Hybrid Force-Position Dynamic Control of the Robots
Using Fuzzy Applications
Luige Vladareanu
1, a
, Victor Vladareanu
2,b
and Paul Schiopu
2,c
1
Institute of Solid Mechanics of the Romanian Academy, C-tin Mille 15, Bucharest 1, ROMANIA
2
“Politehnica” University of Bucharest, Faculty of Electronics II, 313 Splaiul Independenţei, 060042
Bucharest, ROMANIA
a
luigiv@arexim.ro,
b
vladareanuv@gmail.com,
c
schiopu.paul@yahoo.com
Keywords: robot dynamic control, fuzzy control loops, hybrid force-position control, open
architecture systems.
Abstract. The paper presents methods of improving the hybrid force-position dynamic robot
control using fuzzy logic for the error control. The implementation of the open architecture control
system for robots using fuzzy application allows for the control of the hybrid position and force
in Cartesian coordinates through real time processing of the Jacobean matrix obtained out of
forward kinematics using the Denevit-Hartenberg method and calculating the Jacobean inverted
matrix for control in closed loop. The effectiveness of various fuzzy control structures in controlling
the force-position of the robot or mechatronics actuators is presented.
Introduction
The implementation of the open architecture control system for robots with compliant wrist
allows for the control of the hibrid position and force in cartezian coordonates through real time
processing of the Jacobine matrix obtained out of the forward kinematics using the Denevit-
Hartenberg method and calculating the Jacobine inverted matrix for control in closed loop. Using
the joint rate control reprezentation, having J() as the position Jacobean matrix and X as the
generalized position error vector, this process is analyzed in a simultaneous two-way fashion: the
first to determine the X
F
matrix corresponding to the force controled component and the second to
determine the X
P
matrix corresponding to the position controled component. The
F
joint error
of the force component and the
P
position component error are insered to a fuzzy controller.
Fuzzy variables for input and output of the system and the membership function reflecting the
deflection in Cartezian coodonates are studied.
The history of fuzzy logic starts with the paper published in 1965 by L.A. Zadeh, entitled
‘Fuzzy sets’, in which the author introduces his new approach to set theory. Essentially, a fuzzy set
is an extension of a classical bivalent (crisp) set with ‘a membership function which assigns to each
object a grade of membership between 0 and 1’ (Zadeh, 1965) [1]. Subsequent detailed
investigations made by Mamdani [2] and Takagi and Sugeno [3] have led to Fuzzy Logic becoming
an increasingly appealing alternative to classical control for an array of systems (Thomas,
Armstrong-Helouvry 1995) [4].
Jantzen (2007) [5] pioneers the development of algorithms for tuning the fuzzy rule base,
beginning from a linear controller and the adjusting for non – linear behaviour. Further
improvement in this area, which is arguably the most consequential for a fuzzy controller, should at
least lead to improved industry acceptance and solve a key problem with fuzzy controllers today. In
a similar way that the existence of Ziegler – Nichols contributes to the popularity of PID controllers
by guaranteeing an acceptable working solution, a universally accepted general tuning algorithm for
the fuzzy rule base exists would, in all probability, contribute to fuzzy controllers becoming the
standard in non – linear control architectures.
Applied Mechanics and Materials Vol. 245 (2013) pp 15-23
© (2013) Trans Tech Publications, Switzerland
doi:10.4028/www.scientific.net/AMM.245.15
All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of TTP,
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