[Announcement] ROS2 Adaptive Admittance Controller

Developer Aitor Ibarguren has announced the release of the adaptive_admittance_controller, a new open-source controller for the ROS2 Jazzy robotic operating system. Designed as a chainable component that follows a base motion controller, it introduces real-time adaptability for compliant robotic manipulation. Its core innovation is a topic-based interface that allows engineers to dynamically modify critical admittance parameters—like stiffness, damping, and mass—during task execution. This is crucial for operations like assembly or advanced teleoperation, where a robot must frequently shift between rigid and soft behaviors based on contact phases. To ensure stability, the controller implements gradual parameter ramping, preventing dangerous jerks when, for example, stiffness is reduced from 5000 to 500. It also tackles a common hardware issue by estimating and mitigating force/torque sensor bias in real-time.

The controller has been validated on a Universal Robots UR16e, using its built-in force/torque sensor. Testing demonstrated two key workflows: chaining it with a standard joint trajectory controller for executing pre-planned paths with compliance, and pairing it with a custom twist controller for compliant teleoperation using a 6D SpaceMouse joystick. A significant feature is its ability to safely transition between different compliance profiles, such as activating a 'soft Z axis' followed by 'soft XY axes'. The controller's architecture uses KDL for kinematics and Eigen with SVD for matrix calculations, and it offers an open-loop mode to bypass hardware feedback latency. By publishing internal states like wrench and twist values, it provides essential introspection for deployment and debugging. The project is hosted on GitHub, inviting community feedback on its API and feature set.