Driver to decode laser data from a QUANERGY M8 laser scanner, a very small and quiet, cost-effective sensor ideal for applications with constrained form-factors and pricing demands.
- Small / Compact
- 8 laser beams vertical field
- 360° horizontal field of view
- 5 - 20 Hz Spin rate
- 420K points/second
- 150 meter range
- Accurate NMEA/PPS timing
- Laser class 1 (Eye-safe)
Laser stands for L ight A mplification by S timulated E mission of R adiation.
|Driver||QUANERGY M8||Interface Type||Freebase/TCP/IP||Driver Class Type||Freebase|
|UTC Driver||Yes||Input / Output||Input||Executable||DrvLaser.exe QUANERGY_M8|
- All communication to and from the laser unit goes via a LAN network which is accessible through the black 3 foot sensor interface cable.
- The RJ45 connector of the Ethernet sub-cable should go to a dedicated network card of the Qinsy computer.
- The two other sub-cables are used for power and GNSS/Time Synchronization timing.
- Data is broadcast with TCP Ethernet packets using port 4141 of the LAN network.
- It is advisable to use a fast network card (preferably 1 Gigabit), due to real-time scanning and the huge amount of data.
- The scanner must be configured with a static IP address, the use of a dynamic IP assignment is not supported.
- Notice that a Quanergy Processing Unit (QPU™) is not supported and therefore not needed.
The exact LAN IP address of the laser unit should be provided by the manufacturer or your re-seller, or it should be stated in the documentation that comes with your scanner. QUANERGY configures their laser units with IP address 192.168.1.3.
The LAN IP address of your computer's network should be in the same range, except for the last digit. This must be any number 4-254 that does not conflict. In the example below the value 124 is used. The subnet mask must be 255.255.255.0, the default gateway 192.168.1.1.
- Windows 7 / Windows 8:
Control Panel, Network and Sharing Center, Change adapter settings, Click right-mouse on Local Area Connection, Properties, Internet Protocol Version 4 (TCP/IPv4), Properties...
- Windows 10:
Click right-mouse on Start menu, Control Panel, Network and Internet, Network and Sharing Center, Change adapter settings, Click right-mouse on Local Area Connection, Properties, Internet Protocol Version 4 (TCP/IPv4), Properties...
It is recommended to check the network connection between your computer and the laser unit before commencing any scan operation. You may do this by using the ping command from the Windows Command Prompt:
Select Start from the Windows task bar, Run..., Cmd <Enter>, and 'ping' the IP address of your laser unit.
The network connection is okay when you receive a reply three times within a few milliseconds.
Web GUI Control
You should use a standard web browser in order to set some initial settings.
Most important setting is the desired spin rate of the scanner (Frame Rate in Hz) and the used baud rate of the NMEA time message from the external GNSS receiver.
When you enter the IP address of the scanner in the address bar of the browser (most likely http://192.168.1.3:7780), the following page should appear:
In order to change the settings you need to login first, most likely with Username: editor and Password: qeditor.
Press Submit after you have made changes.
The web page will be redirected automatically to another page where you may edit the M8 Network settings, e.g. the IP address.
Cancel this page if no network settings were changed.
For all details about the use of NMEA/PPS Signals please consult the official M8 Sensor User guide.
- In general: the M8 is expecting next to a PPS signal an NMEA $GPRMC or $GPZDA message, of which interfacing should go via the black sub-cable.
- It is recommend to send only one of these two NMEA messages to the unit and if possible, use a high baud rate, e.g. 115200.
- The talker ID is important: the M8 will only recognize the message if it starts with '$GP'
For example, if your NMEA message is coming from an Applanix GNSS device (e.g. APX-15), make sure to enable the option 'Report legacy talker id'.
- Unfortunately there is no feedback from an M8 scanner whether NMEA/PPS is accepted or not: there are no led lights on the scanner, nor specific error messages will be generated or logged.
The only way to verify whether timing is okay (or not) is by going online with Qinsy and using a Generic Display: please see the explanation in the Online - Displays tab panel for further instructions.
Internally the driver is treated as a multibeam system, creating multibeam 'xyz' observations, therefore you will find the laser system drivers under category type Multibeam Echosounders.
