3DX approached the M7 ring road project on one of the largest road projects ever undertaken within the NSW infrastructure projects group. The project itself was a joint venture between Abigroup and Leighton contractors which consisted of the construction of 44km of dual carriage way.
To complete the project, two CMI slip-form pavers were used to lay the concrete pavement surface. Manually operating this machinery involved an enormous amount of survey costs. In traditional pavement control measures require that every seven meters a steel pin has to be positioned within XYZ survey tolerances and then a string- line is tied to each pin at the correct position. 3DX eliminated this process completely.
No other 3D positioning company worldwide, dared to take on such a project. 3DX had to model, develop and implement a custom software controller to fully actuate all control outputs without saturating any internal dynamic system parameters. We customised the steering sensors, elevation sensors long slope sensors (including cross slope sensors and skewing sensors) with tight radius track speed sensor control. This included multiple integrated sensors with custom CANbus protocols which connected to a single vehicle cpu.
Unlike all slip-formpaver systems today, such as those developed by Wirtgen, and Gomaco et al, the 3DX controller had to utilise the pre-existing mechanical control interfaces to measure angles and position via retrofit sensor integration. Modern systems purchased on new machines today now work via a single ip interface with simple a ‘Plug and Play’ methodology.
This was a word-first attempt and a very complicated retrofit controller integration recorded in the history of machine control systems. It also exposed 3DX to unprecedented worldwide success. We were the first to implement the leap-frog method to control the paver with a total station without stopping to re-setup for the next run. We were able to achieve this by designing an algorithm that prioritised and weighted the accuracy to the robotic total station closest to the prism mounted on the paver.