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

Claim 10:
11. An augmented reality device comprising:
a head-mountable frame;
a radar system secured to the frame that includes:
a radar transmitter secured to the frame and initiates execution of a first radar cycle by transmitting a first radio wave;
a radar receiver secured to the frame and detecting the first radio wave after the first radio wave is reflected from a surface;
a radar tracking module connected to the radar receiver and determining a first time between the transmission and the detection of the first radio wave;
a radar mapping module connected to the radar tracking module and generating a first radar map of locations of real-world objects relative to the user based at least on the first time between the transmission and the detection of the first radio wave;
an image processing module connected to the radar mapping module and calculating a first set of radar fingerprints based on the locations of the real-world objects in the first radar map to complete the first radar cycle;
a measurement unit, secured to the frame, and detecting a first measurement value indicative of at least one of position and movement with a measurement unit secured to the frame;
a sensor fusion module connected to the image processing module and the measurement unit and determining a first pose estimate of the first set of radar fingerprints relative to the first measurement value;
wherein the radar system executes a second radar cycle, including:
transmitting a second radio wave;
detecting the second radio wave after the second radio wave is reflected from the surface;
determining a second time between the transmission and the detection of the second radio wave;
generating a second radar map of locations of real-world objects relative to the user based at least on the second time between the transmission and the detection of the second radio wave; and
calculating a second set of radar fingerprints based on the locations of the real-world objects in the second radar map;
wherein the measurement unit detects a second measurement value indicative of a position and movement with the measurement unit secured to the frame;
wherein the sensor fusion module:
determines a second pose estimate of the second set of radar fingerprints relative to the second measurement value;
determining drift of the measurement unit by comparing the first pose estimate with the second pose estimate;
adjusts a measurement unit filter that is connected to the measurement unit 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.