GPS anxiety

[boomerangben]

Drones won’t need the accelerometer to measure movement as they have gps and altimeter data usually. The chip will be 9 axis though I’d imagine, they’re cheap and ubiquitous. The drone would probably use the gyro sensors to complement the magnetic data and to keep the craft upright.

What do you base your claim on?

The helicopter I fly has twin AHRS (attitude, heading reference system) which a 9 axis module, plus two pairs of accelerometers and gyros for each axis, ie 4 separate means of detecting movement in each degree of freedom. Accelerometers are key to providing effective stabilisation in unstable aircraft (rotary or fixed) so would, I imagine would be fundamental in enabling a drone to be a stable platform (since they are unstable aircraft too). So on what do you base your claim that a drone doesn’t need accelerometers?

 

[lustyd]

What do you base your claim on?

It was conjecture based on another post claiming drones only used 6 axis chips. In hindsight it’s obvious he was wrong but at the time it seemed reasonable since they don’t technically need the linear stuff to function. Obviously they do have 9 axis chips and probably do reference all of that data. The linear stuff would be useful to record for stabilisation purposes in editing although I’ve not seen a drone with that feature.

 

[st599]

You do know that spoof is a spoof?

NOTAM B2967/23 | London

Is the one happening overnight tomorrow a spoof too?

 

[lustyd]

I don’t think I could make it to Embankment with the big stick on the roof, but if I ever did I imagine I’d be doing pilotage by that point anyway.

 

[Chiara’s slave]

NOTAM B2967/23 | London

Is the one happening overnight tomorrow a spoof too?

For sure, Scotland Yard is not the origin of any GPS jamming.

 

[Refueler]

It was conjecture based on another post claiming drones only used 6 axis chips. In hindsight it’s obvious he was wrong but at the time it seemed reasonable since they don’t technically need the linear stuff to function. Obviously they do have 9 axis chips and probably do reference all of that data. The linear stuff would be useful to record for stabilisation purposes in editing although I’ve not seen a drone with that feature.

UTTER horse manure ... again ... and bending my words to suit your idea ...

At least you've finally accepted that drones do use accelerometers ...

You seriously need to consider how the word AXIS is being used ... and to actually understand the different roles of each.

The 6 axis as I mentioned are based on the base movements :

1. Rise / lower
2. Slide left / right
3. Fwd / back
4. Roll left / right
5. Yaw left / right
6. Pitch up / down.

The Accelerometers then add the 'acceleration' detection of CHANGE in any of the 3 physical axis ... Vertical, and the two horizontals (side to side and fwd - back).

It is actually a mis-labelling of the accelerometers functions to name them Axis - but to the street punter its a good sales hype. The fact is - that it is in reality you have 6 axis and 3 functions to create the so-called 9 axis.

Previously you mentioned Gyros as in stabilisation. The Gyro reacts to change ... it has no idea of what way up / orientation at all ... On start up - gyro, accelerometers all initialise to set a reference to have unit level in the 3 planes of motion. The gyro reacts based on it wanting unit to stay at that reference setup (subject to mode chosen by user). The accelerometer gives feedback of the rate of being displaced .... The two actions together create the stabilisation needed AND the ability to fly autonomously.

If you cannot understand this ... then that's your problem not mine ... I have better things to do ...

 

[lustyd]

You missed the three axis compass sensors, the main three! No idea what you’re trying to prove but you’re not doing a good job and you’re just reiterating that you don’t understand the sensors again and again.

 

[Refueler]

You missed the three axis compass sensors, the main three! No idea what you’re trying to prove but you’re not doing a good job and you’re just reiterating that you don’t understand the sensors again and again.

Horse to water .... Oh dear ...

I've been putting together own drones and photographic drones for years ... funny that ... hard to do that if I don't know the fundamentals ...

Bye Bye ...

 

[lustyd]

hard to do that if I don't know the fundamentals

And yet here we are with you insisting you have a chip without the compass. Please share the chip number and educate us all on these special chips that nobody else has.

