YDLIDAR G2 User manual

G2
USER MANUAL
Shenzhen EAI Technology Co.,Ltd.
DOC #:01.13.002502
www.ydlidar.com

Copyright 2015-2021 EAI
CONTENTS
1YDLIDAR G2 LIDAR DEVELOPMENT KIT..................................... 1
1.1 Development Kit ................................................................................. 1
2USAGE UNDER WINDOWS............................................................ 2
2.1 Device Connection .............................................................................2
2.2 Driver Installation ...............................................................................3
2.3 Evaluation Software Usage................................................................5
2.3.1 Start Scanning...................................................................................................6
2.3.2 Data Storage......................................................................................................7
2.3.3 Scan Frequency................................................................................................7
2.3.4 Display Mean and Standard Deviation............................................................7
2.3.5 Display Intensity Value.....................................................................................8
2.3.6 Play and Record................................................................................................9
2.3.7 Debug...............................................................................................................10
2.3.8 Filter.................................................................................................................10
3LINUX ROS OPERATION.............................................................. 11
3.1 Device Connection ........................................................................... 11
3.2 Compile and Install YDLidar-SDK.................................................... 11
3.3 ROS Driver Installation.....................................................................11
3.4 Run the ydlidar_ros_driver .............................................................. 12
3.5 RVIZ View Scan Results...................................................................12
3.6 Modify Scan Angle............................................................................13
4CAUTION....................................................................................... 14
4.1 Ambient Temperature.......................................................................14
4.2 Ambient Lighting .............................................................................. 14
4.3 Power Supply.................................................................................... 15
5REVISE.......................................................................................... 16

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1YDLIDAR G2 LIDAR DEVELOPMENT KIT
The development kit of YDLIDAR G2 lidar (hereinafter referred to as G2) is an
accessory tool provided for performance evaluation and early development of the G2.
Through the G2 development kit, and with the evaluation software, users can observe point
cloud data scanned by G2 on your environment or development on the SDK.
1.1 Development Kit
The G2 development kit has the following components：
FIG 1 YDLIDAR G2 DEVELOPMENT KIT
CHART 1 YDLIDAR G2 LIDAR DEVELOPMENT KIT DESCRIPTION
Item
Qty.
Description
G2 lidar
1
Standard version of the G2 Lidar, with internal integrated motor
drive, which can realize motor stall control and motor control
USB Type-C
Cable
1
Use with USB adapter board to connect G2 and PC. USB cable is
both a power supply cable and a data cable
USB Adapter
Board
1
USB to UART, convenient for G2 and PC to quickly interconnect.
Meanwhile, it supports serial port DTR signal to control G2 motor
rotation and stop. 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 power supply multiplexing 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.
G2 Lidar
USB Type-C Cable
USB Adapter Board

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2USAGE UNDER WINDOWS
2.1 Device Connection
When G2 is evaluated and developed under windows, G2 and PC need to be
interconnected. The specific process is as follows：
FIG 2 YDLIDAR G2 DEVICE CONNECTION STEP 1
FIG 3 YDLIDAR G2 DEVICE CONNECTION STEP 2
Connect the adapter board with G2 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 interface board, and the idle mode is used after
G2 is powered on. The motor does not rotate.
The drive current of the USB interface of some development platforms or PC is not
sufficient. G2 need to be connected to the auxiliary power supply of +5V, otherwise the lidar
will be abnormal.

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FIG 4 YDLIDAR G2 AUXILIARY POWER SUPPLY
2.2 Driver Installation
To evaluate and develop the G2 under Windows, you need to install the serial port
driver of the USB adapter board. The USB adapter board of this kit adopts CP2102 chip to
realize serial port (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 G2 DRIVER VERSION SELECTION
Double-click the exe file and follow the prompts to install it.
Development
Platform
5V Power
Supply

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FIG 6 YDLIDAR G2 DRIVER INSTALLING
After the installation is complete, you can 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].
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 G2 and PC interconnection).
FIG 7 YDLIDAR G2 DRIVER INSTALLATION CHECK

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2.3 Evaluation Software Usage
YDLIDAR provides G2 real-time scanning point cloud data visualization software
LidarViewer. Using this software, users can intuitively observe the scanning effect of G2.
YDLIDAR provides G2 real-time point cloud data and real-time scanning frequency. At the
same time, G2 version information can be read, and the scanned data can be saved offline
to an external file for further analysis.
Before using the YDLIDAR software, make sure that the G2 USB adapter board serial
port driver is installed successfully, and interconnect the G2 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 and software type on the top
right corner (top right corner).
FIG 8 YDLIDAR G2 EVALUATION SOFTWARE
If there is no G2 model, please refer to the following parameter to add G2 model:
FIG 9 YDLIDAR G2 PARAMETER CONFIGURATION

