The Emesent Hovermap ST-X lidar is an excellent payload for creating detailed, accurate lidar point clouds.
Hovermap can interact with Astro as a passive payload, for mapping applications that can be flown with good GPS signal in open spaces with few obstacles.
Hovermap can also use the lidar data of the environment around Astro, and build a 3D model in real time. It can use that data for obstacle avoidance, and even allow Astro to autonomously explore GPS-denied areas like under bridges and inside tunnels and mines.
Similar to photogrammetry missions, you can plan a mission inside AMC and upload it to Astro. The process is very similar to planning a mission for the a7R IV Payload:
Hovermap ST-X specific notes:
Flying closer to the terrain or structure will yield better point cloud results. Based on our testing, we recommend staying within 50 meters of the terrain or structure.
If you do need to fly higher than 40m, slow down the mission speed so the lidar has more time to process and gather points from farther away. In our testing, we wouldn't recommend anything farther than 60m at or above 10 m/s from the subject for good results.
Set the camera type to 'Manual (No specs)' so that AMC will display the mission planning parameters in distances rather than GSD.
Download terrain data and enable Terrain Following on the Plan screen of AMC.
Instead of setting the mission path based on '% Overlap', set the distance of each track of the mission to be no more than 50 meters apart.
We recommend flying at around 7 m/s as a starting point for your Hovermap mission. You can increase the density of the point cloud generated by flying slower or lower.
If your survey area has lots of 3D geometry, check the 'refly at 90' option to get more points on vertical faces and overhangs.
Astro + Hovermap ST-X is limited to a maximum ambient temperature of +40C/+104F
When carrying the Hovermap ST-X, Astro is at the upper limit of its maximum takeoff weight. Be cautious when flying Astro in hot or high-altitude environments.
Astro will give warnings if the ESCs or motors start to overheat. Heed the warnings!
Astro and Hovermap ST-X can operate in light to medium rain. Be sure to insert the USB-C plug in the IO panel
Hovermap should boot up when Astro is powered on. Hovermap will connect to Astro once the lights turn from orange to a slow blue flash.
Do not plug or unplug the cable while Astro is powered on as this can damage the Hovermap and/or Astro.
Set up the Hovermap scanning via the Commander app.
Click Non-Autonoumous Mapping Mission.
Follow the prompts for pre-flight checks.
Name your mission and check there is enough free storage on Hovermap.
You may get a caution warning that Shield is disabled, this is normal
Start the scan and wait for Commander to complete the pre-flight check.
Once the scanner is running, switch back to AMC to execute the mission.
You can view a live preview of the point cloud generated by ST-X during the mission in the Commander app.
Stop the scan after landing via the Commander app.
For added situational awareness during the mission, you can view a live video from the aircraft using the Astro FPV Camera.
When using the FPV camera, AMC will try to take photos during the mapping mission. To turn this off:
Set the Start > Camera actions: Stop taking photos
Turn ON the option under Mission > Options 'Images in turnarounds'
If you power off Astro before stopping the scan, the data can be corrupted!
Check out Emesent's documentation for details on how to remove data and post-process for ST-X:
Hovermap ST-X enables assisted (AL1) and autonomous (AL2) flights for Astro in complex environments, allowing pilots to fly around obstacles, map close to objects, fly to difficult to reach places, and fly in GPS-denied in environments.
This wiki page is a high level overview of operating Hovermap on Astro. Please read Emesent's full documentation on how Hovermap works before conducting a flight in assisted or autonomous mode.
In particular, pilots should understand:
For assisted and autonomous missions, Astro parameters need to be updated to enable communication with Hovermap and to increase rate setpoint tracking on Astro. To set these parameters:
Update Astro to 1.5.18 firmware
Power on Astro and Hovermap. Wait for Hovermap to fully boot and connect over ethernet
Start an assisted/autonomous scan. The scan will begin but Hovermap will give an error. This is expected. Astro's parameters have been set by Hovermap but need a reboot to take effect.
Reboot Astro and Hovermap. Parameters are now set, you should be able to start a scan and takeoff.
If you are flying Hovermap with Astro FW 1.6.14 or later, the following parameters need to be set:
Set MAV_2_MODE = Custom
Set COM_RC_IN_MODE = RC Transmitter Only
Set SER_EXT2_BAUD = 500000
These parameters fundamentally change how Astro flies! Do NOT fly these parameters without a Hovermap, as this could lead to instability and possibly a crash!
To reset to the default Astro parameters - go to Advanced > Parameters > Tools > Reset to Vehicle Configuration Defaults
Put the S2 switch in the 'up' position to allow Hovermap to take control. When armed, Hovermap will place Astro in 'Offboard flight mode'. To take control away from Hovermap and give the pilot full authority, move the switch to the middle or down position.
Switching S2 is the only way to remove Hovermap from control. Pressing Position/Altitude/Manual mode without S2 change will allow Hovermap to re-establish control of Astro
Open the Commander app. Click Assisted or Autonomous Mission and follow the prompts to setup the mission
If desired, users can have a split screen view of AMC and the Commander app. This is particularly useful if Astro is configured with the optional FPV module.
We recommend setting your shield settings to be as large as possible, while still being able to complete the mission. The minimum settings we recommend for Hovermap on Astro is:
Horizontal 1.5m
Above 1.0m
Below 1.0m
These are the parameters we recommend for most environments.
COM_OBL_ACT
2
Hold mode if no hovermap and no RC control
COM_OBL_RC_ACT
5
If no hovermap control, switch to hold mode
COM_LOW_BAT_ACT
Warning
Don't trigger action from low battery, let hovermap take control, or let land failsafe kick in if no hovermap
COM_RCL_EXCEPT
4
Ignores RC loss when Hovermap is in control
The shield system is designed to protect Astro and Hovermap from contacting any objects in flight, but it is not foolproof.
The system has limitations, which pilots need to be cautious of when operating Hovermap. The ST-X can collect dense point clouds of objects from several meters away, so it is not necessary to get very close to objects for detailed scans.
It is important to know that Shield is a passive system. It will not protect against objects that are actively moving towards the drone, such as birds, moving ropes or falling rocks.
Always be ready to take over control of Astro in case of unexpected behavior!
The S2 switch in the middle or down position will remove Hovermap from control of Astro and give full authority to the pilot
Read carefully! Ignoring these could result in a crash
Always set the shield limits as large as possible for your mission
After takeoff Aircraft needs to climb above the 'Below' shield threshold before the shield will fully activate.
If the pilot does not climb above this limit, Hovermap will not apply the full shield and it will be possible for the pilot to fly into objects
In gusty environments, it is possible for the aircraft to drift closer to an object than the shield threshold with repeated pilot inputs toward the object.
In particular, this can occur near foliage or other objects like ropes/wires/tarps that can move in the wind, allowing the aircraft to move closer for a brief moment before the object moves back. Hovermap shield is a passive system and won't avoid an obstacle that moves.
It is possible to get the aircraft 'stuck' with obstacles on all sides. If this occurs, take over control from Hovermap and fly Astro to a more open area, then reenable Hovermap.
Calculated RTL path is sometimes inefficient, requiring the aircraft to fly a longer than necessary distance back to the home point
Astro + Hovermap ST-X is limited to a maximum ambient temperature of +40C/+104F
When carrying the Hovermap ST-X, Astro is at the upper limit of its maximum takeoff weight. Be cautious when flying Astro in hot or high-altitude environments.
Astro will give warnings if the ESCs or motors start to overheat. Heed the warnings!
Astro and Hovermap ST-X can operate in light to medium rain. Be sure to install the USB-C plug into the IO panel.
Hovermap should boot up when Astro is powered on. Hovermap will connect to Astro once the lights turn from orange to a slow blue flash.
