Optical Tracking System

High-precision, real-time pose estimation of tools and objects in medical applications

The FRAMOS OTS is a tracking system based on stereo computer vision that can be used for real-time tracking applications requiring high accuracy. Technological advantage lies in the ability to overcome current practical difficulties such as line of sight problems while opening the way for further developments of inside-out tracking solutions in the medical domain.

Application fields

Ultrasound transducer for optical tracking with FRAMOS OTS

The FRAMOS OTS is suitable for all measuring applications of object position and orientation that require high accuracy.

High-precision guidance within robot applications

High-precision guidance or tracking of handheld-devices, i.e. computer aided medical procedures

3D measurement
High-precision localization of handheld or machine-guided measuring tools

Technology description

A stereo camera system examines a specific measuring volume with up to 25 frames per second. The localization of attached passive markers on the surface of the object determines the accurate 3D position of the measuring object. The marker geometry is generic and can be adapted to the specific needs of the application within a one-time learning procedure.


High-precision in real-time
Using reliable industrial hardware components the system achieves for example an accuracy of 20 µm (RMS) with 10 µm (SD) at a frequency of 25 Hz in a 400 x 400 x 300 mm³ volume.

Robust recognition
The inherent implementation of modern image processing methods guarantees a precise pose calculation even in case of partial occlusion of individual or multiple markers, shadowing effects or occlusion due to objects within the direct line-of-sight.
Strong atmospherically and mechanically stressed or stained markers can be easily replaced since the markers consist of a material with a self-adhesive side. A very fast and intuitive learning procedure of the new marker set-up ensures consistently precise measuring results.

Individual marker set-up
The flat markers consist of a self-adhesive, retro-reflective film. Compared to the typically used expensive one-way spheres with a fixed dimension and geometry, our markers are cost-efficient and can be individually adjusted in both position and size. Through a teaching algorithm within the FRAMOS software framework, an arbitrary marker ensemble is applicable on any object geometry; this also masters the detection on difficult multi-coloured surfaces.

Intuitive error analysis
Many tracking systems in the market use different non-visual methods such as, for example, magnet tracking. These methods are highly likely to be disrupted by many factors and lack of reasonable solutions to find the sources of such errors. Using a vision-based method intuitively reveals a malfunction which then can be immediately eliminated.


You can reach the Imaging Systems Team
via phone +49.89.710667-79,
or with the following contact form: