Control electronics and hybrid dynamic system-based API for a 6-DOF desktop haptic interface

A six-degree-of-freedom desktop magnetically levitated haptic interface has been developed by the authors. Its electromechanical design is described in (Salcudean and Parker, 1997). In this paper, aspects of electronic hardware architecture and the control of actuator currents are discussed. To program this device, a new low level applications programming interface (API) that models the haptic interface as a hybrid dynamic system is proposed. The user can define a finite state machine in which every state is a device impedance. State transitions occur upon the satisfaction of linear inequalities in terms of the device location, velocity and force. Examples of the use of such hybrid dynamic systems to produce haptic effects are given.