Comprehensive workspace calibration for visuo-haptic augmented reality

Visuo-haptic augmented reality systems enable users to see and touch digital information that is embedded in the real world. Precise colocation of computer graphics and the haptic stylus is necessary to provide a realistic user experience. PHANToM haptic devices are often used in such systems to provide haptic feedback. They consist of two interlinked joints, whose angles define the position of the haptic stylus and three sensors at the gimbal to sense its orientation. Previous work has focused on a calibration procedures that align the haptic workspace within a global reference coordinate system and an algorithms that compensate the non-linear position error, which is caused by inaccuracies in the joint angle sensors. In our science and technology paper 'Comprehensive Workspace Calibration for Visuo-Haptic Augmented Reality' [1], we present an improved workspace calibration that additionally compensates for errors in the gimbal sensors. This enables us to also align the orientation of the haptic stylus with high precision. To reduce the required time for calibration and to increase the sampling coverage, we utilize time-delay estimation to temporally align external sensor readings. This enables users to continuously move the haptic stylus during the calibration process, as opposed to commonly used point and hold processes. This demonstration showcases the complete workspace calibration procedure as described in our paper including a mixed reality demo scenario, that allows users to experience the calibrated workspace. Additionally, we demonstrate an early stage of our proposed future work in improved user guidance during the calibration procedure using visual guides.