How to make Robonova move smooth like Manoi?

[Sazabi]

Me again:D
Well, i found same qustion here, but not satisfied with answer. What are the main ...mmm... problems with RN? Not fast enought servos? standarts are .20 sec/60deg. hsr5990 works faster at 7.4V- 0.14sec/60deg (like kondo on manoi) + torque is pretty big. Wht else? Does controller speed affect on this? 8Mhz vs 20(or 24) on Manoi. That were my ideas. Any yours?

[StuartL]

There's a lot of interpolation required to smooth the movements. Usually that's done in the controller board to take the precoded sequences and interpolate the curves. If you search for 'curve' on this forum you'll probably find some example sources.

[i-Bot]

The Robonova controller does the interpolation, but only to within 1 degree. One degree is actually quite a large change. Other controllers may have better accuracy to the position and the calculation.

[Sazabi]

So we need interpolation, but is this affected by micro speed(mhz)?Or it depends on micro OS? Also manoi's micro is 16 bit,and robonova is 8.
By the way - manoi has 2 gyros, do these two help to keep it so stable?
P.S. could you plz tell me more about this curve?Or where i can get info to read?

[Sazabi]

One more qstn - why when i read servo position in robobasic, it turns servos a bit, how cold i prevent that?

[i-Bot]

When reading the position the torque is taken off the servos. Try to avoid pressure on the joints when reading position to get accurate reading.

[Sazabi]

it moves servos,that don't have pressure on it,like hand servos.

[i-Bot]

Can you post a short program which consistently demonstrates this problem ? I will take look if it can be fixed or at least expain why.

[Sazabi]

There is no program. In Robobasic, in servomotor realtime control for example, (in G6 mode) when i put a tick on "Select all" (i.e. right hand, looking from behind) on group C and then, with no movement of robot, i uncheck it hand can turn a bit while it's unchecking. If i repeat that check/uncheck hand can move a bit while both operations or may not. Feels like while robobasic sends command to know servo position signal is so fluctuating it makes servo move. Same on "ROBONOVA Motor Control" func. Btw i'm using usb to com converter,but i tried on "clear" COM port and it was the same

[Sazabi]

No ideas on my problem?

[engineer]

There is no program. In Robobasic, in servomotor realtime control for example, (in G6 mode) when i put a tick on "Select all" (i.e. right hand, looking from behind) on group C and then, with no movement of robot, i uncheck it hand can turn a bit while it's unchecking. If i repeat that check/uncheck hand can move a bit while both operations or may not. Feels like while robobasic sends command to know servo position signal is so fluctuating it makes servo move. Same on "ROBONOVA Motor Control" func. Btw i'm using usb to com converter,but i tried on "clear" COM port and it was the same

Hi Sazabi, I-Bot's right when YOU query a servo it relaxes, when the 3024 does however many times a second it does it, the servo returns to the commanded position,and you can't percieve it's moving without a strobe. I recieved a great deal of help from bioblu in setting up my bluetooth in my laptop and RN-! I have had to go through all of the com ports to get a handshake from RN-!to the control depending on the interference present where I was controlling? RN-!

[Sazabi]

not shure i got your point right.I'm agree that servo kind "relaxing" while reading its position. Even according to that relaxing, looks like servo returns to wrong position after reading.

[engineer]

OK. in order to smooth out RN's moves you are going to have to work with the speed and power commands in robobasick if you want a small rotatitional move of the servo quickly your stuck with a fast move which will jerk the robot around with the movement. To counter this you can move an offsetting movement from another servo at the same time,or slow the move down.

[robots42]

From my tests the servos in RN are unreliable if not pulsed continuously, so if you turn one off and on again which the software does when getting its position the servo takes time to recover. See notes at
http://www.davidbuckley.net/DB/RoboNova ... oNotes.txt

The servos do not hold their position because they are not being pulsed while being asked their position and when the pulses restart the servo action can be erratic and or totally unpredictable. Their software is not very good.
You just have to live with the way they are!

David

[Sazabi]

just what i thought and planned to do - new software for nova. Thanks for making me shure:D