Middle-East Journal of Scientific Research 13 (11): 1501-1509, 2013
ISSN 1990-9233
© IDOSI Publications, 2013
DOI: 10.5829/idosi.mejsr.2013.13.11.425
Corresdponding Auhtor: Ravindra Singh, LASTEC, DRDO, Delhi, India.
1501
Performance Comparison of Fuzzy and Choquet Fuzzy Integral
Control for Line of Sight Stabilization Application
Ravindra Singh, M. Hanumandlu, Shahida Khatoon and Ibraheem
1 2 3 3
LASTEC, DRDO, Delhi, India
1
Department of Electrical Engineering, IIT Delhi, India
2
Department of Electrical Engg, Jamia Millia Islamia Delhi, India
3
Abstract: Stabilization and tracking systems maintain the orientation of optical sensor” payloads” so they are
pointed in the scenario dependent directions and held steady in inertial space along the selected orientation.
The stabilization-tracking systems are mechanical assemblies that precisely control the angular position of the
sensor’s line of sight (LOS), so that it is isolated from its base-foundation dynamics and is pointed towards its
intended target. These system form part of modern fire control systems (FCSs). The performance of fire control
system mounted on a mobile platform, decreases exponentially with increase in the disturbance on the line of
sight (LOS). The conventional controller designed to stabilize the LOS are dependent on mathematical model
of the plant. In this modeling process usually the higher order dynamics is ignored and plants are linearized
around the operating point. Fuzzy-knowledge-based-controller (FKBC) design presents a good methodology
to stabilize the line of sight against disturbances and nonlinearities present in the system, but tuning of input
and output membership function parameters is quite a complex process. To overcome this, a choquet fuzzy
integral based control algorithm is developed for this servo system with nonlinear property and some
uncertainties. In this paper we present the design of FKBC and choquet fuzzy controller and their performance
comparison.
Key words: Line of sight (LOS) Bandwidth (B.W) Fuzzy Controller Choquet Fuzzy Integral Q-measure
-measure, Electro-optical fire control system (EOFCS)
INTRODUCTION through -measure [5]. As a result the overlapping
The electro-optical fire control system on movable used for computing the Choquet fuzzy integral. Choquet
carrier causes the vibration in the azimuth and elevation fuzzy control enables the system to have the quicker
direction which induces causes the image blur and leads dynamic response and smaller overshoot. In this paper,
the tracking performance to fail. Hence, the LOS firstly a brief description of -measure and q-measure
stabilization technology must be used to isolate the LOS followed by Choquet integral is given. After that the
from carrier disturbance in order to make sure accurate method of identification is described and finally the
aiming, tracking and firing for the target. results obtained by choquet fuzzy controller are
The LOS stabilized systems are basically motion discussed.
control systems [1, 2]. A few methods for the LOS
stabilized control have been proposed during recent years Problem Statement
[2]. However, a majority of these algorithms are complex Simulation Results of Proposed Choquet Fuzzy Integral
and difficult to be realized. Controller: In this paper, the plants under consideration
Here, a choquet fuzzy integral based control strategy consist of a gimballed payload that is driven by a
is proposed. In this approach, fuzzy integral is treated as permanent magnet DC torque drives. A dual axis
the defuzzified output of the non-additive fuzzy rules [7]. dynamically tuned gyro is used to sense the inertial
These fuzzy rules involve input fuzzy sets having angular rate of the gimbal in elevation and azimuth. The
overlapping information [3, 4]. This overlapping relevant parameters of gimbal system plant dynamics are
information between adjacent fuzzy sets is captured as follows:
fuzzy sets are represented by the fuzzy measures that are