Commissioning experience of ROS

List of articles

Tips ： Here you can add a list of all the articles in the series , The directory needs to be added manually
TODO: Finish writing and then sort it out

---

Preface

Limited cognition , Please forgive me , If you have any questions, I hope to communicate with you more , Grow up together ！

This article first ROS Debugging experience Make a brief introduction , The details will be discussed later , Other modules can refer to my other articles

---

Tips ： The following is the main body of this article

1.【 Hang dependencies and function packs 】

（1） Check the problem method

 The terminal reported an error 

（2） The solution

（1） The corresponding open source feature pack is not installed

（1） Binary installation ：$sudo apt-get install ros-melodic-XXX【 Anti theft mark – Box King hzj】
（2）github Download source installation 

（2） Check whether there is any problem with the dependent version

 Such as eigen、pcl Version issue for 

（3） Modify source code , See if you use this library and dependencies

.
.

2.【 Hang system modules and components , Such as rviz、gazebo】

（1） Check the problem method

 The terminal reported an error 

（2） The solution

（1） Replace the implementation of other modules , Eliminate the causes of system crash caused by other modules , It is possible that other modules caused the module to crash

（2） Replace the implementation of this module , Eliminate the cause of system crash caused by this module 【 Anti theft mark – Box King hzj】

（3） Troubleshoot the workspace directory

 It is best to use a single workspace , Multiple （ Different names ） There may be a problem that the function pack cannot be found in the workspace 

（4） exclude launch File startup sequence problem

launch The starting sequence of the file content is not necessarily , The node is multi-threaded , There is no order , If there are requirements for starting sequence 

【 hang rviz Visualization problems 】

ROS Of rviz visualization marker Display errors may occur for the data type of 
RVIZ Hang up for no reason , Just start rviz Not good either. , Restart the computer to solve 

【 hang gazebo Simulation problems 】

 Open and close frequently gazrbo The simulation environment will report an error , because gazebo Open it again without completely exiting （ Junk computers are even more so ）

 terms of settlement 
$killall gzserver
$killall gaclient

Google is looking for ways
.
.

3.【 Hang the robot model 】

（1） Check the problem method

 The terminal reported an error 

（2） The solution

 Replace a robot model 

.
.

4.【 Hanging coordinate conversion 】

（1） Check the problem method

（1）tf_tree

 Check whether the coordinate relationship between modules is correct , Is there any disconnection between coordinates 【 General troubleshooting 】【 Anti theft mark – Box King hzj】
【rosrun rqt_tf_tree rqt_tf_tree】

tf Coordinate connection can be achieved through rosrun rqt_tf_tree rqt_tf_tree see , If the node is disconnected, it means tf There's a problem with the connection ,
 Go to the source code to see if there is any problem , Really can't, just launch The files are manually linked together with static link instructions （ Just a hidden bug）
. Static link instruction [x,y,z,r,p,y/x,y,z, Four yuan number  ：  Parent node coordinates 、 Child node coordinates ]

（2） The solution

（1） Source code modification

（2） If coordinate dynamic link error , Change source code , Change launch Static coordinate link , Manually static link coordinate relationship

5.【 Hanging node – Documents related to 】

（1） Check the problem method

（1）rgt_graph

 View the connections between nodes , Look at the logic of the whole program , Check the mistakes of the topic 、 Check whether the node is started 【 General troubleshooting 】
【rosrun rgt_graph rgt_graph】

 use rqt_graph When checking whether the node is running normally ,active It is a normal node , choice all,【 Anti theft mark – Box King hzj】
 If there is a node , But the node hangs , There will be “n_” At the beginning 

（2）rosnode info / The node name

 Check the detailed parameters of the corresponding topic 

（3）rosnode list

.
.

（2） The solution

（1） have a look launch Has it started up

（2） have a look cmakelist、package.xml Is there a mistake

（3） See if it's true vscode I forgot to save the modification , Or not catkin_make

（4） See if it's true tf Hang up ,tf If you hang up , Many nodes have problems 【 Anti theft mark – Box King hzj】

（5） See if there is a problem with the program call or running logic

remind
When initializing a node during programming, write a ROS_INFO(XXX_start)

.
.

6.【 Hang up the topic 】

（1） Check the problem method

Use rostopic help To get more help

（1）rostopic list +rostopic echo / Topic name

 Check the specific data released by the topic 【 Topic investigation 】

（2） rostopic pub

【 For debugging 】 Publish data to a topic 

.

（2） The solution

（1） Check whether the topic names of source code publishing and subscribing are consistent 【 There may be a mistake , May not be , But it affects the result 】【 Anti theft mark – Box King hzj】

（2） The logical reason why the node hangs （csv Incorrect format leads to illegal parameters 、 Variable not loaded not found 、gazebo Simulation problems 、 Accidental error report ）

.
.
.

7.【 Type of topic message 】

（1） Check the problem method

（1）rosmsg show xxx($rosmsg show …/…/…)

 Check the message type of the topic , And details 
 see ros Data type of （ Self defined msgs And officially defined msgs） It's best to use instructions to check 【 Anti theft mark – Box King hzj】

（2） The solution

 Look at the source code, publish and subscribe 
ROS Notice the refactoring of message types , Compare message types. Note that the types are consistent , When comparing multiple nested data types, pay attention to whether the timestamp is consistent 

$rosmsg show .../.../...

8.【 Hang the source code to realize the logic 】

（1） Check the problem method

 See the source code syntax and principle by yourself 
 There's no problem compiling , It doesn't mean that the logical effect is ok 【 Test after compilation 】

【 Anti theft mark – Box King hzj】

（2） The solution

（1） backtracking ： Review what you changed that led to the error report , Start looking for errors from the nearest place 【 version management 】（ Learn the method of version management , Local ,gitlab?）

（2） Debugging while writing code ： Write a small function module and compile / To run a , Step by step , Just programming without debugging will overturn your work debug 了 【 Anti theft mark – Box King hzj】

（3） Print log Value looks for problems according to logic ： Print the variable value of debugging at the terminal , When considering whether the program has entered the place you want him to enter , Put a info Information output printing

.
.

9.【debug– Dynamic tuning 】

（1） Check the problem method

（1）Rosrun rqt_configure rqt_configure【 Anti theft mark – Box King hzj】

 Dynamically set parameters for parameter adjustment 

（2）rosrun rqt_steering rqt_steering

 Dynamic setting of the chassis vel_cmd Command parameters are adjusted 

.
.

10.【 Check the operation of nodes 】

adopt rqt_graph View the connections between nodes
adopt topic echo /topic Check the content of the corresponding topic
adopt topic info /topic Check the detailed parameters of the corresponding topic
Use rostopic pub Publish data to a topic 【 Anti theft mark – Box King hzj】
Use rostopic help To get more help
Use rostopic type /topic Check the message type of the corresponding topic
Use rosmsg View the detailed data of the message
Use rosmsg show View the details of the specified message

summary

A mistake itself may not be itself , endeavour , Check Google more , Report mistakes and don't dream about it yourself