Earthquake in Springfield
How the Project Developed
When we began planning what we would do for the Robo Show in June we had quite a few discussions before any building began. After seeking ideas, the one that was eventually settled on was to make a kind of obstacle course and then each of four groups would design models to negotiate the obstacles. The initial idea was that we would quickly come up with a few ideas for obstacles, build them, and then each group could get on with the real task of building the vehicles to tackle the obstacles.
However, as the discussion unfolded, pupils came up with many ideas for obstacles, and the obstacles began to take on a ‘life of their own’. They wanted to incorporate light sensors and touch sensors, etc. into the obstacles, so that they could be activated by the vehicle, as it approached.
They became so engrossed in the ideas for the obstacles that pretty soon the obstacles had taken on as much importance as the vehicles themselves. Eventually one pupil made the suggestion that, instead of having all four groups building vehicles, perhaps two groups should design the obstacles, and two groups design the vehicles.
Surprisingly, there was great enthusiasm for this idea and no difficulty in getting volunteers for these groups. The next day’s discussion had more ideas for obstacles but a new problem emerged. Now the obstacles and the vehicles would be being built at the same time. How would the vehicle-builders design their vehicles for obstacles that were not built yet? For example, one proposed obstacle was to be a ramp that would be hinged in the centre, so that when the vehicle climbed one side and the centre of gravity passed over the fulcrum, the ramp would tilt down in the opposite direction to allow the vehicle move off. The size of the ramp would have implications for the width and length of the vehicles. We now had a classic chicken and egg situation – should the size of the vehicles dictate the size of the obstacles or vice-versa!!
Another problem was that if several obstacles were designed, each demanding some different reaction from the vehicle, there might be problems with not having enough sensor ports. One proposed solution was that, with only two vehicles to be built, perhaps each vehicle could have two RCX’s, which could talk to each other, and therefore double the number of sensors available!!!
Was this realistic?? No-one knew. It would also have further implications for vehicle size, including height. They seemed to agree that two RCX’s directly over each other, with just enough space between them for access to the lower one was the best arrangement. But would two RCX’s communicate with each other if the infra-red windows were directly above each other?
Pupils also proposed that some members of the Obstacle Groups would swap with members of the Vehicle groups on some days to help out the other group and to help co-ordinate the two parts of the project. Would this work?
They also decided to set out at the start what maximum and minimum length/width/height the vehicles should be. After much discussion and measurement figures were agreed. Once construction began, these figures began to change as other considerations came into play. However, the principle that the models had to be built or re-designed with reference to the obstacles and vice-versa, was retained.
Sometimes the imperatives of designing the vehicle forced changes to the obstacles whereas on other occasions the reverse was true. There were many discussions on these issues but generally each group was willing to change to accommodate the other where possible. Often, though, changes that were made had knock-on effects later. They soon realised that the two groups designing obstacles had to come together so that the obstacles demanded different reactions and capabilities from the models, and that the sum of the demands, e.g. the number of sensors demanded, was possible to achieve.
Many of the ideas which came up were very interesting – such as the one where the vehicle was to drive into a giant Pyramid of Egypt and would then have to locate the secret doorway to get out again – but many were way outside the realm of the possible.
There was also the problem that the ideas were so diverse and there were just too many of them. Eventually it was agreed to have a single theme and that all obstacles would fit into that theme and this would help to tie the project together. Most suggestions for themes centred on warfare, disasters, and such like. After much discussion the theme of a city hit by an earthquake was agreed.
The obstacles would now fit in with events that might result from damage caused by an earthquake. As construction began we needed to locate the city and began to look for a name. Springfield, the hometown of the Simpsons, somehow became the chosen city. Now the nature of the obstacles began to take shape.
There would be a bridge, which had been damaged by the earthquake. There would be a number of street junctions and the vehicles would have to select the correct route. But one question remained unanswered. Where were these vehicles trying to go and why? We needed a story on which to hang whole project. More discussion.
A story began to emerge. The earthquake had damaged the nuclear power station. There was some dangerous nuclear waste at the power station. For the safety of the city it had to be transported to safety and the trucks transporting it had to negotiate their way across the city. It was decided that the nuclear waste would be dumped into a disused mine at the other side of town.
As the size of the area required became an issue and as it became clear that there was not much to be gained by having two groups designing vehicles to get past the same obstacles it was decided to co-operate. One vehicle would transport the waste over the first part of the journey and then transfer it to the second vehicle, which would transport it for the remainder of the journey.
Next came the idea of writing a script for the story and when ideas had been drafted it was decided to turn it into a news bulletin for the local television station. The story was allocated to reporters at several locations around the city. The reports were linked by a newscaster in the studio. These reports were recorded and assembled into a PowerPoint presentation to accompany the project.
The pupils had taken on a concept, which was to set problems for themselves and then to solve those problems. As they became involved in the problem-setting, the problems became as much ‘alive’ as the vehicles. Also the problem-setters saw their task as being equally as complex as that of the problem-solvers. A surprising aspect of the project was that those who were setting the problems – the obstacle builders – recognised that success would be achieved, not by ensuring that models could not overcome their obstacles, but by ensuring that they could be overcome – but only with good design.