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Rotary Racer - Car Performance
Coorporate Challedge 2012-04-29
Results
What a wet race! The wetest we have been in. Due to the conditions the race was reduced to two sets of batteries in 160 minutes.
Although we could have just used two drivers, the drivers choose to use 4 drivers so that no one would be out in the cold and wet conditions for more than 40 minutes. This was very much an endurance race, we had further waterproofed the electronics prior to the race after seeing the weather forcast. This obviously helped, we had no issues whatever with the electronics, which was suprising.
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 seventeenth race.
- We used a 17:49 gear ratio as it was very windy and wet on the day.
- The Silversone circuit is 2.637Km long and is fairly flat with sweeping corners. There was a strong wind on the day (40Km/H ?) and it was into wind on the long uphill pit straight.
- The software was car27. The Car electronics worked perfectly. No changes for this race. Was the same as Castle Coombe: 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.
- The Car Computers "Average Current" setting was 16.00 Amps, the Control Speed was about 42 Km/Hour, this was tweaked during the race based on actual average lap current keeping it to around 18.0 Amps. Dan was again in charge of car power management and again did a fine job as usual. We did forget to zero the computers battery power levels at the start of the race. This was done a little into the race.
- Drivers were: Gareth Barnaby, Tom Allington, Ben Millar, and Dawn Barnaby. The drivers drove excellently, went fast and kept out of trouble and keeping well clear of other cars by going around the outside (as far as we could see).
- The motors temperature kept below 35 degrees, it was a cold day.
- The battery packs were kept in warmed battery boxes. They were fine with no noticable drops in power.
- An excellent race considering the conditions and a good 4th place result.