On the Usability of Functional Probes for Design Validation of Playground Equipment in Virtual Reality

The ISO 9001: 2000 requires the phase of design validation in order to demonstrate that the design output are able to satisfy specified or forecasted user requirements; for this reason, generally, physical prototype are realized in order to evaluate real product performances and their correlation with simulated ones. In this paper, the use of virtual functional probes to validate playground equipments design is studied, pointing out limits and defining the optimal test strategies. Through the use of Robust Design (RD) techniques the authors shows that the combined use of real time shadows and positional sound feedback allows to reduce the percentage of wrong inspections in the validation phase of playground equipments design. The authors develop a functional probe simulation tool in virtual immersive environment. In particular, this tool ensure the collision detection through visual and sound feedback and increase the realism of the immersive environment. Finally, an experimental session, using a physical prototype of playground equipment, is carried out in order to compare these results with the ones coming out from the VR experiments. For a specific test entrapment, the authors assess the dependences of false and missed alarm by the diameter of the openings to evaluate and establish an acceptability threshold for the usability of the virtual probes.