The Emesent Hovermap ST-X lidar is an excellent payload for creating detailed, accurate lidar point clouds.

Setting up Hovermap

Operation modes

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.

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.

In particular, pilots should understand:

• How Hovermap works

• How to recognize a SLAM slip

Preflight

Parameters

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:

1. Update Astro to 1.5.18 firmware

2. Power on Astro and Hovermap. Wait for Hovermap to fully boot and connect over ethernet

3. 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.

4. Reboot Astro and Hovermap. Parameters are now set, you should be able to start a scan and takeoff.

Pilot Pro Configuration

• 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.

Shield Settings

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

Astro Failsafe Settings

These are the parameters we recommend for most environments.

Shield Limitations

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.

Hovermap FW v3.2.1 Known Limitations:

• 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

Flight Tips

• 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.

• Stop the scan after landing via the Commander app. You will need to disable the shield to be able to land Astro

Emergency Procedures

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.

Astro can fly both the Sentera 6X and 65R!

Both payloads are compatible with Astro using the Smart Dovetail connector, which sends power and capture commands to the cameras in flight.

Setup

• Install the payload in the Smart Dovetail mount

• Install the GPS mast and cabling securely

Mission Planning

As of Astro firmware v1.5 or later, the 6X and 65R camera settings are selectable in the survey dropdown of the plan screen. Simply select the camera you are using and adjust the mission flight path as needed.

See Sentera's wiki for the recommended flight settings:

Post Processing

Tips:

• Turn off your computer wifi connection and ensure the wired network connection is showing connected to "Sentera 65R".

  • Sentera 65R (use this one) > "Data" folder > "snapshots" folder > select date of flight (folder)s

  • Sentera 65 SMB (don't use this one)

• If you leave the Astro on or hotswap between missions, it'll save all the image in the same folder (annoying for post processing) so ensure you power cycle between missions to make processing easier (create seperate folders).

• In Field Agent (sentera's processing software)

  • Create the field boundary

    • Then in the field menu select said field

    • Go to the map layers tab

    • press the + button in the right corner of the tab

    • Select individual photos from the upload map layer menu

    • Add the images to the upload section

More Information

Additional information can be found on Sentera's website:

Mission Planning

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.

• Set the camera type to 'Manual (No specs)' so that AMC will display the mission planning parameters in distances rather than GSD.

• 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.

Flight Tips

• 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 Non-Autonoumous Mapping 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, 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.

Post Processing

Check out Emesent's documentation for details on how to remove data and post-process for ST-X:

Mounting ST-X on Astro

The mounting kit for Astro can be purchase from Emesent and includes the mounting bracket, fasteners, dampers, and IO cover, and cable.

1. Remove the isolator and payload cable from the lower chassis. Then, screw the Hovermap ST-X dovetail bracket using the shoulder screws.

1. Attach the ZPD connector to the IO panel on Astro.

1. Then screw the cover over the IO panel, torquing the bolts to finger-tight.

2. Connect the cable to the back of Hovermap ST-X.

Mapping Only - Astro Parameter Configuration

Update your aircraft to the latest firmware to enable Hovermap functionality, at least v1.4.6

Assisted or Autonomous - Astro Parameter Configuration

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:

Pilot Pro and Hovermap Configuration

1. 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.

   1. Connect the Pilot Pro tablet to the internet via the wifi settings

   2. Open the camera app on the tablet

   3. Scan this QR code and copy the link when it pops up

1. Open the Freefly Updater app

2. Go to Settings > Repositories

   1. Click on + ADD REPOSITORIES

   3. Exit the Repository menu

3. You might need to enable Freefly Updater app in Settings under Install Unknown Apps

4. Go to Latest > Commander > Install

5. Open the app once it's downloaded

6. Permission Commander access pop up messages

7. Enter

1. Power on Astro, which should also power on Hovermap. Wait until the lights on the back of Hovermap to turn breathing blue.

1. 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

1. Refresh the Commander app and wait for an ethernet connection to be shown. This may take a few minutes.

2. You're connected to Hovermap through Astro!

Mission Planning and Flight

See this section on mapping with Hovermap

Assisted/Autonomous Flight

See this section on flying Astro with assisted/autonomy enabled:

Post Processing

Check out Emesent's documentation for details on how to remove data and post-process for ST-X:

The Gremsy Pixy PE is compatible with the Pixhawk Payload Bus standard and can be integrated with Astro to fly custom payloads. The dovetail mount of the Pixy PE fits into the dovetail mount on Astro and can communicate via Mavlink.

Tips for Integration:

• Astro's stock landing gear is a bit too short for the height of the gimbal, to extend the gear we recommend using standoffs between the aircraft chassis and the landing gear plastic mount. Note that one fastener on each landing gear is longer than the other two. The setup we have used is:

  • Blue loctite

  Each leg needs 3 of the 40mm standoffs, 2 of the 50mm bolts and 1 of the 55mm bolts. The bolts mount to the same holes as the existing landing gear. We haven't extensively tested this configuration, so be gentle on landings to avoid torquing the threaded mounts inside the lower chassis plate.

Tips to Setup Mavlink Control:

On the latest Gremsy gimbal software (version v7.7.3), set the gimbal to Mavlink mode, make sure the baud rate of the gimbal is 912600, and confirm that it saves.

Recommended Gremsy software settings:

• Baud Rate: 912600

• Stiffness: Gyro filter to 1 or 2

• Follow Controls > Pan > Airborne on

• Settings > Mode Settings > Turn Reduce drift by drone > Pan Axis to the far right

The behavior of the gimbal pan changes when the aircraft is armed or disarmed, so if you need to change something be aware that you will likely need to fly the aircraft/gimbal to see how the change affects behavior.

This will allow tilt control by using the wheel on the Herelink after rebooting the gimbal.

Astro is designed to be compatible with a wide variety of payloads.

• Astro utilizes the Smart Dovetail which is the reference design for the

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