Ultra-Wideband Positioning Sensor with Application to an Autonomous Ultraviolet-C Disinfection Vehicle

Abstract

Due to the COVID-19 virus being highly transmittable, frequently cleaning and disinfecting facilities is common guidance in public places. However, the more often the environment is cleaned, the higher the risk of cleaning staff getting infected. Therefore, strong demand for sanitizing areas in automatic modes is undoubtedly expected. In this paper, an autonomous disinfection vehicle with an Ultraviolet-C (UVC) lamp is designed and implemented using an ultra-wideband (UWB) positioning sensor. The UVC dose for 90% inactivation of the reproductive ability of COVID-19 is 41.7 J/m2, which a 40 W UVC lamp can achieve within a 1.6 m distance for an exposure time of 30 s. With this UVC lamp, the disinfection vehicle can effectively sterilize in various scenarios. In addition, the high-accuracy UWB positioning system, with the time difference of arrival (TDOA) algorithm, is also studied for autonomous vehicle navigation in indoor environments. The number of UWB tags that use a synchronization protocol between UWB anchors can be unlimited. Moreover, this proposed Gradient Descent (GD), which uses Taylor method, is a high-efficient algorithm for finding the optimal position for real-time computation due to its low error and short calculating time. The generalized traversal path planning procedure, with the edge searching method, is presented to improve the efficiency of autonomous navigation. The average error of the practical navigation demonstrated in the meeting room is 0.10 m. The scalability of the designed system to different application scenarios is also discussed and experimentally demonstrated. Hence, the usefulness of the proposed UWB sensor applied to UVC disinfection vehicles to prevent COVID-19 infection is verified by employing it to sterilize indoor environments without human operation.

Coverage Planning for UVC Irradiation: Robot Surface Disinfection Based on Swarm Intelligence Algorithm

“…Robots achieve uniform painting thickness through spray gun modeling. In WSN layouts, sensor node deployment and network range are crucial for signal coverage, with network topology models balancing node energy consumption and minimizing sensor redundancy [ 34 ]. In the optimization of Wireless Sensor Network (WSN) sensor layouts, placing multiple controllers in a large-scale WSN is identified as an NP-hard problem.…”

Range-Extension Algorithms and Strategies for TDOA Ultra-Wideband Positioning System

“…In this study, a TDOA positioning network consisting of a master anchor and a few slave anchors was called a group. The communication process can be found in [ 22 ]. The master anchor, usually anchor 1, schedules message slots for all slave anchors, as illustrated in Figure 11 .…”

“…In the downlink TDOA system, the slave anchors are triggered by a master anchor to transmit ranging messages in scheduled slots. The tags can determine the differences in the distance by comparing the receiving timestamps of the ranging messages [ 22 ]. The number of tags in the downlink system is unlimited, as the tags do not need to transmit messages.…”