The Hbot : A Holonomic Spherical Haptic Interface Driven by Non-Holonomic Wheels
This addresses the need for improved haptic interfaces in robotics and simulation, though it appears incremental as it builds on existing spherical robot designs with a focus on singularity avoidance.
The paper tackles the problem of creating a holonomic, singularity-free spherical robot for haptic simulations, resulting in the Hbot prototype that achieves continuous and unlimited spherical motions with experimental validation of trajectory tracking and rotational stiffness rendering.
We present the Hbot, a holonomic, singularity-free spherical robot designed for haptic simulations. The Hbot is made up of a caged sphere actuated by steered and driven non-holonomic wheels to produce continuous and unlimited spherical motions. We analyse the kinematic interface between a sphere and $n$ arbitrarily positioned, steered and driven non-holonomic wheels in the general case. We also present a detailed singularity analysis and show that workspace-boundary and workspace-interior singularities can both be avoided at the design stage. We implement a prototype using two steered and driven non-holonomic wheels and show experimental results for trajectory tracking and rendering of various rotational stiffness levels.