Targetless Calibration of LiDAR-IMU System Based on Continuous-time Batch Estimation

TL;DR

This paper introduces LI-Calib, a continuous-time batch estimation method for accurate, repeatable LiDAR-IMU calibration that does not require artificial targets, validated through simulations and real-world experiments.

Contribution

The paper proposes a novel continuous-time trajectory formulation using B-Spline for LiDAR-IMU calibration, improving accuracy and robustness without artificial targets.

Findings

High calibration accuracy demonstrated in experiments

Method shows good repeatability in various scenarios

Validated on both simulated and real-world data

Abstract

Sensor calibration is the fundamental block for a multi-sensor fusion system. This paper presents an accurate and repeatable LiDAR-IMU calibration method (termed LI-Calib), to calibrate the 6-DOF extrinsic transformation between the 3D LiDAR and the Inertial Measurement Unit (IMU). % Regarding the high data capture rate for LiDAR and IMU sensors, LI-Calib adopts a continuous-time trajectory formulation based on B-Spline, which is more suitable for fusing high-rate or asynchronous measurements than discrete-time based approaches. % Additionally, LI-Calib decomposes the space into cells and identifies the planar segments for data association, which renders the calibration problem well-constrained in usual scenarios without any artificial targets. We validate the proposed calibration approach on both simulated and real-world experiments. The results demonstrate the high accuracy and good repeatability of the proposed method in common human-made scenarios. To benefit the research community, we open-source our code at \url{https://github.com/APRIL-ZJU/lidar_IMU_calib}