Livox Viewer Auto Extrinsics Calibration 外参自动标定功能操作指引

Livox Pioneer

Introduction
Auto extrinsic calibration enables users to automatically calibrate the extrinsic of multiple LiDAR sensors at the same time. It is particularly useful for LiDAR sensors with little or no FOV overlap.

简介
外参自动标定功能主要实现多台 Livox 设备外参进行快速高精度的半自动标定，特别是对于重叠（overlap）较小或者无重叠情况下的多备外标定，具有较好的辅助作用。

Auto Extrinsics Calibration Procedure

1. Click to open the extrinsic parameter tool and select Auto Calibrating.
2. Click to import the calibration data of lvx file. Check Calibration Data Collection Requirements and Calibration Data Collection Scenario Requirements for more information.
3. Click Mapping and wait until the point cloud reconstruction is completed.
4. Select a LiDAR sensor as the Benchmark LiDAR. The extrinsics of the benchmark LiDAR will remain zero during the auto extrinsics calibration. Users can adjust the extrinsics of the remaining LiDAR sensors where necessary.
5. Uncheck the box in column V to hide a LiDAR on the display.
6. Select the extrinsic in the table to adjust. The point cloud data of the selected LiDAR will change to red in the display. Hold Shift and press Up/Down or scroll the mouse wheel to adjust extrinsics by 0.01° or 0.001 m. Hold Ctrl and press Up/Down or scroll the mouse wheel to adjust extrinsics by 0.1° or 0.05 m. The real-time point cloud data will be updated immediately after the extrinsic is adjusted.
7. Once all extrinsics are adjusted, select Calibrating to perform auto extrinsics calibration.
8. After calibration, users can adjust the extrinsics of all LiDAR sensors as a group by checking one of the boxes in column G. Follow Step 6 to perform a coarse or fifine adjustment of extrinsics
9. Click to save the current extrinsics or click Apply to confifirm and update the extrinsics in Livox Viewer and all connected LiDAR sensors.


外参自动标定步骤

1. 点击 打开外参标定界面，点击 Auto Calibrating 按钮选择自动标定；
2. 点击 加载 lvx 格式标定数据（具体请阅读：标定数据采集注意事项和标定数据采集场景要求）；
3. 点击 Mapping 按钮，等待设备点云完成建图；
4. 选择 Benchmark LiDAR 后，选中的设备外参将被锁定，保证标定时基准设备外参为 0，再逐一对其他各个 Livox 设备完成外参粗校准；
5. 在参数表 V 列中取消勾选可隐藏对应设备点云，仅显示勾选中的设备点云；
6. 粗校准时，选中某一列中一个数据，被选中的设备将在点云视图中标记为红色点云。选中后使用键盘 Shift+ 上下键 / 鼠标滚轮进行精调（角度 0.01°，平移 0.001 m），或键盘 Ctrl+ 上下键 / 鼠标滚轮进行粗调（角度 1°，平移 0.05 m）。调整后的数据将实时刷新至点云视图中；
7. 所有设备完成粗校准后，点击 Calibrating 按钮将进行外参自动标定；
8. 若需要组合调节外参，在外参自动标定完成后，勾选参数表 G 列选项，进行整体外参调整，完成最终标定；
9. 如果标定结果符合预期，点击 保存参数表；或者在设备连接状态下点击 Apply 按钮，则会将当前的参数写入到 Livox 设备中并在 Livox Viewer 中生效。

For more detail, please refer to the attachment. 更多详情，请参考附件。