('multibeam' versus 'laser scanning'-terminology: ping = scan, footprint = pixel = pulse = return, swath = line)
1. Edit System Wizard
Add a Multibeam Echosounder system to your template setup and select from the list driver "Laser Scanning - QUANERGY M8".
- The Port number should be 4141. The driver will receive all laser firing data packages via this unique port number.
- It is important to enter the correct IP Address of the laser scanner. This default static IP address is 192.168.1.3.
- Leave the Maximum update rate at zero
2. Multibeam Echosounder Parameters
Important are the Transducer Location (Node) and Mounting Angles (offsets) on the second wizard page.
- The exact values for the roll, pitch and heading offsets should be established with a calibration procedure.
In the online setup it is important to select the correct Scanner Mounting. In that case you can leave the Roll, Pitch and Heading offsets around zero and therefore values like +270, or -90 are not needed anymore.
- Leave the Max. beams per ping value at 9999.
The actual number of beams will be variable, and depends for example on the used on-line settings and on the targets being scanned.
Examples Mobile Scanning Setup
In the first image the unit is mounted underneath a UAV, backward tilted at 90 degrees with the cable pointing upward. Make sure to select in the online setup for the Scanner Mounting setting "Backward Tilted, Cable Up".
In the second image the unit is mounted on top of a car roof, with the cable pointing backward, away from the driving direction. Make sure to select in the online setup for the Scanner Mounting setting "Normal, Cable Backward".
So when using the correct Scanner Mounting, the default alignment offsets should be around 0° (Roll, Pitch and Heading).
3. Echosounder Accuracy Parameters
- You may leave all values on the third wizard page at their defaults.
4. Multibeam Echosounder Corrections
- You may leave all values on the last wizard page at their defaults.
This very first time Windows may pop up a security message:
Just enable all check-boxes!
If you forgot to do this, or if you are not sure if this has been done, you may want to follow the steps as described in the Additional Info or Trouble Shooting section about Windows firewall.
Hardly any other control is needed for this type of laser scanner. Once you make a connection, it starts rotating, scanning and broadcasting the data automatically.
In order to set the desired spin rate you should use the Web GUI. For some additional other control settings you can use the Qinsy Controller:
Select Echosounder Settings, click on the Laser System icon, and select the 'Control' tab page.
In order to communicate with the scanner, the driver must make a network connection first. This attempt to connect will always be done automatically when going online.
Further notice that the driver will automatically disconnect when going offline, so there is no need to do that manually, although you may do so.
This is a very important setting and it informs the driver how the scanner is physically mounted on the vehicle, with respect to its heading.
More mounting scenarios are predefined and may be selected.
Set to 1 to accept all scans. In this case the horizontal angle between two consecutive scans will be 0.07°, when scanning at 10 Hz spin rate.
To use every n-th scan only, set the interval greater than 1.
Notice that excluded data due to this setting will not be recorded!
|Vertical Area Selection||
Physical scan area comprises 8 laser beams and yields vertical 21 degrees (in case the scanner is mounted normally on a horizontal surface)
For example, laser 1 is looking downwards with an angle of -18°, laser 7 (the nadir) is looking forward (0°) and laser 8 is looking a bit upwards with an angle of +3°
Excluded data due to this setting will not be recorded!
|Horizontal Area Selection||
A full circle scan goes from 0 to 360 degrees, counter clockwise, with an angle step that depends on the current spin rate.
0 degrees means forward, 90 degrees means right (starboard side), 180 degrees looking backward, which is the cable direction, 270 means left (port side).
The Horizontal Area selection will be corrected for the selected Scanner Mounting. I.e. that when you have selected the correct scanner mounting, then Starboard will be starboard, Port will be port, etc.
Excluded data d/t this setting will not be recorded!
Set the minimum required range in meters. Valid values: 1 to 200 meters.
Using this setting is recommended, but be careful: Blocked data due to this setting (i.e. all returns less or equal than this range) will not be recorded!
Set the maximum allowed range in meters. Valid values: 1 to 200 meters.
Using this setting is recommended, but be careful: Blocked data due to this setting (i.e. all returns more than this range) will not be recorded!
Set the minimum required intensity (signal strength). Valid values: 0 to 255.
The default minimum intensity is 1, which under normal circumstances only affects the blocking of unwanted 'ghost' returns.
