Driving techniques for phased-array systems
Various techniques for driving phased array systems are described, specifically intended for acoustic phased arrays with applications to mid-air haptics, parametric audio, acoustic levitation and acoustic imaging, including a system: 1) that is capable of mitigating the effect of the changes in the air to provide a consistent haptic experience; 2) that produces trap points in air; 3) that defines phased-array optimization in terms of vectors for the production of more consistent haptic effects; 4) that defines one or more control points or regions in space via a controlled acoustic field; 5) that uses a reduced representation method for the construction of acoustic basis functions; 6) that performs efficient evaluation of complex-valued functions for a large quantity of throughput; 7) that generates a Krylov sub-space of a matrix; and 8) that maximizes an objective described by different control points and/or regions to those used to create the acoustic basis functions.
1 . A method for producing an acoustic output in a mid-air haptic device comprising:
determining a control point and a reference haptic waveform at the control point;
creating a function configured to calibrate an acoustic output relative to the reference haptic waveform; and
driving the acoustic output according to the function to produce a calibrated output that reproduces perceptual characteristics of the reference haptic waveform at the control point.
2 . The method as in claim 1 , wherein the function is non-linear.
3 . The method as in claim 1 , wherein the function is log-linear.
4 . The method as in claim 1 , wherein the function is sigmoidal.
5 . The method as in claim 1 , wherein the control point is moved during the driving of the acoustic output.
6 . A system comprising:
one or more processors configured to:
determine a control point and a reference haptic waveform at the control point;
create a function configured to calibrate an acoustic output relative to the reference haptic waveform; and
drive the acoustic output according to the function to produce a calibrated output that reproduces perceptual characteristics of the reference haptic waveform at the control point.
7 . The system as in claim 6 , wherein the function is non-linear.
8 . The system as in claim 6 , wherein the function is log-linear.
9 . The system as in claim 6 , wherein the function is sigmoidal.
10 . The system as in claim 6 , wherein the control point is moved during the driving of the acoustic output.