Design of Programmable, High-Fidelity Haptic Paddle

Abstract

In this study, we propose the design of a 1-DOF haptic interface for kinesthetic learning applications and educational platforms in some engineering and science courses. The proposed system is a directly-driven, high fidelity, easy-to-build, easy-to-program haptic device and yet still affordable for use in education. The major advantage of the system is that there is no transmission between the motor and human (i.e. direct-drive) motion which greatly reduces the mechanical complexity, improves robustness, reduces some calibration stages, and reduces some of the important costs. The main drawback associated with a direct-drive actuator interface is that effective motion measurement resolution is very low compared to other systems that utilize capstan drive like mechanisms. To overcome this problem, we used an affordable electronic gyroscope to measure angular velocities directly and integrate gyro and encoder measurements using a statistical fusion filter. The core component of the electronic hardware is a 13$ embedded microcontroller board which assured us of 1KHz hard-real-time measurements and programmable interfaces. The human sense of touch has dynamic characteristic whose bandwidth changes according to action and highest bandwidth with the highest stimulus intensity in an action like slippage has a bandwidth of 1KHz. Because of that, a tactile device being 1KHz hard-real-rime is important for many haptic applications. All these features can be used on various virtual tasks as a kinesthetic learning medium. Such a high fidelity and yet affordable haptic interface is suitable for in-class activities and improves the ability of perception of the students especially on physical systems.