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If the connection is correct, you will see the following screen：
FIG 10 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 11 LIDAR SCANNING POINT CLOUD DISPLAY

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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.
FIG 12 SAVE DATA
2.3.3 Scan Frequency
is used to adjust the scanning frequency (motor speed) of the lidar. Click this control,
the system will pop up a frequency setting bar, which can be automatically adjusted
according to requirements. When the lidar is in the scan state, you need to click the scan
control again after adjusting the scan frequency. The speed can be adjusted by dragging
the control, the control of scanning frequency is shown in the figure below
FIG 13 SCAN FREQUENCY ADJUSTMENT
2.3.4 Display Mean and Standard Deviation
Click [Tools] in the main menu, then select [Mean And STD] - [View].
FIG 14 YDLIDAR G2 DISPLAY MEAN AND STANDARD DEVIATION
Choose one according to your needs, move the mouse to the test position, right-click
the pop-up menu, and select [Lock Mouse Tracking].

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FIG 15 LOCK MOUSE TRACKING
2.3.5 Display Intensity Value
Click [Data] in the main menu and select [Intensity histogram].
FIG 16 DISPLAY INTENSITY VALUE
The main window is displayed as follows, the intensity values of a total of 100 points on
the left and right of the mouse lock position.

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FIG 17 DISPLAY INTENSITY HISTOGRAM
2.3.6 Play and Record
Click [Tools] in the main menu, then select [Record and Play].
FIG 18 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:

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FIG 19 PLAY PROCESS
2.3.7 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 20 START DEBUGGING
2.3.8 Filter
Click [Tools] in the main menu, and then select [Filter] to add lidar data filtering
algorithm.
FIG 21 FILTER SETTING
Note: For more functions of LidarViewer, please click [Help], select [More Information], and learn more
about how to use it.

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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 G2 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 you have never installed
the YDLidar -SDK library, or it has expired, you must first install the YDLidar-SDK library. If
you have the latest version of YDLidar -SDK installed, please skip this step, then go to the
next step.
3.3 ROS Driver Installation
1) Cloning GitHub's ydlidar_ros_driver Package:
2) Build the ydlidar_ros_driver software package:
$ 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

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3) Package environment Settings:
Note: Add permanent workspace environment variables. It will be very convenient if
ROS environment variables are automatically added to your bash session every time you
start a new shell:
4) Verify that your package path is set, echo the ROS_PACKAGE_PATH variable.
5) You should see something like this: /home/tony/ydlidar_ws/src:/opt/ros/melodic/share
Create Serial Port Alias [Optional]
Note: After completing the previous operation, re-insert the LiDAR again.
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 G2 scan results, as shown in the figure
below:
Note: G4 lidar is taken as an example by default. If other types of lidars are used, lidar.launch in the
lidar_view.launch file needs to be changed to the corresponding **.launch file. (If G2 radar is
used, it needs to be changed to G2.launch)
$ 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
$ roslaunch ydlidar_ros_driver G2.launch
$ roslaunch ydlidar_ros_driver lidar_view.launch

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FIG 22 YDLIDAR G2 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, you 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:
FIG 23 G2.LAUNCH FILE
$ vim G2.launch

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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 G2 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 24 YDLIDAR G2 COORDINATES DEFINITION
4CAUTION
4.1 Ambient Temperature
When the working environment temperature of G2 is too high or too low, it will affect
the accuracy of the distance measuring system. It may also damage the structure of the
scanning system and reduce the life of the G2 lidar. Avoid use in high temperature (>50
degrees Celsius) and low temperature (<0 degrees Celsius) conditions.
4.2 Ambient Lighting
The ideal working environment of G2 is indoor, and the indoor environment light
(including no light) will not affect the work of G2. However, please avoid using strong light
sources (such as high-power lasers) to directly illuminate the G2's vision system.
If you need to use it outdoors, please avoid the G2'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 G2 standard version will cause interference in the distance measurement under
the conditions of outdoor strong sunlight reflection, please pay attention to it.

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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 G2, the external
power supply of the +5V to the G2 needs to be provided through the USB_PWR interface of
the USB interface board. It is not recommended to use mobile phone power bank because
the voltage ripple of power bank is too large.

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5REVISE
DATE
VERSION
CONTENT
2019-05-28
1.0
Composing a first draft
2020-01-15
1.1
Add auxiliary power connection method, document description,
configuration description, and power supply requirements
2020-06-09
1.2
Adapt to PointCloudViewer2.0 client
2021-08-02
1.3
Adapt LidarViewer client, update SDK and ROS tutorial