Apollo Advanced Lesson | Chapter6-1 ROS

Posted 2022-12-14 Justin-Yip

Contents

• 1. Why`s ROS ?
• 2. ROS的概念
• Apollo ROS 介绍
• Why optimize ROS
• 1. 通信系统优化
• decentralized communication network
• • create node and communication init

–This article is excerpted from Baidu’s official about Apollo, please indicate the source for reprinting–

1. Why`s ROS ?

因为三个特性：

---

ROS Lesson 2

2. ROS的概念

• 松耦合

• node

• topic

• roscore

• msg

• 协作例子
  

---

ROS Lesson 3

Apollo ROS 介绍

Why optimize ROS

• Sensor data is mass.Sensor data transportion latency will be a problem,when through-output is not enough,which will result in extremely danger while driving. Such as:
  • camera data : ~ 5MB/s per camera
  • LIDAR data ：~ 20 MB/s per LIDAR
• centralize communication mechanism
• none real-time OS
  

1. 通信系统优化

1. copy consumption

• class ROS ： 4 times copy

  • 用户态 --> 内核态 --> 用户态 --> node间IPC copy ——> deserialize copy

• Apollo ROS ： 2 times copy

  • 减少了用户态 --> 内核态 --> 用户态的两次copy
    

decentralized communication network

create node and communication init