> ## Documentation Index
> Fetch the complete documentation index at: https://dragonwingdocs.qualcomm.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Enable people tracking with follow_me

> follow_me is a lightweight application that enables robots to track targets in real-time. Currently, it only supports tracking people.

<Frame>
  <img src="https://mintlify.s3.us-west-1.amazonaws.com/qualcomm-prod/SDKs/QIR-SDK-Ubuntu/images/follow_me.gif" alt="Robot running the follow_me application as it detects a person and drives to keep pace behind them." />
</Frame>

## Pipeline flow for `follow_me`

The following figure shows the pipeline flow for `follow_me`.

<Frame caption="The follow_me pipeline.">
  <img src="https://mintcdn.com/qualcomm-prod/EDJV-hu6qJhZi4pm/SDKs/QIR-SDK-Ubuntu/images/follow-me-pipeline.svg?fit=max&auto=format&n=EDJV-hu6qJhZi4pm&q=85&s=c00951aa2eec37e6c8b30dd6a4b93f28" alt="The follow_me pipeline from Orbbec camera color and depth streams through detection to velocity commands on the cmd_vel topic." width="843" height="522" data-path="SDKs/QIR-SDK-Ubuntu/images/follow-me-pipeline.svg" />
</Frame>

## ROS nodes used in the `follow_me` pipeline

The following table lists the ROS nodes used in the `follow_me` pipeline and describes what each node does.

| ROS Node        | Description                                                                                                                                                                                        |
| --------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `follow_me`     | `follow_me` is a custom ROS2 node that supports human detection and posture updates. It can also calculate the necessary control commands for the robot and send them in the standard ROS2 format. |
| `orbbec_camera` | `orbbec_camera` is the `OrbbecSDK` ROS2 wrapper, which provides integration of Orbbec cameras within the ROS2 environment.                                                                         |

## ROS topics used in the `follow_me` pipeline

The following table lists the ROS topics used in the `follow_me` pipeline, with the message type and the publisher of each topic.

| ROS Topic                   | Type                           | Published By    |
| --------------------------- | ------------------------------ | --------------- |
| `/camera/color/image_raw`   | `sensor_msgs::msg::Image`      | `orbbec-camera` |
| `/camera/depth/image_raw`   | `sensor_msgs::msg::Image`      | `orbbec-camera` |
| `/camera/color/camera_info` | `sensor_msgs::msg::CameraInfo` | `orbbec-camera` |
| `/cmd_vel`                  | `geometry_msgs::msg::Twist`    | Controller      |

## Prerequisites

You have set up the device, installed ROS2 Jazzy and the Qualcomm Intelligent Robotics (QIR) SDK on the device according to [Install the QIR SDK](./install-the-qir-sdk).

* Set up the device
* Set up the host computer

## Run out-of-the-box `follow_me`

<Steps>
  <Step title="Install dependencies">
    ```bash Add the package repositories theme={null}
    sudo add-apt-repository ppa:ubuntu-qcom-iot/qcom-ppa
    sudo add-apt-repository ppa:ubuntu-qcom-iot/qirp
    sudo apt update
    ```
  </Step>

  <Step title="Install the sample_apriltag packages">
    ```bash Install the packages theme={null}
    sudo apt install ros-jazzy-orbbec-camera
    sudo apt install ros-jazzy-ncnn
    sudo apt install ros-jazzy-follow-me
    ```
  </Step>

  <Step title="Download model files">
    ```bash Download and install the model files theme={null}
    # Download label file
    wget https://raw.githubusercontent.com/amikelive/coco-labels/master/coco-labels-2014_2017.txt -O labels.txt
    # Download model weights
    wget https://raw.githubusercontent.com/dog-qiuqiu/FastestDet/main/example/ncnn/FastestDet.bin -O FastestDet.bin
    wget https://raw.githubusercontent.com/dog-qiuqiu/FastestDet/main/example/ncnn/FastestDet.param -O FastestDet.param
    # copy model files
    sudo mkdir -p /usr/share/follow-me/model/
    sudo cp FastestDet.bin FastestDet.param labels.txt /usr/share/follow-me/model/
    ```
  </Step>

  <Step title="Set up the Robot base">
    * If you have a Qualcomm's robot base, set it up.

    * If you are using a custom or third-party robot base, apply configurations appropriate to your own robot base. Ensure the robot base can publish odometry data of the type `nav_msgs.msg.Odometry2` on the `/odom` topic.
  </Step>

  <Step title="Set up the Orbbec camera in a new terminal">
    ```bash Launch the Orbbec camera theme={null}
    # color & depth image
    export ROS_DOMAIN_ID=100
    source /opt/ros/jazzy/setup.sh
    ros2 launch orbbec_camera gemini_330_series.launch.py depth_registration:=true enable_depth:=true
    ```
  </Step>

  <Step title="Run the follow_me binary">
    ```bash Run follow_me theme={null}
    #run follow me
    export ROS_DOMAIN_ID=100
    source /opt/ros/jazzy/setup.sh
    follow_me
    ```
  </Step>
</Steps>

## Build and run `follow_me`

<Warning>
  This sample application is for `authorized` users. If you want to get the source code, see [Working with Qualcomm](https://www.qualcomm.com/support/working-with-qualcomm).
</Warning>

<Steps>
  <Step title="Install the dependencies">
    ```bash Install the dependencies theme={null}
    sudo add-apt-repository ppa:ubuntu-qcom-iot/qcom-ppa
    sudo add-apt-repository ppa:ubuntu-qcom-iot/qirp
    sudo apt update
    sudo apt install ncnn-dev
    ```
  </Step>

  <Step title="Download source code from qrb-ros-sample repository">
    ```bash Clone the sample repository theme={null}
    mkdir -p ~/qrb_ros_sample_ws/src && cd ~/qrb_ros_sample_ws/src
    source /opt/ros/jazzy/setup.bash
    git clone https://github.com/qualcomm-qrb-ros/qrb_ros_samples.git
    ```
  </Step>

  <Step title="Build sample from source code">
    ```bash Build the sample theme={null}
    cd ~/qrb_ros_sample_ws/src/qrb_ros_samples/robotics/sample_followme/
    colcon build
    source install/setup.bash
    ```
  </Step>

  <Step title="Run and test">
    Run and test according to steps 4-6 of [Run out-of-the-box follow\_me](./followme#run-out-of-the-box-follow_me).
  </Step>
</Steps>