HARMONIOUS -- Human-like reactive motion control and multimodal perception for humanoid robots (2312.02711v2)

Abstract: For safe and effective operation of humanoid robots in human-populated environments, the problem of commanding a large number of Degrees of Freedom (DoF) while simultaneously considering dynamic obstacles and human proximity has still not been solved. We present a new reactive motion controller that commands two arms of a humanoid robot and three torso joints (17 DoF in total). We formulate a quadratic program that seeks joint velocity commands respecting multiple constraints while minimizing the magnitude of the velocities. We introduce a new unified treatment of obstacles that dynamically maps visual and proximity (pre-collision) and tactile (post-collision) obstacles as additional constraints to the motion controller, in a distributed fashion over the surface of the upper body of the iCub robot (with 2000 pressure-sensitive receptors). This results in a bio-inspired controller that: (i) gives rise to a robot with whole-body visuo-tactile awareness, resembling peripersonal space representations, and (ii) produces human-like minimum jerk movement profiles. The controller was extensively experimentally validated, including a physical human-robot interaction scenario.

• The paper introduces HARMONIOUS, a motion controller that enables humanoid robots to navigate human-populated environments with 17 degrees of freedom.
• It employs quadratic programming to balance joint velocities, natural postures, and real-time collision avoidance using multimodal sensory inputs.
• Real-world tests with the iCub robot demonstrate the system’s robustness and practical applicability in dynamic, cluttered settings.

Introduction to Humanoid Robots and HARMONIOUS

Humanoid robots are advanced robotic systems designed to mimic human form and behavior, which makes them suitable for a wide range of tasks that involve interacting with humans or operating in environments built for people. To be effective, these robots must be capable of moving smoothly and avoiding obstacles, including dynamic ones like humans moving in their vicinity. However, ensuring that a humanoid robot can navigate such complex environments safely and effectively has been a challenging goal for roboticists.

HARMONIOUS: A New Reactive Motion Controller

A significant advancement in this area is the HARMONIOUS system, which stands for "Human-like reactive motion control and multimodal perception for humanoid robots." HARMONIOUS is a reactive motion controller tailored for humanoid robots that must operate amidst human-populated spaces. Unlike traditional robot controllers, HARMONIOUS can command the upper body of a humanoid robot, including two arms and a torso, summing up to a total of 17 degrees of freedom (DoF).

The core of HARMONIOUS is a quadratic programming approach that balances multiple factors including minimizing joint velocities, rewarding natural postures, and dampening motion in the vicinity of kinematic singularities—all while handling real-time collision avoidance.

Collision Avoidance and Obstacle Handling

A unique aspect of HARMONIOUS is its ability to handle obstacles using a unified treatment of multimodal sensory inputs that includes visual, proximity, and tactile information. The system can dynamically process signals from RGB-D cameras, proximity sensors, and a network of 2000 pressure-sensitive tactile receptors, transforming them into real-time constraints on the motion controller. This fusion of data creates a protective safety margin, similar to the concept of peripersonal space in humans, where the robot maintains awareness of its surroundings and can react to avoid obstacles and collisions.

Human-like Motion and Adaptability

HARMONIOUS stands out due to its bio-inspired movement profiles that mimic human motion patterns, such as minimum jerk trajectories that create smooth and natural-looking movements. Additionally, the controller's whole-body awareness and responsiveness to dynamic changes in the environment enable it to effectively manage multiple tasks and avoid collisions. This versatility makes HARMONIOUS adaptable for various scenarios, from moving efficiently in cluttered spaces to interacting with humans in shared workplaces.

Real-world Applications and Future Development

The motion control system has been rigorously tested in simulation and with the iCub humanoid robot across different experimental setups, demonstrating superior performance compared to other state-of-the-art approaches. Real-world applications, including a children's board game where the robot had to interact closely with a human player, showcased the system's robustness and practicality.

Moving forward, the development of HARMONIOUS will focus on incorporating active gaze control for better sensory perception and minimizing noise in sensory inputs. Enhancements like these will continue to improve humanoid robots' capabilities, making them valuable partners in everyday settings, contributing to industries, and assisting in personal and domestic environments.