SIMULTANEOUS POSITION AND STIFFNESS DISTRIBUTION CONTROL OF ELASTIC REDUNDANT CLOSED-LOOP MECHANISM
Journal Title: ROMANIAN JOURNAL OF TECHNICAL SCIENCES - APPLIED MECHANICS - Year 2013, Vol 58, Issue 1
Abstract
The present paper discusses a new design of robotic manipulator having redundant closed-loop mechanism with elastic passive joints. The proposed design is aiming to be utilized for developing robots that are capable to work in complicated and unpredictable environments such as natural environments, disaster sites or daily human living space. In order to deal with various contact conditions between surrounding objects and robot, effective approach called flexibility control is figured out. This methodology includes planning and optimization of force application not only on single considered point on an object but also its distribution among certain contact area. This paper defines the ability to optimize stiffness distribution at a number of contact points as “flexibility” and proposes elastic closed-loop mechanism which has a serial chain of revolute joints with torsion coil springs anchored at two ends to form a closed-loop, as a lightweight and supple hyper redundant mechanism. Output stiffness is formulated based on the minimization of potential energy, the balancing of internal force and the velocity constraint to construct a closed-loop mechanism. Joint input to obtain both the desired stiffness distribution and desired output position simultaneously is derived from partial derivative of the output stiffness and compensation by a learning control scheme. Motion control experiments with a 10R elastic closed-loop robot demonstrate the effectiveness of the proposed control scheme.
Authors and Affiliations
DAISUKE MATSUURA, NOBUYUKI IWATSUKI, MASAFUMI OKADA
Keywords
Related Articles
- EP ID EP179115
- DOI -
- Views 84
- Downloads 0
INVARIANT CHARACTERIZING THERMALLY ACTIVATED PLASTIC FLOW
Thermal activation leads to a reduction of the flow stress below the athermal value (the zero Kelvin flow stress). The ratio between the flow stress at a given temperature and the athermal stress (at given material struc...
SIZE EFFECT ON STIFFNESS AND PULL-OFF FORCE OF THERMALLY ACTUATED GOLD CANTILEVERS
This paper focuses on revealing the size effect on the mechanical behavior (i.e. bending stiffness, Young modulus, pull-off force) of gold cantilevers with lengths ranging from 190 µm to 490 µm. We investigated the tempe...
NON-LINEAR STABILITY OF CYLINDRICAL PANELS MADE OF TRANSVERSALLY FUNCTIONALLY GRADED MATERIAL WITH UNIFORMLY SHORTENED EDGES
The present paper deals with FGM cylindrical panels with uniformly shortened edges when the shear lag phenomenon and distortional deformations are taken into account. A shell model (2D) was adopted. A method of the modal...
PRESSURE WAVE TECHNOLOGY – AN INTERESTING APPROACH IN SUPERCHARGING
The current concerns of mankind on reducing the disastrous effects of global climate warming have led to measures that involve improving the performance of internal combustion engines (ICE). Supercharging is one of the m...
DD3IMP, 3D FULLY IMPLICIT FINITE ELEMENT SOLVER: IMPLEMENTATION OF CB2001 YIELD CRITERION
The strategies and algorithms adopted in the fully implicit FE solver DD3IMP to model the orthotropic behavior of metallic sheets, as well the procedure for parameters’ identification, are the main focus of this work; a...