The PHANTOM Omni as an under-actuated robot
As haptic interactions begin leaving research areas for commercial applications, accurate user interactions with virtual objects take new precedence. A common, low-cost haptic interface device is the PHANTOM Omni. This device has six degrees of freedom for positioning, allowing the user to position and orientate the device anywhere in its workspace. One downside to the PHANTOM is that it only has motors for controlling the position of the device, meaning the orientation of the device does not affect the interactions felt by the user through the haptic code. However, it is possible to incorporate these un-actuated joints to affect the force the user experiences, giving a feeling similar to bending a rod. Two methods are explored: a simple spatial analysis technique using Bezier curves and a more general virtual manipulator synchronization method using a null-space filter to determine device movement.