Amazon Technologies, Inc.

Anran Wang

Trausti Thor Kristjansson

Tarun Pruthi

Krishna Kamath Koteshwara

Spencer Russell

Ali Abdollahzadeh Milani

A system that performs wall detection and localization to determine a position of a device relative to acoustically reflective surfaces. The device emits an audible sound including a frequency modulated signal and captures reflections of the audible sound. The frequency modulated signal enables the device to determine an amplitude of the reflections at different time-of-arrivals, which corresponds to a direction of the reflection. The device then performs beamforming to generate a 2D intensity map that represents an intensity of the reflections at each spatial location around the device. The device detects wall(s) in proximity to the device by identifying peak intensities represented in the 2D intensity map. In some examples, instead of performing beamforming, the device can perform directional wall detection by physically rotating the device and emitting the audible sound in multiple directions. The device may perform ultrasonic wall detection using ultrasonic sound frequencies.

Method for wall detection and localization

Techniques for monitoring devices to use ultrasonic signals to detect and track the locations of moving objects in an environment. To determine distance information, the monitoring devices emit a frequency-modulated continuous wave (FMCW) signal at an ultrasound frequency range. Reflections of the FMCW ultrasonic signal are used to generate time-of-arrival (TOA) profiles that indicate distances between the monitoring device and objects in the environment. The reflections can be processed to suppress undesirable interferences, such as reflections off non-mobile objects in the environment (e.g., walls, furniture, etc.), vibrations off the floorings or the ceilings, etc. After processing the reflections, a heatmap can be used to plot the intensity of the reflections for the different TOAs of the reflections, and depict the movement of the user over time. Finally, a Kalman filter is used to smooth the peaks in the intensity values on the plot, and determine the trajectory of the human.

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Seattle, WA, United States of America

Anran Wang