Barrel Stabilization

[Vince Cutajar]

A quick update :

I must be mad !!!!!
I used my Tiger 1 turret as a test bed !!!!!!

Temporarily fixed the sensor in the turret and crossed fingers.
Tilt the turret forward and barrel goes up. Tilt the turret backward and barrel goes down.
So, in principle, it works. Only drawback is that it's slow. I had changed the elevation mechanism dc motor to a slower motor as I thought the original was too fast. Original motor gear ratio was 18:1 and the motor I am using now has a gear ratio of 60:1. So I guess, with the original motor, it will look better and no, I am not going to change the motor again.

Also, the L298N motor driver I am using reduces the input voltage to the dc motor by 2V which does not help.

I will try to take a video with the help of my wife as it's not a one person job.

So as a proof of concept, it's working. I might try if possible to add software limits to how much the barrel goes up and down.

Stay tuned for the video.

Vince

[Vince Cutajar]

Sorry for the delay but I ended up taking the video by myself with an old camera (hence no sound) on a tripod.

[youtube][/youtube]

The initial barrel twitch is normal telling me that the pitch angle has stabilized.

As I said in my previous post I am using a slow motor so the barrel goes up and down slowly. If I had to use the original elevation mechanism motor, which is faster, it would look better. Having said that, it will never be quick enough to simulate the real thing.

I did not manage to add in the code for the top and bottom limits. I guess that can be done with microswitches. Hopefully, some day, I'll get one of those light bulb moments and I will find a way to make the limits part of the code.

Still not getting proper yaw angles which could be used for the turret stabilization.

Still, I am quite happy with the result.

Vince

[Vince Cutajar]

I will make this pledge...

For everyone who ends up with Barrel Stabilization on their tank... I will send you, gratis, a 1/6th scale Beer Mug so you can demonstrate this!

I know you will pull it off!!! And it will be my pleasure to send the beer mugs, just to see your stabilized tanks in action!

Cheers,

RPR

Robert, do you have the beer mug ready?
I think that eventually you will need to send it to Youngjae in Korea.

Vince

[Stephen White]

Vince, hope you're right, it's a holy grail for this scale of models. The proof will be to see whether the stabilisation gets out of phase with the model, once it's running. Can't fault the effort you and Youngjae have put in but it just shows that stab is not half as simple or easy as it looks at first sight.

[Robert Reid]

I will make this pledge...

For everyone who ends up with Barrel Stabilization on their tank... I will send you, gratis, a 1/6th scale Beer Mug so you can demonstrate this!

I know you will pull it off!!! And it will be my pleasure to send the beer mugs, just to see your stabilized tanks in action!

Cheers,

RPR

Robert, do you have the beer mug ready?
I think that eventually you will need to send it to Youngjae in Korea.

Vince

I will order one tonite!!!! Tell me where to send it via PM!

I seem to remember being pretty convinced that this project would reach fruition/success within a matter of months. Does anyone owe me a steak dinner

Well done!!!!

Cheers,

RPR

[Vince Cutajar]

Stephen and Robert, it's not finished yet but it feels that Youngjae is making good progress.
I have a good vibe about it and keeping my fingers crossed because as Stephen says it's not as simple as it looks.

Keep it up Youngjae.

Vince

[Robert Reid]

Beer mugs ordered, gentlemen....

Cheers,

RPR

[Robert Reid]

And so are we ready for some mugs, gentlemen? Ready to tool around the proving ground with a mug on the barrel?

Cheers,

RPR

[Vince Cutajar]

And so are we ready for some mugs, gentlemen?

Not ready yet.

Vince

[Youngjae Bae]

I replaced IMU sensor with BNO055 instead of MPU9250, drawing a short and concise code.
Also, I found three proportional constants by introducing PID control and realized the stabilization of the main gun.
However, although my laziness is preventing me from completing the device, anyone will be able to watch my video soon.

Anyone can take about 20 hours to learn from the site below to create their own main gun stabilizer.
Anyone can fully understand the principles and concepts of stabilization.

It works perfectly even if you buy a copy of a cheap copy instead of the original BNO055 at a low price.
But please change the sentence as below.

Genuine : Adafruit_BNO055 myIMU = Adafruit_BNO055();
Clone : Adafruit_BNO055 myIMU = Adafruit_BNO055 (55,0x29);

That beer glass is so beautiful!

https://toptechboy.com/arduino-based-9- ... 55-sensor/

Youngjae

[Vince Cutajar]

Looking forward to see your latest video when it becomes available.

That link to that website looks to be very interesting and will surely keep me busy for some time.

Vince

[Youngjae Bae]

Vince, you can fully understand why I like this link.
There's a video of how people who enjoy RC as a hobby can understand and use IMU, which can possibly be very difficult and dislike math or engineering, why they need 9-axis control, what complementary filters are, what Euler are, why they use Quaternion, maybe what Quaternion is.
If you look at the last 25th and 26th rounds, you'll have a very easy understanding of the PID that I've been rambling on.
I think Vince will be busy enough to learn this.
I will try to burn my passion back in my mind around the end of this weekend and make the beer glass smooth.
To do that, I need to clean my messy workshop.
I like to work, but I tend to hate cleaning up after work because I'm too lazy, which slows the work down.
Now it is summer vacation so I am not doing anything and enjoying refreshment.

And thank you so much for the gift you sent me.
I will print this with 3D printer and apply it to my King Tiger.

Youngjae

[Vince Cutajar]

I like to work, but I tend to hate cleaning up after work because I'm too lazy, which slows the work down.

I know that feeling all too well.

I had a quick look at the last two tutorials just to see what code he is using and was amazed how short the code was. I guess most of the filtering and calculation code is on-board. Could be the reason why the BNO055 is more expensive than the MPU9250. Is that the reason you are using the BNO055 now?

I have seen some people complaining that the BNO055 works perfectly when bench testing it but then it stops working when installed on a moving vehicle. I have also seen similar comments regarding the MPU9250. I suspect that these sensors were initially meant for virtual reality headsets where the user is only moving his head.

Also had a look at the Fusion 360 tutorials on that website picking up new tips.

Vince

[Youngjae Bae]

I had a quick look at the last two tutorials just to see what code he is using and was amazed how short the code was. I guess most of the filtering and calculation code is on-board. Could be the reason why the BNO055 is more expensive than the MPU9250. Is that the reason you are using the BNO055 now?

I am using a cheap copy called "GY-BNO055".
If you write "Adafruit_BNO055 myIMU = Adafruit_BNO055 (55,0x29);", it works exactly like the original and costs 1/5 of the original.
However, the X and Y axes turn 90 degrees. This can be achieved by changing the + to - and - to + in a formula.
The three-step calibration of the sensors he conducted in his curriculum has become unnecessary since he used the quarterion.

I was able to understand the functions of IMU thoroughly by following the lectures on the site step by step.
I think it's very attractive that the code gets shorter.
I sponsored him some iced coffee.
Because it is not easy to get this kind of education separately.

Youngjae

[Robert Reid]

So I am sitting here drinking tiny shots of beer out of these little 1/6th scale mugs...

It's really hard to have a pint at this rate.

Is anyone ready for me to ship them some mugs? Contest is still on!

RPR