I need help to set soft limits

[abenaki]

Help someone please!

I am working on a palletizing robot and a NX100 controller. I need to define a work area to protect the robot tool and cell equipments but am not sure how to achieve this.
From Motoman documents, I need to define cubes and set some parameters to either prevent the TCP to enter or exit the cube.
I found how to define cubes and in which system variables the coordinates are stored, but I am unsure how to set it to allow/prevent the tool to enter the cube.

Can cubes be combined to define an permissible work area? Do we need to combine cubes to define the are that is prohibited instead?

There are actually soft limits defined but I cannot see how they were defined. There is 2 cubes defined, but only 1 is used to activate an output. None of them are defined to restrict robot motion.

Robot motion is restricted in areas not defined by cubes.

Is there another way of setting soft limits than with cubes?

Please help. I need to set the work area before production starts.
Any help would greatly be appreciated.

[somar]

I will try to answer you questions, but tou are mixing softlimits and cubes, Those are two different subjects



"I am working on a palletizing robot and a NX100 controller. I need to define a work area to protect the robot tool and cell equipments but am not sure how to achieve this.
From Motoman documents, I need to define cubes and set some parameters to either prevent the TCP to enter or exit the cube.
I found how to define cubes and in which system variables the coordinates are stored, but I am unsure how to set it to allow/prevent the tool to enter the cube.

Take a look a the Motoman drawings, you will see inputs Called Inteference * entrance prohibit   and outputs called in cube *

Can cubes be combined to define an permissible work area? Do we need to combine cubes to define the are that is prohibited instead?

With the standard Motoman set up yo cannot have two cubes, one inside the other and have two differents outputs indicating where you are, basically the PLC will not get that you are in the inside cube

There are actually soft limits defined but I cannot see how they were defined.
They are defined by pulses in parameters S1C200 for + axis 1, S1C201 for + axis 2 and so on   then S1C215 for - axis 1.....

There is 2 cubes defined, but only 1 is used to activate an output. None of them are defined to restrict robot motion.
Are they defined properly ? because the output is automatic, it works thru the robot ladder logic

Robot motion is restricted in areas not defined by cubes.

Is there another way of setting soft limits than with cubes?

Yes, setting up the soft limits for every axis, keep in mind if you restrict, say, axes 5, to 10 degrees motion, it will alwayshave that restiction



Please help. I need to set the work area before production starts.
Any help would greatly be appreciated.

[abenaki]

How do you define complex shapes as cubes? Can't you combine cubes to define a complex shape and use it as a single cube?

Do you have to configure an output to monitor to allow/prohibit robot motion?

Can a cube be defined elsewhere than in the configuration (i.e. interference)?

If robot motion is prohibited in certain area which does not seem to follow the robot axes (Cartesian) or axis angle, where and how could it be defined?
I observed that robot motion was restricted in some areas which did not correspond with robot axes nor would it correspond to the base reference - not parallel.
Rotating the tool and jogging linear in base reference would not limit the motion the way. e.g. rotation the tool CCW would allow to jog the robot closer to its base, in Y coordinate.

Are cubes defined/validated with different tools? Are cube definition translated into pulse counts internally in the controller (they are defined as XYZ coordinates)?
Wouldn't cube definition be in S3C033+ registers? Which seems to be grouped by 8.

Limiting axes rotation would be individual and independent of the other axes limits, right? i.e. We cannot combine limit of axes other than defining a cube to limit them in combination?

[somar]

How do you define complex shapes as cubes? Can't you combine cubes to define a complex shape and use it as a single cube? No complex shapes, just cubes. An you maximun number of cubes is 32

Do you have to configure an output to monitor to allow/prohibit robot motion? To indicate that the robot is in the cube they are 32 preprogrammed output.    To prohibit the robot there are only 4 inputs preprogrammed

Can a cube be defined elsewhere than in the configuration (i.e. interference)? No ,as far as I now

If robot motion is prohibited in certain area which does not seem to follow the robot axes (Cartesian) or axis angle, where and how could it be defined? Cubes  are cubes and not parallelograms, Each face is at 90 degree angle to the adjacents faces 

I observed that robot motion was restricted in some areas which did not correspond with robot axes nor would it correspond to the base reference - not parallel.

Rotating the tool and jogging linear in base reference would not limit the motion the way. e.g. rotation the tool CCW would allow to jog the robot closer to its base, in Y coordinate.



Are cubes defined/validated with different tools? Are cube definition translated into pulse counts internally in the controller (they are defined as XYZ coordinates)? Good question and be carefull.  The cube is defined( dimensioned)  with a particular (doesn't matter which one).  Example Imagine that your cube is a wall 150mm depth, and 2000 mmm by 2000 mm wide and high. You tought this wall/cube using a knife as a tool.  I f you put a sword as a tool, you'll be going thru the wall
Wouldn't cube definition be in S3C033+ registers? Which seems to be grouped by 8. I'm home right now, Give and answer later when at work



Limiting axes rotation would be individual and independent of the other axes limits, right? i.e. We cannot combine limit of axes other than defining a cube to limit them in combination?  Correct, I had a similar situation with a customer And he wanted me to program cubesa nd limits so the operator wouldn't crash the robot.   My answers were 1) I could do it but it will be combinig so many things that it will be almost impossible to move the robot and my 2) answer  GET YOUR PEOPLE TRAINED !!!

Good luck,  keep asking


Somar ( Sunday afternoon at home, Oh man, I love robots !!!!!)

[robotomation]

abenaki,
The reason you were unable to block this cube (or it seemed that way) was probably because you were jogging the robot manually. The Cubes only fuction when you are trying to move to a taught position through a job, or using a "Move to" command.

As Somar said A cube is called a cube, because it is a cube..... not a parallelagram!

Depending on the orientation of your manipulator, you could possibly use a cube set to "Axis" and limit the pulses..... this has to be planned ahead, because you could really get yourself in a jam. As you have more and more complex situations for blocking from crashes (this is not what cubes are meant for), you run into more and more problems with making them work the way you want.

A Motoman employee told me: "... the cubes are supposed to be hardwired from one robot to another to only allow one robot into a work space..." This doesn't explain why they have Cube Prohibits enabled over networks, ie Devicenet, Controlnet, CC-Link, etc.

If you are trying to restrict motion..... I only suggest this if you know fully what you are doing..... use 2 cubes to do it. If you are in the first cube(Coordinate, XYZ), prohibit cube 2 (cube 2 being a wrong path area). That way the robot will stop if it goes in the wrong direction.......

HOWEVER...... If the robot is crashing because of someone using the tech pendant, and running the wrong job, or jogging the robot into an obstruction, then it will still happen..... you will go through all this trouble and end up with a bigger headache.

quoting Somar: "GET YOUR PEOPLE TRAINED !!!"