Boom angle sensor

[Parmin]

A bit late into this discussion,
I have made a stabilized camera boom crane (that was used in filming MadMax movie) using accelerometer a few years ago.
Shouldnt be too difficult.

Posted on: November 25, 2018, 06:08:29 18:08 - Automerged
When the camera and their support gears and harness are over 200 kg lifting from a 5 meters boom from a truck moving at 70 km/h I think it is not too far off from a crane.
Thinking of it, one of the requirement is also going down 45 degree from the horizontal line to shoot from tire axel level.
But hey , who am I to argue  

Back then I have also posted similar question here in Sonsivri and was given quite a few good advices.

[Signal]

A have some some thoughts and doubts.
1) I do not get how could be justified a CRANE and 100$ saving by not buying a proper device.
2) Doing it yourself properly probably will rise a price of your device higher.
3) If an angle between boom and chassis is required then using accelerometers (as well as inclinometers based on accel.) will cause an obvious mismatch
4) Vibrations could be effectively compensated by mechanical and digital filtration, I believe.
5) I'd avoid giving any directions what to do with devices for CRANE to a person that is not able to handle it himself (in accordance with standards and certificates in that area).

[an007_rld]

You can use 2 barometric pressure sensors (today is possible measure a 10cm hight difference) on top of crane and one on bottom and based on the difference you can calculate the inclination; it's not sensitive to vibration...

[vern]

very good, a totally new approach. But you get only the angle between chassis and boom, you don't have the angle relative to earth's surface.

[Parmin]

Should not stop only at putting the inclinometer on the boom, should put one on the truck as well for relative angle to the ground and read the difference.

[CocaCola]

Should not stop only at putting the inclinometer on the boom, should put one on the truck as well for relative angle to the ground and read the difference.

Although I agree, if one is using a barometric pressure sensors all around with a +/- of 10cm for both I don't believe you can resolve to 1 degree of accuracy reliably as the error compounds across both measurements, especially true since the truck's length to height isn't enough to mitigate the +/- 10cm reading tolerance of the sensors well enough...

[an007_rld]

I can give you another one: I'm thinking... what if you run a pipe full with a fluid along the crane arm and place a pressure sensor on the bottom side. The sensor measure the weight of fluid and the exercised force vary based on gravity direction relative to pipe.

For the 1'st idea you can eventually check the following pressure sensor:
https://www.digikey.ca/en/product-highlight/m/measurement-specialties/ms5637-pressure-sensor

[vern]

now it's getting really weird.
There should be a new topic: weird solutions to simple problems.

[Signal]

now it's getting really weird.

It's not so simple to be weird ;)

[snowman]

here's another one...

https://www.aliexpress.com/item/Angle-sensor-0-360-degrees-0-5V-output-full-circle-no-dead-12bit/32611741633.html?spm=2114.search0604.3.2.70755936ixpE9v&s=p&ws_ab_test=searchweb0_0,searchweb201602_1_10065_10068_319_10059_10884_317_5730611_10887_10696_100031_321_322_10084_453_10083_454_10103_10618_10307_538_537_536_5729311,searchweb201603_51,ppcSwitch_0&algo_expid=4857aa03-f1c0-4356-b7e9-7843265a6198-0&algo_pvid=4857aa03-f1c0-4356-b7e9-7843265a6198

[Wizpic]

Please keep this to helping with sensible ideas, If you have not got anything to add or sensible then don't reply.

Signal have you got any further with all the ideas and suggestions that have been made ?

If this continues I will be forced to lock the topic as it does not seem to be going any where.

[Parmin]

Although I agree, if one is using a barometric pressure sensors all around with a +/- of 10cm for both I don't believe you can resolve to 1 degree of accuracy reliably as the error compounds across both measurements, especially true since the truck's length to height isn't enough to mitigate the +/- 10cm reading tolerance of the sensors well enough...

Why would you use barometric sensor?
Accelerometers are great for angle measurement.
A lot are sensitive enough for even less than a quarter of a degree angle against the horizon.

Posted on: 14 December 2018, 06:07:03 - Automerged
The gyroscopic feature of most accelerometer is sensitive down to 200 counts per degree

[CocaCola]

Why would you use barometric sensor?

I wouldn't and that was what I was pointing out...  For clarity, I should have also quoted an007_rld who suggested the barometric sensor as my reply was mostly towards that sensor approach and how it wouldn't resolve to the degree of accuracy, especially when combined with my agreement with you that there should be sensors on the boom and vehicle...

As I said previous, if there is a $100 device already commercially designed for this application, I would not waste my time re-creating the wheel and assuming liability vs just spending $100 on the existing device and calling it a day...

I hope that clarifies it...