fifteenth race.
- We used a 18:49 gear ratio.
- The Castle Combe circuit is 2.977Km long and has a slight hill
with sweeping corners. There was a slight wind on the day (16Km/H
?).
- The
software was car25. The Car electronics worked perfectly. Changes for
this race were: Changed GpsCurrent average to be taked an GPS position
1. This allowed us to obtain the average current for the last lap just
as the car comes into sight/range leaving more time for the operator to
decide and change the power levels. Added battery number switch to car.
This worked well and the battery changers remembered to change it !
- The
battery charge calculations worked well and the Voltage based charge measurement was about spot on.
- The Car Computers "Average Current" setting was 16.00
Amps, the Control Speed was about 44 Km/Hour, this was tweaked during the
race based on actual average lap current keeping it to around 17.5Amps.
- Drivers
were: Dan Dando, Gareth Barnaby, Ben Millar, Stepanie Dando, Louise Barnaby and Dawn Barnaby. The
drivers drove excellently, went fast and kept out of trouble (apart from Dawns almost skirt onto the grass!) and keeping well clear of other cars by going around the outside (as far as we could see).
- The motors temperature kept below 45 degrees, 10 degrees higher than Merrifield but it was a warmer day.
- The battery packs were fine although we did take the first
battery pack (0 RR7,RR8) a bit too low and the voltage levels went down
alarmingly. The other battery packs were not used so heavily. We had
about 15% left in the last set at the end of the race.
- An excellent race an a superb 1st place result with 113miles.
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