Optical Tracking

At a glance

InfraLok is an innovative optical positioning technology that calculates the positions of active markers in the infrared spectrum with a high degree of precision. Compared to many radio-based systems, optical technology has the advantage that it can calculate the position of a large number objects very precisely and also at low cost. Another advantage of optical tracking systems over radio-based systems is that they are not affected by materials such as certain metals. Installing a dense network of image sensors avoids the potential problem of markers being obscured, which disrupts positioning calculations.

How it works

Markers attached to people or objects use LEDs to send out modulated light signals to identify themselves. These signals are received and pre-processed by a network of cameras that monitor the area under observation. The interpreted signals and 2D positions on each camera’s respective image sensors are put together to determine the positions of the markers in the space. Due to the low cost of the camera modules, they can be installed in abundance to cover difficult areas. The central computer can also recognize previously defined events and trigger a certain response such as a signal.

Examples of applications at Fraunhofer IIS

Added value for industry

InfraLok offers great potential to optimize the logistics industry with positioning and tracking systems for industrial vehicles. Downstream analytical applications can also use the positioning technology to achieve efficiencies such as increased throughput of goods.

Added value for virtual reality

To make the illusion of a virtual parallel world as realistic as possible, the images have to match the observer’s own movements. This is an application where harnessing InfraLok’s optical positioning technology really makes sense.


Further applications

Due to its small markers and its great scalability, this system can be used to calculate the position of almost any object. Fraunhofer IIS offers consulting and system evaluation services – for example, through its L.I.N.K Test and Application Center. 

InfraLok system components


The marker is a miniaturized unit made up of a microcontroller and a modulated infrared light source. These small markers are easy to attach to a wide range of different objects. Depending on requirements, the markers can be operated wirelessly with a rechargeable battery or with a fixed power source.


The receiver infrastructure comprises at least three cameras. In their simplest version, the cameras are based on the single-board Raspberry Pi, which means scaling costs are low. If required, the cameras can be wirelessly connected to a central location.


The interpreted signals and the 2D positions of the cameras come together on a central computer, which calculates the three-dimensional positions of all marked objects in real time. It is possible to display them on a 3D surface and to process this further to detect events in a system.

Event detection

The EventObserver automatically detects events that are typical of certain applications. The system acts as middleware for specific evaluations. Any number of software agents can also be added, which analyze various business processes based on the known positions.

What we offer

You can also use InfraLok for other applications. At Fraunhofer IIS, our experts are happy to assist you and take your individual wishes into account. Based on your requirements, we will put together a team of experts to support you and draw up a project plan tailored to your needs. For example, we can extend the coverage of your positioning system or optimize the density of the cameras.

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