Senior Mechanical Engineering project. UPDATE: Completed.

Projects General Guidance
1

Hello all,

Im completely new to this arduino life, so please have some patience with me and i appreciate any help.

Im a senior in Mechanical engineering and my team is building a "large cart" that can transport a 30,000 lb wind blade that is approx 150 feet long. The cart will turn by using two hydraulic actuators that are controlled by an electric pump, which will be powered by at least one 12 V DC car/marine battery.

What I was hoping to accomplish was having an arduino kit that can turn this electric pump on and control the hydraulic actuators. I would like to have it support bluetooth, or some form of wireless communication that can connect to an android or iPhone that has an app with a left and right arrow, and a start button for the electric pump. If this is not possible, than I could make my own wireless controller that will steer the hydraulic actuators and start the electric pump.

Too clarify:

Wheels <-- Hydraulic acctuators <-- Arduino (+ whatever shields it needs) --> sends bluetooth signal --> Phone app or some form of wireless controller

Is anything like this possible? Does anyone have any ideas if so? Honestly anything could help, even a simple guide or tutorial, something I can read to gain more information on this. All help is seriously appreciated!

2

Yes, this is possible, but what you have described is certainly not a project that anyone would recommend for a complete beginner in Arduino.

How many months can you allot to learning the necessary background?

3

So the Arduino controls the cart's steering but not its motive power?
The electric pump directly controls the actuators and not via a hydraulic accumulator?
Are you going to make more than one of these?

4

jremington:
Yes, this is possible, but what you have described is certainly not a project that anyone would recommend for a complete beginner in Arduino.

How many months can you allot to learning the necessary background?

I have until may 2nd to complete this, and about 4 other team members who can help me. I also have coding experience in C++, java and python, and a buddy who's good with arduino but doesn't have the time right now to answer all my questions.

ardly:
So the Arduino controls the cart's steering but not its motive power?
The electric pump directly controls the actuators and not via a hydraulic accumulator?
Are you going to make more than one of these?

Were building the support for the front of the wind blade. The rear will be powered and is not part of our project so i don't need to worry about supplying motive power. Basically the cart thats in the front just needs to be able to turn a small radius. Yes, its an electric pump with a reservoir that will activate the hydraulic actuators in series: As one piston pushes the wheel out, the other piston pulls the opposite wheel in, causing the cart to turn. I am only making one of these.

Im thinking it might be simpler to just have some form of wireless controller and completely ignore the phone idea.

5

Shifting large wind turbine blades around is quite common these days.
Here is a video of a 57m blade making a 90 degree turn to cross a bridge.

The vehicles to carry these loads usually consist of tractor unit and some kind of rear drive bogie. Since these vehicles already exist it seems strange to be trying to develop on rather than to purchase or hire one. It some cases blades are transported partially upright - presumably when there is no wind.

6

ardly:
Shifting large wind turbine blades around is quite common these days.
Here is a video of a 57m blade making a 90 degree turn to cross a bridge.
https://edition.cnn.com/videos/world/2017/10/05/trailer-turning-scotland-wind-turbine-blade-sje-lon-orig.cnn

The vehicles to carry these loads usually consist of tractor unit and some kind of rear drive bogie. Since these vehicles already exist it seems strange to be trying to develop on rather than to purchase or hire one. It some cases blades are transported partially upright - presumably when there is no wind.

Im attending the University of Maine, Orono. They have a composite center where they test wgindbaldes for companies i can't disclose but I'm sure you could figure it out. It needs to be moved in and out of the building and thats all. Doesn't need to go fast, and a tractor is holding and powering the rear. Thats why we were assigned to build something that could steer the front. I agree it would be simpler to buy something that already works, but we don't have a large budget and they are doing this because its basically free labor and teaches us what a real world project might be like.

Anyhow, my buddy just gave me one of his arduino Uno boards. From my understanding I need a relay for the hydraulic actuators and the electric pump, a shield to communicate with some wireless controller, and regulator so the 12 V DC car battery doesn't fry the arduino board. Is this correct? Am i missing anything? Does anyone have any guides or any info they can supply me with to help me get closer to the answers I'm looking for? Iv been trying to google and use youtube but theres so much random info out there.

7

Anyhow, my buddy just gave me one of his arduino Uno boards.

That's a start :wink:

It's dead simple in principle, and you should start simple on your desk. As you move to real life it will need careful design to handle the power of the real motor. Sounds like that motor will just be off or on and only turns in one direction?

No reason why you shouldn't just get a toy motor of say 6V which you can run off a bunch of AAs, with a typical mosfet. Easy to control with Arduino like this. Mosfet like a IRLZ44N or similar may do the trick. But first you need to work though the basic tutorials here or in the IDE in File > Examples.

There are loads of BT / Arduino blogs and such, like this one. Scroll down and there's some basic stuff about getting a BT module to talk to Arduino.

