Electromagnetic Position Sensing and Force Feedback for a Magnetic Stylus With an Interactive Display

This letter describes the design, implementation, validation, and demonstration of an electromagnetic system that can be incorporated into a graphical display to provide computer-controlled planar feedback forces on the tip of a stylus or fingertip-mounted magnet held near the display surface, according to the magnet position and virtual fixtures implemented in software. An array of magnetometer sensors is used to detect the position of the magnet, while a pair of box-shaped coils behind the display produces feedback forces on the stylus parallel to the plane of the display. Electromagnetic analysis for the system design is presented and system implementation is described. Validation results are given for force generation within a 100 mm × 100 mm area and force interaction with a virtual obstacle is demonstrated.