In-Sensor Neural Network Preprocessing for ADAS Computer Systems

Currently available automotive radars are designed to stream real-time 2D image data over high-speed links to a central ADAS (Advance Driver-Assistance System) computer for object recognition, which considerably contributes to the system's power consumption and complexity. This paper presents a preliminary work for the implementation of a new in-sensor computer architecture to extract representative features from raw sensor data to detect and identify objects with radar signals. Such new architecture makes it possible to reduce the data transferred between sensors and the central ADAS computer significantly, giving rise to significant energy savings and latency reductions, while still maintaining sufficient accuracy and preserving image details. An experimental prototype has been built using the Texas Instruments AWR1243 Frequency-Modulated Continuous Wave (FMCW) radar board. We carried out experiments using the prototype to collect radar images, to preprocess raw data, and to transfer feature vectors to the central ADAS computer for classification and object detection. Two different approaches will be presented in this paper: First, a vanilla autoencoder will demonstrate the possibility of data reduction on radar signals. Second, a convolutional neural network based cross-domain deep learning architecture is presented by using a sample dataset to show the feasibility of computing Range-Angle Heatmaps directly on the sensor board eliminating the need for the raw data preprocessing on the central ADAS computer. We show that the reconstruction of Range-Angle Heatmaps can be predicted with a very high accuracy by leveraging deep learning architectures. Implementation of such a deep learning architecture on the sensor board can reduce the amount of data transferred from sensors to the central ADAS computer implying great potential for an energy efficient deep learning architecture in such environments.