0 – Research
· our · research ·Our Scientific Program is the fundamental support for all our product development plant. The goal is to understand how robots can better interact with the environment and the people round.
Over the last 3 years, PULSAR HRI has been investigating the basic principles behind the physical interaction between robot and environment. Our first published paper versed about how to generalise impact response factor for any kind of robot. In that paper, we presented a factor called GIAF (Generalised Impact Absorption Factor), a metric to quantify the capacity of a robot to absorb impacts depending on the rotary inertia of its joints, the configuration of the robot and the characteristics of the impact.
Publications
Abstract
This paper presents the design and experimental results of a proprioceptive, high-bandwidth quasi direct drive (QDD) actuator for highly dynamic robotic applications. A comprehensive review of the mechanical design of the actuator is presented, with particular focus on the design parameters affecting the dynamic performance of the actuator. After the description of the new PULSE115-60 actuator, a full specification is provided. Fundamental parameters to describe the dynamic behaviour of an actuator are discussed, and an experimental method to determine speed and torque bandwidth of the actuator is presented. A rigorous method to determine backdrive torque is also explained. Finally, experimental results quantifying the dynamic performance of the PULSE115-60 actuator are discussed. The PULSE115-60 actuator has a highly dynamic response, surpassing the torque bandwidth at low torque amplitudes showcased in state-of-the-art literature. The differences between current and torque bandwidth, two concepts often conflated in literature, are elucidated. Experimental procedures detailed in previous work are discussed and a novel standardised procedure is proposed for robust characterisation and fair comparison of different actuation systems. Finally, performance results for PULSE115-60 are presented, reaching a real torque bandwidth of 66.3 Hz at an amplitude of 6 N·m, +-0.11º of backlash and 0.37 N·m of backdrive torque.
Full paper
Abstract
Physical Human-Robot Interaction(pHRI) requires taking safety into account from the design board to the collaborative operation of any robot. For collaborative robotic environments, where human and machine are sharing space and interacting physically, the analysis and quantification of impacts becomes very relevant and necessary. Furthermore, analyses of this kind are a valuable source of information for the design of safer, more efficient pHRI. In the definition of the first parameter for dynamic impact analysis, the dynamic impact mitigation capacity was considered for certain configurations of the robot, but the design characteristics of the robot, such as the inertia of actuators, were not included. This paradigm changed when MIT presented the “impact mitigation factor” (IMF) with which, in addition to considering the ability of a certain robot to mitigate impacts for every configuration, it was possible to quantify backdrivability by taking the inertia of actuators into account for the calculation of the factor. However, IMF was proposed as a method to analyse floating robots like. This paper presents the Generalised Impact Absorption Factor (GIAF), suitable for both floating and fixed-base robots. GIAF is a valuable design parameter, as it provides information about the backdrivability of each joint, while allowing the comparison of impact response between floating and fixed-base robotic platforms. In this work, the mathematical definition of GIAF is developed and examples of possible uses of GIAF are presented.
Full paper