Virtual 3D models enable the precise documentation of large machines and their small details. To this end, the researchers at Fraunhofer IOF developed the mobile handheld scanner goSCOUT3D last year. It enables the 2D and 3D digitization of complex objects measuring several cubic metres in volume with a particularly high spatial resolution of less than 0.25 millimetres - such complex objects include aircraft engines, for example.
Until now, the scanner had to be moved by hand around the object to be measured in order to create digital twins, which required high precision in the execution of the measurement and a constant speed in the guidance of the user's sensor head. Potential signs of fatigue or incomplete measurement data were sometimes the result.

Researchers from the Imaging and Sensor Technology department at the Fraunhofer IOF addressed this practical problem. The solution: they combined the 3D scanner with a robot dog from the US company Boston Dynamics, known as Spot. "By integrating the sensor head previously developed in Jena with Spot, the measuring process of the goSCOUT3D scanner should be automated in future and possible without the constant need for human supervision," explains Dr. Andreas Breitbarth, Head of the Image Processing and Artificial Intelligence Group at Fraunhofer IOF. "The robot dog can maneuver goSCOUT3D autonomously through the measurement scene while maintaining the same measurement speed and distance."

More agile and flexible measurement methods

Compared to conventional measuring robots, which are used along production lines, for example, where they are usually permanently mounted, the autonomous walking robot has a decisive advantage: thanks to its ability to move freely in space and on different types of surfaces, the measuring object can be fully scanned from all sides and at different levels - for example underneath a guide rail. Consistent scanning speed and fewer fluctuations in handling also ensure greater reproducibility of the results and reduce the measuring time due to fewer redundancies. This makes the integrated measuring unit particularly interesting for use in serial production processes or quality control.

Autonomous measurement without human interaction

In order to achieve these application goals, reliable coordination between the robot and the 3D sensor is required. For this purpose, the 3D sensor is coupled to the robot's coordinate system using hand-eye calibration. Once the walking robot has been calibrated with the scanner in this way, it can be programmed by human experts to measure predefined objects. "Before the actual measurement process, the speed, exact measurement locations and other important parameters are transmitted to Spot by a human user so that the robot dog can then carry out the scans just like a human without having to be physically present," Breitbarth continues. In this way, Spot could take over routine measurements in the future, for example. Furthermore, the coupling of the scanner with an agile robot should also enable methods for remote control and monitoring.

Presentation at Control 2024

The goSCOUT3D and Spot unit will be presented to the public for the first time at Control 2024. The measuring system will be presented at the international trade fair for technology and quality assurance from April 23 to 26 in Stuttgart (Hall 8, Stand 8201).

Researchers at Fraunhofer IOF developed the goSCOUT3D 3D handheld scanner in 2023 in collaboration with MTU Maintenance. To create complex 3D models, the sensor head, which weighs just 1.3 kilograms, captures two-dimensional color images of the selected measurement scene with a 20-megapixel color camera. The 3D data of the entire scene is calculated from these images using photogrammetry.