Does a Mast Mounted GPS cause flight Instability?

[jxo]

I recently replaced an mRo GPS with a mast mounted HERE. Goal was to remove the leg compass that was causing Mag Interference errors with a Sony mirrorless camera mounted mid bottom of the drone.

The Mag Interference error was fixed but I am noticing some drone wobbling and shake that I did not have before with this camera and the mRo. This is particularly bad when the camera is mounted in the nose area of the drone-- ostensibly causing a bigger weight un-balance issue.

Am curious whether the mast length and moving the GPS those few inched above the drone is causing a negative feedback loop starting with any instability from the big Sony camera getting accentuated b/c the HERE GPS will, by definition, move more than the centrally located mRo unit.

Am probably over thinking it. BTW, it is not the props.

 

[makatanav]

i think it's becouse of that mass center is moved forward.
I hadn't checked mine, but without gimball and camera, the drone is more stable than with

 

[IrishmanPDX]

A mast mounted GPS is fairly light compared to a Gimbal and Camera. The only way I can imagine it causing flight instability is if you made the mast and mount from a very heavy material............ like lead.

 

[jxo]

Yup. My concern is these heavy cameras cause some instability causing the mast to move the GPS in greater distances than would be the case with an internally mounted GPS. Think of a flag on a rocking sailboat mast moving relative to an object on the deck. I am overthinking it, I know but I can't figure out why I only get this drone shaking with the mast mounted GPS. I have experimented on 3 different Solos with the same result.

 

[just_bruce]

In mathematical theory, if you have a weight distribution and CG that is either just *barely* stable or just barely unstable, then altering the input to the EKF by the small amount that using the mast constitutes COULD cause an unkillable oscillation as the PID and control loops wrestle with the edge of the filter cliff.

Note that this is theory and speculation based on knowledge of control theory and some small knowledge of the inner workings of the software on the Cube. So take it with a grain of salt. A large one.

 

[RichWest]

Just a curiosity, have you done the sorbothane mod? This was prescribed back when to reduce a main board flex, basically sorbo sandwiched between the main board and the battery tray.

I'd think structural stability of the mast has more influence than the distance and weight...obviously everything within reason.

 

[jxo]

I did not do the sorbothane mod. Will look into. I am just puzzled why I am getting a high degree of drone shake/wobble now for the first time. Never had it before. I have been mounting this Sony camera for a year and half without it happening. Had mRo GPS before switching one of the Solos to the HERE on the mast to obviate the mag interference PITA when the camera was too close to the old leg compass.

 

[timgilley]

More likely related to the Sony camera since installing the mast gps includes all the parameters necessary for its use. Flight characteristics are adjustable in the parameters, but requires you understand exactly what you are doing. Your speed, yaw and stick behavior that you set in Solex or Solo app are modifying parameters. Except for these most people do not adjust parameters. My guess without specific information/parameter to adjust it will be a tedious process to resolve the wobble.

 

[jxo]

I experimented with several Solos and do not believe the mast is the cause of the new shaking and wobbling. I am experiencing the same issue with 2 other Solos with internal mRo GPS units. The other recent change to all 3 Solos was the install of Open Solo 3.0. Possible the parameter changes from OS are making the sensors extra sensitive to the extra weight from the Sony camera. This is being addressed in another thread in the Help forum.

 

[looninho]

I were experienced this behaviour with my DIY drone when the GPS was not well fixed on the mast. But you said that it also happens with internal GPS, so in my though check the vibration with MissionPlanner.

 

[timgilley]

I were experienced this behaviour with my DIY drone when the GPS was not well fixed on the mast. But you said that it also happens with internal GPS, so in my though check the vibration with MissionPlanner.

Thanks for mentioning the help thread. All of my Solos are on 3.0. One is green cube and the other two are stock. I haven't noticed any problems. I'm using the 'first' stable build and not the 3.7 which is still a work in progress.

 

[Housspin]

Hi. Im new in this forum. I got my 1 3DR Iris plus it came with some accessories that i have no clue. Can you guys pls help me with? Thx

 

[Housspin]

Hi. Im new in this forum. I got my 1 3DR Iris plus it came with some accessories that i have no clue. Can you guys pls help me with? Thx

Images of the accessories

 

[just_bruce]

Images of the accessoriesView attachment 10385View attachment 10386

Please post a *new* thread in the appropriate forum and don't simply jump onto whatever thread you see first. Thread hijacking isn't cool

 

[IrishmanPDX]

Please post a *new* thread in the appropriate forum and don't simply jump onto whatever thread you see first. Thread hijacking isn't cool

Unlike hijacking Nakatomi Plaza , USS Missouri, an airplane midflight to steal three suitcases full of uncirculated bills valuing over $100 million over the Rocky Mountains, The Red October, Pelham 123, or a speeding city bus. All of which are prefectly good entertaining Hijacks which are not to confused with Drone Threads.
In order to keep this relevant... since the drone mast and internal GPS are also resulting in vibration issues, then you could also look at prop balancing to reduce vibration and securing the internal wiring a bit better. Failing that, didn't everyone's ex favorite youtube personality (The Basic Pilot) recommend a pluggin before for removing vibration during video editing?