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Topic: UGV/robot Motor sizing..... I need some guidance  (Read 256 times) previous topic - next topic

Megatronx

Hi Everyone

I am building a UGV which will be used for underground/pipe cleaning purposes. On it there will be cleaning tools which will be around 100 kg. Also the UGV will be pulling a hose and cables (for power & Camera) which will weigh about 300 kg to 500 kg.
it will work in environment where there will be liquids and possible acids. 

I am using arduino uno to control it however I need some help and recommendation on what types of motors I can use/the size of them?

Can you help and show me how to select/calculate in the correct manner?
I would appreciate if someone with previous similar project history to be my mentor/supervisor on this project for guidance.

Thank you very much

MorganS

I think you should get 500kg of hose and drag it along the ground to measure the force required. Add some corners too.

Does the robot grip the pipe top and bottom? Without that extra traction it will be impossible to drag that weight of hose with only 100kg of robot.
"The problem is in the code you didn't post."

Robin2

I agree with what @MorganS has said.

But really this is a serious mechanical engineering question that is far beyond the scope of this Forum.

...R
Two or three hours spent thinking and reading documentation solves most programming problems.

MorganS

And serious electrical engineering. From the specs so far, this sounds like 1000m of cable to transmit power and control the robot. So high voltage and a interference-resistant communication.
"The problem is in the code you didn't post."

Megatronx

well indeed its not going to be easy I know. hence I am here asking for your help.
The robot will be gripping on the pipe walls. so will have a grip that way. 4 corners @ 45 deg. on each side top and bottom. it will be manually fixed.

What would be realistic to say?
shall I make further smaller robots to place on the hose for pull force support? lets say these robots will be placed every 50 meter to pull the hose along with the mother robot all pulling at the same speed?

There has been many ideas but I am struggling to find experienced advice!

if 500kg is not possible, will 300kg be more realistic?

Thanks

Robin2

well indeed its not going to be easy I know. hence I am here asking for your help.
The robot will be gripping on the pipe walls. so will have a grip that way. 4 corners @ 45 deg. on each side top and bottom. it will be manually fixed.

What would be realistic to say?
shall I make further smaller robots to place on the hose for pull force support? lets say these robots will be placed every 50 meter to pull the hose along with the mother robot all pulling at the same speed?

There has been many ideas but I am struggling to find experienced advice!

if 500kg is not possible, will 300kg be more realistic?

Thanks
I don't usually quote a complete message but I have done in this case to illustrate the following question ...

Why do you think that people who program Arduinos as a hobby would have the expertise to advise you on any part of that?


You need the advice of a suitably qualified professional engineer - and it probably won't come cheap.

...R
Two or three hours spent thinking and reading documentation solves most programming problems.

Paul_KD7HB

How will your robot handle joints and welds in the pipe?

Paul

Megatronx

I don't usually quote a complete message but I have done in this case to illustrate the following question ...

Why do you think that people who program Arduinos as a hobby would have the expertise to advise you on any part of that?


You need the advice of a suitably qualified professional engineer - and it probably won't come cheap.

...R
They will not answer if they don't know... I am asking for someone who knows!
I don't mind paying a professional engineer to do it for me, but I want to learn my self which is why I am here.

Thanks

Megatronx

How will your robot handle joints and welds in the pipe?

Paul
Hi Paul

The robot will be similar to a high pressure centralizer which is used for jetting/HP cleaning. it will not be passing through bends more than 45 Deg.

My main question is how do I size my motors to carry that weight? nobody seems to be able to give me the answer of theoretical design steps where I can calculate this to be able to size my motor correctly. now the weight can be reduced but it means the distance of cover will be reduced. but I want to know what is the best I can get to with the full weight.

Thanks Paul

MorganS

Design steps? That seems obvious. But maybe it is only obvious to me because I am actually a professional mechanical engineer.

A. Start with answering my question in reply #1.
B. Estimate the rolling resistance of the robot.
C. Determine the maximum slope this is expected to climb.

The total drive force = A + B + weight*sin(C)

The total power = force * speed

That should get you started on selecting a motor with enough power.



Then you need to select a gear ratio...

Torque at the wheels = force * diameter/2

Torque at motor = wheel torque / gear ratio

Motor speed = wheel speed * gear ratio
"The problem is in the code you didn't post."

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