Hesai Pandar128 User manual

Pandar128
128-Channel
Mechanical LiDAR
User Manual
HESAI Wechat
www.hesaitech.com
128-en-2001A3

Contents
1 Introduction........................................................................................................4
1.1 Operating Principle
..............................................................................................
4
1.2 LiDAR Structure
.....................................................................................................
5
1.3 Channel Distribution
...........................................................................................
6
1.4 Specifications
.........................................................................................................
7
2 Setup....................................................................................................................8
3 Data Structure................................................................................................. 18
3.1 Point Cloud Data Packet....................................................................... 19
3.2 GPS Data Packet...................................................................................... 24
4 Web Control.....................................................................................................30
4.1 Home..........................................................................................................31
4.2 Settings
..................................................................................................................
32
4.3 High Resolution
..................................................................................................
36
4.4 Operation Statistics
...........................................................................................
37
4.5 Monitor
..................................................................................................................
38
4.6 Upgrade.....................................................................................................39
5 PandarView......................................................................................................40
5.1 Installation
............................................................................................................
40
5.2 Use
...........................................................................................................................
41
5.3 Features
.................................................................................................................
43
6 Communication Protocol............................................................................. 47
6.1 Packet Structure
.................................................................................................
47
6.2 Frequently Used Commands............................................................... 48
7 Sensor Maintenance......................................................................................56
8 Troubleshooting............................................................................................. 57
Appendix I Channel Distribution................................................................... 59
Appendix II Absolute Time and Laser Firing Time.................................... 68
II.1 Absolute Time of Point Cloud Data Packets.................................... 68
II.2 Start Time of Each Block....................................................................... 69
II.3 Laser Firing Time ofEach Channel
..............................................................
70
Appendix III PTP Protocol............................................................................... 86
Appendix IV Certification Info......................................................................... 88
Appendix V Support and Contact..................................................................89

Safety Notice
PLEASE READ AND FOLLOW ALL INSTRUCTIONS CAREFULLY AND CONSULT ALL RELEVANT NATIONAL AND INTERNATIONAL SAFETY REGULATIONS
FOR YOUR APPLICATION.
◼ Caution
To avoid violating the warranty and to minimize the chances of getting electrically shocked, please do not disassemble the device. The device must not be
tampered with and must not be changed in any way. There are no user-serviceable parts inside the device. For repairs and maintenance inquiries, please
contact an authorized Hesai Technology service provider.
◼ Laser Safety Notice – Laser Class 1
This device satisfies the requirements of
▪ IEC 60825-1:2014
▪
21 CFR 1040.10 and 1040.11 except for deviations (IEC 60825-1 Ed.3) pursuant to Laser Notice No.56, dated May 8, 2019
NEVER LOOK INTO THE TRANSMITTING LASER THROUGH A MAGNIFYING DEVICE (MICROSCOPE, EYE LOUPE, MAGNIFYING GLASS, ETC.)
1

2
◼ Safety Precautions
In all circumstances, if you suspect that the device malfunctions or is damaged, stop using it immediately to avoid potential hazards and injuries. Contact an
authorized Hesai Technology service provider for more information on device disposal.
Handling
This device contains metal, glass, plastic, as well as sensitive electronic components. Improper handling such as dropping, burning, piercing, and squeezing
may cause damage to the device.
In case of dropping the device, STOP using the device immediately and contact Hesai technical support.
Enclosure
This device contains high-speed rotating parts. To avoid potential injuries, DO NOT operate the device if the enclosure is loose or damaged.
To ensure optimal performance, do not touch the device’s enclosure with bare hands. If the enclosure is already stained, please refer to the Sensor
Maintenance chapter in user manuals for the cleaning method.
Eye Safety
Although the device meets Class 1 eye safety standards, DO NOT look into the transmitting laser through a magnifying device (microscope, eye loupe,
magnifying glass, etc.).
For maximum self-protection, avoid looking directly at the device when it is in operation.
Repair
DO NOT open and repair the device without direct guidance from Hesai Technology. Disassembling the device may cause degraded performance, failure in
water resistance, or potential injuries to the operator.
Power Supply
Use only the cables and power adapters provided by Hesai Technology. Only the power adapters that meet the device’s power requirements and
applicable safety standards can be used. Using damaged cables, adapters or supplying power in a humid environment can result in fire, electric shock,
personal injuries, product damage, or property loss.

