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Ashu175181
07-24-2010, 08:17 PM
Hey there

I am designing a Solar energy operated Glass cleaning Robot.
For that i need as much as material possible on slip stick actuators.
Also i want to know their dealers in India

docel
07-25-2010, 10:01 PM
I think you have the wrong combination for the task:
1. Solar energy cannot drive anything run-time.
2. Glass cleaning is a tricky business. You'll have discovered this if you have cleaned glass anytime by hand. The mechanism needed for it will be quite complicated and expensive.
3. The Slip-stick actuators are basically vacuum drive devices if they have to bear the heavy machine.
4. If you are cleaning the Glass, the slip-stick mechanism has to be fail proof, as the very act of cleaning glass is a slippery method.

Now, the million dollar question is: aRe these Robots practical? Would they really be a serious working Robot useful enough for the myraid types of windows on high-rise buildings?

There are several points to ponder here.
1. The biggest point is Safety. Suppose it falls.....
2. What happens to the resultant muck collected after cleaning? It is difficult to prevent the cleaning agent etc., from running down from above and dirtying the already cleaned windows.
This requires kilometers of tubes that will weigh a 'ton' in reality.
3. The Robot itself will itself get dirty after several windows.

We made a couple of these robots some years ago and concluded that it is impractical to have a glass cleaning Robot other than for demos and technology generation. If the primary intent is automation, then the robot cannot fit the bill at all.

It will be better to have some detailed discussion in this regard before you take up the job seriously.

Ashu175181
07-25-2010, 11:03 PM
I understand your point that making a glass cleaning robot for automation is impractical and costly.
I am trying to design this robot as a part of my B-Tech project, and i am not much concerned about its practical utility.
Right now, i was worried about its Gait, and with this regard i needed intel on slip stick actuators.
As you said you have designed demos in past, so can you please give me some insight into your Design.It will do me a great help.

Thanks for your reply and looking forward to hearing again from you.

docel
07-25-2010, 11:30 PM
Ok, so lets hear about your plan: what do you have in mind?

Without any knowledge of what you plan to do , it may not be possible to give you any suggestions. If you aren't concerned about its practical utility, as a BTech project, I fail to understand what exactly you want the thing to do..

It will be appropriate if you can explain the mechanism that you want in one post rather than dropping one hint per post. This will prevent any confusion and help get to the core problem soon. There are others here on the Forum who have tried this too and will help out.

The simplest I can think of is a reverse hovercraft. All you need is a paper plate , a small motor, a gift-wrapper film and a small propeller.

lolman_returns
07-25-2010, 11:40 PM
Check out this toy, it runs on the principle that doc just mentioned

http://www.geekologie.com/2008/09/whee_toy_car_runs_on_walls_cei.php

Ashu175181
07-25-2010, 11:43 PM
1.)The robot will derive its power from solar cells, so power constraints are decided accordingly.
2.)The robot will have, say 4 legs. Each of these legs will have pneumatic suction pad as end effectors.
3.) Now at any instant 3 out of 4 legs will be flexed (slip stick actuators may be used for this purpose though we are free to use any other means). The vacuum grip of these 3 legs remains intact. The vacuum at the 4th suction pad (which is not flexed) will then be removed. Because of the flexing, the 4th leg has a stress which it will relieve by moving in the appropriate direction as soon as this vacuum is removed. This will give the robot a small displacement.
4.)The same step will be repeated for each leg (i.e. all other legs are flexed and one particular leg is de-vacuumed). Many steps like these will give the robot a random motion over the glass surface.
5) We do not require an active power source i.e. we can wait for the solar cell to build sufficient power before it implements the next step.The speed of the robot is not important too.

As we are never lifting the legs and the motion is only by removal of suction, the power constraints might be accounted for.

docel
07-26-2010, 12:58 AM
Thats a good description of the your design !! Quite realistic too, and can be made to work reasonably with bare minimum resources.

