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Leonardo F. Dos Santos

Publications and source records attributed to Leonardo F. Dos Santos.

3 recordsLinked to original sources

Leveraging Port-Hamiltonian Theory for Impedance Control Benchmarking

This work proposes PH-based metrics for benchmarking impedance control. A causality-consistent PH model is introduced for mass-spring-damper impedance in Cartesian space. Based on this model, a differentiable, force-torque sensing-independent, n-DoF passivity condition is derived, valid for time-varying references. An impedance fidelity metric is also defined from step-response power in free motion, capturing dynamic decoupling. The proposed metrics are validated in Gazebo simulations with a six-DoF manipulator and a quadruped leg. Results demonstrate the suitability of the PH framework for standardized impedance control benchmarking.

cs.RO↗

Impedance Space Method: Time-Independent Parametric Ellipses for Robot Compliant Control

This paper proposes a novel 3D graphical representation for impedance control, called the impedance space, to foster the analysis of the dynamic behavior of robotic compliant controllers. The method overcomes limitations of existing 2D graphical approaches by incorporating mass, stiffness, and damping dynamics, and associates the impedance control parameters with linear transformations to plot a parametric 3D ellipse and its projections in 2D for a mass-spring-damper impedance under sinusoidal reference. Experimental evaluation demonstrates the effectiveness of the proposed representation for analysis of impedance control. The method applies to various compliant control topologies and can be extended to other model-based control approaches.

eess.SY↗

Construction of an Impedance Control Test Bench

Controlling the physical interaction with the environment or objects, as humans do, is a shared requirement across different types of robots. To effectively control this interaction, it is necessary to control the power delivered to the load, that is, the interaction force and the interaction velocity. However, it is not possible to control these two quantities independently at the same time. An alternative is to control the relation between them, with Impedance and Admittance control, for example. The Impedance Control 2 Dimensions (IC2D) bench is a test bench designed to allow the performance analysis of different actuators and controllers at the joint level. Therefore, it was designed to be as versatile as possible, to allow the combination of linear and/or rotational motions, to use electric and/or hydraulic actuators, with loads known and defined by the user. The bench adheres to a set of requirements defined by the demands of the research group, to be a reliable, backlash-free mechatronic system to validate system dynamics models and controller designs, as well as a valuable experimental setup for benchmarking electric and hydraulic actuators. This article presents the mechanical, electrical, and hydraulic configurations used to ensure the robustness and reliability of the test bench. Benches similar to this one are commonly found in robotics laboratories around the world. However, the IC2D stands out for its versatility and reliability, as well as for supporting hydraulic and electric actuators.

cs.RO↗