3
Prolonged Exposure to Hot Surface
Prolonged exposuretothedevice’shotsurfacemay causediscomfort or injury. Ifthedevicehasbeen poweredandoperating foralong time, avoidskin
contact with the device and its power adapter.
Vibration
Strong vibration may cause damage to the deviceand should be avoided. If you need the mechanical vibration and shock limits of this product, please
contact Hesai technical support.
Radio Frequency Interference
Please observe the signs and notices on the device that prohibit or restrict the use of electronic devices. Although the device is designed, tested, and
manufacturedtocomply withtheregulations onRFradiation,theradiationfromthedevicemaystillinfluenceotherelectronicdevices.
Medical Device Interference
Some components in the device can emit electromagnetic fields, which may interfere with medical devices such as cochlear implants, heart pacemakers and
defibrillators. Consult your physician and medical device manufacturers for specific information regarding your medical device and whether you need to
keep asafedistance from thedevice. Ifyoususpectthatthe device isinterfering with your medical device, stop using the device immediately.
Explosive Atmosphere and Other Air Conditions
Do not use the device in any area where potentially explosive atmospheres are present, such as high concentrations of flammable chemicals, vapors or
particulates (including particles, dust, and metal powder) in the air. Exposing the device to high concentrations of industrial chemicals, including liquefied
gases that are easily vaporized (such as helium), can damage or weaken the device’s function. Please observe all the signs and instructions on the device.
Light Interference
Some precision optical instruments may be interfered by the laser light emitted from the device.

4
1 Introduction
This manual describes the specifications, installation, and data output format of Pandar128.
This manual is under constant revision. Please contact Hesai for the latest version.
1.1 Operating Principle
Distance Measurement: Time of Flight (ToF)
1) A laser diode emits a beam of ultrashort laser pulses onto the object.
2) Diffuse reflection of the laser occurs upon contact with the target object. The beams are detected by the optical sensor.
3) Distance to object can be accurately measured by calculating the time between emission and receipt by the sensor.
Figure 1.1 ToF Formula

5
1.2 LiDAR Structure
128 pairs of laser emitters and receivers are attached to a motor that rotates horizontally.
Figure 1.2 Partial Cross-Sectional Diagram
Figure 1.3 Coordinate System (Isometric View)
Figure 1.4 Rotation Direction (Top View)
The LiDAR’s coordinate system is shown above. The Z-axis is the axis of rotation.
The origin is shown as a red dot in Figure 1.6 on the next page. After geometric transforms, all the measurements are relative to the origin.
Each laser channel has an intrinsic horizontal angle offset. When Channel 42 passes the zero degree position (y-axis) illustrated in Figure 1.4, the azimuth
data in the corresponding UDP data block will be 0°.

6
1.3 Channel Distribution
The vertical resolution is
▪ 0.125° from Channel 26 to Channel 90
▪ 0.5° from Channel 2 to Channel 26, as well as from Channel 90 to Channel 127
▪
1° between Channel 1 and Channel 2, as well as between Channel 127 and Channel 128
▪ detailed in Appendix I
Figure 1.5 Channel Vertical Distribution
Figure 1.6 Laser Firing Position
Each channel has an intrinsic angle offset, both horizontally and vertically. The angle offsets are recorded in this LiDAR unit’s calibration file.
Users can obtain the calibration file by sending the TCP command PTC_COMMAND_GET_LIDAR_CALIBRATION, as described in Section 6.2.