 

[Refueler]

And yet here we are with you insisting you have a chip without the compass. Please share the chip number and educate us all on these special chips that nobody else has.

Where did I say I have no compass ??? Oh pray do tell .....

In fact I do have a number of 6 axis chips with additional accelerometers without compass ... they are designed to have a separate solid state compass connected .... but usually I will buy with compass included to simplify and reduce weight of the units on small drones. The separate units are more for the larger drones .. such as 400's and bigger.

The chips as you call them ... which again is mis-use of a term ... the boards will have the Gyro and Accelerometers built onto it ... then you have the pinouts to connect to items such as camera and compass ...

Example :

30,5x30,5mm HAKRC 45AF7 V2 Stack F7 Flugsteuerung mit Dual Gyro und 5V 10V BEC Ausgang, 45A BL_S 2-6S 4in1 ESC Flytower Unterstützung DJI O3 Air Einheit für DIY RC FPV Racing Drone

and just to show - drone separate compass unit ....

Foxeer M10Q 180 5883 Kompass GPS M10 Chip mit integrierter Keramikantenne für RC-Drohne FPV Racing

I can put up loads more examples if you like ... but TBH - for what - you think you are right ... so sad !

 

[Refueler]

Deleted .....

 

[lustyd]

So you’re using a 2d single axis compass on a drone.
There’s a reason proper drones use 9 axis chips, and if you were less impolite someone might care to help you learn.

 

[Refueler]

So you’re using a 2d single axis compass on a drone.
There’s a reason proper drones use 9 axis chips, and if you were less impolite someone might care to help you learn.

You really are blinkered ... you ASK for examples ... you mix up terminology ... you fail to comprehend whats explained in depth to you ...

Those two example units are just that EXAMPLES ... not what I have on bench ... they were to show how wrong you are ..... you said quote :

And yet here we are with you insisting you have a chip without the compass. Please share the chip number and educate us all on these special chips that nobody else has.

Who's the one failing to learn ???

Proper drones ..... and I suppose the drones I have from the likes of DJI and the 400 series ... toothpick racers ... etc that I build from components are not 'proper drones' ....

Get real and stop digging a hole for yourself ... quit while you just look silly ...

 

[Refueler]

For those who may be wondering what a 3 axis Compass is - given the drivel "lustyd" is giving out ...

A compass is a single axis unit in physical terms ... but an electronic solid state compass has an added ability that physical compass has a problem with .... 'tilt'. A physical compass will tilt so far and then card is unable to tilt further ... cannot swing freely.

Quote :

3-axis electronic compass can be used when idle, or moving at low speeds. This compass is also tilt compensated, meaning the device can be held in any position and will still give a compass reading. At times, this compass may also require calibration.

It is widely believed that all electronic compass are able to deliver at idle or low speed ... this is not strictly true in electronic terms ... there those that actually require movement to cause deflection - as the unit passes through flux ... or are working based on GPS iterations. - the compass functions. The evolution of the '3 axis' version was to overcome the orientation of the unit - that no matter how tilted / upside down etc. - the compass would still function. It has no other data to deliver. If you want more than that basic - then a Magnetometer comes into play.

Solid state compass is not same as solid state magnetometer ... they can perform similar - but are not exactly same ...

Quote :

Digital magnetometer is a three-axis unit that detects the strength and direction of a magnetic field and communicates the x, y and z components directly to a computer or other suitable receiver

Just to add .... given the matter derives from a 'wristwatch ?' ... I could go back and find the post - but lets just say we can let Garmin themselves speak ?

Quote :

Garmin Outdoor handhelds will use one of three different compass options:

• GPS Compass - Found in handheld devices lacking an electronic compass, this compass uses GPS to determine heading. This requires you to move at approximately 2-3 miles per hour in order to get a reading. When stopped, or moving at speeds slower than 2 miles per hour, the compass may not function as intended.
• Standard Electronic Compass - The electronic compass functions more like a traditional compass. It can be used when idle, or moving at low speeds. The device must be held level in order to give a reading, and may at times require calibration.
• 3-Axis Electronic Compass - Similar to the electronic compass, the 3-axis electronic compass can be used when idle, or moving at low speeds. This compass is also tilt compensated, meaning the device can be held in any position and will still give a compass reading. At times, this compass may also require calibration.

