Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Design of Fuzzy self-tuning PID controller for pitch control system of
  aircraft autopilot   A variety of control systems have been proposed for aircraft autopilot
systems. Traditional approaches such as proportional controller and
conventional PID (CPID) controller are widely used. PID controller has a good
static performance especially for linear and time-invariant systems, but a weak
dynamic performance and discouraging function on nonlinear, time-varying, and
uncertain systems. Fuzzy control theory can improve dynamic response in various
conditions of system performance. This paper designs fuzzy self-tuning PID
(FSPID) controller to improve disadvantages of conventional PID in aircraft
autopilots. We apply proposed controller to pitch angle of aircraft then the
abilities of proposed controller will be compared to the conventional PID and
proportional controller. Inner feedback loop acts as oscillation damper in
traditional schemes, but here is removed to compare the capabilities of Fuzzy
self-tuning PID, conventional PID, and proportional controller. Based on the
simulations, both of Conventional and Fuzzy self-tuning PID controllers can
properly damp oscillations in lack of the inner feedback loop, but proportional
controller cannot do. Then short-period approximation is assumed to assess the
function of FSPID and CPID controllers in confront with abrupt and continuous
disturbances, in addition to inappropriate tuning of parameters. Simulation
results of short-period approximation show a better anti-disturbance function
for Fuzzy self-tuning PID compare to the conventional type. Fuzzy self-tuning
PID can tune the PID parameters for achieving the optimal response in view of
speed, overshoot, and steady-state error in conditions of inappropriate tuning
of PID parameters, based on the results of simulation in short-period
approximation, the proposed controller can adaptively improve the system
response by on-line setting of PID parameters.

5
The categories of this paper are: gr-qc
35
The categories of this paper are: mtrl-th
12
The categories of this paper are: nucl-th
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The categories of this paper are: nucl-ex
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The categories of this paper are: hep-ex
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The categories of this paper are: q-bio
11
The categories of this paper are: hep-lat
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The categories of this paper are: econ
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The categories of this paper are: chao-dyn
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The categories of this paper are: alg-geom
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The categories of this paper are: cmp-lg
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The categories of this paper are: eess
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The categories of this paper are: q-alg
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The categories of this paper are: astro-ph
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The categories of this paper are: nlin
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The categories of this paper are: math-ph