Sensor Fusion Question w/ GPS, VIO, and downward distance sensor on Starling 2

shawn_ricardo

Following up on your reply in the post "Running VIO w/ GPS Active". I am flying a Starling 2 and have been unable to conclude how Modal handles various sensor input streams to PX4.

I see that the Starling 2 has a downward distance sensor, VIO, and GPS (in addition to IMU). This is where the confusion begins because I also see that default Starling PX4 parameters only have Vision enabled for heading, velocity, and position via EKF, that GPS is disabled & set to not exist, and that downward lidar sensor input is disabled.

Does the VOXL perform some sort of sensor fusion on these input sources, then send the output of fusion to PX4 through the vision topic such that vision encompasses GPS, downward distance sensor, and VIO? Or is it the case that the sensor streams other than VIO are actually ignored by PX4 and/or not sent by default (in which case I can simply enable the sensor input and update EKF parameters).

Could you provide more clarity and maybe any recommendation on how I could leverage the sensors in PX4?

shawn_ricardo

Hi @Eric-Katzfey @Alex-Kushleyev , would y'all be able to answer the questions above?

Just to recap, I ordered the Starling 2 and the default PX4 parameters shown via QGC have pretty much everything but vision sensor input turned off. As far as I know, the Starling 2 comes with a GPS (no mag) and downward facing distance sensor. Both could be used as sensor input sources into PX4s EKF. So, I'm curious if y'all use those sensors as input into your VIO implementation as a sort of upstream sensor fusion. In which case I can leave those PX4 parameters as is

Eric Katzfey

@shawn_ricardo Historically, PX4 hasn't dealt well with GPS combined with VIO. That's supposedly not the case anymore but we haven't yet proven to ourselves that we can run them concurrently. So, we provide parameter sets that allow you to choose between different configurations. See them here: https://gitlab.com/voxl-public/voxl-sdk/utilities/voxl-px4-params/-/tree/master/params/v1.14/EKF2_helpers?ref_type=heads. But you are more than welcome to test with GPS and VIO concurrently to see how it works for you.