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Topic: Motorized pan/tilt, zoom and focus videoscoping setup for field use. (Read 2196 times) previous topic - next topic

VidiBot

[edit 30-12-2012: added side view of the pan tilt construction (it looks too small for it is not scaled ) and changed trackballs on remote to thumbsticks . ]

Hello there and nice to meet you,

lately I've been looking into a lot of arduino videos on yt and I think this platform is the key to realize the following project:
A super smooth pan/tilt head that is remotely controlled and able to record and accurately reproduce all (motor) movements.
It should be as light weight, energy efficient, silent and cheap as possible  :smiley-eek: .
Since I am a noob in robotics and programming I'm hoping you can help me a bit.

This is what I have in mind for the hardware setup:



The part of the setup that has to be moved weighs  2.5 Kg.
Used for filming with a magnification up to 200x movement it should be really smooth and accurate.

All motors have a different task;

-The Tilt motor has to be the strongest and must have sufficient holding power, I'm not sure about the belt drive but I figure it
 filters out vibration a bit and enables the motor to sit in the centre of the setup.
-The pan motor doesn't have to be as strong as the tilt motor but it should be relatively fast.
-The focus motor should be small but strong enough and doesn't have to be fast.
-The zoom motor should be really small but doesn't have to be strong or fast.

What motor is most efficient/suitable for what task (type, specs) ?

I also need a small actuator or something that can physically push the record button on my camera.

What can I use for that ?

A 9DOF IMU should be the main reference for the whole system so there is no chance of drift.

Is the latency low enough, is it accurate enough, what is the best sensor ?
Should I have motors for pan/tilt with a hall sensor build in and use the IMU signal for PID to correct the motor movement ?

Battery and processing module are mounted on the tripod and wired to the motors, actuator and sensor.
The arduino due seems to be the best choise, more processing power and less voltage.

What is the best arduino, motordriver and battery ?
(I hear dewalt batteries are used for medical field use röntgen applications. )

The other part is a remote control:




The remote is wired to the arduino and the 2 cameras. It has it's own battery pack.
A trackball (2 rotary encoders in one knob ) and a potentiometer (controlled by a game controller like trigger ) to control the direction and speed of the motors seems to be ideal for precision operation.

I have a 7" video monitor that has an HDMI input (connects to the main camera) but I would like to have a tablet pc with an HDMI input ... but there seem to be no tablets with that option ..
Is there a way to "hack" a tablet computer to have a hdmi input ? (have touch screen and run a program)  

Should I stick with the monitor I have and make the arduino display an onscreen menu via hdmi or composit video ?

Your feedback is very much appreciated.

Martijn










http://www.youtube.com/user/Strunkgx/videos

Drew Davis

Quote
I also need a small actuator or something that can physically push the record button on my camera.


I would use one of these options...

http://www.robotshop.com/productinfo.aspx?pc=RB-Sbo-109&lang=en-US

http://www.robotshop.com/productinfo.aspx?pc=RB-Fir-40&lang=en-US

You could also use a regular servo to push it with a beam fixed on the horn...

http://www.robotshop.com/productinfo.aspx?pc=RB-Hit-27&lang=en-US

Quote
What is the best arduino motordriver


Your going to need more then one and probably different ones because the amperage of each motor will be different.Here are some I like….


https://www.sparkfun.com/products/9457?


http://www.robotshop.com/productinfo.aspx?pc=RB-Dfr-19&lang=en-US

You could also build your own easily. If you chose to do that order the parts from http://www.digikey.com… Best prices ever!!!

Best of luck,
Drew Davis




Drew Davis

Depending on the battery voltage you need you could uses vex batteries. They have worked well for me, last a long time, and are nicely priced. Robot shop also sells their charger.

This is one kind they sell...
http://www.robotshop.com/productinfo.aspx?pc=RB-Inn-179&lang=en-US


zoomkat

You could send your pix to the below servocity peeps and have them suggest what parts they have that might work for you.

http://www.servocity.com/html/pan_tilt_roll___accessories.html
Google forum search: Use Google Advanced Search and use Http://forum.arduino.cc/index in the "site or domain:" box.

cr0sh

If you have enough money to spend on the kind of telephoto glass you are depicting - you have enough money for a serious professional solution.
I will not respond to Arduino help PM's from random forum users; if you have such a question, start a new topic thread.

VidiBot

Thanks Drew and zoomkat, this is already some useful info.
@cr0sh, I could indeed buy a pan tilt head from servocity, they are just in my price range but then I still wouldn't have the remote and functionality I'm looking for. The other thing is the challenge to build it myself and learn about robotics along the way ..
http://www.youtube.com/user/Strunkgx/videos

Drew Davis

Thats the spirit!!!

The one thing I don't understand about your project is how you plan to move your camera around. Are you adding the motors to an existing tripod or are you making your own. Before I can recommend motors to you I need to know how they will attach… gears, pulleys, shafts, etc.

VidiBot

@ Drew

I put a side view (nothing is really scaled in these pics btw) on the "Camera Setup" picture to give a better idea.
I'm planning to make the pan tilt head from scratch with prefab carbon fiber rectangular tubes. Maybe I use some existing parts to be able screw it on a basic tripod and maybe I also use an existing bearing ( so the total pan part of a normal camera head ) for the pan action.
My idea looks a lot like the servocity pan tilt heads, but I like to have less weight and preferably no motors sticking out on the side for they can catch more wind .. which is already a bit of an issue filming outdoors, and it should fit on a standard tripod.

I have been looking into geared motors and there are a lot of different ones, all different rpm and different voltage so the final gear ratio and the load it has to cope with are very important I guess. I know the scope + camera + bracket weighs about 2 Kg, some things will be added so finally it will be like 2.5 Kg that has to be moved up, down, left and right.

Any comment that would lead me in the right direction will be useful :)

Thanx in advance.


(If you are interested in seeing some of my vids: http://www.youtube.com/user/Strunkgx/videos
Moving my rig around by hand isn't nearly useable for movie, it's basically a photo setup, that's why I want to try to realize this rig.)


http://www.youtube.com/user/Strunkgx/videos

zoomkat

A question might be is how will you know when the camera is properly aimed at the subject?
Google forum search: Use Google Advanced Search and use Http://forum.arduino.cc/index in the "site or domain:" box.

VidiBot

@zoomcat

The "Remote" is a screen ,where direct feed from the hdmi out of the camera is displayed *, with controllers on the side to operate the system, so there I can see if it's all aimed, zoomed and focused right.
For the recall, where the system goes back to a saved position (lets say a birds nest), zoom and focus it should get back into that exactly position with feedback from the 9dof sensor.
To get to the exact zoom and focus these motors should "know" their exact position .. I'm hoping using motors with a hall sensor should  be able to do this ..

* also I should be able to switch on this screen to the wide view camera, where the center is exactly the center of the main camera, so I can aim the system to that certain spot more easy. 
When you see a bird land in a tree 200 meters away and you have to find that spot with only the the main camera/scope it can be really difficult because you only have a very narrow view.
When I'm then aimed at that spot I turn back to main camera view, adjust the pan and tilt a bit, set zoom and focus and start filming.

http://www.youtube.com/user/Strunkgx/videos

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