Interacting With a Large Virtual Environment by Combining a Ground-Based Haptic Device and a Mobile Robot Base

Ground-based haptic devices provide the capability of adding force feedback to virtual environments; however, the physical workspace of such devices is very limited due to the fixed base. By mounting a haptic device on a mobile robot, rather than a fixed stand, the reachable volume can be extended to function in full-scale virtual environments. This work presents the hardware, software, and integration developed to use such a mobile base with a Haption Virtuose™ 6D35-45. A mobile robot with a Mecanum-style omni-directional drive base and an Arduino-compatible microcontroller development board communicates with software on a host computer to provide a VRPN-based control and data acquisition interface. The position of the mobile robot in the physical space is tracked using an optical tracking system. The SPARTA virtual assembly software was extended to 1) apply transformations to the haptic device data based on the tracked base position, and 2) capture the error between the haptic device’s end effector and the center of its workspace and command the robot over VRPN to minimize this error. The completed system allows use of the haptic device in a wide area projection screen or head-mounted display virtual environment, providing smooth free-space motion and stiff display of forces to the user throughout the entire space. The availability of haptics in large immersive environments can contribute to future advances in virtual assembly planning, factory simulation, and other operations where haptics is an essential part of the simulation experience.