ModalAI Forum

@Chad-Sweet

Update:

• I have performed the calibration process as you mentioned for both Stereo camera and tracking camera by following the calibration documentation https://docs.modalai.com/calibrate-cameras/ though they are not moved from their original position of VOXL flight deck.
  

• While performing the calibration for stereo cameras I have also fixed the focus for both left and right camera. But after the calibration process the collision prevention does not seem to be working any more.

• By that I mean the the obstacle topic does not seems to detect anything even it is very close or far from the wall. I also tried with different object to see if the camera can pick up the difference but it does not seems to be consistent any more.

• At 0 degree angle it mostly shows 0 m. It only shows some value while it is in the ground but once flying it is completely 0 m in withing +- 30 deg angle range.

• After several try I decided to perform the calibration process again, and after the process I found same result. I also tried to change the CP_dist from QGC parameter ranging from 0.5- 10 meter but it does not seems to work anymore.

• Then i realized I have made a big mistake by not saving the default calibration.stereo.xml file for calibration and then I found the sample calibration file in the voxl-camera-calibration git folder which then I replaced it with the calibrated file.

• Once this process is complete I then fly the Modal AI m500 and it worked almost as before but the CP_dist value of 1.5 m seems now too much and we reduced it to 0.8 meter.

• This the sample calibration.xml snippet from the git hub link:
  

• I also noticed the focal_length_x and y for calibrated camera is ranging from 488-490 for both camera value which is much higher value after the calibration process compared with the sample calibration file shown above.

Please let us know what can be done to correct this calibration problem or at least how I can obtain the default factory calibration data from modal ai.

@Chad-Sweet Thanks for your reply. This is the exact answer I was looking for. The flight core is perfect but here at our company we need to use different Pixhawk board for some specific application.

@tom I was able to access the web interface by plugging the Add-on Microhard unit into a development board. And indeed I found the Network ID is mismatched and was set to as pMDDL instead of pDDL. Also the frequency was set to 76-2477 which is okay since I tried with multiple band with the slave unit as well. See the default configuration of the Add-on unit before changing

@Chad-Sweet Thanks for you reply, But my important question is No.2 Which is, can I separate the VOXL autonomy board from the flight core, let say by cutting the board from the complete board as shown below:
or is it possible to turn the flight core unit OFF for adding another Pixhawk

.

Let me know your answer.

@tom Thanks for your reply. Let me know if you can come up with some solution. In the mean time I am trying to get a development board for the Microhard unit to plugin and see if I can log in to the config-webpage.

@tom This is the image showing LED behaviour.

From the bottom

1. Lnk/ACT : OFF
2. Lnk/100 : ON
3. Lnk : ON
4. CPU : ON
5. RSSI_1, RSSI_2, RSSI_3 : blinking one after another
6. RX : ON (continuous)
7. TX : Blinking (low)

Note: One thing I noticed now is that the Standalone microhard unit we have is 128 bit AES encryption model, where the Modal AI add-on module is showing 256 bit AES encryption model. Do you think this is the reason they are not communicating? All the microhard unit we have here is 128 bit AES model. If that is the case how can we access the Add-on Microhard unit?

@tom Microhard module that is in the add-on board from Modal AI as an add on to m500 unit and same is pDDL2450

@tom I have not been able to establish connection between these two Microhard modules. But independently the slave standalone unit has been used for another system as well and I know It is working.
Standalone unit

Hi, we wanted to know few things about the VOXL unit. I will list the questions below:

• Is it possible to use different Pixhawk (e,g. Cube 2.1 or mRO Control zero) with VOXL autonomy computer? If yes, then what is the connection process and details.
• FYI, We have a M500 complete VOXL unit with Flight core. Is it possible to separate them and use different Pixhawk instead?
• Is it possible to increase the Stereo camera cable in each direction by 12-24 inch? I saw that there is 5.7 inch extension cable available in the Modal AI store but it will not be enough for our requirement. Any suggestion is much appreciated on how to increase the length for the stereo camera.

@tom We are using microhard from Airborne innovations 2400 MHz unit on the other side. And I can access the slave standalone unit perfectly with PC.

@Chad-Sweet we did not re-calibrated the stereo camera since we moved it from the M500 unit it came with. I can try the calibration process and let you all know.

@shlee853 I think we are using volx-suite 0.2.0, here is the screen shot of the version:

Note: Though it shows continuous collision warning from the QGC we still tested the flight against a wall for collision prevention test. It performs as expected and stops at 1.5 meter from the wall. The only issue it shows continuous collision warning sign.

@tom I have already checked the ifconfig and it shows the the VOXL is connected with microhard

and also I have tested master mode in microhard by holding the button for 10 sec. The IP ping test as follows:

I have also tested the VOXL microhard unit by putting it in slave mode by pressing the button for 5 sec and it also shows in the ping result as follows:

The problem is that, it does not connect with another microhard unit whether we keep that in master or slave. There must be some configuration issue that we must be missing and or it not matching with another unit. Can you please tell me what is the default Network ID: pDDL. For us the slave unit has pDDL. And the channel frequency is set as Channel-Frequency: 75_ 2476 MHz .

@tom Thanks for reply. I followed all the configuration steps and I have also tested by keeping the Microhard further, but the connection does not seems to work. I have also tried to use lowest TX power but same result. The only possible solution I see is to access the VOXL microhard unit and check all the configuration to match with slave unit, but I do not know how to access the Microhard using USB port or from the VOXL ssh terminal. Can you suggest ?

We have the same issue here with the Microhard pairing as posted in this https://forum.modalai.com/topic/251/issue-in-microhard-paring-with-slave-unit. We also tried to follow the instruction but its not paring.

The m500 unit we received came with a microhard 2.4 GHz and we were trying to connect it with our Microhard unit that is configured as Slave unit with am IP address of 192.168.168.2. And also we were trying to configure the VOXL unit with the following setup instruction in the link https://docs.modalai.com/microhard-add-on-manual/, but this instruction does not seems to connect with the slave unit we have. Is there any other parameter we need to change and how can we access the Microhard connected with m500 VOXL unit.

The slave wireless is configured as shown below, so we were wondering if the frequency or the ID is not matching, which is causing not to pair.
Is there any way to access the Microhard in the voxl unit?

Hi, We were testing the collision avoidance feature in the voxl Modal 500 drone, and we found it was working fine with the frame it came with. We then wanted to change the frame and we used one of our frame with Octo Coaxial setup. After initial setup and changing all the necessary parameter as shown in the links 1. https://gitlab.com/voxl-public/flight-core-px4/px4-parameters/-/tree/master/helpers , 2. https://gitlab.com/voxl-public/flight-core-px4/px4-parameters/-/blob/master/helpers/collision_prevention.params, 3. https://gitlab.com/voxl-public/flight-core-px4/px4-parameters/-/blob/master/helpers/ekf2_indoor_vio.params , we thought the collision avoidance will be same. But after arming every time when we are applying any pitch or roll command the PX4 QGC is showing us Collision Warning error as shown in here

Also at the same time the vehicle is not moving in any direction. Below are the parameters applied to the vehicle

We also tried to debug whether the distance topic is populated using voxl-vision-px4 by using the voxl-vision-px4 -s command and these the results

But if we do not use the collision and use a negative value in the cp_dist the vehicle works fine in outdoor using GPS.

We will appreciate any help regarding solving this issue.