Deploy a ROS application to your robot

In the previous exercises, you used RoboMaker with Cloud9 to build, bundle and simulate two different robot applications. In the final activity of this workshop, we will deploy the simple Hello World application we built in the first activity.

In RoboMaker, simulations use Gazebo, which runs in AWS on a fleet of servers with x86 CPU architecture. However, many physical robots use different CPU architectures, such as ARM. Before a robot application can be deployed and invoked on a physical robot, it may need to be rebuilt and rebundled for the target CPU architecture of the robot.

In this workshop, you’ll be deploying an application to a TurtleBot 3 Burger robot. This robot uses a Raspberry Pi, which is based on the ARMHF architecture. Within the RoboMaker Cloud9 environment, we have pre-installed a Docker container that simplifies the process of compiling for alternate architectures. The initial build and bundle operation for an alternate architecture may take up to 20 minutes, so it is outside the scope of this workshop. If you have time after completing this exercise, you can review the detailed steps for building for alternate architectures in the RoboMaker documentation. For this exercise, we have pre-created a bundle for the TurtleBot3 Burger robot. We will use that bundle to deploy the application to your robot.

This activity covers the steps required to prepare a physical robot to receive a ROS application using RoboMaker. When complete, you will have learned:

  • How to register your robot in RoboMaker.
  • How to deploy authentication certificates to your robots.
  • How to create robot application versions, and robot fleets.
  • How to deploy a bundled ROS application to your robot.

Activity tasks

  1. Open the Cloud9 development environment you used in exercise 2 of this workshop.

  2. For this activity, you need the ARN for the deployment role that was created in the cloudformation template. Look in the Outputs tab and copy the value of the Arn, it should look similar to this:

    arn:aws:iam::123456789012:role/robomaker-deployment-role
    
  3. Using the ARN you found in the previous step, run the command below to allow Greengrass to use it for deployment:

    # replace DEPLOYMENT_ROLE_ARN with your ARN
    aws greengrass associate-service-role-to-account --role-arn $DEPLOYMENT_ROLE_ARN
    
  4. The bundle that we will use for this step has been pre-created, you simply need to tell RoboMaker where to find it. Open the RoboMaker console, and review the Robot Applications (Development->Robot Applications). Click on the name of the robot application, RoboMakerHelloWorldRobot, to review its details.

  5. To view the location of the bundle files for the application, click on the $LATEST link, under Latest version.

  6. You will now see the details for the RoboMakerHelloWorldRobot application, including the Sources. Notice that it currently has only one source: the X86_64 version (this is the version you just used for simulation). To tell RoboMaker about the ARMHF version, click the Update button.

  7. Copy the following robot tar file into your S3 bucket.

    aws s3 cp s3://robomakerbundles/turtlebot3-burger/hello-world/robot-armhf.tar s3://<YOUR_BUCKET_NAME>/hello-world/robot-armhf.tar
    
  8. In the ARMHF souce file text box, paste the new S3 location for the ARMHF bundle:

    s3://<YOUR_BUCKET_NAME>/hello-world/robot-armhf.tar
    

    Click Create.

  9. Before RoboMaker can deploy to a physical robot, you need to configure your robot. You need to create authentication certificates that will enable the device to securely communicate with AWS. You also need to register your robot in RoboMaker. To get started with this task, click on the Robots link under Fleet Management.

  10. Click on the Create robot button.

  11. Give your robot a friendly name (i.e. HelloRobot), and set the Architecture to ARMHF. By setting this value, you’re telling RoboMaker to use the ARMHF bundle when deploying to this robot.

  12. RoboMaker uses AWS GreenGrass to deploy your robot bundles to your device. You must now configure RoboMaker’s GreenGrass settings. You can leave the AWS Grengrass group and AWS Greengrass prefix settings as their default values.

  13. For IAM role, choose “robomaker-deployment-role”. This role was created in exercise 1 of this worksop. This role is assumed by your robot application when it runs on your device and gives your device permission to access AWS services on your behalf.

