DC Servomotor-based Antenna Positioning Control System Design using PID and LQR Controller

Authors

  • Linus A. Alwal
  • Peter K. Kihato
  • Stanley I. Kamau

Keywords:

Antenna-Positioning Systems, DC servomotor, Linear Quadratic Regulator-LQR, PID Controller

Abstract

There are increasing needs to develop control systems that can be used to automatically point Direct Current (DC) servomotor driven parabolic antennas to moving targets, notably in satellite tracking, to maintain the desired line of sight for quality communication. Although many researchers nowadays focus on artificial intelligence (AI) techniques, this work reckons that a well designed optimal linear controller can still give acceptable results at reduced system cost and complexity. In this paper the design and control of DC servomotor-based antenna positioning system has been addressed and simulated in MATLAB/SIMULINK software. The response of the system is analyzed and results are first obtained by using well tuned Proportional-Integral-Derivative (PID) controller. The PID controller is then replaced by Linear Quadratic Regulator (LQR) which apart from optimizing the system response increases the accuracy of the state variables by estimating the states. It has been shown that the LQR results are much better than the results obtained by PID controller in terms of reduced steady state error, settling time and overshoot. Moreover, since low speed rotations are required and assuming linear conditions, the results obtained with LQR method
can challenge those obtained by AI based techniques.

Author Biographies

Linus A. Alwal

Department of Electrical and Electronic Engineering, JKUAT

Peter K. Kihato

Department of Electrical and Electronic Engineering, JKUAT

Stanley I. Kamau

Department of Electrical and Electronic Engineering, JKUAT

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Published

04-04-2022