What is Rotation Averaging?

Problem¹

Given a set of rotation matrices \(C_i, i=\{1,2,...,n\}\), the average of them is ? Rotation Averaging is to calculate the average of a set of rotation matrices. Averaging is to get the best estimate of all rotations. (Single rotation averaging)

Or equivalently, Rotation Averaging is the problem of estimating a set of \(n\) unknown orientations \(R_1,...,R_n \in SO(d)\) from noisy measurements \(\bar{R} \in SO(d)\) of the relative rotations \(R_i^{-1}R_j\) between them. (Multi rotation averaging)

In practical the rotation averaging problem could be categoried into : Single rotation averaging、Multi rotation averaging and Conjugate rotation averaging.

ROS编译

• catkin_make是cmake，make的进一步封装。路径位于workspace下，src之上使用:catkin_makeros会自己找到src下面的源代码，并开始build，如果src下面有好几个源代码，就通过DCATKIN_WHITELIST_PACKAGES指定一个就行：

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catkin_make -DCATKIN_WHITELIST_PACKAGES="package1;package2"

• 安装则catkin_make install, 使用catkin_make -DCMAKE_INSTALL_PREFIX=/opt/ros/groovy install指定要安装在哪里。

• 清理安装文件catkin_make clean。

泡泡机器人SLAM与你一同成长❤

使用之前先看看本地都有哪些镜像和容器。

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sudo docker ps -a

查看现有容器以及状态。

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CONTAINER ID   IMAGE                                              COMMAND                  CREATED         STATUS                   PORTS                                       NAMES
0ac8c062fa10   pointclouddl:segmentation                          "/bin/sh -c 'service…"   8 minutes ago   Up 8 minutes             6006/tcp, 50051/tcp, 0.0.0.0:2224->22/tcp   brave_kilby
cd8b9c9c5b07   stereolabs/zed:3.0-gl-devel-cuda10.0-ubuntu18.04   "/bin/bash"              4 weeks ago     Exited (0) 5 hours ago                                               jolly_feynman
af07110a5157   stereolabs/kalibr                                  "/ros_entrypoint.sh …"   4 weeks ago     Exited (0) 4 weeks ago                                               modest_leakey

e.g.现有用于laser slam的镜像, 设置了界面，ssh，基于amazinghao/ubuntu:graph_slam_clean镜像。

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CONTAINER ID   IMAGE                                COMMAND          CREATED         STATUS         PORTS                            NAMES
fe7323d95d8f   amazinghao/ubuntu:graph_slam_clean   "./startup.sh"   9 seconds ago   Up 7 seconds   22/tcp, 0.0.0.0:5900->5900/tcp   laser_slam_env

一些容器内部设置必须在创建的时候就设置好，不然就只能重新创建。比如端口映射，文件夹挂载，设置别名，虚拟内存设置，时区设置等。

用户宏

  由于在开发时不可避免的会遇到多个环境，在不同环境之间进行切换是一个很麻烦的事情，因此使用用户宏可以很好的帮助我们进行环境切换和别名替换，便于多人协同开发。
在属性管理器中选中任意配置环境中的Microsoft.Cpp.x64.user ，弹出如下页面：

泡泡机器人SLAM与你一同成长❤

可视化

其实关键就是添加一个可视化的应用，如X11 apps (and GL), is the key for display inside the docker，e.g.

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#!/bin/bash
# This file is covered by the LICENSE file in the root of this project.
docker build -t api --build-arg uid=$(id -g) --build-arg gid=$(id -g) .
docker run --privileged \
       -ti --rm -e DISPLAY=$DISPLAY \
       -v /tmp/.X11-unix:/tmp/.X11-unix \
       -v $1:/home/data/ \
       api

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docker run --privileged -ti --rm -e DISPLAY=$DISPLAY -v /tmp/.X11-unix:/tmp/.X11-unix -v /home/amazinghao/Data:/home/data/ api

• -e DISPLAY=$DISPLAY，after this the gui inside the docker will show in the host machine

• --privileged，will make all extend equippment available for the docker