International Journal of Recent Technology and Engineering (IJRTE)
ISSN: 2277-3878, Volume-8 Issue-4, November 2019
3902
Published By:
Blue Eyes Intelligence Engineering
& Sciences Publication
Retrieval Number: D8324118419/2019©BEIESP
DOI:10.35940/ijrte.D8324.118419
Abstract: In the field of mobile robotics, path planning is one
of the most widely-sought areas of interest due to its nature of
complexity, where such issue is also practically evident in the case
of mobile robots used for waste disposal purposes. To overcome
issues on path planning, researchers have studied various
classical and heuristic methods, however, the extent of
optimization applicability and accuracy still remain an
opportunity for further improvements. This paper presents the
exploration of Artificial Neural Networks (ANN) in
characterizing the path planning capability of a mobile
waste-robot in order to improve navigational accuracy and path
tracking time. The author utilized proximity and sound sensors as
input vectors, dual H-bridge Direct Current (DC) motors as target
vectors, and trained the ANN model using Levenberg-Marquardt
(LM) and Scaled Conjugate (SCG) algorithms. Results revealed
that LM was significantly more accurate than SCG algorithm in
local path planning with Mean Square Error (MSE) values of
1.75966, 2.67946, and 2.04963, and Regression (R) values of
0.995671, 0.991247, and 0.983187 in training, testing, and
validation environments, respectively. Furthermore, based on
simulation results, LM was also found to be more accurate and
faster than SCG with Pearson R correlation coefficients of
r
x
=.975, n
x
=6, p
x
=0.001 and r
y
=.987, n
y
=6, p
y
=0.000 and path
tracking time of 8.47s.
Index Terms: Path Planning, Mobile Waste Robotics, Artificial
Neural Networks, Levenberg-Marquardt, Scaled Conjugate
Gradient
I. INTRODUCTION
One of the most challenging competencies in the design of
a mobile robot is autonomous navigation, which is a process
model used to reach a specific goal while avoiding obstacles.
Shown on Fig. 1 is the autonomous navigation process
composed of four fundamental sub-processes [1]. Initially,
the robot must perceive its environment to extract meaningful
data through the utilization of sensors. From these data, the
robot should be able to navigate and locate its position in the
environment. From then, the robot should be able to cognize
and plan its path in order to achieve its goal. Lastly, it should
be able to control and modulate its motions to achieve the
desired trajectory while simultaneously avoiding obstacles
[2]. Among these four sub-processes of autonomous
navigation, path planning is considered to be the most
common issue particularly in unstructured environment. Such
issues are likewise practically true in the case of mobile robots
Revised Manuscript Received on November 15, 2019
Ralph Sherwin A. Corpuz, Ph.D., Director of Quality Assurance and
Assistant Professor, Electronics Engineering Technology, Technological
University of the Philippines, Manila, Philippines.
used for waste disposal purposes. In path planning, a mobile
robot aims to navigate from a start point to an end point, also
known as target or goal, and maintains a collision-free
trajectory. Some of the strategies sought toward successful
path planning are not limited to shortest distance, smoothness
of path, minimum energy consumption or a combination
thereof such as shortest distance with minimal possible time,
among others [3, 4].
Fig. 1.Autonomous Navigation Process
To overcome issues associated with path planning,
researchers explored various classical and heuristic methods.
Some of the popular classical methods include cell
decomposition, potential field, sampling-based, subgoal
network and probabilistic roadmap. These classical methods
are preferred for real-time motion planning applications
because they are easy to implement, and modestly obtain
good results [2, 3]. On the other hand, however, these
classical methods do not produce optimal paths and are
unstable in dynamic environments with multiple obstacles [2,
5]. In order to overcome the inefficiencies of classical
methods, heuristic methods are employed for this purpose.
Some of the popular heuristic methods used in mobile
waste-robots include Artificial Neural Networks (ANN) [6],
Fuzzy Logic Control (FLC) [7], or hybrid algorithms [8] etc.
Of all these heuristic methods, ANNs are among the most
recently-explored. ANN is a tool that acts like a human brain
by learning and modelling complex relationships between
input and output data [9] in order to achieve autonomous
navigation. They are found to be efficient in terms of
nonlinear mapping, learning ability and parallel processing,
hence, they are highly recommended for heuristic methods of
path planning [2]. On the other hand, however, ANNs are
time-consuming, impractical for simple logic functions, and
do not guarantee optimal solutions. With that said, the extent
of optimization applicability and accuracy of ANNs still
remain an opportunity for further study. The motivation of
this paper focuses in characterizing the path planning
capabilities of a mobile-waste robot in order to ensure
navigational accuracy and path
tracking time through the use of
Characterization of a Mobile Waste-Robot: A
Heuristic Method to Path Planning Using
Artificial Neural Networks
Ralph Sherwin A. Corpuz