Impedance control approach vs. adaptive nonlinear design in simulated push-button haptic interface

General purpose haptic interfaces are receiving increasing attention, because they can simulate different kinds of interaction between user and virtual objects/environments. The paper describes the control of a special-purpose haptic interface devoted to simulating the behavior of a push button, with the aim of performing user tests on different geometries and designs. The control task is to provide a reaction to the external solicitation as similar as possible to that of real buttons.