Section: New Results

VR and Ergonomics

Participants : Charles Pontonnier [contact] , Georges Dumont, Pierre Plantard, Franck Multon.

The use of virtual reality tools for ergonomics applications is a very important challenge in order to genezalize the use of such devices for the design of workstations.

We proposed in collaboration with Thierry Duval (Lab-Stic, Telecom Bretagne, Brest) a new architecture for information sharing and bridging in collaborative virtual environements in application to ergonomics studies. We particularly presented this year how we implemented the design engineer role in the collaborative environment [30] , [29] . We are currently evaluating the complete framework for collaborative ergonomics by defining use-cases and trying to find the best design mode to efficiently solve this problem. Moreover, we have developed and evaluated some manipulation techniques, such as the 7-handle technique which is particularly efficient to manipulate large objects in an immersive environments [6] , [27] . A demonstration of this technique has been presented during the ICAT-EGVE conference [37] .

We also contributed in the on-site motion analysis field. Microsoft Kinect is a promising tool to evaluate human poses without markers, calibration and manual post-processing. It has been applied to a wide set of applications, such as entertainment, rehabilitation, sports analysis and more recently in ergonomics. In MimeTIC we wish to develop innovative approaches based on a Kinect in order to assess the potential risks of musculoskeletal disorders. However analyzing humans in work places is challenging because of many potential occlusions and displacements of the user. Hence it is a key point to evaluate to which extent this method could be applied to real work places, in real work condition. Most of previous works aiming at evaluating the Kinect sensor generally focus on simple 2D poses. In this work we proposed to evaluate the reliability of Kinect measurements for assessing the movement of operators in ergonomic studies with complex 3D upper-limb poses [38] . To this end we asked subjects to perform complex 3D arm motions concurrently measured with a Kinect and a Vicon motion capture system. The results demonstrated that most of the poses were correctly estimated with the Kinect but specific poses are badly reconstructed, leaded to errors going up 30°. Hence, experimenter should take this information into account when using a Kinect on a work place in order to avoid experimenting these bad results.

At last, we proposed a new approach for the use of virtual reality with haptics in the Product Development Process loop for testing deformable parts by introducing the user in the loop and proposing a two-stage deformation simulation method for real time haptic interaction. Such an approach is of importance to let the designer be able to handle and validate the design of a product or a workstation respecting multiple constraints, e.g. ergonomics, bulk or productivity. This approach has been fully detailed in a book chapter published this year [34]