What Is A 3D Motion Analysis?

In a 3D motion analysis, movements of objects, machine components or (human) bodies in 3D space are recorded over time via sensors using stereo cameras. The data collected can then be analyzed and used for optimization measures. With a 3D motion analysis, a wide variety of kinematic parameters are recorded depending on the application, for example accelerations, rotational speeds or deflections of guides or drives.

Systems consisting of stereo camera sensors, hardware and software for data processing and so-called measurement markers are usually used for 3D motion analysis. These measurement markers, which, depending on the intended use, can be self-adhesive or temperature-stable, are attached to the points to be measured on the object before the measurement process. The stereo camera sensor - also known as the measuring head - is then positioned on a tripod in front of the measurement object. The measurement object with the measuring markers is set in motion and the cameras start recording the test setup. In modern systems, this image recording is, triggered flexibly for one or more load states - the performance of the camera thus automatically adapts to the conditions of the object to be recorded. The significant advantage of 3D motion analysis: Thanks to the stereo camera technology, any number of measuring points in the space can be determined at the same time with an accuracy of 30-40 μm/m!

Modern measuring devices for 3D motion analysis are based on optical measuring methods. The possible applications of optical metrology are diverse - this is also reflected in applications of 3D motion analysis. Optical metrology can be scaled for different sample sizes from a few millimeters to several meters and adapted to the measurement tasks and environmental conditions.

As a result, 3D motion analysis using optical measurement systems is now executed in many industries, including:

• Automotive
• Aerospace
• Consumer goods industry
• Biomechanics
• Machine capability analysis, process monitoring, manufacturing process optimization

Not all parts within a work area can be captured directly by a stereo camera sensor. If blanks or tool tips covered by the tool carrier are to be analyzed, adapters are used. Any point groups are defined on these adapters in advance and the adapter is calibrated accordingly. This “detour” also makes it possible to analyze hidden, complex parts and assemblies without any problems.

By combining appropriate software with fast data transmission, 3D motion analysis can also be used in the context of real-time analysis. A typical example of this application is a deformation analysis on sheet metal forming machines. Using 3D displacement vectors and diagrams, deformations such as deflections, torsion or bending can be tracked in real-time and accelerations, speeds or structural vibrations can be examined. Depending on requirements, the reports can be issued in the form of images, videos, tables, diagrams or as a practical PDF file using these systems.

No, on the contrary: the setup of an optical measuring system such as ARAMIS from ZEISS, is limited to a maximum time of less than one hour which includes the attachment of measuring points to the specimen. Modern systems can be adapted quickly and flexibly to different measurement field sizes - from the smallest postcard-sized objects to complete wind turbines. Optical measuring systems such as ARAMIS can not only be used for precise measurements of moving parts, but also toreplace displacement transducers (LVDT) and acceleration sensors (accelerometers)!