Introduction

These pages describe a PICAXE-controlled buggy project which has been used as a practical exercise in GNVQ, AVCE and BTEC National IT modules with a control systems element.

The project is based on a Fischertechnik chassis, although Lego or a ready-built chassis would serve equally well, uses contact and infrared reflective sensors and is controlled by a PICAXE18 project board. It is programmed using PICAXE BASIC.

It is described as an "AGV" to dispel the idea that it is just a line follower. In the project brief it is presented as a model for an automated hospital laundry delivery and collection system and it has a range of required behaviours.

There is more to the project than meets the eye. Firstly, in order to manage the range of behaviours, learners will find it necessary to adopt a logical, structured approach to the programming. Secondly, it is necessary to prioritise behaviours - for example, the vehicle must deal correctly with a collision even if it happens to be busy steering at the time.