The whole subject is actually quite interesting and deeper than 'lustyd' realises .... simply stating 9 axis is far from the real facts ... once the actual functions and interpretation by each unit is looked into and hopefully 'lustyd' will understand one day ... the interactions are complex.

We can only hope !!

 

[boomerangben]

It was conjecture based on another post claiming drones only used 6 axis chips. In hindsight it’s obvious he was wrong but at the time it seemed reasonable since they don’t technically need the linear stuff to function. Obviously they do have 9 axis chips and probably do reference all of that data. The linear stuff would be useful to record for stabilisation purposes in editing although I’ve not seen a drone with that feature.

Conjecture means that you are making a guess, educated at best. You are not saying you know anything about the details about whether or not drones use accelerometers. Just by watching how stable a drone is in flight you can see that it responds to planar ie non rotational disturbances which can only be picked up by accelerometers. I know that linear accelerometers play a vital role in aircraft stabilisation systems (and much larger aircraft are less likely to experience pure planar disturbances due to their size). And before you start on GPS reference, non survey GPS isn’t accurate enough to hold cm scale stability, particularly in heave.

Might your conjecture be wrong?

 

[AntarcticPilot]

Conjecture means that you are making a guess, educated at best. You are not saying you know anything about the details about whether or not drones use accelerometers. Just by watching how stable a drone is in flight you can see that it responds to planar ie non rotational disturbances which can only be picked up by accelerometers. I know that linear accelerometers play a vital role in aircraft stabilisation systems (and much larger aircraft are less likely to experience pure planar disturbances due to their size). And before you start on GPS reference, non survey GPS isn’t accurate enough to hold cm scale stability, particularly in heave.

Might your conjecture be wrong?

Centimetre accuracy in flight using GPS is possible; we use it in Antarctica to provide scene centres for aerial photography; the aircraft is a DH Twin Otter, so hardly a high performance job! But I agree it needs survey quality equipment, and I think it also requires a fixed ground station. Certainly not something that a drone would be equipped with! In Antarctica it's cost-effective because putting in survey points in the field is expensive and slow!

 

[lustyd]

Might your conjecture be wrong?

As I said, I was trying to explain someone else’s assertion, hence conjecture. As I also said, proper drones obviously do use 9 axis chips.

 

[GHA]

Banged on the head by the boom, pot of boiling soup flying off the cooker burning half your body - both very scary & very possible.

GPS down so you get lost and bad things happen? Never met or even heard of this happening (possibility during the coronation in west end of london really doesn't count ), not even slightly scary

 

[lustyd]

The whole subject is actually quite interesting and deeper than 'lustyd' realises .... simply stating 9 axis is far from the real facts ... once the actual functions and interpretation by each unit is looked into and hopefully 'lustyd' will understand one day ... the interactions are complex.

Having written software to utilise 9 axis chips I understand them well. You’ve demonstrated a lack of understanding in every post and instead tried to start a fight with a stranger instead of discussing and learning. I’ve no idea what your aim is here but you look like an angry fool.
One piece of software I wrote uploads the 9 individual readings from a Garmin in real time to the cloud and has been used alongside machine learning to carry out various tasks including fall detection in care homes and road humps caused by braking in mining operations, which drastically reduces down time for those huge dumper trucks carrying ore and waste. They shut down automatically and need resetting and checking if the load cells detect a big enough bump, so this is to be avoided. I certainly do understand the chips and their readings as well as what they can be used for. We (global tech company) have customers all around the world benefitting from my work on such devices so think what you like, I’m all good with my understanding.

 

[Refueler]

Its easy to say something - but a lot different to understand why something works ....

Putting A to B ... C to D ... easy ... but sorry - you illustrate what is wrong today ...

I know many programmers who can program just about anything ... but ask them how it works ... not a clue - so please stop the BS.

Good bye ..