3 research outputs found
Robots that look like humans : a brief look into humanoid robotics
This article provides a brief overview of the technology of humanoid robots. First, historical development and hardware progress are presented mainly on human-size full-body biped humanoid robots, together with progress in pattern generation of biped locomotion. Then, «whole-body motion» ? coordinating leg and arm movements to fully leverage humanoids? high degrees of freedom ? is presented, followed by its applications in fields such as device evaluation and large-scale assembly. Upper-body humanoids with a mobile base, which are mainly utilized for research on human-robot interaction and cognitive robotics, are also introduced before addressing current issues and perspectives
IPM-HLSP: An Efficient Interior-Point Method for Hierarchical Least-Squares Programs
Hierarchical least-squares programs with linear constraints (HLSP) are a type
of optimization problem very common in robotics. Each priority level contains
an objective in least-squares form which is subject to the linear constraints
of the higher priority hierarchy levels. Active-set methods (ASM) are a popular
choice for solving them. However, they can perform poorly in terms of
computational time if there are large changes of the active set. We therefore
propose a computationally efficient primal-dual interior-point method (IPM) for
HLSP's which is able to maintain constant numbers of solver iterations in these
situations. We base our IPM on the null-space method which requires only a
single decomposition per Newton iteration instead of two as it is the case for
other IPM solvers. After a priority level has converged we compose a set of
active constraints judging upon the dual and project lower priority levels into
their null-space. We show that the IPM-HLSP can be expressed in least-squares
form which avoids the formation of the quadratic Karush-Kuhn-Tucker (KKT)
Hessian. Due to our choice of the null-space basis the IPM-HLSP is as fast as
the state-of-the-art ASM-HLSP solver for equality only problems.Comment: 17 pages, 7 figure
Nut fastening with a humanoid robot
International audienceWe study the HRP-2Kai humanoid robot's ability to conduct the precise industrial task of fastening bolts in aircraft production. Our contribution stands mainly in high integration of different modules within the whole-body Quadratic Programing-based controller that has not been yet confronted to tasks demanding high precision in the execution and tuning. This includes the use of a robust visual servoing algorithm which allows the robot to move autonomously to a desired target and the design of specific tasks and estimators: a learning and admittance control that enables the robot to interact smoothly with its environment, and a fast and safe method to autonomously detect correct tool on nut insertion. We then show that the controller indeed enables our humanoid robot to achieve such a high precision task