Unitree Z1 Robotic Arm: Wine Pouring Task

Abstract

This project showcases the Unitree Z1 6 DOF robotic arm performing the task of pouring wine into a glass. The robot utilizes a full pose impedance controller, enabling compliant and precise manipulation of the bottle to achieve smooth pouring. The controller manages both position and orientation, allowing the arm to adapt to contact forces and ensure safe, accurate execution of the task.

Methodology

The project leverages advanced robotics control and simulation techniques:

Robot Control Implementation

  • Full pose impedance control for compliant and safe manipulation
  • 6 DOF control of the Unitree Z1 robotic arm
  • Real-time force and torque feedback for adaptive pouring
  • Trajectory planning for bottle grasping, lifting, and pouring

Simulation & Experimentation

  • Physics-based MuJoCo simulation for controller validation
  • Integration with Unitree Z1 hardware and sdk
Official Unitree Z1 Arm Wine Pouring GIF
Figure 2: Official demonstration GIF from Unitree's website

This GIF shows the planned replication of the wine pouring task as presented by Unitree on their official website.

Grasping bottle at Location A — overhead camera view
Grasping — Bottle at Location A (Overhead Camera)

Demonstrates the robot grasping a bottle placed at Location A. Overhead camera view used for visual servoing and localizing the bottle relative to the gripper during approach and lift.

Grasping bottle at an Angle
Grasping — Bottle at an Angle (Overhead Camera)

Shows the robot grasping a bottle presented at an angled orientation. Highlights the gripper approach and wrist accommodation for secure, adaptive grasping of a tilted object prior to lifting and pouring.

Grasping bottle at Location B — hand-eye calibration view
Grasping — Bottle at Location B (Hand–Eye Calibration)

Shows the robot performing a grasp on the bottle positioned at Location B. Calibration and alignment between camera and wrist frame ensure a robust closed-loop grasping behavior.

Grasping bottle at Location C — grasp pose estimation overlay
Grasping — Bottle at Location C (Grasp Pose Estimation)

Example of the robot selecting and executing a grasp for a bottle at Location C. Predicted grasp proposals are overlaid to illustrate candidate poses and the chosen secure, ergonomic grasp used before pouring.

Unitree Z1 Robotic Arm Pouring Wine
Figure 1: Unitree Z1 robotic arm pouring wine into a glass using impedance control

The robot demonstrates compliant pouring, adapting to contact forces and glass position.

Watch Real Robot Implementation

Key Innovations

Full Pose Impedance Control

Enables compliant, safe, and precise manipulation of the bottle for pouring tasks.

6 DOF Robotic Arm

Utilizes the Unitree Z1's full range of motion for complex manipulation.

Adaptive Task Execution

Real-time feedback and control for robust pouring, even with environmental uncertainties.

Impact and Future Directions

This project demonstrates advanced compliant control and manipulation capabilities with the Unitree Z1 robotic arm, paving the way for safe human-robot interaction and automation in service robotics:

Educational Value

Illustrates modern impedance control and its application in real-world tasks.

Technical Innovation

Demonstrates full pose impedance control for safe, adaptive manipulation.

Service Robotics Applications

Potential for automation in hospitality, healthcare, and domestic environments.

Future Enhancements

Conclusion

The Unitree Z1 robotic arm wine pouring project demonstrates the effectiveness of full pose impedance control for compliant, precise, and safe manipulation. The robot successfully adapts to contact forces and environmental uncertainties, making it suitable for service robotics and automation tasks requiring delicate handling.

Back to Projects