Hydraulic axis positioning and synchronization

Hello everybody.

I need  some help from you guys. I have a course project which requires a 500T structure to be folded/unfolded . The folding/unfolding is achieved in several steps via a variable axial piston pump and  2 hydraulic cylinders each 5000kN. I would manage to implement the control buttons, switches,sensors and limit switches for the auxiliary devices (also hydraulically driven) but I face some problems with the control of this 2 cylinders. Basically they should be extended 650 mm  in synchronization , secured and then retracted to home position again in synchronization/ And like this several times till the full unfolding. The position of the cylinders will be controlled by 1 linear encoder for each of them. I have already chosen cylinders,proportional valves for them, linear encoders, pressure sensors and Axial piston pump as well. After a lot of time in internet researches  I have found 2 options for the control. 

Option1: Simatic S1200 with Sinsmics S120 and , CU-320and HLA module using Telegram 166

With this option e I can directly connect the encoders, the pressure sensors and the cylinders to one HLA module and is supported by Tia Portal V.14 (which I have access to)

Option2: Simatic S1500 with SimaHyd library. I have access to Tia Portal V14 which does not supprot this option (at least this is what I understood)

So my questions..

1.  Which function block should I use to command Sinamics S120 with HLA module and how to implement it with the telegram? If I have any example for V.14 I will understand it easily.

2. Do I have any other options to synchronously control these cylinders?

Any help from you will be appreciated !

PS: The end result of course project is not so important. I am really interested in the topic. 

Regards

Martin

 Hi,

I don't have the exactly configuration, but in my experience, I saw an application like that with Sinamics just in master/slave mode. Syncing in this mode is more simple I guess. Does it fit your application? Hope it helps.

Martin Vasilev

Hello everybody.

I need  some help from you guys. I have a course project which requires a 500T structure to be folded/unfolded . The folding/unfolding is achieved in several steps via a variable axial piston pump and  2 hydraulic cylinders each 5000kN. I would manage to implement the control buttons, switches,sensors and limit switches for the auxiliary devices (also hydraulically driven) but I face some problems with the control of this 2 cylinders. Basically they should be extended 650 mm  in synchronization , secured and then retracted to home position again in synchronization/ And like this several times till the full unfolding. The position of the cylinders will be controlled by 1 linear encoder for each of them. I have already chosen cylinders,proportional valves for them, linear encoders, pressure sensors and Axial piston pump as well. After a lot of time in internet researches  I have found 2 options for the control. 

Option1: Simatic S1200 with Sinsmics S120 and , CU-320and HLA module using Telegram 166

With this option e I can directly connect the encoders, the pressure sensors and the cylinders to one HLA module and is supported by Tia Portal V.14 (which I have access to)

Option2: Simatic S1500 with SimaHyd library. I have access to Tia Portal V14 which does not supprot this option (at least this is what I understood)

So my questions..

1.  Which function block should I use to command Sinamics S120 with HLA module and how to implement it with the telegram? If I have any example for V.14 I will understand it easily.

2. Do I have any other options to synchronously control these cylinders?

Any help from you will be appreciated !

PS: The end result of course project is not so important. I am really interested in the topic. 

Regards

Martin

Thanks pal,

I found the application you are talking about. I believe it will be suitable for me.

As I understand when selecting a communication telegram between the drive and the PLC during commissioning it is automatically inserted in the S1500 Motion Control FB of the technology object and I don't need to deal any more with it.I need just to specify for which axis I am using the FB. Am I right? I was confused because I found one application that used custom FB and the telegram had to be specified in the function blog.(FB file attached).

Please correct me if I am wrong.

Hello Martin Vasilev,

I would go definitely Option2: Simatic S1500 or its smaller brother ET200sp s7-1512-SP just without any  Library.

Since you got proportional valves, scale there position measurement from 0-100% and check how do you control them, with PLC AI giving them reference from 4-20 or 0-10VDC?

In either case proportional valves got some dead band, and usually they can be controlled easily with just one simple PID mathematical equation.

So I would suggest to use FB41, PID.  Set it's Low and High limit to the -100  and 100.

• 100 would mean that your cylinder is moving with maximal speed in one direction
• -100 would mean that your cylinder is moving with maximal speed in opposite direction

Do the same for the second cylinder.

Best Regards Soble

Hi Soble,

Sorry for the late reply but I was kinda a busy the last days. 

At the beginning I was thinking to use just a simple PID control but since I am a beginner I am struggling to figure out how I will synchronize them and how to control exactly the desired position.It may be just a course project but I really want to do it the right way and I don;t want to leave the control  of 5000 kN cylinders  in "the hands" of my own FB. So I decided to use an integrated Siemens solution. Finally what I have decided is still to use Sinamics S120 with HLA module which is exactly meant for hydraulic cylinders and proportional valves and can be easily configured. For the program in TIA Portal I will use the integrated Motion Control Functions of S-1500 MC_POWER, MC_MOVE RELATIVE,  MC_MOVE JOG etc. I think I am on the right way. Now I have to find some time to sit down and writte the program and to find a way how to add HMI considering that I have only  WinCC basic on my TIA Portal and I have poor choice of HMIs with this version. The same is valid for STARTER. Maybe I will just download tehir trial versions for three weeks and I hope it will be enough to finish the project. 

Thank you both for the help :)