# Robust Localization and Tracking of VRUs with Radar and Ultra-Wideband Sensors for Traffic Safety

## TL;DR

This paper introduces a system that combines radar and UWB sensors to accurately track vulnerable road users in urban areas, even in poor visibility or blind spots.

## Contribution

The novel integration of radar and UWB sensors with a hybrid Kalman filter improves VRU tracking in complex urban environments.

## Key findings

- Sensor fusion of radar and UWB reduces tracking uncertainties in urban traffic scenarios.
- The system performs reliably in adverse weather and occluded areas where optical sensors fail.
- The hybrid Kalman filter approach enables continuous and accurate tracking of VRUs and vehicles.

## Abstract

What are the main findings?
The paper presents a novel approach to enhancing Vulnerable Road User (VRU) protection by integrating radar sensors and a widespread network of Ultra-Wideband (UWB) nodes through sensor fusion, in order to detect and track VRUs in urban environments.The experimental results demonstrate that the fusion of radar and UWB measurements reduces tracking uncertainties and improves the accuracy of VRU tracking, particularly in areas with blind spots or occlusions.

The paper presents a novel approach to enhancing Vulnerable Road User (VRU) protection by integrating radar sensors and a widespread network of Ultra-Wideband (UWB) nodes through sensor fusion, in order to detect and track VRUs in urban environments.

The experimental results demonstrate that the fusion of radar and UWB measurements reduces tracking uncertainties and improves the accuracy of VRU tracking, particularly in areas with blind spots or occlusions.

What is the implication of the main finding?
The proposed system has the potential to contribute to the development of intelligent road infrastructures, enhancing urban traffic safety and reducing the risk of accidents involving VRUs, particularly in complex traffic scenarios where both vehicles and VRUs are present.The use of a widespread network of UWB nodes in conjunction with radar sensors enables the creation of a more comprehensive and robust VRU tracking system, which can be integrated into intelligent road infrastructures and contribute to the development of smarter and safer urban transportation systems, ultimately reducing the risk of accidents involving VRUs and improving overall traffic safety.

The proposed system has the potential to contribute to the development of intelligent road infrastructures, enhancing urban traffic safety and reducing the risk of accidents involving VRUs, particularly in complex traffic scenarios where both vehicles and VRUs are present.

The use of a widespread network of UWB nodes in conjunction with radar sensors enables the creation of a more comprehensive and robust VRU tracking system, which can be integrated into intelligent road infrastructures and contribute to the development of smarter and safer urban transportation systems, ultimately reducing the risk of accidents involving VRUs and improving overall traffic safety.

The increasing risk to Vulnerable Road Users (VRUs) at urban intersections necessitates advanced safety mechanisms capable of operating effectively under diverse conditions, including adverse weather like heavy rain. While optical sensors such as cameras and LiDAR often degrade in poor visibility, Radio Frequency (RF)-based systems offer resilient, all-weather tracking. This paper presents a novel approach to enhancing VRU protection by fusing two RF modalities: radar sensors and Ultra-Wideband (UWB) technology, a strong candidate for Joint Communication and Sensing (JCS). The research, conducted as part of the VIDETEC-2 project, addresses the limitations of existing vehicle-based and infrastructure-based systems, particularly in scenarios involving occlusions and blind spots. By leveraging radar’s environmental robustness alongside UWB’s precise, cost-effective short-range communication and localization, the proposed system delivers the framework for continuous vehicle and VRU tracking. The fusion of these sensor modalities, managed through a hybrid Kalman filter approach integrating an Unscented Kalman Filter (UKF) and an Extended Kalman Filter (EKF), allows reliable VRU tracking even in challenging urban scenarios. The experimental results demonstrate a reduction in tracking uncertainty and highlight the system’s potential to serve as a more accurate and responsive safety mechanism for VRUs at intersections. This work contributes to the development of intelligent road infrastructures, laying the foundation for future advancements in urban traffic safety.