7
Mechanical Rotation
Scanning Method
SENSOR
905 nm
Wavelength
MECHANICAL/ELECTRICAL/OPERATIONAL
PTP Clock Accuracy ≤1 μs
1.4 Specifications
Channel 128 Laser Class Class 1 Eye Safe
Range 0.3 to 200 m (at 10 reflectivity)
Ingress Protection IP6K9K
RangeAccuracy ±5 cm (0.3 to 1 m) Dimensions Height: 122.7 mm
±2 cm (1 to 200 m) Top/Bottom Diameter: 118.00 / 116.00 mm
FOV (Horizontal) 360° Operating Voltage DC 9 to 48 V
Resolution (Horizontal) Configurable on-the-fly
0.1°/0.2° (10Hz) 20 W (at 0.2° horizonalresolution)
0.2°/0.4° (20 Hz)
FOV (Vertical) 40° (-25° to +15°) Weight 1.63 kg
DATA I/O
0.5° (+2° to +14°, -6° to -24°) DataTransmission UDP/IP Ethernet (1000Mbps)
1° (+14° to +15°, -24° to -25°)
Frame Rate 10 Hz, 20 Hz Data Points Generated Single Return: 4,608,000 points/sec (max)
Dual Return Mode: 9,216,000 points/sec (max)
Dual Return (Strongest, Last)
Clock Source GPS / PTP
PTP Clock Drift ≤1 μs/s
NOTE Specifications are subject to change without notice.
NOTE The range and horizontal resolution of each channel is shown in Appendix I (Channel Distribution).
NOTE Range accuracy as the average range error across all channels may vary with range, temperature and target reflectivity.
FDA
CERTIFICATIONS
Returns Single Return
Data Outputs Distance, Azimuth Angle, Intensity
Resolution (Vertical) 0.125° (-6° to+2°)
Operating Temperature -40℃ to 85℃
Power Consumption 25 W (at 0.1° horizonal resolution)

8
Point Cloud Data Packet
854 bytes
GPS Data Packet
554 bytes
Ethernet Header
42 bytes
UDP Data
812 bytes
Ethernet Header
42 bytes
UDP Data
512 bytes
Pre-Header
6 bytes
Header
6 bytes
Body
772 bytes
Tail
24 bytes
Additional Info
4 bytes
LiDAR Data
2.
Set up
Please find operational manual
3. Data Structure
1000 Mbps Ethernet UDP/IP is used fordata output. The output data includes Point Cloud Data Packets andGPS Data Packets.
All the multi-byte values are unsigned and in little endian format.
Figure 3.1 Data Structure

9
2.1 Point Cloud Data Packet
2.1.1 Ethernet Header
Each LiDAR has a unique MAC address.
The source IP is 192.168.1.201 by default. The destination IP address is 0xFF FF FF FF and in broadcast form.
Point Cloud Ethernet Header: 42 bytes
Field
Bytes
Description
Ethernet II MAC
12
Destination: broadcast (0xFF: 0xFF: 0xFF: 0xFF: 0xFF: 0xFF)
Source: (xx:xx:xx:xx:xx:xx)
Ethernet Data Packet Type
2
0x08, 0x00
Internet Protocol
20
Shown in the figure below
UDP Port Number
4
UDP source port (0x2710, representing 10000)
Destination port (0x0940, representing 2368)
UDP Length
2
0x0334, representing 820 bytes (8 bytes more than the size of the Point Cloud UDP Data)
UDP Checksum
2
-
Figure 3.2 Point Cloud Ethernet Header – Internet Protocol

10
3.2.2 UDP Data
◼ Pre-Header
Pre-Header: 6 bytes
Field
Bytes
Description
0xEE
1
SOP (start of packet)
0xFF
1
SOP (start of packet)
Protocol Version Major
1
Major version number of the protocol: to distinguish between product models
0x01 for Pandar128
Protocol Version Minor
1
Minorversionnumberoftheprotocol:for eachproductmodel,toindicatethecurrentprotocolversion
Currently 0x03 for Pandar128
Reserved
2
-
◼ Header
Header: 6 bytes
Field
Bytes
Description
Laser Num
1
0x80 (128 channels)
Block Num
1
0x02 (2 blocks per packet)
Echo Count
1
The type of return of the first block in this data packet
0x00 – in the Single Return mode
0x01 – last return in the Dual Return mode
0x02 – strongest return in the Dual Return mode
Dis Unit
1
0x04 (4 mm)
Echo Num
1
The number of returns (i.e. echoes) that each channel generates
0x01 – Single Return 0x02 – Dual Return
UDP Seq
1
Whether the packet includes a UDP sequence number field
0x00 – UDP sequence OFF (default) 0x01 – UDP sequenceON

