Analog Two Degree of Freedom PID Controllers and Their Tuning by Multiple Dominant Pole Method for Integrating Plants

This paper investigates modelling and control issues associated with a two-degree-of-freedom inertial platform for naval applications. In the modelling part, the dynamics of the system are physically characterized and then experimentally identified. It is found that due to the inverted-pendulum structure and the use of hydraulic actuators, the system is open-loop unstable and exhibits different frequency responses when the amplitude of the input signal changes. Moreover, the identification experiment reveals that the inclinometer used has a major resonant peak that will limit the control system performance. Therefore, a complimentary filter scheme is proposed to condition the sensor signals so as to produce a more acceptable absolute-angle measurement. In the control part, two proportional-integral-derivative (PID) controllers, whose control parameters are computed using a non-linear optimization scheme to achieve optimal disturbance rejection with reasonable robustness and noise sensitivity properties, are respectively designed for the pitch and the roll subsystems. Experimental results indicate that when the platform's base frame encounters a biaxial sea-wave motion, the resulted control system can attenuate the vibration to within 10 per cent.

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Two-Degree-of-Freedom PID Controllers Structures

Model-Reference Robust Tuning of PID Controllers - Advances in Industrial Control ◽

10.1007/978-3-319-28213-8_2 ◽

2016 ◽

pp. 7-19 ◽

Cited By ~ 4

Author(s):

Víctor M. Alfaro ◽

Ramon Vilanova

Keyword(s):

Degree Of Freedom ◽

Pid Controllers ◽

Two Degree Of Freedom

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Two-Degree-of-Freedom PID Controller, Its Equivalent Forms and Special cases

IAES International Journal of Robotics and Automation (IJRA) ◽

10.11591/ijra.v4i4.pp269-283 ◽

2015 ◽

Vol 4 (4) ◽

pp. 269

Author(s):

Haresh A. Suthar

Keyword(s):

Control System ◽

English Language ◽

Control Strategies ◽

Software Tool ◽

Degree Of Freedom ◽

Pid Controllers ◽

Transport Delay ◽

Point Tracking ◽

Special Cases ◽

Two Degree Of Freedom

<p>The design of control systems is a multi-objective problem so, a two-degree-of-freedom (abbreviated as 2DOF) control system naturally has advantages over a one degree- of-freedom (abbreviated as 1DOF) control system. The main objective of 2DOF control is to control both set point tracking and disturbance rejections.Various 2DOF PID controllers and its equivalent transformations were proposed for industrial use by different researchers. Most of the above researches were published in Japanese language and have not been translated into English language yet. An objective here is to provide detail analysis regarding structure of 2DOF controller, its equivalent forms and its special cases. A system transfer function having transport delay and load disturbance is considered as a test bench to verify various 2DOF control strategies. MATLAB is used as software tool to verify the various 2DOF control strategies. The analysis will be helpful to the engineers and researchers to understand the topic in detail for further exploration.</p>

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Grasshopper Optimization Algorithm-Based Fuzzy-2DOF-PID Controller for LFC of Interconnected System With Nonlinearities

International Journal of Social Ecology and Sustainable Development ◽

10.4018/ijsesd.2021070102 ◽

2021 ◽

Vol 12 (3) ◽

pp. 11-29

Author(s):

Debasis Tripathy ◽

Nalin Behari Dev Choudhury ◽

Binod Kumar Sahu

Keyword(s):

Optimization Algorithm ◽

Pid Controller ◽

Firefly Algorithm ◽

Pattern Search ◽

Optimization Techniques ◽

Degree Of Freedom ◽

Pid Controllers ◽

Grasshopper Optimization Algorithm ◽

Grasshopper Optimization ◽

Two Degree Of Freedom

The load frequency control (LFC) is an automation scheme employed for an interconnected power system to overcome the frequency deviation issue because of load variation in the most economical way. This work puts an earliest effort to study the LFC issue of a three-area power systems including nonlinearities using fuzzy-two degree of freedom-PID (F-2DOF-PID) controller optimized with grasshopper optimization algorithm (GOA). Initially, GOA optimized PID controllers are considered for a two area non-reheat thermal system including generation rate constraint to validate the superiority over PID controllers tuned with some recently reported optimization techniques, such as hybrid firefly algorithm-pattern search, firefly algorithm, bacteria foraging optimization algorithm, genetic algorithm, and conventional Ziegler Nichols technique. Then the work is reconsidered for the same system to verify the supremacy of F-2DOF-PID controller over other controllers such as fuzzy-PID, two degree of freedom-PID, and PID with GOA framework. Furthermore, the study is extended to a three-area system considering the effect of nonlinearities to verify effectiveness and robustness of proposed controller.

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