A team of industry leading experts in 3D Concrete Printing based at Loughborough University, led by Dr Richard Buswell and Dr Peter Kinnell, have recently adopted OptiTrack technology to improve the accuracy of their products.
Using large industrial ABB IRB 6640 robots to control the printing head, they produce 3D printed concrete that is very strong, and can be deposited accurately, meaning they can make more complex parts with it than usually possible, parts that can be hollow or have internal intricacies.
THE ISSUE Because of the nature of their work, the robotics equipment often gets dirty, meaning that many 3D position sensor solutions are not appropriate. As the robot can manoeuvre to many different positions, there are also potential issues around occlusion and visibility when tracking the movement.
THE SOLUTION Target3D installed OptiTrack technology into two robotics cells at the university. Firstly, recommissioning a PrimeX 13 system they already had in one lab then installing a higher accuracy PrimeX 41 and PrimeX 22 system into their second cell.
The Optitrack system is currently being used by university researchers Jim Dobrzanski, Danny De-Becker, Jerry Xu and Connor Gill to track movement of items in the robotics lab. By setting up a number of markers as a rigidbody, the team can easily keep track of the robot’s tool, which is used for path verification, tool definition and full kinematic calibration.
Connor Gill explains, “Due to the dynamic nature of our research work, we keep a couple of PrimeX 13 cameras floating around on stands which allows us to tailor our setup to the work we’re doing that week and ensure that we always have a measurement system that suits our needs. Similarly, for projects which require more accurate measurements to be taken, the PrimeX 41 & PrimeX 22 cameras plugged seamlessly into our workflow, only took a few hours to set up and let us capture the whole 30m3 volume with submillimetre accuracy.”
The team aims to control the robots directly from the Optitrack data stream, rather than from their internal controllers to increase the accuracy of our printing head, which in turn will produce more accurate products.
THE FEEDBACK Commenting on working with Target3D Connor Gill reported, “Target3D have been brilliant to deal with. Their team has helped us answer any questions that we have about the products and it’s clear that they are genuinely interested in us getting the most out of their products.” Speaking about the tracking system he added, “The technology is incredibly easy to install and use. We are finding it easy to integrate the data from Optitrack into our workflow. The NatNet SDKs make it easy to access the live data streams coming from Optitrack, which we are currently combining with the robot’s own data stream to run online calibration for the robots.”
Why 3D Concrete Printing? 3D printed concrete is very strong, and can be deposited very accurately. This means more complex parts are able to be created than usually possible. For example, the first image in this article shows a double-walled freeform plate. The smooth curve of the part and the gap between the two walls make it difficult to use traditional methods like casting for this. 3D Concrete Printing allows this part to be made from scratch, without having to produce moulds, bespoke supports or use excess material. Similarly, the bench that is pictured above has a nice smooth shape, good aesthetics, internal cavities, and internal support beams. All of these are difficult to achieve using traditional methods. The end goal is to have a process that is able to take advantage of the mechanism of concrete printing to create buildings faster than before, while using less material, and allowing for more interesting architecture.
Target3D work closely with universities and researchers, providing innovative tracking solutions for robotics, VR & AR, and training and simulation. Speak to us today.