Patent ID: 8798923
Filing Date: 2014-08-05
Classification: G01C,G01S

Abstract:
1. A method of non-echo ultrasonic Doppler used for corrected inertial navigation of a mobile device, the method comprising the steps of: providing at least one ultrasonic emitter within an environment, each emitter configured for transmitting an ultrasonic tone of a predefined frequency; establishing, by a controller of the mobile device, an initial location of the mobile device within the environment; initiating, by the controller of the mobile device, dead reckoning procedures using sensors within the mobile device; receiving, by a microphone circuit of the mobile device, at least one ultrasonic tone of a predefined frequency transmitted from at least one of the emitters in the environment; converting, by an analog-to-digital converter coupled to the microphone circuit of the mobile device, the at least one ultrasonic tone into a digital waveform; determining, by a digital signal processor coupled to the analog-to-digital converter of the mobile device, at least one peak frequency of the digital waveform; subtracting, by the digital signal processor, the at least one peak frequency from each predefined frequency to determine at least one Doppler shift; and correcting, by the controller of the mobile device, the dead reckoning of the mobile device using the at least one Doppler shift.