YDLIDAR X4 User manual

Shenzhen EAI Technology Co.,Ltd.
DOC#:01.13.000002
www.ydlidar.com
X4
USER MANUAL

Copyright 2017 EAI All Rights Reserved
CONTENTS
1YDLIDAR X4 LIDAR DEVELOPMENT KIT ............................................1
1.1 Development Kit ........................................................................................ 1
2USAGE UNDER WINDOWS .....................................................................1
2.1 Device Connection .................................................................................... 1
2.2 Driver Installation ...................................................................................... 2
2.3 Evaluation Software Usage...................................................................... 4
2.3.1 Start Scanning......................................................................................................... 5
2.3.2 Data Storage............................................................................................................ 5
2.3.3 Display Mean and Standard Deviation............................................................... 6
2.3.4 Play and Record ...................................................................................................... 6
2.3.5 Debug ....................................................................................................................... 7
2.3.6 Filter .......................................................................................................................... 8
3LINUX ROS OPERATION .........................................................................8
3.1 Device Connection .................................................................................... 8
3.2 Compile and Install YDlidar-SDK............................................................ 8
3.3 ROS Driver Installation.............................................................................. 9
3.4 Run the ydlidar_ros_driver ....................................................................10
3.5 RVIZ View Scan Results ..........................................................................10
3.6 Modify Scan Angle...................................................................................10
4CAUTION................................................................................................. 11
4.1 Ambient Temperature ............................................................................11
4.2 Ambient Lighting.....................................................................................12
4.3 Power Supply............................................................................................12
5REVISE..................................................................................................... 13

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1YDLIDAR X4 LIDAR DEVELOPMENT KIT
The development kit of YDLIDAR X4 lidar (hereinafter referred to as X4) is an accessory tool
provided for performance evaluation and early rapid development of the X4. Through the X4
development kit, and with the evaluation software, users can observe point cloud data scanned by X4
on your environment or development on the SDK.
1.1 Development Kit
The X4 development kit has the following components：
FIG 1 YDLIDAR X4 DEVELOPMENT KIT
CHART 1 YDLIDAR TG SERIES LIDAR DEVELOPMENT KIT DESCRIPTION
Item
Qty.
Description
X4 Lidar
1
Standard version of the X4 Lidar. The X4 has an integrated motor drive for
despin control and motor control.
USB Type-C
Cable
1
Use with USB adapter board to connect X4 and PC. USB cable is both a
power supply cable and a data cable.
USB Adapter
Board
1
Realize the function of USB to UART, which is convenient for the fast
interconnection between X4 and PC. Serial port DTR signal to control X4
motor despin control. In addition, a Micro USB power interface (PWR) for
auxiliary power supply is provided.
Note: USB Adapter board has two USB TYPE C interface：USB_DATA、USB_PWR.
USB_DATA: Data powered interface. In most cases, this interface can be used to meet power and
communication requirements.
USB_PWR: Auxiliary power supply interface. The USB interface of some development platforms has weak
current drive capability. At this time, auxiliary power supply can be used.
2USAGE UNDER WINDOWS
2.1 Device Connection
When evaluating and developing X4 under windows, X4 and PC needed to connected. The
specific process is as follows:
X4 Lidar
USB Type-C Cable
USB Adapter Board

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FIG 2 YDLIDAR X4 DEVICE CONNECTION STEP 1
FIG 3 YDLIDAR X4 DEVICE CONNECTION STEP 2
Connect the adapter board with X4 first, then connect the USB cable to the USB port of the
adapter board and the PC. Note that the Type-C interface of the USB cable is connected to the
USB_DATA of the USB adapter board.
The drive current of USB interface of some development platforms or PC is not sufficient. X4
need to be connected to the auxiliary power supply of +5V, otherwise the lidar will be abnormal.
FIG 4 YDLIDAR X4 AUXILIARY POWER SUPPLY
2.2 Driver Installation
To evaluate and develop the X4 under Windows, the serial port driver of the USB adapter board
needed to be installed. The USB adapter board of this kit adopts CP2102 chip to realize serial port
Development
Platform
5V Power
Supply

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(UART) to USB signal conversion. Its driver can be downloaded from our official website or
downloaded from the official website of Silicon Labs.
https://www.ydlidar.com/dowfile.html?id=97
http://cn.silabs.com/products/development-tools/software/usb-to-uart-bridge-vcp-drivers
After decompressing the driver package, run the CP2102's Windows driver installation file (exe
file under CP210x_VCP_Windows). Please select the 32-bit version (x86) or 64-bit version (x64)
installation program according to the version of the windows operating system.
FIG 5 YDLIDAR X4 DRIVER VERSION SELECTION
Double-click the exe file and follow the prompts to install it.
FIG 6 YDLIDAR X4 DRIVER INSTALLING
After the installation is complete, right-click on [My Computer] and select [Properties]. On the
open [System] screen, select [Device Manager] from the left menu to access the [Device Manager].

