Sonic Full-Body Teleoperation

This guide explains how to deploy and use Sonic full-body teleoperation on ELF3, including robot-side dependency installation, PICO Motion Tracker calibration, XRoboToolkit network configuration, full-body motion following, and the exit procedure.

• Motion-control repository: bxi_rl_controller_ros2_example
• Sonic Mod repository: com.bxi.sonic
• PICO client: XRoboToolkit-PICO-1.1.1.apk

Environment

Choose the Project Directory

Use the project path that matches how the robot is started. Do not place the Sonic Mod inside the App project or its private_git_mods; install it in the independent /opt/bxi/mods directory, which is outside the App download and survives App updates.

mv ~/bxi_ws/bxi_rl_controller_ros2_example/src/bxi_example_py_elf3/mods/private_git_mods/com.bxi.sonic \
  ~/bxi_ws/bxi_rl_controller_ros2_example/com.bxi.sonic.backup

When following the commands below, use the project path for your startup method. Clone the Sonic Mod into the independent /opt/bxi/mods/com.bxi.sonic directory.

Prepare the Robot

0. Clone the Sonic Mod

The Sonic Mod is maintained in a separate repository. Clone it manually into the motion-control project's private Mod directory before building:

sudo mkdir -p /opt/bxi/mods
sudo git clone https://github.com/konodoki/com.bxi.sonic.git /opt/bxi/mods/com.bxi.sonic

If the directory already exists, update that repository separately:

cd /opt/bxi/mods/com.bxi.sonic
git pull --ff-only

The parent project does not track this directory. At runtime, the configured /opt/bxi/mods root is scanned recursively, so the Mod remains available after an App update.

1. Update the Motion-Control Project

Update bxi_rl_controller_ros2_example on the robot to the latest version:

cd /home/bxi/bxi_ws/bxi_rl_controller_ros2_example
git pull --ff-only

After updating the source, rebuild the project as described in the repository README and source the environment:

source /opt/ros/humble/setup.bash
source /opt/bxi/bxi_ros2_pkg/setup.bash
cd /home/bxi/bxi_ws/bxi_rl_controller_ros2_example
bash build.sh
sudo systemctl restart ros_elf_launch.service

2. Install Sonic Dependencies

Before using Sonic for the first time, switch to the root user on the robot and install the Python dependencies required for PICO connectivity:

sudo su
python3 -m pip install -r /opt/bxi/mods/com.bxi.sonic/requirements-pico.txt

The dependencies normally need to be installed only once. Run the command again after an update if requirements-pico.txt has changed.

3. Install the PICO Application

Download XRoboToolkit-PICO-1.1.1.apk and install the APK on the PICO headset. After installation, XRoboToolkit is available under Unknown Sources in the PICO Library.

Enter the Sonic Ready State

1. Start ELF3 normally, confirm that the robot has completed its self-check, and use the remote controller to put the robot into walking mode. The robot should hold its normal standing posture.

1. Press LB + RB + X simultaneously on the robot remote controller to request Sonic full-body teleoperation.

2. Wait for the state transition to finish. The robot assumes the ready posture shown below. Continue with PICO calibration and motion following only after the posture is stable.

Calibrate the PICO Motion Trackers

Recalibrate the Motion Trackers before each full-body teleoperation session to reduce body-pose and floor-height errors.

1. Secure one Motion Tracker to each leg. The side with the button and indicator light must face upward along the body. Press the button to turn on each tracker.

2. Put on the PICO headset and pick up both controllers. Select Motion Tracker in the lower-right corner of the PICO home screen.

1. Confirm that both leg trackers are connected. Select Start Calibration and follow the instructions in the headset.

1. After calibration, select Adjust Floor and follow the instructions to align the virtual floor with the physical floor.

1. Observe the avatar on the screen. When the operator moves their head, hands, and legs, the avatar should follow those movements and its feet should remain close to the floor.

Connect XRoboToolkit

1. Return to the PICO Library and open XRoboToolkit under Unknown Sources.

1. Confirm that PICO and the robot are connected to the same LAN, then obtain the robot's LAN IP address.

2. In the Network section of XRoboToolkit, select Enter next to PC Service, enter the robot's IP address, and connect.

3. Check the tracking and transmission options against the table below:

1. Confirm that Status in the Network section shows WORKING and that the log does not contain continuous errors.

Calibrate the Reference Posture and Start Following

1. Face the same direction as the robot and stand upright. Let the upper arms hang naturally, bend the elbows approximately 90 degrees, and hold the forearms horizontally in front of the body as shown below.

1. Hold the posture steady and press A + B + X + Y across the two PICO controllers at the same time. This aligns PICO three-point tracking with the robot's reference posture.

2. After calibration, continue matching the robot's posture and heading. Confirm that body tracking in the headset does not show significant drift.

3. Press A + X simultaneously on the PICO controllers. The robot begins following the operator's full-body motion. Move the arms slowly first, then make small torso and leg movements to verify that all motion directions are correct.

4. To pause following and return the robot to its default posture, press A + X simultaneously again.

5. After confirming that real-time following has stopped, press RB + X simultaneously on the robot remote controller to return the robot to normal walking mode.

Common controls:

Acceptance Check

After deployment, verify all of the following:

1. Both leg trackers show as connected in the PICO Motion Tracker screen;
2. The avatar's head, hands, and legs follow the operator's movements;
3. XRoboToolkit shows WORKING, Mode is set to Full-body, and Send is selected;
4. The robot enters and stably holds the Sonic ready posture after LB + RB + X is pressed;
5. After calibration with A + B + X + Y, pressing A + X makes the robot follow small movements with low latency;
6. Pressing A + X again returns the robot to its default posture, and pressing RB + X returns it to normal walking mode.

Troubleshooting

XRoboToolkit Cannot Connect to the Robot

• Confirm that PICO and the robot are on the same LAN;
• Confirm that PC Service contains the robot's IP address, not the PICO IP address;
• Check whether the IP address changed after switching networks;
• Confirm that XRoboToolkit shows WORKING, and review its log for connection errors.

The Avatar's Legs Do Not Follow or Its Feet Float

• Confirm that both leg trackers are connected and sufficiently charged;
• Make sure the button and indicator side of each tracker faces upward along the body;
• Run Start Calibration and Adjust Floor again;
• Confirm that XRoboToolkit uses Full-body mode with Num set to 2.

The Robot Cannot Enter the Sonic Ready State

• Confirm that the robot has completed its self-check and is in normal walking mode;
• Confirm that LB + RB + X is pressed as a three-button combination;
• Confirm that the project has been updated to the latest version and rebuilt;
• On first use, confirm that the packages in requirements-pico.txt were installed into the Python environment used by the robot process.

The Robot Does Not Follow After Calibration

• Confirm that Send is selected in XRoboToolkit and its status is WORKING;
• Confirm that the avatar in PICO Motion Tracker follows the operator correctly;
• Return to the initial posture and press A + B + X + Y again;
• Wait for calibration to finish, then press A + X to start real-time following.

The Robot Moves in a Different Direction From the Operator

Stop real-time following, face the same direction as the robot, and recalibrate. If only the heading is offset, press X alone on the robot remote controller while no shoulder or trigger button is held to reset heading alignment.

Motion Stutters or the Posture Jumps

Stop large movements and check the wireless network quality between PICO and the robot, the tracker connections, and the XRoboToolkit log. Before resuming, verify the initial posture and surrounding safety again. If the issue continues, exit Sonic, then recalibrate and reconnect.

References

• bxi_rl_controller_ros2_example
• Sonic Mod repository
• XRoboToolkit Unity Client