A Simple and Cost-Effective Physical Distancing Violation Detector Using a Rotating Time of Flight Lidar

In this work, a simple and cost-effective physical distancing violation detector using a commercial lidar has been developed. Our system comprises time of flight (ToF) lidar, mounted a stepper motor to rotate ToF Lidar and range an object on the top. We control a rotation of the stepper motor, record the distance between the object and the ToF Lidar by using a microcontroller, and analyze the measuring data using a computer program. This system can also indirectly estimate the distance between two objects by applying a simple vector operation. This paper successfully detects and evaluates the distance between two dummy objects placed with various configurations. We obtained the estimated distances using our proposed method nearly equal to the actual distances measured manually. In addition, our system has been tested to measure the physical distances among people with three volunteers who stood 200 cm and 80 cm distances in an indoor environment. The experiment results show that the distance between volunteer 1 and volunteer 2 is 186.5 cm and the distance between volunteer 2 and volunteer 3 is 73.0 cm. These indicate our system could provide information whether a safe distance or a risk distance. This research work can help the authorities provide an instrument for reducing contagious diseases, especially COVID-19 pandemic outbreaks, by installing at a fixed location or in portable instrument services.