Notice that blocked data due to this setting (i.e. all returns less than this intensity) will not be recorded!
Set the maximum allowed intensity (signal strength). Valid values: 0 to 255.
Notice that blocked data due to this setting (i.e. all returns more than this intensity) will not be recorded!
|Multiple Return Measurement||
One emitted laser pulse may hit one or several targets, causing one, two or three echo pulses.
Select the type of echo pulse you want to decode:
Notice that excluded data d/t this setting will not be recorded!
|Store Laser Location||
If enabled, an additional pixel with zero range will be added to each ping, in order to indicate the exact laser scanner location in the resulting point cloud.
This extra pixel will always have beam number 1, its intensity value will be 255 and its quality value will be zero.
This setting is highly recommended, in order to use exact time stamping of the laser data.
When enabled, the laser unit must receive a valid PPS/Time Synchronization pulse from an external GNSS receiver and NMEA time-tag message.
The Status Flag value will be masked with the value 2 when external timing is okay.
Notice that this option is disabled while connected, so change setting Connected first from Yes to No in order to change it.
When changing settings, the theoretically expected points/sec will be calculated, which should not exceed the recommended maximum points/sec.
The expected points/sec depends on the selected Scan Interval, the Vertical Area Selection, the Horizontal Area Selection and the Multiple Return Measurement.
Qinsy handles only approximately 250 thousand measurements per second. However, this value can be safely much higher but depends highly on the used hardware.
As an advanced user you may overrule this limitation of max 250 thousand points per sec: Disable the Validation Check in order to ignore the warning and continue.
|Capture Raw Data||
Enable this option if you want to store the raw binary data stream coming straight from the unit to a log file on disk.
The Generic Display can be used to validate the laser data integrity. It shows the numerical values for the number of beams (laser returns) being scanned per ping, the number of beams being scanned per second, the ping rate (scan rate in Hz), range values, etc.
Important value to monitor is the Ping Age , especially when setting 'Use PPS' is enabled. The Ping Age is the difference between the current computer time and the time of the last received data package. This value should be small, around zero!
Notice that when a GNSS/PPS is connected (using the sensor interface cable) there is no feedback whether the unit has accepted pulse and/or time-tag.
For example, if you see a very high Ping Age value (+ve or -ve), then this is a severe indication that the initial timing inside the laser unit is wrong.
The Beam Quality value contains the actual beam number (1 - 8), so it has nothing to do with any quality or intensity value.
The Status Flag value indicates whether PPS/Time Synchronization is used and accepted or not, and whether multiple returns are detected in the last received ping.
|Status Flag||Use PPS||Multiple Returns detected|
You may use the attached example Generic Display Layout file as an example: Copy this layout (Use 'Save Link As...') to your current Project's Settings\Display folder and open it using a new Generic Display. You only have to select the correct laser system as defined in your template setup (Select Edit, Layout…, go to RAW DATA, Multibeam Echosounder (2), and select your laser system for the parent item).
Raw Multibeam Display
Open View Properties and set the Backscatter Intensity range between 0 and 100 (or 255).
Enable Waterfall scrolling, and set both scroll values to 0 (zero) pixels.
If you want to see the intensity while online, open View Properties and set the Color Coding to Backscatter.
The M8 has the following features and limitations:
- The vertical angle resolution between each of the 8 lasers is about 3.0°.
- The horizontal angle resolution depends on the spin rate. The smallest angle is 0.035° at 5Hz, 0.07° at 10 Hz and 0.14° when spinning at 20Hz.
- Spin rate of the unit is 5 Hz, 10Hz (recommended) or 20 Hz max.
- Maximum deliverable of approximately 420 thousand measurements / second.
Each single laser fire may generate up to three unique returns, so theoretically the maximum number of points / second could be three times as much. Whether the driver will decode these multiple returns depends on the selected setting 'Multiple Return Measurement'.
- Maximum range 200 meters (although 150 is recommended).
- The decoded intensity will be a value between 0 and 255 and depends on the target's surface being hit.
'Ghost' returns will normally have a value of 0 or 1, but also real returns may have a low intensity value.
Newer shipped M8 units will support true calibrated intensity values. It means based on a logarithmic scale, compensated for distance and laser intensity. Please contact the manufacturer or your local dealer to check if your unit already supports this.