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Expand [Port] to see the serial port name corresponding to the identified USB adapter, that is,
the driver installation is successful. The following figure shows COM3. (Note that the port must be
checked in case of X4 and PC interconnection).
FIG 7 YDLIDAR X4 DRIVER INSTALLATION CHECK
2.3 Evaluation Software Usage
YDLIDAR provides Point Cloud Viewer, a point cloud data visualization software LidarViewer
for X4 real-time scanning. Users can intuitively observe the X4 scanning effect chart. GDL real- time
point cloud data and real-time scanning frequency are provided on YDLIDAR. At the same time,
users can save the scanned data offline to an external file for further analysis. Visualization software
download link: https://www.ydlidar.com/Public/upload/download/TOOL.zip
Before using the YDLIDAR software, make sure that the X4 USB adapter board serial port
driver is installed successfully, and interconnect the X4 with the USB port of the PC. Run the
evaluation software: LidarViewer.exe, select the corresponding serial port number and model
number. Meanwhile, users could choose language on the top right corner.
FIG 8 YDLIDAR X4 EVALUATION SOFTWARE
If the connection is correct, it will show the following screen：

Copyright 2017 EAI All Rights Reserved 5 / 13
FIG 9 POINTCLOUD VIEWER INTERFACE
2.3.1 Start Scanning
Click to start scanning and display the environment point cloud, the upper left corner
displays the angle & distance information of the red line position (unit: mm). Click to stop it. as
shown below:
FIG 10 LIDAR SCANNING POINT CLOUD DISPLAY
2.3.2 Data Storage
During lidar scanning, click [File] in the main menu, select [Export to Excel], and save point
cloud data according to the prompts. Then the system will save the point cloud information scanned
in a circle in Excel format.

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FIG 11 SAVE DATA
2.3.3 Display Mean and Standard Deviation
Click [Tools] in the main menu, then select [Mean And STD] - [View].
FIG 12 YDLIDAR G4 DISPLAY MEAN AND STANDARD DEVIATION
Choose one according to needs, move the mouse to the test position, right-click the pop-up
menu, and select [Lock Mouse Tracking].
FIG 13 LOCK MOUSE TRACKING
2.3.4 Play and Record
Click [Tools] in the main menu, then select [Record and Play].

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FIG 14 RECORD AND PLAY
The main window is displayed as follows:
To record lidar data, click to start recording, and click to stop recording.
In non-scanning mode, click to start play.
The play process is as follows:
FIG 15 PLAY PROCESS
2.3.5 Debug
Click [Tools] in the main menu, and then select [DebugON] to output the raw lidar data to the
"viewer_log.txt" and "viewer_log_err.txt" files.
FIG 16 START DEBUGGING

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2.3.6 Filter
Click [Tools] in the main menu, and then select [Filter] to add lidar data filtering algorithm.
FIG 17 FILTER SETTING
Note: For more functions of LidarViewer, please click [Help], select [More Information], and learn more about
how to use it.
3LINUX ROS OPERATION
There are many Linux versions，this article only uses Ubuntu 18.04, Melodic version ROS as
an example.
SDK driver address：
https://github.com/YDLIDAR/YDLidar-SDK
ROS driver address：
https://github.com/YDLIDAR/ydlidar_ros_driver
3.1 Device Connection
Under Linux, the X4 and PC interconnect processes are consistent with those under Windows.
See Device Connection under Window.
3.2 Compile and Install YDlidar-SDK
YDLIDAR_ROS_DRIVER depends on the YDLIDAR-SDK library. If never installed the
YDlidar-SDK library before, or it has expired, it is necessary to install the YDlidar-SDK library. If
the system has installed the latest version of ydlidar-SDK, please skip this step, then go to the next
step.