1. I still don't agree to the Solar cell theory.
2. You will need 4 motors to move the 4 legs. each motor will weigh around a minimum 60gms, including connectors and wires.
3. The slip- stick actuators can be those 2 rupee per silicone suction cup meant to stick on glass.
Now, this is the real problem.... It takes some force to press down for adhesion and some real force to peel....
4. The Suction pad needs some mechanics to slide and hold, apart from the movement motors.
The smallest suction cup has a 3kg pull strength. At this adhesive force, it will not slide. Some of the vacuum must be released (partially) for it to slip across but still have some grip.

yaniv
07-26-2010, 07:21 PM
@docel
How about we use suction balls like these as wheels would'nt it t solve the problem? instead of using suction cups on legs ?
http://www.deepfun.com/suction.jpg

docel
07-26-2010, 08:27 PM
well....... It can be used alright- on an inclined plane; but the problem is that the vehicle is moving against gravity. You need a substantial horizontal force to make it 'stick' to the wall. This will necessitate another force component that is perpendicular to the moving plane. Besides, the ball and its cups are too pliant and tends to be pulled down by the weight of the vehicle in the static phase. This will peel it off of the wall.....

vikas
07-27-2010, 02:43 AM
http://www.youtube.com/watch?v=EJaC3gnMsGQ

1. Solar would not work ... too weak
2. Clean glass urself as said by Docel ... it aint easy to get good results
3. The simple suction cups will not work , try buying and experimenting ... they require a lot of force to get a good grip , hard to achieve at an incline by simple pressing.
4. Best way is to use the technique in the above video , Pumps for each custom suction cup , but such an arrangement is might be highly inefficient like the inverted hovercraft approach.

docel
07-27-2010, 06:36 AM
Yes!
What people ignore or fail to understand:
The wall climber involves sticking force that is in the direction away from gravity. You cannot rely on gravity at all.
It is upto you to provide all the forces for this effort. The total forces and their directions are up against gravity + horizontal towards the wall + Newtons 3rd Law.
Any effort to "push" against the wall ( eg. the leg ) will also push the body AWAY from the wall. Therefore , the force needed to keep the body sticking to the wall alone should be greater than twice the weight of the machine.

Before even thinking of methods, one must work out all the Force vectors in several dimensions / axes and their scalar equivalents - a matter of simple high-school Physics.

A review of Force, Energy & Motion is a must!!

lolman_returns
07-27-2010, 10:59 AM
For beginners, I would suggest for you to use more legs. Have you ever worked with a quadruped on ground?, its anyways tough to make it walk.

If you are trying to mimic nature then mimic the majority. What I am trying to say is, insects are way more efficient at this (without the need of tails) as the points of contact to the surface are way more (thats only one of the reason though).

Use atleast six legs, even the gait will be easier. The weight will definitely increase but when the force is spread evenly throughout the body unlike in the case of 4 legs, you will have more stability.

Also, completely agreeing with others, forget solar power, that's for emergency lights and calculators for now. In any case you wont be able to afford the "better" ones and the cheap ones wont be able to make it walk on ground let alone vertical walls and inclines.

Ashu175181
07-28-2010, 01:56 PM
We do not require an active power source i.e. we can wait for the solar cell to build sufficient power before it implements the next step.The speed of the robot is not important too.

What i wanted to say was, i don't care if my robot takes 1 whole day to cover a glass of dimension say 2mX 2m....
Let the solar panel charge the battery enough to provide a few pulses to the slip stick actuator( its a piezoelectric actuator BTW
which will be enough for the robot to move a few inches.
The battery will die now, no biggie, let it charge again, it will then cover a few inches.
The point is once we have installed the robot, we don't want it to continuously move on the glass and clean it every hour, let it take a day!

Solar panel will be a costly affair, but how much money are we talking about? If we remove the solar element then there is nothing new about this Robot, for $10 you can get Climbatron which walks on glass with two legs!There is a myriad of research papers + you tube videos on glass climbing robot but none on solar operated climbing Bot.

I know this whole idea might fail but whats the harm in trying, without having a solid proof it wont work.

docel
07-28-2010, 03:35 PM
We do not require an active power source i.e. we can wait for the solar cell to build sufficient power before it implements the next step.The speed of the robot is not important too.