Due to the TCP broadcast characteristic of the M8 a ping (or full scan) does not contain all the beams from one full rotation. A ping in Qinsy will be filled with all laser firing data received from ten consecutive Ethernet packets. One packet contains 50 times data for all 8 lasers, so a Qinsy ping contains a maximum of 4000 beams. Notice that the beam quality value is 'mis-used' in order to store the real beam number (1 - 8). You may color-code on 'quality' in the Validator for an indication of which beams have been used.
It is important to prepare the project prior to the start of the scanning by optimizing all parameters to meet the necessary requirements:
Select the right Vertical and/or Horizontal Area selection and/or range blocking in order to decrease the number of expected points per second.
Due to the enormous amount of data to be expected while scanning and recording, it is recommended to keep the system overhead as low as possible.
Here you'll find some tips and tricks in order to fine-tune your setup.
However, these are not strict rules, because each project is different and depends on the current situation and hardware being used. Your goal should be to keep your system CPU usage as low as possible.
Make use of Solid State Drive (SSD), or fast SATA hard drive (7200 - 10000 rpm).
Your network card speed should never be lower than the scanner's network speed. Use a network card that can be configured for 100Mbit or 1Gbit speed. Do not use USB Networking Adapters, because this may result in loss of data when huge amounts of data are being broadcast.
Disable Virus Scanner, or at least the setting 'Scan Files when Writing/Reading to/from disk'.
Task Manager CPU
General Task Manager CPU Usage should be less than 50%. CPU load of each display must be less than 10-15%.
Make sure that the 'Working Set (Memory)' column for process Multibeamer.exe and/or DrvResultOut.exe is not constantly increasing, especially during recording.
Laser Device Settings
During project preparation, establish the optimum settings in order to achieve the required results.
The most benefit you will gain from setting the Scan Speed, Scan Rate, Scan Resolution, Angle Resolution, Vertical Area Selection, Scan Area Selection and Sector Reduction as well as possible.
Especially the Vertical or Scan Area Selection is very important. Make use of Mask schemes to define areas which you don't want to scan.
Raw Multibeam Display
Open only one Raw Multibeam Display.
Open only one Navigation Display.
|3D Point Cloud Display||
It is not recommended to use a 3D Point Cloud Display.
If you do so, make sure your hardware contains a high-spec video card.
Under Sensor settings set the Time window setting to a short period, e.g. 10 sec
- Sounding Grid
- Dynamic Surface
Storage to a Sounding Grid is not recommended, and should be purely for display purposes: e.g. for checking the scan coverage or for showing the 95% Confidence Level statistics.
If you do want to see the scan coverage then it is advisable to store to a sounding grid and not to the dynamic surface
Do not use a small cell-size, preferably not less than 1.0 meter.
If you notice in the Navigation Display that the real-time sounding grid is drawn/updated with a delay, then please increase the cell-size or disable the storage completely.
Offline (Replay) there are no limitations and you may use small cell-sizes, e.g. 0.10 meter.
In Replay there are no limitations as mentioned above: use as many displays as you like, store to sounding grids with small cell-sizes, update the dynamic surface, etc.
All this may only affect the replay speed, but the data integrity of your final DTM processing files should be fine.
|Controller Computation Setup||
While working online, disabling the laser system in your Computation Setup will have the most effect on the performance
Footprints will not be geo-referenced, nor corrected for motion, heading or timing in real-time. This will save a tremendous amount of CPU power and memory usage.
This tip allows you to get the most out of your scanner: maximum scanning speed and maximum scanning rate, without the risk of losing scans due to performance issues.
To create a final DTM and/or Sounding Grid file you need to Replay the recorded databases afterwards.
Real-time Performance Monitoring
Daily Laser Log File
All user actions, system information and reported errors are logged in a daily laser log file which can be found in the current project's LogFiles subfolder.
The filename convention for this ASCII log-file is <System Name> DD-MM-YYYY.log, so every day there will be a new one.
Note that all time stamps in this log file are by default in UTC. An advanced user may change this to local time zone (LTZ) by changing the registry key:
HKEY_CURRENT_USER\Software\QPS\QINSy\8.0\Drivers\DrvLaser\Settings\TimeLogFileUtc value from 1 to 0.