Piecewise-linear and piecewise-affine subspace transformations for high dimensional touchpad (HDTP) output decoupling and corrections

摘要

Methods for piecewise-linear and piecewise-affine transformations parameter decoupling in High Dimensional Touchpad (HDTP) user touch interfaces including those with multitouch capabilities are described. A calculation chain provides a first-order calculation of a subset of a collection of touch parameters (including for example left-right, front-back, downward pressure, roll angle, pitch angle, yaw angle) responsive in real-time to user touch on a touch-responsive sensor array. A piecewise-affine transformation is applied to these first-order calculations to produce parameter decoupling. The piecewise-affine transformation can be structured to depend only on current numerical values from the first-order calculation. Alternatively, the piecewise-affine transformation can be structured to additionally depend on the positive or negative direction of change over time of at least one numerical value from the first-order calculation, thereby providing a correction for hysteresis effects.

主权项

1. A method for decoupling or correcting measured parameters in a touch-based user interface using at least one computational processor, the method comprising:
receiving tactile image data responsive to data generated from a user touch to a user touch interface comprising a sensor array; processing the tactile image data with a series of operations to produce a first processed data vector, the series of operations comprising at least one rotation operation, the first processed data vector comprising a plurality of numerical values responsive to data generated from the user touch interface; and further processing a proper subset of the variables comprised by the first processed data vector, the further processing comprising a piecewise-affine computational operation on the proper subset of the variables comprised by the first processed data vector, the piecewise-affine operation using at least one provided linear transformation and at least one provided offset vector, the at least one provided linear transformation selected from a plurality of possible linear transformations and the at least one provided offset vector selected from a plurality of possible offset vectors; wherein the selection of the linear transformation from the plurality of possible linear transformations and the selection of the offset vector from the plurality of possible offset vectors is determined by conditional tests made on at least one of the numerical values comprised by the first processed data vector, and wherein the further processing produces a second processed data vector comprising a plurality of numerical values responsive to data generated from the user touch interface.