  14. Click Create.

  15. You must now download the certificates that need to be installed on your robot. When installed on your robot, they will give your robot access to call AWS services. Click the orange Download button. There is no need to download the Greengrass Core software. Your device has been pre-configured with the Greengrass binaries. This will download a zip file named HelloRobot-setup.zip (or similar, depending on the name you provided for your robot in Step 9 above).

    3_download_certs

  16. The certificates you just downloaded need to be copied to the physical robot and extracted to a directory on the device. These instructions use scp to copy files to the device, and ssh to connect to the device. Both commands are available in Terminal on macOS, and in the Windows PowerShell. However, availability of these tools may vary, depending on your configuration (particularly on Windows).

  17. If you’re using a Windows computer, skip to the next step. On macOS, open Terminal by pressing Command-spacebar to launch Spotlight and type “Terminal,” then double-click the search result. Skip the next step regarding Windows, and proceed to step 17.

  18. If you’re using Windows, press the Windows key, or click the Windows (Start) button, and type “PowerShell” and press Enter.

  19. On your laptop, navigate to the directory where you downloaded the certificates in Step 13 above. ($ cd Downloads)

  20. Copy the zip file to your robot. Replace the file name with the file name of the file you downloaded. The IP address for your robot was provided with the robot. You will be prompted for a password. The password for the pi user is: robomaker.

    # replace FILE_NAME with the value for your zip file
    $ scp FILE_NAME.zip pi@<ROBOT_IP_ADDRESS>:/home/pi
    
  21. Connect to the robot, flash the OpenCR board, configure the certificates and start the Greengrass service. In this step, you use ssh to connect to the robot, and then you unzip the certificates file to the location used by Greengrass. Finally, you start the Greengrass service. This enalbes the device to retrieve your robot bundle and deploy it to the robot. As a reminder, the user is pi and the password is robomaker.

    # use SSH and connect to the robot.  Replace ROBOT_IP_ADDRESS with the IP address for your device
    $ ssh pi@<ROBOT_IP_ADDRESS>
    # enter password: robomaker.
    $ sudo su
    # enter password: robomaker.
    
    # unzip the certificates into the /greengrass directory.  Replace FILE_NAME with file you copied earlier.
    $ unzip FILE_NAME.zip -d /greengrass
    
    # update the CA certificate used by RoboMaker
    $ cd /greengrass/certs/
    $ wget -O root.ca.pem https://www.amazontrust.com/repository/AmazonRootCA1.pem
    
    #start the Greengrass service
    $ /greengrass/ggc/core/greengrassd start
    
  22. Create a Fleet and add your robot to the Fleet. Fleets enable you to manage a group of robots. For example, you can deploy the same robot application to all robots in a fleet. Then ensures that all your robots are running the same software. If you need different robots to run different software, you can create multiple fleets. In this workshop, you’ll create a single fleet that contains a single robot. In the AWS RoboMaker console, choose Fleets under Fleet managment. Click the Create fleet button.

  23. Give your fleet an appropriate name and click Create.

  24. You now must add your robot to the newly-created fleeet. On the fleet page for your new fleet, click the Register new button under the Registered robots section.

    3_register_new

  25. Select your robot, and choose Register robot. Congratulations, your robot is now a member of your fleet!

  26. The final step is to deploy our application to our fleet. To get started, click Deployments under Fleet management, and choose Create deployment.

  27. Choose the Fleet and Robot application (RoboMakerHelloWorldRobot) you created earlier.

  28. For Robot application version, choose Create new, and click Create on the confirmation. This will create a new version for the HelloRobot_application robot application.

  29. For Package name, enter hello_world_robot. This is the ROS package contained in our bundle that contains the startup file for our robot.

  30. For Launch file, enter deploy_rotate.launch. This is the launch file within the above package. It contains information about the ROS nodes that will be started on the device.

  31. All other fields can use their default values. Scroll to the bottom and choose Create.

Within a few seconds, your robot will begin to download the robot bundle. Because this is the first time this application is being deployed to your robot, the bundle size is large (~600MB). It will take about 15 minutes for the robot to download and extract the contents on the robot. You can follow the deployment progress in the Robots status section:

3_robots_status

When the bundle has been successfully deployed, the robot application will automatically be launched on your robot!