Dear All,
I a have the same problem with our kuka iiwa,
The external interaction torque that is shown in the "joint torques" section in teach pendant is not zero even after calibration with the provide program. the order of external interaction on joints is max=1 N.m.
this for sure affects on the measurement of force on the end-effector. Unfortunately it is configuration dependent and the idea of subtraction from initial error sound ineffective.
is there any way to calibrate that?
Regards
Thanks,
I also tried the smartServoLIN sample. It is more precise but yet much difference exist between the commanded trajectory and real one... even by increasing the acceleration and velocity variables!
ServoMotion.setMaxTranslationAcceleration();
ServoMotion.setMaxTranslationVelocity(…)
I am wondering how the commanded camera velocity out of visual servoing algorithm can be realized. The stability of the systems are usually shown assuming perfect tracking of the camera velocities. Thus how the stability is preserved!?
I appreciate for your informative information,
I try to use iiwa_stack as well.
one other problem I just noticed:
in smartServoSampleSimpleCartesian example a sinusoidal motion is set for the TCP in Z direction. but looking at the motion of the robot you can find that it does not follow exactly the given trajectory. It is supposed to move in only z direction but the robot moves in x and z direction not precisely.
try
{
// do a cyclic loop
// Do some timing...
// in nanosec
double omega = FREQENCY * 2 * Math.PI * 1e-9;
long startTimeStamp = System.nanoTime();
for (i = 0; i < NUM_RUNS; ++i)
{
// Insert your code here
// e.g Visual Servoing or the like
// Synchronize with the realtime system
theServoRuntime.updateWithRealtimeSystem();
// Get the measured position
Frame msrPose = theServoRuntime
.getCurrentCartesianDestination(_toolAttachedToLBR.getDefaultMotionFrame());
// Do some Computation
// emulate some computational effort - or waiting for external
// stuff
ThreadUtil.milliSleep(MILLI_SLEEP_TO_EMULATE_COMPUTATIONAL_EFFORT);
// do a cyclic loop
curTime = System.nanoTime() - startTimeStamp;
double sinArgument = omega * curTime;
// compute a new commanded position
Frame destFrame = aFrame.copyWithRedundancy();
double offset = AMPLITUDE * Math.sin(sinArgument);
destFrame.setZ(destFrame.getZ() + offset);
theServoRuntime.setDestination(destFrame);
}
}I increased the "MILLI_SLEEP_TO_EMULATE_COMPUTATIONAL_EFFORT" to let the controller reach to the given destination. Yet no change is observed. I also increased the values
aSmartServoMotion.setJointAccelerationRel(1.0);
aSmartServoMotion.setJointVelocityRel(1.0);
but not special improvement is seen.
WHY?
Thanks
Dear All,
I am going to use kuka iiwa for a visual servoing scenario.
Here is my plan...
I have connected a camera -mounted on flange, to a remote computer to do all the image processing on the remote computer. on the robot computer side, I am going to use smart servo.. based on the provided sample program "SmartServoSampleSimpleCartesian".
The remote computer is going to receive the information (for instance pose of the robot) from the robot and send proper commands back to the java program over a UDP connection.
essentially, Is that a proper plan to do that?
How can I establish this connection?
Do I have to use KLI for client-server programming?
Thanks in advance.
Thanks,
unmastering and then mastering in KRF /Joint space solved the issue.
Hi,
I experienced similar problem for joint 2.
it is now out of its limit. How did you solve the problem?
Mastering and KRF mode not working...
Dear All,
I received the following error after running the PickAndPlaceExample in kuka iiwa R820 robot.
Actually the second joint moved fast out of its limit (now it is at 176 > 170) and the errors appeared
Bus interface error of Thin4MAdapter.BusIF
Max. following error exceeded (ID2)
Hardware limit exceeded drive 2 (.)!
Nothing works even in KRF mode.
any idea how to solve this?
Thanks.
Thanks DRG,
when we set the sampling rate on 2ms, the latency is 5 ms. How much the latency is supposed to be if I install a real time OS on client?
I am connecting the remote computer Lan port directly to the KONI port by cross cable...
The sampling rate set in the java program is 5 ms. when I set the sampling rate to 2 ms the latency is 5ms by the above command.
Thus I feel that the command latency issues the whole send and receive time in between two computers. Thus, if I am right, the delay between two computer in is only 1 ms. isn't it ?
Dear Vinay,
would you please let me know how to connect remote computer to kuka computer with cross cable. do we have to set any special ip setting.
now i am accessing through straight cable with around 11 ms latency in ubuntu (Not realtime)
btw, about the media flange, it was great information..sharing with us.
Regards
Dear DrG,
I appreciate for your information.
I tried to install lowlatency ubuntu package
https://adamstechblog.com/2017…-ubuntu-server-16-04-lts/
the latency is same as before. Now i would like to install a hard realtime patch for ubuntu. can you tell me how to do that?
btw, what do you mean by "get the FRI Application into realtime mode", is there any setting on fri codes, that must be checked after installing realtime?
I reinstalled the station configuration. Now it works but the error happens once among a time and i have to restart to get rid of that.
I also noticed that if the robot is left idle for a while the error happens. I don't know why this happens!
No, How do I do that? where is this login page?
I have restarted the robot several times and this error yet exists. The robot can not be jogged. nothing works!
I tried to unmaster and master some joints. It goes unmastered but do not masters.
I experience similar issue on torque referencing randomly which is solved by running "PositionAndGMSReferencing".
However, I receive "position sensor not referenced" almost every time I turn on the robot. Do we have to run "PositionAndGMSReferencing" on every startup?
The mediaflange dynamic parameters is not included in the system from the factory?
Are you sure if we have to use mediaFlange.attachTo(lbr_iiwa.getFlange()); ?
Hi
write a forward kinematic program that convert joint space variables (joint positions) to task space variables (cartesian position).
you can find the forward kinematic of iiwa on the net.
I hope this is helpful.
Dear all,
I am working with FRI c++ SDK on a remote computer with ubuntu (not real time) and windows.
The latency is 11 ms and the quality of FRI connection is poor, obtained by following commands
FRIChannelInformation chanInfo=friSession.getFRIChannelInformation();
chanInfo.getLatency()
chanInfo.getQuality()
Nevertheless, the system works fine in position mode with sampling rate set to 5ms under above conditions. However, in torque mode it sounds unstable.
How can increase the quality and decrease the latency.
Regards.
Dear all,
Recently, I received the following error in our KUKA iiwa robot under safety control on teach pendant;
"Communication to Sunrise failed "
[1.jpg][/img]
Nothing works anymore!
The last time the robot was working fine. I didn't do any update, or any special change in sunrise configuration.
I had experienced this error also before and a rebooting was fixed the problem. But this time the error exists even after several rebooting.
some times the robot is not recognized and the station status on left up corner is N/A.
Any idea how to resolve the problem?
during the start up of the sunrise this error is also shown:
(I am not sure if this is related to the above error)
12:00:21 KCP FSOE
EtherCat Commiunication timeout
Packets missing
[2.jpg][/img]
All the best.
