ActivePaD surface haptic device

We present a new surface haptic interface that combines a variable friction device (the Large Area TPaD) with an impedance controlled planar mechanism. This device configuration is novel because it allows control of the frictional force in the static friction regime, control of the direction of force in the kinetic friction regime, as well as a degree of control over the transition between the two regimes. The range of operating modes combined with a large force capability make the device an appropriate platform for exploring surface haptic control algorithms. The design of the system is explained, two major categories of control algorithm are introduced, and the implementation of a virtual dimple is discussed. Experimental data are used to compare a virtual dimple to its physical analog, and to reveal areas for improvement.