Indoor Location Identification for Smart Speakers Leveraging 3-D Acoustic Images

The indoor location awareness has drawn increasing attention for smart speakers as they become essential to provide function-location services. Existing indoor localization solutions either require add-on equipment or could only achieve room-level accuracy, which could not provide a function-location service for smart speakers. In this work, we propose a location identification system utilizing 3-D acoustic images, which are derived from the smart speaker by emitting a beep signal and sensing echoes created by objects in the surrounding environment with its microphone array, as the proof to identify some pre-defined indoor locations. Given the recorded acoustic samplings captured by the microphone array, our image construction component constructs a virtual imaging hemisphere and steers the array towards each grid of the hemisphere to generate a 3-D acoustic image of the surrounding environment. Moreover, we design a transfer-learning based model to derive effective features from the constructed images, and propose a data augmentation scheme for generating synthesized training images. To achieve a more accurate location identification, we further design a distance estimation scheme to identify the distances between the smart speaker and some major surrounding objects by utilizing the constructed 3-D acoustic image, and then adopt such distance information for location identification. Our experimental results show that our proposed system is accurate and robust for location identification under various real world scenarios.