Traj-LO: In Defense of LiDAR-Only Odometry Using an Effective Continuous-Time Trajectory

LiDAR Odometry is an essential component in numerous robotic applications. However, current LiDAR-only methods have poor performance in aggressive situations. Unlike the mainstreamed approaches that focus on improving accuracy by the additional inertial sensors, this letter demonstrates that LiDAR is enough to achieve the similar capability through a continuous-time perspective. Firstly, the measurements of LiDAR are regarded as streaming points continuously captured at separate time. Secondly, the LiDAR movement is parameterized by a simple yet effective continuous-time trajectory. Therefore, our proposed method named Traj-LO can recover the spatial-temporal consistent movement of LiDAR by tightly coupling the geometric information from LiDAR points and kinematic constraints from trajectory smoothness. This framework is generalized for different kinds of LiDAR as well as multi-LiDAR systems. Extensive experiments on the public datasets verify the robustness and effectiveness of our proposed LiDAR-only approach, even in scenarios where the kinematic state exceeds the IMU's measuring range.