Patent US 9,851,828

A touch sensitive input system for an electronic device includes a deflection sensor configured to generate a deflection signal based on deflection of a control or sensing surface, and a processor in signal communication with the deflection sensor. The processor is operable to generate a deflection or displacement map characterizing displacement of the surface based on the deflection signal, and a force map characterizing force on the surface based on a transformation of the displacement map. The transformation may be based on a generalized inverse of a compliance operator, where the compliance operator relates the displacement map to the force map. The compliance operator is not necessarily square, and does not necessarily have a traditional inverse.