Patent ID: 11885871
Assignee: MAGIC LEAP, INC.
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 9:
10. An augmented reality device comprising:
a head-mountable frame;
a radar system that includes:
at least a first radar device having:
a first radar transmitter secured to the frame and transmitting a radio wave at first and second times in a slow domain;
a first radar receiver secured to the frame and detecting the radio waves after the radio waves are reflected from a surface;
a radar tracking module connected to the first radar receiver and determining first and second time intervals in a fast domain between the transmission and the detection of the radio waves, respectively;
a radar mapping module connected to the radar tracking module and generating first and second radar maps of locations of real-world objects relative to the user based at least on the respective times in the fast domain;
an image processing module connected to the radar mapping module and calculating a first and second sets of radar fingerprints based on the locations of the real-world objects in the first and second radar maps, respectively;
a measurement unit, secured to the frame, and detecting a first and second measurement values at the first and second times in the slow domain, each measurement value being indicative of at least one of position and movement of the measurement unit;
a measurement unit filter connected to the measurement unit;
a sensor fusion module connected to the image processing module and operable to (i) determine first and second pose estimates, the first pose estimate being based on the first set of radar fingerprints relative to the first measurement value and the second pose estimate being based on the second set of radar fingerprints relative to the second measurement value, (ii) determine drift of the measurement unit by comparing the first pose estimate with the second pose estimate, and (iii) adjust the measurement unit filter to correct for the drift;
a rendering module to determine a desired position of a rendered object based on the second pose;
an eyepiece secured to the frame; and
a projector secured to the frame and operable to convert data into light to generate the rendered object and displaying the rendered object in the desired position to the user through the eyepiece.