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Rotary Racer - Car Performance
Rockingham 24+ 2013-07-08
Results
A superb race, we managed 3rd in the F24+ race at an average of 39.2MPH, 21% higher than the last race. Unfortunately no full data logs as there was no SD card in the computer :(
Telemetry worked well though, so there is a fair amount of data available.
A superb day weather wise, warm with a small breeze.
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.
F24+
F24
Practice Laps Data
Notes
- The Car was RR9b. This was the cars third race.
- We used a 18:48 gear ratio.
- Driver was: Ben Millar.
- Average current in the first half was about 27.5 Amps and in the second stint about: 27.5 Amps. These are approximate. Batteries were at about 22V and 22.17V at 30 amps.
- We estimate that we can take about 32Amps out so an extra 15% of energy is available. This would provide about 5% more speed.