Method and system for laser-IMU external parameter calibration

Abstract

The invention provides a method and system for laser-IMU external parameter calibration. The method comprises steps of acquiring IMU measurement data and laser radar measurement data; carrying out IMUpre-integration of the obtained IMU measurement data, carrying out calculation to obtain an IMU pose transformation estimated value of the IMU relative to the IMU initial pose at the next moment, andaccording to the estimated value and an actual measurement value of the IMU at the next moment, obtaining an associated residual error associated with the data; processing measurement data of the laser radar, utilizing IMU pre-integration to obtain projection coordinates of reprojecting a plurality of laser radar points to a world coordinate system, and calculating a reprojection error from eachlaser radar point to a calibration target map; adopting a nonlinear least square method to iteratively optimize laser radar-IMU external parameter calibration so that the external parameter calibration result can be obtained. The method is advantaged in problems that in laser-IMU external parameter calibration, mechanical external parameters are not easy to obtain, manual measurement errors are large, and measurement is troublesome are solved, defects of the laser radar and the IMU are mutually overcome to a certain extent, and pose solving precision and the speed of the SLAM method can be improved.

Description

technical field [0001] The present disclosure relates to the technical field related to robots, and in particular, relates to a method and system for calibrating external parameters of a laser-IMU. Background technique [0002] The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art. [0003] In recent years, the robotics industry has proposed various multi-sensor fusion approaches for simultaneous localization and mapping, all of which rely on precise external calibration and synchronization between sensing devices. The robot is in a lack of map information and no GPS environment, such as indoors, forests, and mines. The robot's SLAM (Simultaneous Localization and Mapping) technology plays an important role. In the simultaneous positioning and mapping process, the real-time and accuracy of the solution of the robot pose directly determines the effect of SLAM mapping. [0004] Iner...

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Problems solved by technology

[0005] In order to solve the above problems, the present disclosure proposes a method and system for laser-IMU external parameter calibration, realizes tight coupling between Lidar and IMU, accurately calibrates laser-IMU external parameters, and solves the problem of laser-IMU external parameters. In the parameter calibration, the mechanical external parameters are not easy to obtain, the manual measurement error is large, and the measurement is troublesome. To a certain extent, the respective shortcomings of the Lidar (Lidar) and the IMU can be compensated for each other, which can improve the pose solution accuracy and pose of the SLAM method. Velocity, the external parameter calibration method of the present disclosure can be applied to the combined system of LiDAR-IMU two kinds of sensors

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