What i wanted to say was, i don't care if my robot takes 1 whole day to cover a glass of dimension say 2mX 2m....
Let the solar panel charge the battery enough to provide a few pulses to the slip stick actuator( its a piezoelectric actuator BTW
which will be enough for the robot to move a few inches.
The battery will die now, no biggie, let it charge again, it will then cover a few inches.
The point is once we have installed the robot, we don't want it to continuously move on the glass and clean it every hour, let it take a day!

Solar panel will be a costly affair, but how much money are we talking about? If we remove the solar element then there is nothing new about this Robot, for $10 you can get Climbatron which walks on glass with two legs!There is a myriad of research papers + you tube videos on glass climbing robot but none on solar operated climbing Bot.

I know this whole idea might fail but whats the harm in trying, without having a solid proof it wont work.

Well well Well.... I KNEW this was a cheap gimmick Project with NO practical or technical use - other than cheap publicity !!!

The Worlds first solar Wall Climber !!!

Just another fraud in the name of Engineering !!!

Shame.

Ashu175181
07-28-2010, 04:47 PM
I never covered it up from the beginning. I said in my previous post that i am not concerned with the practical utility.
As an undergraduate who is exploring the realms of Robotics all i cared was the knowledge i ll gain from this project. This idea struck me, and i wanted to work upon it.I never wanted to patent my bot or anything.
Thats why i came here cause people who are much experienced and enlightened with this art will hear me.

I don't know if i made it sound like i am gunna make 'Worlds first solar bot', all i wanted to say was the information on this particular topic is scarce.

Already in India where in events like ROBOWARS a wooden board fitted with a motor driving 4 wheels qualifies as a Robot, being a little creative will not hurt, considering the entries in the same event organized by ASME or MIT are incomparable to ours.
Not because they have better facilities but only by their sheer creativity.

allbits
07-28-2010, 09:46 PM
SO this IS a BTech Project.
:)


Solar panel will be a costly affair, but how much money are we talking about? If we remove the solar element then there is nothing new about this Robot, for $10 you can get Climbatron which walks on glass with two legs!There is a myriad of research papers + you tube videos on glass climbing robot but none on solar operated climbing Bot.

Thats a good Idea!! If your project is all about solar panel, buy the climbatron and fix the solar panel into it. !

Have a few questions to the OP, :)

Do you plan to actually demonstrate
a) your robot climbing on the glass?
b) your robot cleaning it?
c) Your robot running on Solar?

do you actually want to demonstrate all of them, or some of the above??
or do you want to submit the work as a paper/report as a part of your project?


If your critical point is about robot running on Solar, you need to learn a LOT on solar panels.
eg .. : how much power you can derive from a square inch of panel - crystalline or amorphous.. In that way you can calculate how much TIME your panel will take to charge your battery, and then it also means you need to know how to charge a battery.
You need light weight batteries, probably Li chemistry, and you cannot charge them like that with a Solar panel..

Please do basic math on power required/power derived from the solar, and that will help you understand the core points of the replies you already got in the thread.
I do not mean to discourage, but if you seriously want to demonstrate all three points I asked you, make sure your pants have deep pockets, and that you have at least a year before your presentation, if you plan t do it yourself, as you got to learn a lot, a real lot to have an indigenous design of this kind running on vertical glass surface.

ps: I get irritated when students say 'there is nothing new in a robot if 'this thing' is not there. I have also seen them ending up with doing nothing new, noting creative. Students should look at themselves and understand how much they know about a topic before they start designing a project. Understanding ones strength helps a lot, if not, they will end up using somebody else's brain and time.

Ashu175181
07-28-2010, 10:24 PM
As things have turned i am currently worrying only about how it will move on a glass using solar energy.
And fortunately i do have a year to complete it, and yes i plan to demonstrate it and also write a research paper.
But the cleaning part, that really looks tough as for now!

So following your advice i ll spend my time learning about solar Cells as much as i can first.
And yes sir from my past post i sound just the kind of student who says ''there is nothing new in a robot if 'this thing' is not there."
But i assure you i am doing this not because this is unique or something ,or it will get me better marks, but only cause i want to.

allbits
07-29-2010, 02:48 AM
make a couple of 200mA motors run with solar cells.
Come back after that.
:):)
But, you still have not answered my questions :P:P