Hi!
Excellent share!

Jay Hind!!!

Quote from: Karthick Ashwath on January 09, 2020, 10:42:08 PM
Ha!As always,yet another Indian attempt at making a solar UAV in hibernation!(including me :-))

Haha!! Yes, we are in hibernation . A few pics of our build from a few months ago can be found in the link below. Will share more when we completely wake up from our slumber 

https://www.dropbox.com/sh/d7w3xgdz6yvukti/AAD8ktSsBioKZ07j4wTIL3xNa?dl=0

Quote from: hobbydrone on January 10, 2020, 04:03:21 PM

Quote from: Karthick Ashwath on January 09, 2020, 10:42:08 PM
Ha!As always,yet another Indian attempt at making a solar UAV in hibernation!(including me :-))

Haha!! Yes, we are in hibernation . A few pics of our build from a few months ago can be found in the link below. Will share more when we completely wake up from our slumber 

https://www.dropbox.com/sh/d7w3xgdz6yvukti/AAD8ktSsBioKZ07j4wTIL3xNa?dl=0

From the pics it looks like you made a good start, possibly with help from someone with experience of building balsa airplanes.
Why did you stop?

You said your budget was Rs 1.5 lacs, in addition to the 1 lac already spent
That's a lot of money. What did you spend 1 lac on? 

Regards

Actually, tried to do 4 years ago. I realised that I was highly inexperienced and not ready to build a solar plane. So now the project is in hibernation until May 2020.

Hello Mr. Iyer.

We did not stop, but had to shift focus to other aspects (algortihm development, etc.). Now, we are back to building the airframe and hoping to flight test soon.

Regards,
Parithi

I have been actively collecting information for the past few months on how to improve my Solar UAV concept.I would like to share what I have collected so far:

1.(starting with the basics) Ensure that your motor and propeller are well balanced.This will reduce noise,improve efficiency and make your motor bearings last longer.

2.Try to go for a flying wing type design(maybe in your next iteration).It is a proven way to decrease drag and reduce the thrust required.

3.Increase the aspect ratio(if possible) to increase glide performance

4.Try to go for a slow(as slow as possible) spinning propeller with a larger area to get the same thrust albeit at lesser power draw than a smaller but faster spinning one.

5.Use FOC(Field Oriented Control) ESC's to reduce motor noise and to improve efficiency.
Here's a link that may help:


(though such esc's are quite a bit pricey)

6.Use supercapacitors in parallel with the solar cells to even out current consumption from the battery and decrease the number of charge and discharge cycles that the battery will go through in flight. Supercapacitors on the other hand have a much higher number of cycles that they can go through in comparison to batteries.I believe that this is very important given that current draw from the motor may vary very fast and power produced by solar panels fluctuate a lot. Here's a link to the company that produces the world's most energy dense supercapacitor(the energy
density is about two thirds that of lipo's) http://zoxcell.com/

7.If you are desperate for even more efficient solar cells here's a company that produces the world's most efficient ones(they are used even by NASA!)https://www.altadevices.com/technology/

8.For helping you with the financial part,I suggest you try DRDO's Dare to Dream program.If they think your UAV's will be useful for defense, they may give you financial support upto 10 lakhs! https://drdo.res.in/kalamdb

9.You can try hydrogen fuel cells which offer upto 960 Wh/kg for more dense energy storage than li-ion batteries.
   https://www.hes.sg/?gclid=CjwKCAiA9JbwBRAAEiwAnWa4Q_-hx4kK-mSti4hUPeNAGkfkYGwTQfWvKRikrjtIgNWD2T1lmVEXzhoCbjAQAvD_BwE

10.Now this part is a bit sketchy...but bear with me
A team working at the Alternative Energy and Nanotechnology laboratory at IIT Madras has developed a groundbreaking sodium sulphur battery that has an energy density of over 1447 Wh/kg!It is also not very costly to the best of my knowledge. Their patent is still pending, but see if you can get your hands on this battery.If you do,you can make your UAV stay in the air 24x7 in Indian conditions without doing any of the above!
Here's a link to the lead author's profile(to the best of my knowledge) and their website:
https://physics.iitm.ac.in/~ramp/aenl/our-team/
https://www.researchgate.net/profile/Ajay_Piriya_V_S(this is the link to one of the author's of the paper.This author has also made other groundbreaking discoveries like this in the past,check out her papers)

In the day,your UAV must climb and gain altitude as well as recharging its bbatteries.In the night,an assisted glide must be performed which will consume less power than cruising at night.

Now here's something that is not very relevant to efficiency improvement:Try using LoRa 433Mhz modules for control and telemetry.They have a range of over 100km(without using directional antennae!) and 433 Mhz is probably the least used frequency in India in the ISM band.This means that interference from

There goes the secrecy of my solar UAV concept!

Now that I have given everything that I have meticulously collected over the few months,could you share some of your results of your modelling and solar cell testing?I am pretty sure we can't copy them with just your results!
#OpenSourceForever

After a good deal(4 hours or so) of search I stumbled upon this cheap foc esc product.I think it will be of great use to you:
https://www.mouser.in/ProductDetail/STMicroelectronics/STEVAL-ESC001V1?qs=5aG0NVq1C4yCAYcThcQ3Ew%3D%3D
It is a 20A 3s-6s esc

Here is the next version of it(somehow it is cheaper than the first one)
https://www.mouser.in/ProductDetail/?qs=l7cgNqFNU1hqucyPrM36%252Bg%3D%3D

Hello,
Great job !
Excelant information keep sharing!

Thanks,
Rina Roy
Dot Net Training

these are available in element14 to and there is a bigger version

https://in.element14.com/stmicroelectronics/steval-esc001v1/eval-board-bldc-pmsm-motor-controller/dp/2761535

Trinamic stuff right now are best as they have hardwired FOC or check microchip pure software.

Trinamic is very costly though...I don't think its worth it

its not about cost but easy to tune and use ( no math required when doing FOC calculations).