Hi every body ;

My graduation project is about automated tower crane using PLC , And I am supposed to implement a prototype for this crane also.
and to be more specific in my questions , I am asking about criteria of project and information ;

1-implementation of prototype is possible
2-seq. of operation
3-sensors availability

I`ll appreciate every single information from u

thnx in advance.

 

You have to be a little more specific than that.

How big is this crane?
What type of crane?
What is it going to be fabricated from?
What types of motors are you planning on using?
What will be the power source?
What PLC are you using?
Will you be using Ladder Logic?

there are so many more questions......

So a little more info on your project would be great...

My .02

 

You have lots of things to consider:
1. Y variable, up and down and speed. Motor 1
2. X variable, in and out and speed. Motor 2
3. Z variable, Angular rotation, Fwd, Rev. and speed. Motor 3
4. Weight determination, what does this? strain gage, motor current monitor?
5. Emer. stop, by mechanical means? How? pull cable-limit switch?
6. Power Fail monitor, battery backed-up Emer. Stop controls?
7. High Wind Warning, anemometer input to PLC?
8. Ice Warning, analog thermocouple input to PLC?
9. Flux Gate Compass Input.

Anything else...Regards, DPW [ Spent years making heaters out of op-amps.]

 

Thanks BMORSE for ur attention and thanks DPW for ur great info. ;

and for BMOSE ... many of ur questions are those which i need answers for !! like type of motors I`ll use ? and What is the prototype for this tower crane going to be fabricated from?
I have a seimens plc with enough I/O Ex. and I`ll be using ladder diagram for programing

I think the motors will be stepper motor ... is that right ??
I also need to know a few ideas about the prototype implementation .

thnx in advance

 

First I have to ask, are we talking about some kind of Masters / Bachelors degree graduation, or high-school?

What is the exact task you are supposed to do? - like "Design and fabricate a full-scale crane with 5t maximum load, controlled by PLC logic device"

I think the motors will be stepper motor ... is that right ??I also need to know a few ideas about the prototype implementation. thnx in advance

This depends on my second question, is it gonna be an one meter high "toy" crane, or a full scale 40m construction site crane?

 

hi kubeek ;

yes , It is a bachelor degree graduation project , and it should be a simple prototype about one or two meter/s high ( laboratory size) crane which can tilt around the base, translate through the arm connected to the base at a constant height, and can lift and lower the load to simulate the real industrial crane.

 

Well my 0.02 is you should atleast be able to answer the first 3 questions on your own if it is a capstone project for YOUR program...

 

well, for a 2 meter high crane ........ I am not sure what materials are available to you but you can either build it all out of extruded aluminum (which would be expensive), or you could build the crane out of PVC pipe and fittings (which would be cheap, lightweight and easy to assemble if PVC couplers are used, no gluing the assembly is necessary everything can be pressed fitted together)...

and I would use DC Gear Motors, they will offer more torque than a stepper for your application, and use encoders to monitor crane / load position.... use an H-Bridge IC to control the motors (use the LMD18200T it has current output so you can use that to monitor crane movement in case it hangs up on something or the "Load" is too heavy), you can use 555 timers (or microcontroller) to produce PWM signal to drive motors (so they would be more efficiently driven for higher torque at lower speeds, which in this case is what is needed since a crane does not move that fast or else you would swing your load around like a pendelum!).

Use a "lazy Susan" (use google to find out what this is if you don't already know) type of device for the swiveling base (these can be found at a local home improvement store in the kitchen cabinets section).

Make sure you use bearings on all shafts driven by the motors to minimize drag and wear on your motors and loading, especially on the base.....

 

Does your school pay for the materials needed? If yes then it shouldn´t be too hard to get appropriate sensors for the positions and force. You just need to control three motors, that shouldn´t be that hard. But why do you have to use PLC, can you use CPLD or FPGA for it? What type of logic device you can use?