Posts by mikalaanning

Hello! We have done some more changes to the code, among others we realized that our implementation of the frame "playGround" had its flaws since it didn't have "canvas" as its parent. We then realized that when we put "canvas" as a parent to "playGround" and the points used in "drawPlayGround" had "playGround" as a parent, we could cut out a generation of parents and make "canvas" the parent of the points. We then hit another wall.

The issue we have now may be simple to fix, but we can't get our heads around it.

Here you see the motion when our robot moves to its home position, this works without any issue.

Here you see the motion of the batch drawing the playground. The coordinates showing are the right calculated one based on the canvas itself.

And here you see the "Canvas" Base.

So our question now is;
How can we make the robot draw from the points calculated on another frame that is set as a base?
Are we on the right track? If not, could you show us the way?

This is the error we're getting.

Thanks a lot again!

Quote from DrG

Hi barely_sane,

from a quick glance on your code,

Code

@Inject
	Tool tool;
	LBR robot;

I would expect, that the Nullpointer exception stems from a missing "@Inject"

Code

@Inject
	Tool tool;
@Inject  /// <<<< Missing Inject? In this case, the Robot is not initialized, which might lead to the reported Null-Pointer exception
	LBR robot;

Greetings,
DrG

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Forgot to mention this, we have initialized the robot and managed to move the robot down to a point we calibrated in the origo, but when using the movement in the motion batch the robot just stops and gives us the Error code showed. We belive this to be because we have made points out of the canvas frame.. read this another place saying that it were something with different parameters ect.. but couldnt find an solution..

Quote from NullReference

This method "getApplicationData().getFrame("/canvas").copy();" exists in the superclass "RoboticsAPIApplication". Line 22 gets executed when the class is being constructed and before this child class inherits anything from the superclass. That means when you call the method getFrame() which exists in the context of the super class it won't exist in your class context (yet). You can fix this by calling this method in your initialize method instead.

If you want handguiding in manual mode you need the white enabling switch on the flange.

Ahh! That explains why it wouldn’t work! I’ll move it back into initialize as you suggested! When it comes to the handguiding it worked before we started our project, we could push the white button and than guide the arm around.. but recently it haven’t worked.. this may be because we have done some work in the safety configuration ect.. do we need to implement a package or something with the handguiding software? Any help here would be usefull.

Quote from razzo

I will try to get ride of your error which causes this exception which you posted (screenshot).

1. You try to inject your tool, which is good idea. I hope you have already created a tool template otherwise you cannot injected it.
2. If you have a tool template you have to inject it by name. Take a closer look in the manual chapter 15.10

Code

@Inject
@Named("NameOfYourToolTemplate")
private Tool gripper;

3. You have a field robot of the class LBR. The easiest way to get your instance of this object is to inject it.

Code

@Inject
private LBR robot;

So you should be able to execute xour application at least until 'initialize'.

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Yeah, we have initialized the tool in the template and have given that a TCP in the program which we initialized using the 4point.

When it comes to the calibration of both the canvas and the tool, is there any way we gan do this once and then save it in the program? So much hassle to do it every time we upload the code to the robot.

Thanks again guys.

Quote from NullReference

Did you do a 3 point calibration on the canvas base?

Post your modified code.

Following the code you provided we managed to mark one single point, and then we tried to work from there. but we got a nullpoint exception at the line where we made the frames using the two-dimensional array. We're going to try to work around this by making each point without using an array. Planning to do this tomorrow, and then we'll provide the updated code.

And to answer your question, no. We did not do a 3 point calibration on the canvas base. Only figured out how to mark once. The most optional would be to have points in each of the four corners of the whiteboard making that the canvas. And then just using lin on this frame. Any idea on how we can achieve this?

Quote from NullReference

For this I'm going to assume you have a grasp of the basic principles of robotics and object oriented programming.

Before doing anything you have to create your project with the correct configuration, this is covered fairly well in the manual.

