Navigation by light
In a BMBF joint project, OSRAM, Götting, KEB Automation and Fraunhofer IEM have researched the possibilities of light-based positioning, particularly for use in industrial applications. At the end of the project, they came to a promising conclusion: navigating by light is practical, flexible and reliable – and holds great potential for Industry 4.0.
The result of the three-year collaborative research project is a positioning system that navigates driverless transport vehicles by light through a logistics or production hall. Positioning takes place using LED lights mounted on the hall ceiling, each of which emits a clear identifier via modulated – i.e. specific pulsating – light. This modulation is completely invisible to the human eye, so no changes are necessary to the lighting situation. Explaining the advantages of the solution, Christian Fechtelpeter, scientist at Fraunhofer IEM, commented: “Easy and flexible navigation for autonomous vehicles is possible using light-based positioning. If, in future, we link these to the existing LED ceiling lighting, the technology could be a key driver for Industry 4.0.”
For illustrative purposes navigation was implemented in the modular transport system KATE (Kleine autonome Transporteinheit = small autonomous transport unit) from the company Götting. While the standard version of the vehicle is controlled using optical guidelines and transponders installed on the floor, track guidance can now be achieved using the new system. OSRAM modified standard industrial LED lights and developed a camera-based sensor system to receive the modulated light. An in-vehicle evaluation unit developed by Götting processes the camera and other sensor data to facilitate navigation via a user interface. The interdisciplinary development of the complete system was coordinated by Fraunhofer IEM using various methods of system engineering. The primary factors for success were the model-based specification of the overall architecture as well as the test case planning.
Implementation in the test field for electronics production at KEB Automation shows that light-based positioning offers advantages over other navigation technologies when it is ready for the market. Companies can easily use their existing lighting infrastructure. Since obstacles on the hall floor do not interrupt communication between sender and receiver, navigation is largely trouble-free. The route taken by driverless transport systems can be flexibly reprogrammed. This allows processes to be streamlined and smooths workflows
The LiONS project (light sensor-based positioning and navigation services for autonomous systems) was funded from October 2015 to December 2018 by the Federal Ministry of Education and Research as part of the announcement of the promotion of “Sensor-based Electronic Systems for Applications for Industry 4.0 (SElekt I4.0)”.
- OSRAM developed both the modified LED lights and the corresponding sensors for the transport vehicle.
- Götting KG is developing a special evaluation module in the project for its driverless transport system KATE.
- As an application partner, KEB used its own production processes to illustrate – and thus validate – the application in use under real conditions.
- Fraunhofer IEM was responsible for the overall system design as well as test case planning and coordinated the entire project. In the sense of model-based systems engineering, the system of light-based positioning was conceived on a holistic and model-assisted basis, whereby all necessary departments were included from the beginning.