A 1.15 TOPS/W Energy-Efficient Capsule Network Accelerator for Real-Time 3D Point Cloud Segmentation in Mobile Environment

Abstract

An energy-efficient capsule network accelerator is proposed for real-time 3D point cloud segmentation in mobile devices. The proposed accelerator adopts the pipelined heterogeneous core architecture to achieve $1.55\times $ throughput enhancement. Furthermore, the proposed dynamic route skipping controller predicts unimportant operations and skips them to reduce the external memory access by 39.1%. At last, the new squash activation function unit exploits the look-up table (LUT) based computing with L2-norm approximation to minimize the power and area overhead. The proposed architecture is implemented with the FPGA, Altera Cyclone V 5CEBA9F31C7 and we test capsule network-based 3D point cloud segmentation application. It consumes 2.15 W power and shows 0.05 TOPS/W energy-efficiency. Also, the architecture is simulated with the 65nm CMOS technology, showing 94.3mW power consumption and 1.15 TOPS/W energy-efficiency.