The challenge

Cambridge University’s world-renowned Department of Geography had a flume for researching fluvial or tidal erosion in a controlled environment. Essentially it allows researchers and students to test the accuracy of mathematical models and reflect reality. The department wished to extend the research potential the flume offered by introducing a tidal wave generator.

Our solution

A specialist in hydraulics had designed a system whereby a paddle would move water down the tank to generate life-like waves, but this needed a programmable controller that could offer many wave shapes and repeat count permutations for different areas of research.

The Department of Geography did not want the system to be over-complicated, but it had to be fit-for-purpose, whether it was being used for a major research project or by undergraduates learning about wave power. They realised the flume system would require some bespoke modifications if it was going to be able to generate the range of water movements they required.

Our implementation is based on a 32bit Arduino with a custom shield. This shield allows interfacing with the hydraulic power pack and sensors which are specified to industrial standards and as such will not interface directly. The power pack will drive the paddle in an arbitrary motion against a significant head of water, presenting a very simple electrical interface to the Arduino.

The system is controlled by a simple text-based scripting language. Programs are designed on a PC, and saved to an SD card which is inserted into the controller. Because the user has complete freedom with regard to the content of the programs, the software has to be extremely robust to defend against errors. Useful diagnostic information is displayed on the LCD screen if problems are discovered during the parsing process. The Arduino platform has the lowest barrier to entry in the industry, and thus allows future enhancements without vendor lock-in.

VERSATILITY

The programming scheme offers the user a high degree of control over system operation. Each program line is an instruction with multiple parameters, which can also be repeated either singly or in blocks.

CLOSE COLLABORATION

We worked closely with the academic team to make sure the controller we designed was both flexible and easy to use. There were lots of meetings to ensure the technical requirements could be translated into an achievable appliance.