How to Use the IAI Servo Press: Real Life Example

Hello this is Ray Marquiss, Senior Application Engineer with Valin Corporation, and this video is going to show a short practical application of using two different modes with IAI servo press product. One will be “speed control-holding load”-or stopping at load-and speed control-stopping at distance-or “keeping distance”.

I’m going to go through the process of setting up a program to push these snaps, and you can see I've got a beveled Shim. In the background here, and there's a part on one end a part in the middle, and then if I move this you can see a part on the other end over here. This piece is higher than these other two pieces, so let's say that the middle piece is the one that's in a good position, and even this top one could be good. So what I'm going to do is go in to the intelligent actuator software. In the trial operation mode, and I'm going to jog this down and watch the numbers as I move in order to determine how I want to set up my program. So I've already determined that if I move down to about 50, or rather 75, I'll just move directly down there. That's pretty close. So now I've got my speed set at 1 millimeter a second, and I can jog very slowly and you can see the actuator moving there on the right. I'm going to look over here at the current load to determine about where I should start looking for that part. I'm going to start at that 75 position. just moved back up there again. I'm going to start there. Look a little bit from a, sort of, a little farther out. And I'm going to start looking at the feedback, the current load, as I go down. I'm going to just kind of keep moving slowly. And slowly. Just slowly going down. And I can see that current load starting to go up a little bit…so there it just went up to two. At about 79 millimeters I see 2 newtons.

I'm going to jump back into my program. The approach motion is pretty good. I went to 75 millimeters. That's where I want to start. And then once I get there, I'm going to transition to this work search motion. I've got the speed set to 3 millimeters a second. That's fine and I'm going to make it transition to the press motion phase once it sees 2 newtons of load coming back and then, this is important, if I don't see a part by the time I reach 80 millimeters, that gives me about 5 millimeters to start looking for this part, and see the terminating load value of 2 newtons. Once I do I'm going to transition to the press motion part, and I'm going to change the speed to 5 millimeters and I'm going to look for a terminating load of 32 Newton meters.

Why do I look for that? Let's watch the part on the right as I just slowly jog down and will look at the current load value also in the window. I'm going to go slow. I'll just keep tapping it and you can see the current load going up and up. It's at 19. It's at 20 and it's going to snap back to zero once that part mates, so we'll watch it's 12…look, it's getting easier. And it's snapping into place. It's getting lower and lower, so I want to make sure that I pushed it in. So I'm just going to keep pushing on it just a tiny bit. Until I get to 30 about 37 or 32 newtons. I don't want to crush it, but I want to make sure to pop that part in and it does go up to about 20 and then it snaps down to a lower value. So if I just stopped at 20 newtons it's not going to push the part all the way in. I want to make sure it gets in there. There are other ways to do this. I could use another mode of pressing but I am using this one just for now I know I'm going to reach about 32 newtons, so I'll go back here and I go to my program and I say I want to go 32 newtons. That's when I want to stop. And I want to make sure that I stop before I hit 86 millimeters. Right now I'm at 82. That gives me four more millimeters to press once I found the part. So now I'll just jog this back up, or what I could do is go in here and enter zero and then just. In reality, I really need it to be about 50. I don't want to go that whole distance every time. So let's start here. I also go back to the program home position and I put that at 50. So that's where it's going to go after it completes its press. I set these parameters in there.

Let's go back here and we'll see how they work. I have to adjust the part...just pull that out. And then put it back in carefully. It's kind of a pain. It always wants to fall apart. Alright, and then let's run our program.  We're going to program operation now. Normally, if I was making these changes on the fly, which I did when I originally set this up, I'd have to go save this by clicking on the “Load to controller” button. But I've already done that with the settings that you just helped me discover. So now this is program #7 and so you can see here that I'm going to go back to the program control. I want to make sure that I've selected program 7 and I'm going to run it. Let's watch it on the right.  It’s going to press…oops, It got too far before it found the press force. So what did I do wrong?

You probably just saw some magic where the actuator moved instantaneously while I figured out what I did wrong. Well, what I did wrong was I have the search window too small. Because I'm at 79 millimeters here, almost 80, and I don't have any force feedback, so I need to just kind of keep going and try this out again and figure out what the proper number is. So there's 81, so I really need to be…. Yeah, it's pretty close. I probably need to change that to about 81 millimeters, let's try that. And then I'll save it.

Next I'll return the actuator back up to its starting position of 50 millimeters. And then let's try to run the program again. I go back here to program operation and run. It puts that part in. It's holding it because I just wanted you to see it pressing that in, and I set up a time in my program for it to hold there for five seconds, you can leave that at zero, or you can make it 1 or whatever it is you need to do.

