用evo工具评估SLAM轨迹

evo github 地址：https://github.com/MichaelGrupp/evo

不同格式的轨迹文件及相互转换：https://github.com/MichaelGrupp/evo/wiki/Formats

问题汇总：https://github.com/MichaelGrupp/evo/issues?q=is%3Aissue+is%3Aclosed

1、安装 evo

sudo apt install python-pip
pip install evo --upgrade --no-binary evo

出现问题： 

Could not install packages due to an EnvironmentError: [Errno 13] Permission denied: '/usr/lib/python2.7/dist-packages/dateutil/relativedelta.pyc'
Consider using the `--user` option or check the permissions.

解决：

pip install evo --upgrade --no-binary evo --user

2、测试

cd ~/alan_dataset/EuRoC/mav0/state_groundtruth_estimate0
evo_traj euroc data.csv --plot

出现问题：

name:	data
infos:	19753 poses, 91.747m path length, 98.760s duration
/usr/lib/python2.7/dist-packages/matplotlib/font_manager.py:273: UserWarning: Matplotlib is building the font cache using fc-list. This may take a moment.
  warnings.warn('Matplotlib is building the font cache using fc-list. This may take a moment.')
[ERROR] Unhandled error in evo.main_traj
Traceback (most recent call last):
  File "/home/jinshan.lan/.local/lib/python2.7/site-packages/evo/entry_points.py", line 90, in launch
    main_module.run(args)
  File "/home/jinshan.lan/.local/lib/python2.7/site-packages/evo/main_traj.py", line 342, in run
    from evo.tools.plot import PlotMode
  File "/home/jinshan.lan/.local/lib/python2.7/site-packages/evo/tools/plot.py", line 36, in 
    import mpl_toolkits.mplot3d.art3d as art3d
  File "/usr/lib/python2.7/dist-packages/mpl_toolkits/__init__.py", line 2, in 
    __import__('pkg_resources').declare_namespace(__name__)
  File "/usr/lib/python2.7/dist-packages/pkg_resources/__init__.py", line 2927, in 
    @_call_aside
  File "/usr/lib/python2.7/dist-packages/pkg_resources/__init__.py", line 2913, in _call_aside
    f(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/pkg_resources/__init__.py", line 2940, in _initialize_master_working_set
    working_set = WorkingSet._build_master()
  File "/usr/lib/python2.7/dist-packages/pkg_resources/__init__.py", line 637, in _build_master
    return cls._build_from_requirements(__requires__)
  File "/usr/lib/python2.7/dist-packages/pkg_resources/__init__.py", line 650, in _build_from_requirements
    dists = ws.resolve(reqs, Environment())
  File "/usr/lib/python2.7/dist-packages/pkg_resources/__init__.py", line 834, in resolve
    raise VersionConflict(dist, req).with_context(dependent_req)
ContextualVersionConflict: (numpy 1.11.0 (/usr/lib/python2.7/dist-packages), Requirement.parse('numpy>=1.12.0'), set(['pandas']))

[ERROR] evo module evo.main_traj crashed - no logfile written (disabled)

解决：

pip install numpy --upgrade --user

运行结果：

3、将 EuRoC 数据集中 .csv 文件形式的 groundtruth 转换为 TUM 形式的轨迹文件

evo_traj euroc data.csv --save_as_tum

TUM 形式的轨迹文件格式：

每行8个数，用空格分隔，包含时间戳（单位：秒）、位置和旋转（四元素表示）

timestamp x y z q_x q_y q_z q_w

4、多轨迹显示（轨迹未对齐）

（a）上面将 EuRoC 数据集中 MH_04_difficult 序列的 groundtruth(.csv文件) 转换为 TUM 形式的轨迹文件，文件名为 data.tum

（b）通过双目 ORBSLAM 跑 MH_04_difficult 数据集得到 TUM 形式的轨迹文件，文件名为 FrameTrajectory_TUM_Format.txt

见：ORB_SLAM2 & VI-ORBSLAM 相关（#alan#）

将两个 TUM 形式的轨迹文件放入同一个文件夹 (test_evo) 中

cd ~/Desktop/test_evo
evo_traj tum FrameTrajectory_TUM_Format.txt --ref=data.tum -p

运行结果：

 

5、计算绝对位姿误差（轨迹对齐）

evo_ape tum data.tum FrameTrajectory_TUM_Format.txt -va --plot

运行结果：

    

 

参考：

知乎：一种评估SLAM系统参数的实用工具

使用 evo 工具评测 VI ORB SLAM2 在 EuRoC 上的结果