Novel Pulse Detection System Using Differentiation: Prototyping and Experimental Results

Light Detection and Ranging (LiDAR) sensors play an important role in obstacle detection and avoidance in autonomous vehicles. In a Direct Time Of Flight (DTOF) Li-DAR, pulse detection is an important function which is often accomplished using high speed ADCs with sampling rates in the range of 0.5-1 giga samples per second. This poses problems for multi-channel single-chip LiDAR sensors due to area and power requirements of giga sample ADCs. In this paper, experimental results are presented from an implementation of pulse detection using differentiation by employing comparators, a novel method. A prototype for pulse detection mechanism has been implemented on a PCB using an array of sample and hold capacitors followed by a comparator. The performance of a low-area, low-power comparator-based pulse detection has been compared to that of a high-area, high-power ADC-based pulse detection system. The control circuitry and data processing are implemented on a Xilinx ZYNQ-based FPGA. Results of emulation of distance measurement show that the performance of comparator-based system is similar to that of an ADC-based system but potentially with less than 50% of area and power on a single-chip implementation.