A support system based on automatic spatial alignment for distance spatial collaboration

When a person remotely provides instructions to or cooperates with others to execute a three-dimensional task, such as assembling a machine, he or she and a collaborator often encounter serious problems that do not normally appear, or that appear only trivially, in face-to-face collaborations. Among those problems associated with distance collaboration, we here address that of misalignment of operators' viewpoints. To solve this problem. we analyzed various distance spatial collaboration problems and groupware functions for supporting such collaboration. On the basis of this analysis, we developed a system to support distance spatial collaboration based on an automatic alignment of reference frames using computer graphics (CG). The system detects the positions and movements of the objects to be operated, and the relative angles between the objects and the users' bodies. Then the system depicts the objects and operation in CG and display the at each user's site. The CG viewpoint is automatically aligned with the actual viewpoint in each user's real workspace so that it reduces the cognitive load of the users. In this paper, we give an overview of the developed system, report the results of evaluations conducted. and discuss how the aligning of reference frames affects the efficiency of a given collaborative task.