Create your first application, use the provided wizard in workbench. The wizard creates a java class that inherits from the super class RoboticsAPIApplication, because of this your application has access many functions for manipulating the robot. Note, all these functions can be obtained without extending the RoboticsAPI, you just have to import them yourself.

Now it's time to write some code. Inside your application you'll see 2 abstract methods that sunrise has implemented for you, namely "run" and "initialize". The run method is called from the API once when your application is started and the initialize method is called once just before the run method is called. Just as the name suggests, you should initialize your program withing the initialize method. Usually you attach your desired tool to your robot (see sample code).

Now you have a tool that is attached to your robot that you can command to different positions in space. You can calculate where you want the robot move or you can teach it. Teaching is done from the SmartPad. Teaching is simply storing the current robot position in a variable. If you want to learn how to declare and teach positions then I suggest you read the manual.

The most common way to move the robot is by commanding the attached tool to certain position. The tool must be attached to the robot for this to work, see code below.

For your tic tac toe you're going to need to create a base. The main advantage with using a base in this case is it makes calculations easier and you can move the surface you're going to draw on fairly easily.

I'm going to provide you with some code to get started.

Code

package application;


import javax.inject.Inject;
import javax.inject.Named;


import com.kuka.roboticsAPI.applicationModel.RoboticsAPIApplication;
import static com.kuka.roboticsAPI.motionModel.BasicMotions.*;
import com.kuka.roboticsAPI.deviceModel.LBR;
import com.kuka.roboticsAPI.geometricModel.Frame;
import com.kuka.roboticsAPI.geometricModel.Tool;
import com.kuka.roboticsAPI.motionModel.CIRC;
import com.kuka.roboticsAPI.motionModel.CartesianPTP;
import com.kuka.roboticsAPI.motionModel.LIN;
import com.kuka.roboticsAPI.motionModel.MotionBatch;


public class TicTacToe extends RoboticsAPIApplication {


	// Here you fetch the tool you created, the injector finds the right tool if
	// you add the named annotation
	@Inject
	@Named("YourToolName")
	Tool tool;
	// Here we will use the robot to find its flange position so we can attach
	// our tool to it.
	@Inject
	LBR robot;


	// Contains the center points of all 9 squares
	private Frame[][] squares = new Frame[3][3];


	private double canvasWidthHeight;
	double squareWidthHeight = canvasWidthHeight / 3;


	@Override
	public void initialize() {
		// Here we attach our tool to the flange, the flange becomes the tools
		// transoformation provider, this means that the tool will follow the
		// flange when it moves.
		tool.attachTo(robot.getFlange());
	}


	@Override
	public void run() {
		// Get the canvas base, this can be done by drag and drop.
		Frame canvas = getApplicationData().getFrame("/Canvas").copy();


		// Populate the square array
		for (int i = 0; i < 3; i++) {
			for (int j = 0; j < 3; j++) {
				// Calculate the position on the XY plane.
				squares[i][j]
						.setX((squareWidthHeight / 2 + (squareWidthHeight * j)));
				squares[i][j]
						.setY((squareWidthHeight / 2 + (squareWidthHeight * i)));
				// The parent becomes the canvas base. Now our squares will
				// follow the canvas if you recalibrate the canvas base.
				squares[i][j].setParent(canvas);
			}
		}


		// Implement code to wait for command and draw a shape according to
		// input
		// Remember that grid positions are 0 based
		drawCircle(2, 1);
		drawCross(2, 2);