11
◼ Body
Body: 772 bytes (2 blocks)
Block 1
Block 2
Azimuth 1
Azimuth 2
Channel 1
Channel 1
Channel 2
Channel 2
…
…
Channel 128
Channel 128
Under the Dual Return mode, the ranging data from each firing is stored in the two blocks of one packet:
▪ Block 1 is the last return, and Block 2 is the strongest return
▪
If the last and strongest returns coincide, the second strongest return will be placed in Block 2
▪
The Azimuth of Block1 and Block 2 is the same
Block size = Size of Azimuth + 128 * Size of Channel XX = 386 bytes
Each Block in the Body: 386 bytes
Field
Bytes
Description
Azimuth
2
Current reference angle of the rotor
Azimuth[15:0]: lower byte Azimuth_L[7:0], upper byte Azimuth_H[15:8].
Azimuth Angle (in degrees) = [Azimuth_H, Azimuth_L] / 100 = Azimuth / 100
Channel XX
3
2-byte Distance
Distance[15:0]: lower byte Distance_L[7:0], upper byte Distance_H[15:8]
Distance Value = [Distance_H, Distance_L] * 4 mm = Distance * 4 mm
Maximum Distance Value = (2 ^ 16 – 1) * 4 mm = 262.14 m
1-byte Reflectivity
Reflectivity, in percentage (0 to 255 )

12
◼ Tail
Tail: 24 bytes
Field
Bytes
Description
Reserved
6
-
High Temperature
Shutdown Flag
1
0x01 for high temperature; 0x00 for normal operation
▪ Whenhigh temperatureisdetected,the shutdown flag will be setto0x01, and the system will shut down after
60 s. The flag remains 0x01 during the 60 s and the shutdown period
▪ When the system is no longer in high temperature status, the shutdown flag will be reset to 0x00 and the
system will automatically return to normal operation
Reserved
3
-
Motor Speed
2
speed_2_bytes [15:0] = speed (RPM)
Timestamp
4
The “μs time” part of the absolute time of this data packet (defined in Appendix II.1)
Unit: μs
Range: 0 to 1000000 μs (1 s)
Return Mode
1
0x37 for Strongest Return mode, 0x38 for Last Return mode, and 0x39 for Dual Return mode
Factory Information
1
0x42 (or 0x43)
Date & Time
6
Date and time in decimal: year, month, date, hour, minute, second
◼ Additional Info
Additional Info: 4 bytes
Field
Bytes
Description
UDP Sequence
4
Sequence number of this UDP packet
1 to 0xFF FF FF FF in little endian format

13
3.1.3 Point Cloud Data Analysis
The analysis of point cloud UDP data consists of three steps.
◼ Analyze the vertical angle, horizontal angle, and distance of a datapoint
Take Pandar128’s Channel 5 in Block 2 as an example:
1) Vertical angle of Channel 5 is 12.165°, according to Appendix I Channel Distribution
NOTE The accurate vertical angle is recorded in this LiDAR’s unit’s calibration file
Users can obtain the calibration file by sending the TCP command PTC_COMMAND_GET_LIDAR_CALIBRATION, as described in Section 6.2
2) Horizontal angle = current reference angle of the rotor + horizontal angle offset
▪ Define clockwise in the top view as the horizontal angles’ positive direction
▪ Current reference angle of the rotor is the Azimuth field of Block 2
▪
Horizontal angle offset of Channel 5 is 1.093°, according to Appendix I Channel Distribution
NOTE The accurate horizontal angle is recorded in this LiDAR’s unit’s calibration file
3) Actual distance in real world millimeters = distance measurement * Distance Unit (4 mm)
Distance measurement is the Distance field of Channel 5 in Block 2
◼ Draw the data point in a polar or rectangular coordinate system
◼ Obtain the real-time point cloud data by analyzing and drawing every data point in a frame

14
2.2 GPS Data Packet
GPS Data Packets are triggered every second. All the multi-byte values are unsigned and in little endian format.
Before NMEA messages are available from the external GPS module
Each rising edge of the LiDAR’s internal 1 Hz signal triggers a GPS Data Packet.
The time and date in the GPS Data Packets are unreal, starting from 00 01 01 00 00 00 (year, month, day, hour, minute, second) and increasing with the
internal 1 Hz signal.
Once the LiDAR receives the PPS (pulse-per-second) signal and NMEA messages
The internal 1 Hz signal will be locked to the PPS. Each rising edge still triggers a GPS Data Packet.
Meanwhile, the LiDAR will extract the actual date and time from NMEA messages ($GPRMC or $GPGGA), and stamp them into both Point Cloud Data
Packets and GPS Data Packets.
▪ Point Cloud Data Packets: 6-byte Date & Time (year, month, day, hour, minute, second) in decimal
▪ GPS Data Packets: 6-byte Date (year, month, day) and 6-byte Time (second, minute, hour) in ASCII
The GPS module sends first the PPS signal and then the NMEA message. At the rising edge of the PPS pulse, the corresponding NMEA message is not yet
available. Therefore, the LiDAR extracts date and time from the previous NMEA message and automatically adds 1 full second.
When GPS signal is lost
The LiDAR will still trigger GPS Data Packets by the rising edge of the internal 1 Hz signal. However, the GPS time in the packets will be counted by the
internal 1 Hz signal and will drift from the actual GPS time.