8

wilfredmedlin:
That's a start :wink:

It's dead simple in principle, and you should start simple on your desk. As you move to real life it will need careful design to handle the power of the real motor. Sounds like that motor will just be off or on and only turns in one direction?

No reason why you shouldn't just get a toy motor of say 6V which you can run off a bunch of AAs, with a typical mosfet. Easy to control with Arduino like this. Mosfet like a IRLZ44N or similar may do the trick. But first you need to work though the basic tutorials here or in the IDE in File > Examples.

There are loads of BT / Arduino blogs and such, like this one. Scroll down and there's some basic stuff about getting a BT module to talk to Arduino.

Awesome, thats the kind of info I am looking for. I will check those tutorials out. He also gave me a kit with this and 9V batteries. Ill start getting the items in the kit to work with the board so I understand the code and basic functions.

9

Indeed basically straightforward to build but with quite some complications, your hardest part is probably going to be to control those high power hydraulics.

For the bluetooth part, look at the HC-05 or HC-06 modules. Commonly used, should be easy to communicate with your phone.

You'll also have to write your own app for this to use on your phone.

It's good you don't try to control the actual powering of the wheels, as if that goes wrong it's much more likely to be catastrophic.

10

What you've described seems straightforward and possible. Does your Arduino friend agree? Make sure you've got enough outputs for the number of motors you're driving.

..and about 4 other team members who can help me. I also have coding experience in C++, java and python, and a buddy who's good with arduino but doesn't have the time right now to answer all my questions.

In that case "the Arduino" shouldn't be a big deal. You can get a Wi-Fi or Bluetooth shield and there are programming libraries for these. However, you might need a 5th team member to help with the electrical/electronics. And someone will have to write the phone app. I kinda' feel like the phone app will require more programming (and more difficult programming) than the Arduino...

It wouldn't hurt to learn something new but you don't want to get bogged-down by something that's not in your field-of-study.

11

An alternative to using Bluetooth would be a pair of nRf24L01+ modules - one in the cart and one in a hand-held Arduino unit.

Bluetooth is fine if you have a suitable program on your phone or are capable of creating that program. If not, the nRF24s system may be easier to implement.

...R
Simple nRF24L01+ Tutorial

12

wvmarle:
Indeed basically straightforward to build but with quite some complications, your hardest part is probably going to be to control those high power hydraulics.

For the bluetooth part, look at the HC-05 or HC-06 modules. Commonly used, should be easy to communicate with your phone.

You'll also have to write your own app for this to use on your phone.

It's good you don't try to control the actual powering of the wheels, as if that goes wrong it's much more likely to be catastrophic.

Do you have any recommendations on how I might go about controlling the hydraulics? I can either run them as a series or run them individually, it hasn't been determined yet. Basically the arduino would just be telling the pump to supply pressure to the hydraulics. From my understanding so far, its a relay that runs from the power supply to the arduino and the hydraulic actuator? If i run it to a series than I think i really only need one signal to the controller. Which would send a signal to the ardunio, starting the electric pump and supplying the needed pressure to the hydraulic actuators. Most pumps come with a switch already and i could probably strip those wires and run them to the ardunio. I would just use a cabled controller but the "client" is asking us to create a wireless one.

DVDdoug:
What you've described seems straightforward and possible. Does your Arduino friend agree? Make sure you've got enough outputs for the number of motors you're driving.
In that case "the Arduino" shouldn't be a big deal. You can get a Wi-Fi or Bluetooth shield and there are programming libraries for these. However, you might need a 5th team member to help with the electrical/electronics. And someone will have to write the phone app. I kinda' feel like the phone app will require more programming (and more difficult programming) than the Arduino...

It wouldn't hurt to learn something new but you don't want to get bogged-down by something that's not in your field-of-study.

Yes my arduino friend believes that it shouldn't be too difficult and that it certainly possible to do. He recommended i ask questions here due to him being busy with his own senior project. I agree with you about the iPhone app, and in fact i might scrap that idea all together. Is it possible to build a simple controller, just a start button for the electric pump and a left and right arrow (or joystick) for the hydraulic actuators?

I know what you mean about not getting bogged-down, but the "client" is asking us to create a wireless controller to turn it, so i really don't have too much of a choice right now.

Robin2:
An alternative to using Bluetooth would be a pair of nRf24L01+ modules - one in the cart and one in a hand-held Arduino unit.

Bluetooth is fine if you have a suitable program on your phone or are capable of creating that program. If not, the nRF24s system may be easier to implement.

...R
Simple nRF24L01+ Tutorial

https://www.amazon.com/Makerfire-Arduino-NRF24L01-Wireless-Transceiver/dp/B00O9O868G
Is that what you are referring too? Then i would just need to buy a receiver for a controller and program that as well?

I think i will drop the bluetooth phone idea, as the consensus seems to be that it will make everything more difficult.

13

Jtfox12:
Yes, its an electric pump with a reservoir that will activate the hydraulic actuators in series: As one piston pushes the wheel out, the other piston pulls the opposite wheel in, causing the cart to turn. I am only making one of these.