Set up the Hovermap scanning via the Commander app.
Click Autonoumous Mission.
Follow the prompts for pre-flight checks.
Name your mission and check there is enough free storage on Hovermap.
Start the scan and wait for Commander to complete the pre-flight check.
Once the scanner is running, arm Astro, then click the 'Takeoff' button in the Commander App
You can view a live preview of the point cloud generated by ST-X during the mission in the Commander app.
Hovermap will automatically return home when it calculated RTL time reaches 0. This timer can be seen on the top of the Commander app. The RTL time is calculated based distance, altitude, and manuevers needed to reach the home point
Stop the scan after landing via the Commander app. You will need to disable the shield to be able to land Astro
For added situational awareness during the flight, you can view a live video from the aircraft using the Astro FPV Camera.
When using the FPV camera, AMC will try to take photos during the mapping mission. To turn this off:
Set the Start > Camera actions: Stop taking photos
Turn ON the option under Mission > Options 'Images in turnarounds'
If you power off Astro before stopping the scan, the data can be corrupted!
If Hovermap is causing Astro to behave erratically, drifting, or otherwise abnormally, the pilot can takeover and remove Hovermap from control:
Place S2 switch in middle or down position
Astro will exit Offboard mode. If Astro has GPS lock, the aircraft will transition into Position mode. If not, Astro will transition to Altitude mode.
Switching S2 is the only way to remove Hovermap from control. Pressing Position/Altitude/Manual mode without S2 change will allow Hovermap to re-establish control of Astro
The mounting kit for Astro can be purchase from Emesent and includes the mounting bracket, fasteners, dampers, and IO cover, and cable.
Remove the isolator and payload cable from the lower chassis. Then, screw the Hovermap ST-X dovetail bracket using the shoulder screws.
Use a 2.5mm driver and Loctite 222 on the screws. Be sure to tighten them down all the way!
Attach the ZPD connector to the IO panel on Astro.
Then screw the cover over the IO panel, torquing the bolts to finger-tight.
Connect the cable to the back of Hovermap ST-X.
Update your aircraft to the latest firmware to enable Hovermap functionality, at least v1.4.6
For assisted and autonomous missions, Astro parameters need to be updated to enable communication with Hovermap and to increase rate setpoint tracking on Astro. See the autonomous section for more details:
Live preview and connection is currently only supported with Pilot Pro + Astro
Install the Emesent Commander App on Pilot Pro. You will need to add your Pilot Pro to the Emesent channel of apps to download it.
Connect the Pilot Pro tablet to the internet via the wifi settings
Open the camera app on the tablet
Scan this QR code and copy the link when it pops up
Open the Freefly Updater app
Go to Settings > Repositories
Click on + ADD REPOSITORIES
Paste the link you copied from the QR code (alternatively type this: http://freefly-updater.freeflysystems.com/v1_third_party/emesent/stable_repo/)
Exit the Repository menu
You might need to enable Freefly Updater app in Settings under Install Unknown Apps
Go to Latest > Commander > Install
Open the app once it's downloaded
Permission Commander access pop up messages
Enter
The latest tested version of Commander is 1.2.0_10
Check that Hovermap is running hvm_st_3.2.1 firmware or later. If not, follow Emesent's documentation on firmware updates.
Latest Hovermap firmware for Astro is v3.3.2.
This can be found once connected in the Commander app in the 'Web UI' page
Power on Astro, which should also power on Hovermap. Wait until the lights on the back of Hovermap to turn breathing blue.
Open Commander the app and click on the ethernet icon in the upper left corner. Click Change Hostname and set the IP address to 192.168.144.101
Refresh the Commander app and wait for an ethernet connection to be shown. This may take a few minutes.
You're connected to Hovermap through Astro!
See this section on mapping with Hovermap
See this section on flying Astro with assisted/autonomy enabled:
Check out Emesent's documentation for details on how to remove data and post-process for ST-X:
