Analytical FOPID Controller Design based on Bode’s Ideal Transfer Function for Desired Closed Loop Response

2020 ◽  
Vol 12 (5) ◽  
pp. 9-20
Author(s):  
Amit Kumar Sahoo ◽  
Sudhansu Kumar Mishra
Keyword(s):  
Transfer Function ◽  
Closed Loop ◽  
Controller Design ◽  
Bode’S Ideal Transfer Function

scholarly journals Active Controller Design for Microgravity Isolation Systems

2002 ◽  
Vol 9 (6) ◽  
pp. 307-317
Author(s):  
Nan-Chyuan Tsai
Keyword(s):  
Control System ◽  
Transfer Function ◽  
Closed Loop ◽  
Controller Design ◽  
Relative Displacement ◽  
Absolute Acceleration ◽  
Active Isolation ◽  
Space Experiments ◽  
Acceleration Feedback ◽  
Isolation Systems

This paper examines the performance of active isolation systems for microgravity space experiments as a function of desired transmissibilities that are chosen to be either much below or close to what can be tolerated. The control system utilizes two feedback signals: absolute acceleration and relative displacement of the controlled mass. The controller transfer function for acceleration feedback is chosen to avoid marginally stable pole-zero cancellations. The controller transfer function for relative displacement feedback is determined to achieve the desired transmissibility function. The issue of stability and properness of this controller transfer function are discussed. The required input forces and equivalent closed-loop stiffness are examined for various examples of desired transmissibilities.

scholarly journals On PID Controller Design by Combining Pole Placement Technique with Symmetrical Optimum Criterion

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Viorel Nicolau
Keyword(s):  
Transfer Function ◽  
Closed Loop ◽  
Controller Design ◽  
Open Loop ◽  
Pole Placement ◽  
Loop Transfer Function ◽  
Heading Control ◽  
Pid Controller Design ◽  
Analytical Expressions ◽  
Placement Technique

In this paper, aspects of analytical design of PID controllers are studied, by combining pole placement technique with symmetrical optimum criterion. The proposed method is based on low-order plant model with pure integrator, and it can be used for both fast and slow processes. Starting from the desired closed-loop transfer function, which contains a second-order oscillating system and a lead-lag compensator, it is shown that the zero value depends on the real-pole value of closed-loop transfer function. In addition, there is only one pole value, which satisfies the assumptions of symmetrical optimum criterion imposed to open-loop transfer function. In these conditions, by combining the pole placement technique with symmetrical optimum criterion, the analytical expressions of the controller parameters can be simplified. For simulations, PID autopilot design for heading control problem of a conventional ship is considered.

Predictor-based fractional disturbance rejection control for LTI fractional-order systems with input delay

2020 ◽  
Vol 42 (16) ◽  
pp. 3303-3319
Author(s):  
Sajad Pourali ◽  
Hamed Mojallali
Keyword(s):  
Transfer Function ◽  
Fractional Order ◽  
Disturbance Rejection ◽  
Closed Loop ◽  
Reference Model ◽  
Open Loop ◽  
Input Delay ◽  
Fractional Order Systems ◽  
Disturbance Rejection Control ◽  
Bode’S Ideal Transfer Function

In this paper, a predictor-based fractional disturbance rejection control (PFDRC) scheme is proposed for processes subject to input delay. The proposed scheme can be generally applied to open-loop stable, integrative, and unstable integer-order processes, but it can be particularly utilized for open-loop stable fractional-order systems. A closed-loop reference model is formulated based on Bode’s ideal transfer function. The primary control design objective is to enable the output of input-delay process to follow the closed-loop reference model. Towards this end, the closed-loop transfer function of the PFDRC must take the same structure as that of the reference model. Meanwhile, the adverse effects of the input delay must be mitigated. To meet the latter, a filtered Smith predictor (FSP) is employed to provide a prediction of delay-less output response. To address the former, process dynamics are treated as a common disturbance; then, a fractional-order extended state observer (FESO) is introduced to estimate the delay-less output response and also the total disturbance (i.e. external disturbance and system uncertainties). The PFDRC feedback controller is easily derived by the gain crossover frequency of Bode’s ideal transfer function which facilitates the tuning process. The convergence analysis of the FESO is carried out in terms of BIBO stability. The effectiveness of the proposed control scheme is verified through three illustrative examples from the literature.

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