There are various ways in which we could improve the model. We wouldn't want it to be too good, however: learners are expected to critically review their projects, which means they must be able to identify strengths, weaknesses and possible improvements.


Among the strengths are that the final model meets the specification they were given and enables many aspects of a full-sized system to effectively modelled and investigated. Algorithms developed and solutions found to problems would all be useful if the project were to proceed to a full-sized version. The in-circuit programming of the Picaxe chip is quick, convenient and saves wear and tear on components.


Among the weaknesses, it is often said that the chassis are not sufficiently robust, although we think they withstand handling (and dropping) better than, say, Lego. The collision detector only detects obstacles placed directly in front of the switch. The steering mechanism - stopping one wheel at a time - is crude and results in somewhat jerky steering.

Potential Improvements

A purpose-built robot chassis would be better, particularly if it avoids the need to use Blu-Tack to secure heavy components such as battery packs. The use of proper fastenings or adhesives for such components would maintain the robustness of the basic chassis.

A full-width bumper or skirt would improve the collision detector. A greater improvement still, however, would be to use proximity detectors so that the vehicle could stop before colliding with an obstacle.

Steering could be improved by proportional speed control of the motors, rather than simple on/off control, especially with an array of sensors to provide a measure of how far the vehicle has deviated from the track.

A configuration with a steerable wheel or wheels would also allow smoother line following than the present tank-steering arrangement. In such a configuration, the driving wheels would ideally be driven by a single motor via a differential.