I'm trying to go from one speed to another gradually from one point to another. Any help will be appreciated.
Robot speed.
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Wellrick -
January 5, 2024 at 2:29 PM -
Thread is Unresolved
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Not sure if this is what you're after (perhaps you should clarify exactly what you mean?) but from the top of my head try something like this:
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I'm trying to move evenly from the inside of the circle to the outside of the circle or vice versa at 3" per sec there's more area on the outside of the circle and less as I move to the center requiring a slower speed on the outside and increasing the speed as it moves to the center
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I can figure out the speed for the inside and the out side. I was hoping there is a way it can gradually go from one speed to the other during the transition of going from one point to the other
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This machine is so old that it doesn't have the for command. I'm pretty sure. It doesn't
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That's a tricky problem to solve. Theoretically if you get the ACC set correctly you could do it in a single move. Try ACC 50 and see what happens.
Also due to the trapezoid shape of the robots motion profile, you may need your starting point to be before and ending point after the circle. The robot will be starting at 0 speed, ramp up to your commanded speed, then ramp down to 0 at the end point.
How precise do you need to be? I think with a robot this will be more of a trial and error type of solution. If you need very precise control, then a stand alone servo would be a better fit.
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Thanks for your input. I really appreciate it. I don't understand the trapezoid motion profile statement. I was going from the the outside of the circle to the inside while it was spinning. I ended up doing it with more moves changing the speed. I used a tape measure and math equation. I was just wondering if there was a way you could start at one point at a desired speed and end up at another point at a different speed by it ramping up after the first speed given to the second speed given gradually. Thanks again
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It's applying tungsten carbide measured in thousands of an inch. I've got enough experience to keep it in tolerance withoit all the right moves. It would be nice to obtain the right moves even at a trickling speed. They are truly priceless. Thanks again
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I'm doing these parts now. I've tried several different ways to do these. I think the radius is too small for the size of the gun. The ideal way to do these would be vertical with circular motions following the radius. But I haven't been able to obtain this either. Lol. I still get them done though.
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By trapezoid I mean the graph of robot TCP speed vs time. It ramps up to the commanded speed, then stays at that speed for a while, then ramps down to stop at your end point. If you draw that out on paper your actual speed makes the shape of a trapezoid.
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Oh ok. I get it. Is there a way to control the speed in increments while the program is running or something similar
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You could do a bunch of cnt 100 points but it would be difficult to get the timing right.
Another idea would be to control the program override % in the background based on current position system variables.
Either way is not exactly cut and dried.
Can you control the deposit rate at all besides controlling robot speed? What about your rpm of the wheel? Maybe you can approach it the other way around. Robot speed is what it is and you control the other devices. That's how sealant dispensing is done.
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I would opt for HawkME 's solution. Move the robot at a fixed speed (maybe make sure to have the starting position outside of the disc so you are sure that when the tcp enters the "area of interest", it has a constant speed (in other words, make sure that the acceleration of the tcp occurs outside of your working area)).
Then using the positional information from the robot (or in worst case: time) modulate the speed of the disc.