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3.3 ROS Driver Installation
1) Cloning GitHub's YDlidar ROS Driver Package:
2) Build the Ydlidar_ROS_Driver software package:
3) Package environment Settings:
Note: Add permanent workspace environment variables. It will be very convenient if ROS
environment variables are automatically added to the bash session every time when start a new shell:
4) Verify that the package path is set, echo the ROS_PACKAGE_PATH variable.
It can be seen something like this: /home/tony/ydlidar_ws/src:/opt/ros/melodic/share
5) Create Serial Port Alias [Optional]
Note: After completing the previous operation, re-insert the LIDAR again.
$ git clone https://github.com/YDLIDAR/YDLidar-SDK.git
$ cd YDLidar-SDK/build
$ cmake ..
$ make
$ sudo make install
$ git clone https://github.com/YDLIDAR/ydlidar_ros_driver.git
ydlidar_ws/src/ydlidar_ros_driver
$ cd ydlidar_ws
$ catkin_make
$ source ./devel/setup.sh
$ echo "source ~/ydlidar_ws/devel/setup.bash" >> ~/.bashrc
$ source ~/.bashrc
$ echo $ROS_PACKAGE_PATH
$ chmod 0777 src/ydlidar_ros_driver/startup/*
$ sudo sh src/ydlidar_ros_driver/startup/initenv.sh

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3.4 Run the ydlidar_ros_driver
Run ydlidar_ros_driver with startup file, as shown below:
3.5 RVIZ View Scan Results
Run the launch file and open rviz to view the X4 scan results, as shown in the figure below:
Note: Take G4 as an example by default, if use other types of lidar, need to change lidar.launch in
lidar_view.launch file to the corresponding **.launch file. (If X4 lidar is used, it needs to be changed to
X4.launch)
FIG 18 YDLIDAR X4 RVIZ
3.6 Modify Scan Angle
The scanning data seen by running the launch file is displayed by default with 360- degree data.
To modify the display range, need to modify the configuration parameters in the launch file. The
specific operation is as follows:
1) Switch to the directory where the corresponding [launch file] is located, edit the file, and its
content is as shown in the figure:
$ roslaunch ydlidar_ros_driver X4.launch
$ roslaunch ydlidar_ros_driver lidar_view.launch

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FIG 19 X4.LAUNCH FILE
Note: For more information about the file contents, please refer to:
https://github.com/YDLIDAR/ydlidar_ros_driver#configure-ydlidar_ros_driver-internal-parameter
2) The X4 lidar coordinates follow the right-hand rule within ROS, with an angle range of [-180,
180]. "angle_min" is the start angle, and "angle_max" is the endangle. The specific scope needs
to be modified according to actual use.
FIG 20 YDLIDAR X4 COORDINATES DEFINITION
4CAUTION
4.1 Ambient Temperature
When the working environment temperature of X4 is over high or over low, it will affect the
accuracy of the distance measuring system. It may also damage the structure of the scanning system
$ vim X4.launch

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and reduce the service life of the X4 lidar. Avoid using in high temperature (>50 degrees Celsius)
and low temperature (<0 degrees Celsius) conditions.
4.2 Ambient Lighting
The ideal working environment of X4 is indoor, and the indoor environment light (including no
light) will not affect the work of X4. However, please avoid using strong light sources (such as high-
power lasers) to directly illuminate the X4 vision system.
If the user need to use it outdoors, please avoid the X4's vision system directly facing the sun,
which may cause permanent damage to the vision system's photosensitive chip, which will invalidate
the range finding.
The X4 standard version will cause interference in the distance measurement under the
conditions of strong sunlight reflection outdoors, please pay attention to it.
4.3 Power Supply
During the development process, since the drive current of the USB interface of each platform
or the USB interface of the computer may be too low to drive the X4, the external power supply of
the +5V to the X4 needs to be provided through the USB_PWR interface of the USB interface board.
It is not recommended for use mobile phone power bank because the voltage ripple of power bank is
too large.

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5REVISE
Date
Version
Content
2017-12-05
1.0
Composing a first draft
2018-01-22
1.1
Added auxiliary power connection method, document description,
configuration description, and power supply requirements
2018-04-03
1.2
Adapt to PointCloudViewer2.0 client
2021-08-02
1.3
Adapt LidarViewer client, update SDK, ROS tutorial