Well, you have already failed the exam. Think about driving a car. The inside wheel on a turn has to be at a greater angle than the outside wheel or one wheel will be dragged on the road.

You HAVE to control each wheel turning individually and at angles that are in the correct ratio to the axle width.

Paul

14

Paul_KD7HB:
Well, you have already failed the exam. Think about driving a car. The inside wheel on a turn has to be at a greater angle than the outside wheel or one wheel will be dragged on the road.

You HAVE to control each wheel turning individually and at angles that are in the correct ratio to the axle width.

Paul

I thought this is how a steering piston rack works? We're basically doing the same thing, correct? We really don't need that large of a radius, and it will be moving slower than 5 mph so we planned on attaching them to the back side of the hubs. Sorry if I'm misunderstanding you, I believe i do get what you are saying, and if thats so then I can just use separate hydraulic actuators and not run them in series to account for the different angles.

Edit:I appreciate the correction, criticism, and help. I confirmed my understanding of what you mean after i read about it. Will this really make a difference if I'm going at such a slow speed though? Like i said it won't be moving faster than 5 mph.

15

Jtfox12:
Are you sure thats correct, this is how a steering piston rack works? We're basically doing the same thing, correct? Sorry if I'm misunderstanding you, I believe i do get what you are saying, and if thats so then I can just use separate hydraulic actuators and not run them in series to account for the different angles.

Look at the steering mechanism of any road vehicle. If you design the wheel mechanism properly, with a "tie rod" you can use one hydraulic cylinder to move both at the same time. That is how you car works with assisted steering.

Go talk to someone familiar with automotive design.

Paul

16

Paul_KD7HB:
Go talk to someone familiar with automotive design.

Look up Ackerman steering, which gets the two steering wheels at the correct angles to allow for the different radii. You can mock it up easily in Mecanno, that's been done loads of times, and I'm sure there will be plans around.

17

I think it is time for some more detailed discussion of the cart you are planning.
How many wheels?
Often, carts have 4 wheels, 2 steering and 2 non steering. Is that your configuration?
One hydraulic actuator controlling the steering of each steering wheel?
A pic would be helpful. Use this handy image guide.

Are you going to have any position feedback of the steering position? So that the arduino knows when the hydraulics have turned the wheel far enough?

18

wilfredmedlin:
Look up Ackerman steering, which gets the two steering wheels at the correct angles to allow for the different radii. You can mock it up easily in Mecanno, that's been done loads of times, and I'm sure there will be plans around.

Okay thanks! Ill check it out.

vinceherman:
I think it is time for some more detailed discussion of the cart you are planning.
How many wheels?
Often, carts have 4 wheels, 2 steering and 2 non steering. Is that your configuration?
One hydraulic actuator controlling the steering of each steering wheel?
A pic would be helpful. Use this handy image guide.

Are you going to have any position feedback of the steering position? So that the arduino knows when the hydraulics have turned the wheel far enough?

Yes a cart with 4 wheels, none are powered, front two steer.
Either one hydraulic actuator controlling the steering or two different ones. I talked to the head engineers at the school a few minutes ago and they said that since were moving slow enough and the turning radius of the wheel doesn't need to be that high, then I don't really need to account for one wheel dragging, as paul mentioned earlier.

I was either going to have a position feedback like you mentioned or calculate and apply a piston rod that can only travel as far as the max radius of the wheel that we are looking to turn. We really don't have a lot of help, and they are trying to let us fail or figure it out, so we are going by what we have learned, our intuition, and advice/help from others that we ask. Making it a difficult project for us as this is the first time we are applying concepts, and you really don't know anything until you've been out in the field for awhile, or so iv been told over and over again.

I can upload a design in an hour or so, meeting with my group then and we have a design mocked up. I should also have it completed in Solidworks by Thursday.

19

Awesome. 4 wheel cart holding the front end of a 150 ft long, 30,000 lb blade.
I assume (but would like confirmation) that the cart has a cradle of some sort to hold the blade.
And that cradle can rotate, allowing the cart to rotate under the blade as you turn the cart.

You had mentioned a wireless steering input. There are common wireless steering input devices available.

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But whatever you choose, I would think it would require positional awareness, so that you can make large steering input to start a large change in direction, and also make small adjustments to hold a straight line.
Think of driving a car. You are constantly making small corrections as you go.

20

I wouldn't worry too much about the niceties of ackerman steering. If the wheels have pneumatic tyres the angular relationship between the tyres and the road and the turning force generated by each wheel is very complex. Generally, for example, the outer wheel will need to provide a greater turning force because the turn causes more load on that side. To produce a higher turning force the tyre needs to run at a higher slip angle - i.e. less ackerman effect.

Just make sure both wheels turn in the same direction.

Jtfox12:
Is that what you are referring too? Then i would just need to buy a receiver for a controller and program that as well?

Yes. You will need an nRF24 and an Arduino (or maybe just an Atmega 328) in the hand-control unit and another nRF24 in the cart.

...R