Using Smartphone as On-board unit (OBU) Emulator Implementation Study

This project aimed at using smartphones to emulate the On-Board Unit (OBU) for Infrastructure-to-Vehicle (I2V) and Pedestrian-to-Vehicle (P2V) applications. In order to achieve the objectives, the following tasks were performed. The research team first reviewed existing studies and practices to fully understand smartphone sensors, roadside sensors, data communication technologies, and OBU technologies and applications. Smartphone apps were developed to collect smartphone sensor data, and the cloud server was set up to allow the apps to upload and receive data. The feasibility of using smartphones as OBU emulators was validated by examining the data communication latency and smartphone battery consumption. The system was programmed to collect the data of smartphone sensors, such as Global Positioning System (GPS), Accelerometer, Gyroscope, and Magnetometer, into the cloud server. Different methods and algorithms were developed and programmed to obtain users’ traffic parameters, including position, surrounding environment, speed, acceleration, transportation mode, and turning movement. The accuracy of the users’ traffic parameters was evaluated by conducting various experiments, which suggested that the data could well reflect users’ statuses. In addition to smartphone data, the camera was used as a type of external sensor to provide additional information. The computer vision technology was used to detect pedestrians even if they did not have the developed apps. The camera was further applied to detect queue length at intersections in real time. The accuracy of computer vision technologies was tested and validated. A communication system was set up to upload the camera data to the cloud server with low latency. Based on the communication system between smartphone apps and the cloud server, the research team used smartphones to emulate the OBUs for I2V applications. Two applications were included: (1) curve warning; (2) queue warning. The warning logic was proposed under different scenarios and programmed into the system. Besides, the authors further used smartphones as OBU emulators for P2V warning. The P2V warning considered two conditions: (1) both drivers and pedestrians have the developed smartphone apps; (2) only drivers have the developed smartphone apps and pedestrians were detected by cameras. Different warning logics were proposed at intersections and segments. Different drivers’ turning movements, including driving through, turning left, and turning right, were incorporated into the system. Extensive experiments were conducted to validate the developed OBU emulator system. The results suggested that the authors successfully used smartphones as OBU emulators for I2V and P2V applications. It is intended that the developed system could expand the benefits of OBUs by leveraging smartphones, which have a high market penetration.


  • English

Media Info

  • Media Type: Digital/other
  • Edition: Final Report
  • Features: Figures; Maps; Photos; References; Tables;
  • Pagination: 236p

Subject/Index Terms

Filing Info

  • Accession Number: 01746656
  • Record Type: Publication
  • Contract Numbers: BDV24-977-30
  • Created Date: Jul 14 2020 9:27AM