15
2.2.1 Ethernet Header
The source IP is 192.168.1.201 by default. The destination IP address is 0xFF FF FF FF and in broadcast form.
GPS Ethernet Header: 42 bytes
Field
Bytes
Description
Ethernet II MAC
12
Destination: broadcast (0xFF: 0xFF: 0xFF: 0xFF: 0xFF: 0xFF)
Source: (xx:xx:xx:xx:xx:xx)
Ethernet Data Packet Type
2
0x08, 0x00
Internet Protocol
20
Shown in the figure below
UDP Port Number
4
UDP source port (0x2710, represents 10000)
Destination port (0x277E, represents 10110)
UDP Length
2
0x208,representing 520bytes(8bytesmorethan thesizeoftheGPSUDPData,showninFigure3.1)
UDP Checksum
2
-
Figure 3.3 GPS Ethernet Header – Internet Protocol

16
2.2.2 UDP Data
GPS UDP data: 512 bytes
Field
Bytes
Description
GPS time data
18
Header
2 bytes
0xFFEE, 0xFF first
Date
6 bytes
Year, month, and day (2 bytes each, lower byte first) in ASCII
Time
6 bytes
Second, minute, and hour (2 bytes each, lower byte first) in ASCII
μs Time
4 bytes
In units of μs (lower byte first)
GPRMC/GPGGA data
84
ASCII code, valid till 2 bytes after ‘*’
NMEA sentence that contains the date and time information
Users can select either GPRMC or GPGGA in the Settings page of web control, as shown in Section 4.2
reserved
404
404 bytes of 0xDF
GPS positioning status
1
ASCII code, obtained from $GPRMC or $GPGGA
When $GPRMC is selected: When $GPGGA is selected:
A (hex = 41) for Valid Position 0 = invalid
V (hex = 56) for Invalid Position 1 = GPS fix (SPS)
NUL (hex = 0) for GPS being unlocked 2 = DGPS fix
3 = PPS fix
6 = estimated (dead reckoning)
flag of PPSlock
1
1 – locked 0 – unlocked
reserved
4
-

17
◼GPRMC Data Format
$GPRMC, <01>, <02>, <03>, <04>, <05>, <06>, <07>, <08>, <09>, <10>, <11>, <12>*hh
Field #
Field
Description
<01>
UTC Time
Hour, minute, and second
Can be in hhmmss (hour, minute, second) format
<02>
Location Status
A (hex = 41) for Valid Position
V (hex = 56) for Invalid Position
NUL (hex = 0) for GPS being unlocked
…
<09>
UTC Date
Date information
Can be in ddmmyy (day, month, year) format
…
The LiDAR’s GPS data interface is compatible with a variety of GPRMC formats, as long as:
<01> is the hour, minute, and second information
<09> is the date information.
For example, the following two formats are both acceptable:
$GPRMC,072242,A,3027.3680,N,11423.6975,E,000.0,316.7,160617,004.1,W*67
$GPRMC,065829.00,A,3121.86377,N,12114.68322,E,0.027,,160617,,,A*74

18
◼GPGGA Data Format
$GPGGA, <01>, <02>, <03>, <04>, <05>, <06>, <07>, <08>, <09>, <10>, <11>, <12>*hh
Field #
Field
Description
<01>
UTC Time
Hour, minute, and second
Can be in hhmmss (hour, minute, second) format
…
<06>
GPS Fix Quality
0 = invalid
1 = GPS fix (SPS)
2 = DGPS fix
3 = PPS fix
6 = estimated (dead reckoning)
…
The LiDAR’s GPS data interface is compatible with a variety of GPGGA formats, as long as:
<01> is the hour, minute, and second information
For example, the following two formats are both acceptable:
$GPGGA,123519,4807.038,N,01131.000,E,1,08,0.9,545.4,M,46.9,M,,*47
$GPGGA,134658.00,5106.9792,N,11402.3003,W,2,09,1.0,1048.47,M,-6.27,M,08,AAAA*60