An Energy-Efficient, High-Frame-Rate, and Reconfigurable EKF-SLAM Processor With Full Acceleration for Autonomous Mobile Robots

Abstract

In many intelligent edge applications involving Autonomous Mobile Robots (AMRs), efficient and real-time localization and mapping is a fundamental issue. Extended Kalman Filter Simultaneous Localization and Mapping (EKFSLAM) algorithm is a classic and successful solution to realize localization and mapping, while it is computationally intensive and poses a challenge for real-time tasks in small and micro robots. To address this issue, this work proposes an energy-efficient, highframe-rate, and reconfigurable EKF-SLAM processor. Firstly, a heterogeneous dual-core architecture is proposed to enable full acceleration of both matrix operations and nonlinear calculations in EKF-SLAM at the hardware architecture level. Secondly, a Reconfigurable Matrix Accelerator (RMA) and Reconfigurable Nonlinear Accelerator (RNA) are proposed to maximize data reuse and support diverse nonlinear functions at the data flow level. Thirdly, a data property-aware strategy is proposed at the data property level, which exploits matrix symmetry, sparsity, and dependency to reduce storage significantly and eliminate redundant computations. FPGA validation results show that the proposed design can achieve a frame rate of 774 fps and an energy efficiency of 0.66 mJ/frame, when performing mapping processes involving 60 landmarks at 100 MHz.