Electronics is not needed for a successful competitive Greenpower car. However it can help and is an excellent way of presenting engineering to the pupils especially in the fields of electronics, instrumentation, software and control systems and Greenpower is all about promoting engineering. The following information is intended to provide an in-sight into some of the uses of electronics in a Greenpower car and some pointers on how to achieve it. Many of the examples are based on our GpSpeed controller kit, but the basic information I hope is useful to other strategies.
One of the core things to get right in a Greenpower race is to manage the use of the batteries energy so that the car can last the race, just. To much average energy usage and you will stop on the track near the end watching all of the other cars go past and damaging your batteries in the process, Too little average energy usage and you could have gone faster/further in the race. Its a fine line and so managing the average energy usage is important. This can be done with changeable ratio gears, but often the step in radio is to great for good control. Variable ratio gear systems sound ideal, but their efficiency can be very low. Another way is to use fixed gears to get close and then use an electronic speed controller to tweak the motors energy output up and down a little.
See SpeedController for more information.
In order to use the available battery energy to the maximum but not run out you need to measure things. The core things you need to measure is the available energy left in the batteries and how much the car is using. This can be accomplished by measuring and averaging the batteries voltage and the electrical current drawn by the motor over time.
See VoltageCurrent for more information.
Information is power! Having data on how your car is performing allows you to determine what happened during a race. The data can be analysed in the calmer conditions back in the schools Greenpower sessions.
See DataLogging for more information.
Information on battery usage, motor temperature etc can be presented to the driver so they can control the cars power levels.
See DriverDisplay for more information.
A good extension is to send the data log data live to a pit-side laptop. This will allow the pupil pit side engineers to look at and analyse the data on the fly and give instructions to the drivers.
See Telemetry for more information.
See MotorTemperature for more information.
See SpeedSensing for more information.
See CarHorn for more information.
See Batteries for more information.
See TestRigs for more information.
See the Software page for more information.