This tutorial aims to enable you to work with the Kuka iiwa robot arms by yourself. For detailed information, please refer to the corresponding user manuals.

IMPORTANT: Safety notes

There are three emergency stops. Each pad has one on top that switches off the respective robot. Additionally, there is the yellow master emergency stop stored on the front left of the table which can switch off both robots together. For safety reasons, always keep in mind the following points:

  • When not operating the robots, the emergency stops must be always locked!
  • If someone has to enter the robots’ workspace while they are running, another person must be outside the workspace holding the master emergency stop and ready to press it if needed!


Setup - overview

Up to three computers are needed to work with the robots:

  • The “Robot PC”, running on Ubuntu 14.04., located within the table (screen is to the left of the table),
  • the “Java PC”, running on Windows, located on the right of the table,
  • the “Simulink PC”, running on Ubuntu 18.04., also located on the right of the table (setup can change, search for the markings on the PCs).

The passwords of the PCs are listed at the end of this tutorial.


The following image shows the wiring of the two KUKA Sunrise Cabinet controllers within the table.

Figure 1

Figure 1


The upper box is connected to the left robot and the lower box is connected to the right robot. The cables have the following purposes:

  • Thick dark gray cables: connections to the pads
  • Thick light gray cables: connections to the robots
  • Black LAN cable: connection to the Java PC (only one robot at a time)
  • Blue LAN cable: connection to the Robot PC

Except from the black LAN cable, the cables usually do not need to be reconnected.

First Steps

Figure 2

Before starting to work with the robots, the following steps are always necessary:

  1. Open the transparent door.
  2. Switch on the robots (green switches) and the Robot PC (on/off switch on top).
  3. Ubuntu 14.04 is now the default OS. Select Ubuntu 14.04 in the robot PC’s boot menu. This must be done manually and fast enough, since otherwise another Ubuntu version, which is the default operating system, is selected automatically.
  4. Take the master emergency stop, which can switch off both robots together, from its socket on the front left of the table. Only proceed if you know what you are doing. Release the switch and press the green button. Wait for some seconds and then press the green button again (start).

Now, you can use the pads to control the robots.










                   Figure 2                      

How to use the pads

The pads are basically the interface to controlling the robots. They have two operation modes: manual and automatic. To select the desired mode, turn the key on top to the right and select either manual (T1/T2) or automatic (AUT). Then, release the emergency stop on the top right of the pad. Start an application:

  1. Set operation mode to AUT and then turn the key back into its initial position.
  2. Choose an application via “Applications” on top of the screen (Figure 3).
  3. Press the lower green play-button (to the left of the screen)
  4. Stop the application by pressing the emergency stop and then the square red stop-button (to the left of the screen)

Manual movement:

  1. Set operation mode to T1. Using T2 is not recommended.
  2. Press “LBR_iiwa_14_R820” to the upper right of the screen (Figure 4).
  3. Select either “Cartesian Position” (Figure 6) or “Joint Position” (Figure 5).
  4. Click on the small button on the very right of the screen depicting a robot to select the frame to operate in (e.g. world, tool).
  5. Change joint angles or pose in the world frame with the “+” and “-“ symbols on the right of the screen. Motions are only possible if one of the white bars on the back of the pad is pressed simultaneously (indicated by the gray letters on the very right of the screen becoming bright).


Figure 3

Figure 4

Figure 5

Figure 6

Figure 3

Figure 4

Figure 5

Figure 6

Robot-PC

This PC must be running to use the robots. When booting, its operating system must be changed manually to Ubuntu 14.04.

This PC can be used to upload Simulink models to the robots and interact with the robots in real-time, e.g., by changing parameters in the Simulink model. The following steps are required to upload a Simulink model:

  1. Go into folder: ~/Desktop/iiwaBase. Copy this folder and rename it to iiwa<YourName>. Use this folder for your future projects.
  2. To create your own model, copy iiwaControl17.slx from iiwaBase and use it as a start.
  3. Build the Simulink model by pressing the blue build-button on top. If that does not work, make sure that the Matlab workspace folder is /home/ncs/Desktop/iiwa<YourName>.
  4. Connect to the Robot PC by typing ssh murola@129.187.231.157 in a terminal window. If that does not work, check if the IP address of the Robot PC matches the one above by opening a terminal window on the Robot PC and typing ifconfig eth8. Create your own folder on the Robot PC and change into it. Once the ssh connection is established, step 3 does not have be performed again.
  5. In a new terminal: Copy the Simulink file to the Robot PC:
    scp <file_name> murola@129.187.231.157:~/<desired_folder>
    Example:
    scp iiwaControl17 murola@129.187.231.157:~/pablo

To run the uploaded model, do the following:

  1. On the pads: Start your application (see Java-PC). Usually, you can use FriImpSmart.
  2. In the terminal where you connected to the robot PC: Start the Simulink file that you just copied to the Robot PC by typing ./file_name.
    Example:
    ./iiwaControl17.slx
  3. In Simulink: Click “Connect To Target”. You can now change parameters such as the desired end-effector velocity in real-time.
  4. To stop the robots, press the emergency stops. Also, press CTRL+C in the terminal where you started the Simulink file.

Java-PC

This PC can be used to upload new Java applications to the robots with the Sunrise Workbench IDE. Typically, this PC is only needed to change the initial configuration and the parameters of the impedance controller. Exemplary applications can be found in the already existing project folders (FriImpSmart). To compile the Java code, click “Synchronize project” on the top left of the screen. Then, in the window popping up, select “Deploy to controller” and click “Execute”. In the StationSetup.cat file, make sure that the IP address matches that of the respective robot (left robot: 192.170.10.2, right robot: 192.170.10.3). Every time something is changed in the StationSetup, the controller must be reinstalled. Therefore, when working with both robots, it is recommended to use a separate project folder for each robot so that you don’t have to change the IP address every time you want to program the other robot. Keep in mind that you must replug the black LAN cable when changing the robot to which you upload an application (left robot: upper socket, right robot: lower socket)

Passwords

  • Robot PC: “aLoRuM”
  • Java PC: “ifac”
  • Simulink PC: “ncs”
  • IIWA: "argus" (This is should not be needed)

FAQ

  • Connection to one of the robots lost after some time, robot stopped moving, but pinging was still possible.

       → Restarting the respective robot solved the error.

  • Connecting from the Simulink PC to the Robot PC does not work.

       → Check the IP address of the Robot PC and enter the correct one when running ssh ...