Problem of accuracy

When I use the learning mode, uarm reproduces the movement but always 3cm to the right, what can I do to fix this problem ? It does the same thing when I place the effector of uarm somewhere and click on get position (in the move xyz tool) with UCS 1.2.2, Uarm miss the position about 3cm when i click play.

Thanks !

P.S : It is the first day I use it

In the learning mode, it will be less accuracy. If you want more accuracy you’d better use the normal mode(set position). Since the accuracy of the servos are not good, we finished some calibration data during the manufacturing. But in the learning mode we didn’t use the calibration date because of the flash size of uno.

It is quite annoying because I bought uarm only for UCS and for the learning mode and i’m not able to pick an object with uarm since it always miss it …

What make me think that it is a problem with my uarm is that when I see the UCS tutorials on internet, there isn’t this big offset when they use the move xyz command with the get position.
Moreover, there is only an offset with the x axis, more the uarm turn to the left, more the offset is on the right.
Also, if it make the movement several times, it will always hit the same bad point, it seems that the problem is that the servo x doesn’t return the good coordinates …

Do you think that I need to calibrate my uarm ? Is there a risk that it damage it ?

I hope that it could be solve …

Thanks !

According to your explain, I think there are two way to solve this issue:

  1. Define a config flag for setting unused code removal (e.g. uart communication), so you will get more code space for using calibration data in learning mode, then let user to choose which type of firmware they want.

  2. Write a PC program to enhance the learning job, if user need a higher accuracy in learning mode, they have to connect the uArm to their PC.

A big thanks for your answer ! :slight_smile:

I’m a real beginner and I am absolutely not able to do that ! :smiley:

I think I found the cause of the problem ! : when uarm is in his default position or when it is at his x axis 0 (with uclient) the arm is a little to the right ! I think it is the only problem and that the fact that the offset is bigger and bigger when the arm turns is due to the simple geometry fact that the distance to the base is bigger so as a consequence, the offset off the end effector is also bigger ! :smiley:

How can I remove this offset ?
(I never calibrate uarm, I’m waiting for instructions)

Thanks !

The x axis of the arm is at 0 according to uclient !

I known it, it’s not only hard for you, but also for me, 'cause we don’t know the arrangement for calibration data inside the EEPROM (maybe the source code could tell, I’m not sure), my precious reply was sent to TONY, I think he will give you a good answer.

To Tony:
I think enhance the learning mode inside UCS is the best way for Onetchou, 'cos he is using the learning mode inside the UCS.

Considering the former customers of uarm metal, the latest firmware is still based on the original calibration data. And the original calibration is not good enough. Later I will release the guide of improving the calibration data.

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