Now. Let's see how this program works. If our part moves a little bit. And we'll do that by moving in this one. Which is a little closer to the bottom of the actuator. Sorry my fixture is not great, but you can see that it is a little closer to the bottom of the actuator. Let's run it and see what happens. Since it was within our tolerances that we set, it still did the press and then it released. So that's pretty good. It gives it a little bit of a tolerance, but what if we don't want that kind of tolerance? What if we want it to not just basically go down and press on everything that is underneath it? 
We're going to move this one over. So that this one is a little farther away from the actuator end. So let's see what happens with that. It didn't find the part soon enough. It's hard to tell, I’ll reset the alarm and try it again, but you can tell if you look at the position here, or, sorry, the location, in the axis status. He gets down, 77 goes to 80 and it never saw any force feedback, so that part is too far away and it's not going to press on it. Essentially, it didn't find a part. If we wanted to accept that part, then we'd go back into our program and open up the window here for the search portion of the press program.  We might make this like 83 millimeters or 82 millimeters to see if it's going to find that part and then press. This program is “speed control-stopping at a load value”, so it's not looking for a position to stop at before it decides it's pressed the button together. It's looking for a terminating load value, so once it reaches this it stops. Doesn't matter where it is, as long as it's within the values that we set for this work search and then the limiting position for the press motion.  If it had to go farther than 86 millimeters before it got to 32 newtons, then it would fault out.
Maybe that mode isn't the correct mode for pressing this part together, because. We need to push with so much extra force just to determine that we've gotten the part put together just because it has that snap in. Action where the force goes up quite a bit and then it decreases as the part finishes seating in the proper position. So maybe we'll change the program instead of using “speed control-holding load”, let's go and say we're going to do “Speed control-keeping distance”. That means that once we find the part with the work search motion step, then we're going to move a fixed distance from the point at which we contact the part; which that's what the work search motion portion is supposed to do is basically just come in contact with the part. And then will press. So instead of this being an end position like it was when we had a it set to the different press motion mode, this is now the end distance. So in other words, if we found this at 80 millimeters, then we're going to try to go 86 millimeters more, which is not correct for what we want to do. Let's go back to the program control here and going to go down to the 75 millimeter mark, which is where we start looking for the part. Next I'm going to just move very slowly. I want to find out where we get that two Newton load to determine that we've come in contact with the part. I'm just moving really slowly, and I'm watching the current load value down here in the axis status. So there's a little bit: 2 newtons right there at about 79 millimeters.  OK, so let's remember that: 79 millimeters.

Next I'm going to push slowly and you can see the part getting pushed together on the right side there in the background, in the camera view. And if you keep going back and forth then the load went up to about 27, and now it's actually going back down. So it's hard to do that based on the push force, 'cause if we stopped at 27 the parts wouldn't be put together yet. We're going to keep going. It snaps into place. And it just snapped. And we're at 81 millimeters. So basically we're going 79 to 81 millimeters, and that's 2 millimeters in distance. I'm going to go back to the program and change this 86, which is the end distance from our previous set up, to 2 millimeters. We have to save that.  It's red. That means it’s not saved.  We’ll save it.

I'm going to go back to the operation and put this back at the starting point by typing 50 in here and then go.  You'll see my hand come into the screen here to fix the part; Put it back in place. Let's run the program and see how it looks. Still program #7…I'll go back to program operation; It’s program #7. Let's see how it looks. So it's finished the push and it's waiting, and if it goes up, if you go back and watch the video previously of how we push down, you'll notice that we really push on this thing. There's a little bit of space right here. That we were pushing hard on this to make sure that we had that part inserted. Now we're not pushing quite as hard to get that part in, so we have less chance of damaging it.
So that's a different mode of operation.  You can see that it works differently than the first one that we had.  There are nine of these. You'll be able to pick one and play around with the different modes in order to come up with the right solution for your application. In addition to that pass fail criteria, we have some up here where we can judge that we know the position should be, let's say between 80 and 86. Once it snaps the part in so we could go and set the upper limit for the position at 86, and the lower at 80. Now, if we found the part at 32 newtons but it was outside of these limits then we would get an error.  That that is done during the judgment phase after the press.  We could also do the load limit, so if we didn't want to have too much load or too little load, it's looking for 32. But maybe we say if it's 33 that's too much and if it's 31 that's not enough. And so now we have these brackets around the load. And the position. And that looks like this. We've got a bracket for the position and we've got a bracket for the load and we have to fall right inside that sweet spot in order to pass once we've done our press.

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