Research Article
Optimal Position Fuzzy Control of an Underactuated
Robotic Finger
Francisco J. Espinosa Garcia ,
1,2
Esther Lugo-Gonz ´ alez ,
3
Arturo Tell´ ez-Vel´ azquez ,
4
Manuel Arias-Montiel ,
3
and Marco Ceccarelli
2
1
Postgraduate Division, Technological University of the Mixteca, Huajuapan de Le´ on 69000, Mexico
2
LARM 2, University of Rome Tor Vergata, Rome 00133, Italy
3
Institute of Electronics and Mechatronics, Technological University of the Mixteca, Huajuapan de Le´ on 69000, Mexico
4
Institute of Computing, Technological University of the Mixteca, Huajuapan de Le´ on 69000, Mexico
Correspondence should be addressed to Manuel Arias-Montiel; mam@mixteco.utm.mx
Received 18 March 2022; Revised 27 May 2022; Accepted 28 June 2022; Published 20 July 2022
Academic Editor: Ardashir Mohammadzadeh
Copyright © 2022 Francisco J. Espinosa Garcia et al. is is an open access article distributed under the Creative Commons
Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is
properly cited.
In this paper, the optimal position control of an underactuated robotic finger is presented. Two trajectories, one for the proximal
and the other for the medial phalanx, are proposed in order to emulate the finger’s flexion/extension movements. A Mandani
fuzzy control is proposed due to the lack of a precise dynamical model of the system. In order to obtain the control parameters, an
optimization strategy based on the membership functions is applied. Genetic algorithms (GA) are commonly used as an op-
timization method in diverse applications; however, in this case, the use of an autoadaptive differential evolution method is
proposed in order to obtain a superior convergence behavior. Simulations of the virtual prototype are carried out using MATLAB/
Simulink software to display the trajectory tracking. e results show that the maximum error between the proposed and obtained
trajectories is 3.1352E − 04 rad.
1. Introduction
Currently, control development for robotic hands continues
to be a topic of interest as researchers seek to recreate human
hand interaction with their environment when developing
prototypes and their interaction with the environment. is
objective is difficult to achieve due to the challenging nature
of controlling robotic hands, as they are relatively complex
mechatronic systems, which allow the user to hold, ma-
nipulate, and make use of different objects and tools. As a
possible solution, some researchers have focused on im-
proving control tasks in order to generate a robust grasp to
reliably hold any object. In addition, the selection criteria of
actuators are an important factor because the size, weight,
and torque are variables that must be considered. Generally,
the control systems have a closed-loop structure, since they
seek to reduce errors so that the hand finger can maintain a
specific desired position [1, 2], by using pneumatic [3–5] and
touch [6–8] sensors. In the literature, the most common
control schemes are the proportional-integral-derivative
(PID) control [9–11] and fuzzy control [12–14]. Controllers
based on fuzzy logic are an alternative solution that does not
require a mathematical model such as the PID [15]. A fuzzy
logic controller (FLC) is a heuristic approach composed of a
rules base proposed by the designer. e FLC is a nonlinear
system with a knowledge based on fuzzy If-en rules, and
in most cases, the fuzzy rules are proposed by an expert who
knows the process. In order to generate an output, mem-
bership functions are used to specify the degree of mem-
bership based on inputs. FLC must have a flexible behavior
to adapt to various situations, as well as being robust to
maintain the state of the desired output. e implementation
of FLC is fairly common for solving problems, where (a) the
systems are partially defined, (b) systems with variables that
cannot be measured, and (c) system with large disturbances
[12, 14, 16]. e principal fuzzy systems are Mandani and
Hindawi
Mathematical Problems in Engineering
Volume 2022, Article ID 2091337, 12 pages
https://doi.org/10.1155/2022/2091337