EPG at the 2013 Shell Eco Marathon
On Sunday 12th of May, EPG members set off to Rotterdam for the 2013 Shell Eco Marathon. After debuting in 2012, Peggie, the team car, was returning with a new drivetrain, driver interface, PV array and an ambition to break the original target she set of 366km/kWh (or Paris to Naples on a pint of petrol). The event seeks to find the vehicle which can complete 10 laps of a 1.6km track at an average speed of 25kph using the least amount of energy from the propulsion batteries.
Fig 1: Peggie after her 2013 make-over. New features include: a mobile application that provides the driver with a real time position on the drivetrain's efficiency map; a clutch scheme enabling efficient coasting and regenerative braking; a reconfigurable PV array that manoeuvres the maximum power point of the solar panel to coincide with the battery terminal voltage.
On arriving in central Rotterdam, the team boarded “HMS Holiday Boat” where they would sleep during the 8 day event:
Fig 2: HMS Holiday Boat moored in the Rotterdamse Schie, displacement 20 tonnes (draft), beam 5.5m, LWL 26m, bale 1500ft^3...
Once cabins had been allocated, naval hierarchy established and bilge pumps primed, the team made their way, with Peggie, to the Ahoy centre where she was subjected to a rigorous technical inspection:
Fig 3: Peggie going through technical inspection, note the apprehensive stance of team members (far right)
After several hours of interrogation, mainly centred around the brakes and reconfigurable PV control circuitry, the technical inspectors finally gave Peggie a clean bill of health enabling her to attempt some practice runs on the track:
Fig 4: Peggie out on track with Lucy Mahoney behind the handlebars
Initially, Peggie was plagued with teething problems, these included:
- An M3 grub screw, responsible for torque transfer from the propulsion motor to the gear train, coming loose
- An auxiliary battery cell popping out of its case causing the contactors to open and car to die
- Shell dragging on front tyres due to warped axle limiting top speed to 18kph
- Main battery balancing wires coming loose from connectors causing the battery management to get upset
In the end the team managed to prevail against numerous problems to register 3 valid attempts and a 50%+ improvement on last year's range, achieving 564km/kWh (Oxford to Minsk on a pint of petrol). Team Peggie were awarded the overall technical innovation prize out of a pool of over 200 teams from across Europe. The collective sense of relief can be seen in the team photo:
Fig 5: The team collecting 1500 Euros and Technical Innovation Award Trophy
We'd like to take this opportunity to thank our sponsors:
Future Electronics, IXYS, Shetland Composites, Accenture, Oxford Martin School, Maxon Motors, Goodrick Gears, Arm, Frankie's Paint Shop, Christ Church, Balliol, Mansfield, Pembroke.
A more thorough thank you is provided by the following video: