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

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>

Modelling and Control of a Hydraulically Actuated Two-Degree-of-Freedom Inertial Platform

2005 ◽  
Vol 219 (6) ◽  
pp. 405-417 ◽  
Author(s):  
T-J Yeh ◽  
C-Y Su ◽  
W-J Wang
Keyword(s):  
Control System ◽  
Linear Optimization ◽  
Angle Measurement ◽  
Open Loop ◽  
Degree Of Freedom ◽  
Resonant Peak ◽  
Pid Controllers ◽  
Sensor Signals ◽  
And Control ◽  
Two Degree Of Freedom

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.

Robust Two-degree-of-freedom Control Based on H∞ Method for PMSM Drive System

2020 ◽  
Vol 13 (4) ◽  
pp. 496-506
Author(s):  
Qixin Zhu ◽  
Lei Xiong ◽  
Hongli Liu ◽  
Yonghong Zhu ◽  
Guoping Zhang
Keyword(s):  
Control System ◽  
Control Theory ◽  
Position Control ◽  
Dynamic Performance ◽  
Servo System ◽  
Degree Of Freedom ◽  
Trade Off ◽  
Standard Design ◽  
Position Controller ◽  
Two Degree Of Freedom

Background: The conventional method using one-degree-of-freedom (1DOF) controller for Permanent Magnet Synchronous Motor (PMSM) servo system has the trade-off problem between the dynamic performance and the robustness. Methods: In this paper, by using H∞ control theory, a novel robust two-degree-of-freedom (2DOF) controller has been proposed to improve the position control performance of PMSM servo system. Using robust control theory and 2DOF control theory, a H∞ robust position controller has been designed and discussed in detail. Results: The trade-off problem between the dynamic performance and robustness which exists in one-degree-of-freedom (1DOF) control can be dealt with by the application of 2DOF control theory. Then, through H∞ control theory, the design of robust position controller can be translated to H∞ robust standard design problem. Moreover, the control system with robust controller has been proved to be stable. Conclusion: Further simulation results demonstrate that compared with the conventional PID control, the designed control system has better robustness and attenuation to the disturbance of load impact.

scholarly journals Force Control of Flexible Arm Using Two-Degree-of-Freedom Control System.

1998 ◽  
Vol 64 (620) ◽  
pp. 1382-1389 ◽  
Author(s):  
Kouji OKUDA ◽  
Kazuyuki KUHARA ◽  
Minoru SASAKI ◽  
Fumio FUJISAWA
Keyword(s):  
Control System ◽  
Force Control ◽  
Degree Of Freedom ◽  
Flexible Arm ◽  
Two Degree Of Freedom

A Design Method for Two-Degree-of-Freedom Simple Multi-Period Repetitive Control Systems

2010 ◽  
Vol 36 ◽  
pp. 243-252 ◽  
Author(s):  
Yoshinori Ando ◽  
Tatsuya Sakanushi ◽  
Kou Yamada ◽  
Iwanori Murakami ◽  
Takaaki Hagiwara ◽  
...  
Keyword(s):  
Control System ◽  
Control Systems ◽  
Transfer Functions ◽  
Design Method ◽  
Output Characteristic ◽  
Degree Of Freedom ◽  
Disturbance Attenuation ◽  
Input Output ◽  
Attenuation Characteristic ◽  
Two Degree Of Freedom

The multi-period repetitive (MPR) control system is a type of servomechanism for periodic reference inputs. Using MPR controllers, transfer functions from the reference input to the output and from the disturbance to the output of the MPR control system have infinite numbers of poles. To specify the input-output characteristic and the disturbance attenuation characteristic easily, Yamada and Takenaga proposed MPR control systems, named simple multi-period repetitive (simple MPR) control systems, where these transfer functions have finite numbers of poles. In addition, Yamada and Takenaga clarified the parameterization of all stabilizing simple MPR controllers. However, using the simple MPR repetitive controller by Yamada and Takenaga, we cannot specify the input-output characteristic and the disturbance attenuation characteristic separately. From the practical point of view, it is desirable to specify the input-output characteristic and the disturbance attenuation characteristic separately. The purpose of this paper is to propose the parameterization of all stabilizing two-degree-of-freedom (TDOF) simple MPR controllers that can specify the input-output characteristic and the disturbance attenuation characteristic separately.

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