	}


	private void drawCross(int i, int j) {
		Frame corner1 = squares[i][j].copy();
		Frame corner2 = squares[i][j].copy();
		Frame corner3 = squares[i][j].copy();
		Frame corner4 = squares[i][j].copy();


		corner1.setX(corner1.getX() + squareWidthHeight / 2);
		corner1.setY(corner1.getY() + squareWidthHeight / 2);


		corner2.setX(corner2.getX() - squareWidthHeight / 2);
		corner2.setY(corner2.getY() - squareWidthHeight / 2);


		corner3.setX(corner3.getX() - squareWidthHeight / 2);
		corner3.setY(corner3.getY() + squareWidthHeight / 2);


		corner4.setX(corner3.getX() + squareWidthHeight / 2);
		corner4.setY(corner3.getY() - squareWidthHeight / 2);


		// Create all the motions and send them as a batch to the controller
		CartesianPTP toPrePosition = ptp(corner1.setZ(50));
		LIN toCorner1 = lin(corner1);
		LIN toPreCorner1 = lin(corner1.copy().setZ(30));
		LIN toPreCorner2 = lin(corner2.copy().setZ(30));
		LIN toCorner2 = lin(corner2);
		LIN toPreCorner3 = lin(corner3.copy().setZ(30));
		LIN toCorner3 = lin(corner3);
		LIN toPreCorner4 = lin(corner4.copy().setZ(30));
		LIN toCorner4 = lin(corner4);


		// Move the robot to a start position so we know it can plan the motions
		robot.move(ptp(getApplicationData().getFrame("/HomePosition"))
				.setJointVelocityRel(0.3));


		MotionBatch batch = new MotionBatch(toPrePosition, toCorner1,
				toPreCorner1, toPreCorner2, toCorner2, toPreCorner2,
				toPreCorner3, toCorner3, toPreCorner3, toPreCorner4, toCorner4,
				toPreCorner4);


		batch.setJointVelocityRel(0.3);
		tool.move(batch);


		// Return to the start position
		robot.move(ptp(getApplicationData().getFrame("/HomePosition"))
				.setJointVelocityRel(0.3));
	}


	private void drawCircle(int i, int j) {
		Frame auxiliarry = squares[i][j].copy();
		Frame StartEnd = squares[i][j].copy();


		StartEnd.setX(StartEnd.getX()
				- ((squareWidthHeight / 2) - (squareWidthHeight / 10)));
		auxiliarry.setX(auxiliarry.getX()
				+ ((squareWidthHeight / 2) - (squareWidthHeight / 10)));


		// Move the robot to a start position so we know it can plan the motions
		robot.move(ptp(getApplicationData().getFrame("/HomePosition"))
				.setJointVelocityRel(0.3));

		// Create all the motions and send them as a batch to the controller
		CartesianPTP toPrePosition = ptp(StartEnd.copy().setZ(50));
		LIN toStartCircle = lin(StartEnd);
		CIRC drawCircle = circ(auxiliarry, StartEnd);


		MotionBatch batch = new MotionBatch(toPrePosition, toStartCircle,
				drawCircle);

		// Return to the start position
		robot.move(ptp(getApplicationData().getFrame("/HomePosition"))
				.setJointVelocityRel(0.3));
	}
}

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Code never tested.

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This helped alot! Thanks!

Quote from NullReference

What is it exactly you're struggling with? The manual is pretty comprehensive (Im assuming you were referring to the systems integrator manual).

I'm struggling with the basic approach of the program, like finding out which functions to use and how to use them. I've been reading the Sunrise Workbench Manual, but I can't really get my head around how to make the robot draw the lines and figures I want it to without going below the surface of the table. So I'm wondering about how to make a World that represents the 1 by 1 meter surface of the whiteboard where I can simply put in points to make the robot draw a line from one point to another, making the squares for the game and drawing the X's. And then to draw in a circular motion for the O's.

Hello! I've now been struggling to learn myself how to write a code for basic movements for the KUKA LBR iiwa 7 R800. The task on hand is to make the robot draw the X's and O's in an TicTacToe game. I've been reading some manuals and figured out that I should be using the PTP and CIRC functions for the basic drawing movements, but the lack of example codes frustrate me. It would be awesome if any of you would give me some tips when it comes to coding.

Thanks!