CarSpeedNet: A Deep Neural Network-based Car Speed Estimation from Smartphone Accelerometer
Accurate vehicle speed estimation for mobile robots and autonomous ground vehicles using only low-cost triaxial accelerometers—such as those embedded in smartphones—remains challenging, especially without gyroscopes, wheel odometry, vehicle bus data, or external positioning signals. Method: This paper proposes an end-to-end deep neural network that operates exclusively on sliding-windowed temporal accelerometer measurements. It incorporates long-range temporal modeling to enhance robustness in dynamic driving scenarios and directly learns the nonlinear mapping from acceleration sequences to instantaneous speed. Contribution/Results: To our knowledge, this is the first work achieving sub-meter-per-second speed estimation (mean absolute error of 0.72 m/s) using smartphone-grade accelerometers alone, validated over 13 hours of real-world road testing across diverse conditions. The method delivers high-output frequency (10–100 Hz), significantly surpassing GPS (1 Hz), and runs entirely offline—requiring no vehicle interfaces or real-time external assistance.