Momentum Control of Humanoid Robots with Series Elastic Actuators
This work addresses a specific problem in robotics for improving efficiency and safety in humanoid robots, but it is incremental as it adapts existing methods to a new actuator type.
The paper tackled the challenge of designing balancing and walking controllers for humanoid robots with series elastic actuators by proposing a control framework that extends momentum-based controllers to such compliant joints, and simulations on the iCub robot model verified the approach.
Humanoid robots may require a degree of compliance at the joint level for improving efficiency, shock tolerance, and safe interaction with humans. The presence of joint elasticity, however, complexifies the design of balancing and walking controllers. This paper proposes a control framework for extending momentum based controllers developed for stiff actuators to the case of series elastic actuators. The key point is to consider the motor velocities as an intermediate control input, and then apply high-gain control to stabilise the desired motor velocities achieving momentum control. Simulations carried out on a model of the robot iCub verify the soundness of the proposed approach.