DGIST develops ‘physical AI-based vehicle state estimation technology’ to enhance electric vehicle’s driving safety

□ A research team led by Professor Kanghyun Nam from the Department of Robotics and Mechanical Engineering at DGIST (President Kunwoo Lee) developed a ‘Physical AI-based Vehicle State Estimation Technology’ that accurately estimates the driving state of electric vehicles in real time through international joint research with Shanghai Jiao Tong University in China and the University of Tokyo in Japan. This technology is viewed as a key advancement that can improve the core control performance of electric vehicles and greatly enhance the safety of autonomous vehicles.

□ ‘Sideslip Angle,’ which shows how much an electric vehicle slides sideways during sharp turns or on slippery surfaces, is crucial information for safe driving.

□ Since this value is difficult to measure directly with in-vehicle sensors, automakers depend on complex physical models or indirect estimates. These methods face issues due to low accuracy and limitations across different driving conditions.

□ To address these issues, Professor Kanghyun Nam's team created a new ‘Physical AI-based Estimation Technology’ that combines AI and physical models. The main idea is that it significantly enhances accuracy by merging a physical model describing vehicle motion with data from sensors measuring lateral tire force and an AI-based regression model (GPR).

□ To address nonlinear tire behavior and environmental changes that are difficult for physical models to explain, the research team developed a hybrid estimation framework that combines a physical tire model with an AI-based learning model. Specifically, by using an unscented Kalman filter (UKF) observer integrated with Gaussian Process Regression (GPR), the team secured both the flexibility of data-driven learning and the reliability of the physical model. This combination enables more accurate and faster estimation of the vehicle's slip angle compared to traditional methods.

□ During actual electric vehicle platform testing, this technology exhibited high accuracy and strong estimation performance across different road surfaces, speeds, and cornering conditions. Accurate vehicle state estimation is essential for driving stability control, autonomous driving safety, and energy efficiency in electric vehicles. This achievement is seen as a major technological breakthrough for future mobility, as it opens new possibilities for AI-based physical vehicle control.

□ Professor Kanghyun Nam stated, "Through a new approach that combines physical models and AI, we can estimate the driving conditions of electric vehicles with greater precision and reliability. This research will serve as a core foundation for next-generation autonomous driving and electric vehicle technology." He also added, "We will further develop this technology through joint research with global automakers and expand it into a technology applicable to actual industrial settings."

This research was funded by the National Research Foundation of Korea’s (NRF) Excellent Young Researcher Program. The results of this collaborative project with DGIST, Shanghai Jiao Tong University, and the University of Tokyo were published in the renowned academic journal ‘IEEE Transactions on Industrial Electronics.’