How can I get the TCP position(Cartesian) in coordinate system

Hello everyone,

My robot system like shown bellow.
->DX200
->R1+S1(2 Axes)
->SETUP - GRP COMBINATION - R1+S1:S1 finished
->ROBOT - ROBOT CALIB finished : the TCP can track the axes in SYNCRO mode

My question is how can I get the Cartesian coordinates in the coordinate system.
Now I can find the current position in ROBOT - CURRENT POSITION, but the R1 and S1 are not combined to a coordinate system.
If I move the robot, (X, Y, Z, Rx, Ry, Rz) will be changed, if I move the external rotation axes, (S1:1, S1:2) will be changed.
However, I need to get a position(X, Y, Z, Rx, Ry, Rz) include the R1 and S1.
With KUKA robot, I can get this position in the WORLD coordinate system, the if the robot is shifted, the XYZ will be changed, if the external axes are rotated, the XYZABC will be changed.

I don't know how to get what I want, is there a INFORM or a Motoplus API can supply this? Or I need another option?

Thank you.
Kind regards,
Jonson

Quote from Motouser

I think that you need a command in INFORM:

GETS $PX001 $PX000 //this instruction gets the coordinate in pulse mode and store it in P001(for example)
GETS $PX001 $PX001 //this instruction gets the coordinate in CARTESIAN mode and store it in P001(for example)

The difference (as you can see above) is the second variable PX000(for pulse mode), PX001(CARTESIAN)

When you have an external axis the GETS instruction will work the same but will write also the EX00x variable.

Ex.

GETS $PX010 $PX001

the variable P010 and EX010 will be the storage variable of your cartesian position for R1(P010) and S1(EX010).

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But I just want get one coordinate in Cartesian, if there is a L type positioner, I need get (X Y Z Rx Ry Rz) without S1:1 and S1:2, but with the S1:1 into Rz and S1:2 into Ry.

Ex.

With KUKA robot, if I have a L type positioner, I calibrate the external axes use Base[32], then in the Base[32] coordinate system, if I move the 8th axis and keep the robot stop, I can find that the robot position in the Base[32] is changed.

Thank you for your reply.

Jonson

Quote from Motouser

You could create this routine:

GETS PX090 $PX001
'now you have PX090(ROBOT CART. POSITION), EX090 (S1 POSITION)

GETE D000 EX090(1)
SETE P090(4) D000
'you'll put tha value of S1(1) in Rx
'I don't remember if iyou can do this directly: SETE P090(4) EX090(1)

GETE D001 EX090(2)
SETE P090(5) D001
'you'll put tha value of S1(2) in Ry

SETE P090(6) 0
'erase the Rz value

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Firstly, thank you for your help.
Your code make the S1:1 and S1:2 into Rx and Ry. But I need a combination of two coordinate system.
You can see the attachment picture, the robot keep to stop, and the 8th axis rotate about 45°, you will find the TCP in the sync. coordinate system is change as the green line shown. You can consider the green line is the vector from the origin of this coordinate system to the TCP.
We assume that before moving the 8th axis, the position is X=100,Y=0,Z=0,Rx=0,Ry=0,Rz=0, after moving the 8th axis about 45°, we can also consider that we rotate the 8th axis aroud the Z axis. So the position after moving is X=-100/sqrt(2),Y=100/sqrt(2),Z=0,Rx=0,Ry=0,Rz=45.
So you can find the position in the sync. coordinate system in Cartesian is not equal to the result of directly adding.

Thank you.

Jonson

Quote from Motouser

Just a question: but you have a Master tool frame (MTU) for the master robot?

Maybe I can see the Master Tool, but I have no idea how to setup it and where to find it. So, any relationship with this?

Quote from Motouser

OK. Let me explain.

I have an R1+S1 robot (so I have only a rotation axis not two like you, but I think that will worl the same).

I have also a MTF (unfortunately it's a paid option and I have setted it instead of the User Frame 1, so when I rotate the ex. axis I see here the TCP change), this frame gives me the position of the robot respect the rotation of the axis, so if I keep the robot in a point (X,Y,Z,Rx,Ry,Rz) and I rotate only the axis, the point's coordinate change (like the picture in the attachments).

So, geometrically, you have a vector from the MTU to your TCP.

I don't know if there's a $PX00x usable for the MTU, but you can get the position in cartesian and the convert it in MTU (it's like you are using a matrix rotation).

Example
GETS PX090 $PX001
'now you have PX090(ROBOT CART. POSITION), EX090 (S1 POSITION)

CNVRT PX091 PX090 MTF
'now you have your point referenced to the MTF

For the position of the ex. axis you can do as I say before.

I hope this is what you need.

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Yes, exactly what I want. But where can I find MTU and how can I calibrate this frame like a User frame.
With KUKA robot, when I calibrate the SYNC. coordinate system, it will let me to specified a BASE[X] to save the frame. But with motoman, the MTU will be created and saved automatically?

Thank you Motouser, you help me a lot.

BR,
Jonson

Quote from Motouser

Hi,
as I said it's paid option and the fact that you have a DX200 doesn't help.

If you go at https://www.motoman.com/manuals/ you can dowload (maybe you've it) the INDEPENDENT/COORDINATED CONTROL FUNCTION, you'll find a chapter called "Calibration between Manipulator and Station".

These instructions are the first step to create the MTF and then there is routine to set it properly ( I mean in a User Frame).

Two problems:

1. It's a paid option (are involved FD parameters)
2. I've done this procedure for a DX100 (I think that there isn't difference but I'm not sure)

I suggest you to contact Yaskawa, maybe if you already created a master tool and the FD are setted, you need a simply program to put the MTF in a User Frame.

Sorry

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Hey, thank you, maybe I have finished all you said. I can find a Master tool in the P variable. But I need to have a test if the coordinates are changed as what I want.
So, thank you very much.

BR,
Jonson

Hey Motouser,

I find another problem that is I can get the position in MTF in Motoplus, but I can not transform a position(x y z rx ry rz) from MTF to BF or RF.
For example, there is vector (x=5,y=5,z=5,rx=0,ry=0,rz=0) in the MTF, how can I transform it to the BF or RF.
If this can be done in the Motoplus, I think that is very nice.

Thank you,

BR,
Jonson

I want to correct the robot path in real time, but I can only calculate the bias in the MTF. And in the Motoplus, there isn't a API to correct the robot path in MTF, but in BF or RF. So, I need transform them from MTF back to BF or RF.

Quote from Motouser

My knowledge of MotoPlus is very limited ( I just have the manuals and I studied it in the past, but I never programmed in this environment). if you don't have API to correct the path nor to convert a point in another reference frame, I think that you have to create a code by yourself but I don't know how.

P.S.

:REALLY???
Just curiosity

I also have no idea how to do.

In the Motoplus you can correct the robot path every interpolation cycle which is about 4ms. I think you can find in the Reference Manual of the Motoplus.

Thank you a lot.

BR,
Jonson

Quote from Kswitz

what would be the input to cause the path to correct in real time? Thru arc sensing, laser ?

Both are OK. As long as you can supply the sensor data every interpolation cycle.