Better Work Safety Thanks to Motion Capturing

Motion Capturing records movements digitally. This not only creates fantasy creatures or improves motion sequences, but also revolutionizes entire work systems and production lines.

Ford uses body tracking at the Spanish engine plant in Valencia. Photo: Ford

The beginnings lie in Hollywood: The aliens in “Avatar” or the mythical creature Gollum in the “Lord of the Rings” movies are computer-animated fantasy creatures. But on the screen they move as smoothly and realistically as real creatures. This is due to “Motion Capturing” technology. Actors or gymnasts wear special suits, which are equipped with markers at certain points of the movement apparatus like joints. These are recorded by cameras and, if necessary, additional special sensors. The results are recorded curves for the movements of each individual point in space. If the computer graphic artists then place these curves on their digitally constructed models of aliens or mythical creatures, these take over the natural motion sequences. In addition to thousands of cinema productions, computer games also benefit from this technology.

Ford Investigates Ergonomics in Engine Plant

But there are a number of other applications for digital recording and analysis of motion that extend far beyond the entertainment industry. For example, carmaker Ford used the process to record the movements of 70 employees for a year at its engine plant in Valencia, Spain. A total of 21 work areas in the plant were examined in this way. The special suit had 15 sensors, which made it possible to track the movements of the head, neck, shoulders and limbs. Four specialized motion-capture cameras were installed in the work areas to record the motion patterns of the 15 sensors.

The purpose of the project: Ergonomics specialists from the Instituto Biomecánica de Valencia analyzed the recorded movement data in order to derive improvements for employees’ work processes and postures. Even small changes have a big impact here, as Javier Gisbert, Production Area Manager at Ford’s Valencia engine plant, confirms: “For our employees, changes in their work areas can ensure that they can also work comfortably on a long day. Ford is already considering extending the project to other European locations.

The employees wear a suit that is equipped with motion sensors. Photo: Ford

A video game system allows serious research

Ford is by no means alone with this approach. For example, the Institute of Ergonomics (IAW) at RWTH Aachen University is carrying out a number of similar projects. The “Sensor-supported ergonomic stress analysis” project, funded by the Federal Ministry of Education and Research (BMBF) and supported by the VDI engineering association, examines postures and work-related stress. The aim is to prevent damage to health. The special feature of this project, which is being carried out in various companies in and around Aachen, is that a consumer camera and motion tracking system – namely the Microsoft Kinect, which was actually developed for computer players – are used for observation. According to Professor Christopher M. Schlick, who is responsible for the project, the depth sensor of the computer player camera makes it possible to automatically record postures without the need for special suits or marker points. The evaluation of stress and posture is also automated and is based on the established OWAS (Ovako Working Posture Analysing System) procedure, Professor Schlick continues. If certain aspects require a higher degree of accuracy in motion detection, his institute also relies on a marker-based motion capturing system, though.

Designing New Production Lines with Transaction Data

Not only existing workplaces and workflows can be improved due to the findings of tracking systems. The Fraunhofer Institute for Industrial Engineering (IAO) combines motion capturing with virtual human and workplace models as well as real-time visualizations in order to incorporate existing knowledge into the design of new production lines or entire factories, for example. Günter Wenzel, head of the Virtual Environments team at the Fraunhofer IAO, explains the possible applications: “Virtual human models can be used to simulate different user behaviors and applications – from barrier-free, age-appropriate apartments to ergonomically designed vehicle interiors and the operation of machines and plants. To this end, the Fraunhofer researchers simulate the movements of virtual people in virtual models of the environments to be investigated long before they actually exist. For example, products and workstation systems can be tested for different, even extreme body dimensions and proportions, says Günter Wenzel.

Body tracking is supposed to improve the work situation, for example for employees in the production department. Photo: Ford

Digital Human Models as the Basis for Future Occupational Health and Safety Regulations

Evaluating data from body tracking systems with the help of increasingly specialized algorithms and simulation models is a clear trend. Their influence grows significantly beyond the concrete environment of a specific individual workplace. Under the catchword “Digital Ergonomics”, the Federal Institute for Occupational Safety and Health (BAUA) and the University Hospital Greifswald, for example, are pursuing the goal of generating “anthropometric” data sets that can then be analyzed with regard to a wide variety of applications and developments. The project results will then not only be used to design individual workplaces or work systems, but will also be incorporated into the definition of standards and occupational health and safety regulations. And last but not least, as Professor Thomas Kohlmann, head of the Institute for Community Medicine at the University of Greifswald, points out, movement data and virtual human models could then be used in future research projects. What began as special effects technology for the cinema would then have an impact on countless aspects of everyday working life and also on many other areas of everyday life.

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