Maximum Peak-Gain Margin 2DOF-IMC Tuning for a 2DOF-PID Filter Set Point Controller Under Parametric Uncertainty

The specification of controller setting for a standard controller typically requires a trade-off between set point tracking and disturbance rejection. For this reason two simple strategies can be used to adjust the set point and disturbance responses independently. These strategies are referred to as controllers with two degree of freedom. Unfortunately, the tuning parameters in the case of model uncertainty at two degree of freedom structure controller is difficult to obtain. Juwari et al (2013) has introduced maximum peak-gain margin (Mp-GM) tuning method to obtain setting parameter of two degree of freedom structure controller based on model uncertainty. This tuning method are able to obtain the good controller parameter even under processes uncertainties on standard two degree of freedom (was abbreviated as 2DOF) IMC. This research will be conducted on development maximum peak-gain margin tuning method for a two degree of freedom PID filter set point structure controller. The simulation results show that the maximum peak gain margin tuning method can give a good target set point tracking, disturbance rejection and robustness in system a 2DOF-PID filter set point controller

PID control system analysis, design, and technology

Designing and tuning a proportional-integral-derivative (PID) controller appears to be conceptually intuitive, but can be hard in practice, if multiple (and often conflicting) objectives such as short transient and high stability are to be achieved. Usually, initial designs obtained by all means need to be adjusted repeatedly through computer simulations until the closed-loop system performs or compromises as desired. This stimulates the development of "intelligent" tools that can assist engineers to achieve the best overall PID control for the entire operating envelope. This development has further led to the incorporation of some advanced tuning algorithms into PID hardware modules. Corresponding to these developments, this paper presents a modern overview of functionalities and tuning methods in patents, software packages and commercial hardware modules. It is seen that many PID variants have been developed in order to improve transient performance, but standardising and modularising PID control are desired, although challenging. The inclusion of system identification and "intelligent" techniques in software based PID systems helps automate the entire design and tuning process to a useful degree. This should also assist future development of "plug-and-play" PID controllers that are widely applicable and can be set up easily and operate optimally for enhanced productivity, improved quality and reduced maintenance requirements

Analytical design of a generalised predictor-based control scheme for low-order integrating and unstable systems with long time delay

In this study, the problem of controlling integrating and unstable systems with long time delay is analysed in the discrete-time domain for digital implementation. Based on a generalised predictor-based control structure, where the plant time delay can be taken out of the control loop for the nominal plant, an analytical controller design is proposed in terms of the delay-free part of the nominal plant model. Correspondingly, further improved control performance is obtained compared with recently developed predictor-based control methods relying on numerical computation for controller parameterisation. The load disturbance rejection controller is derived by proposing the desired closed-loop transfer function, and another one for set-point tracking is designed in terms of the H-2 optimal control performance specification. Both controllers can be tuned relatively independently in a monotonic manner, with a single adjustable parameter in each controller. By establishing the sufficient and necessary condition for holding robust stability of the closed-loop control system, tuning constraints are derived together with numerical tuning guidelines for the disturbance rejection controller. Illustrative examples taken from the literature along with temperature control tests for a crystallisation reactor are used to demonstrate the effectiveness and merit of the proposed method.This work was supported in part by the National Thousand Talents Program of China, NSF China Grants 61473054, the Fundamental Research Funds for the Central Universities of China, and the Grants TIN2014-56158-C4-4-P and PROMETEOII/2013/004 from the Spanish and Valencian Governments.Chen, Y.; Liu, T.; García Gil, PJ.; Albertos Pérez, P. (2016). Analytical design of a generalised predictor-based control scheme for low-order integrating and unstable systems with long time delay. IET Control Theory and Applications. 10(8):884-893. https://doi.org/10.1049/iet-cta.2015.0670S88489310

Complex-Variable Sliding-Mode Control of Instantaneous Complex Energy and Power for Grid-Tied Inverter

A complex-variable sliding-mode control (SMC) algorithm is proposed to govern inverters interfacing renewable energy sources (RESs) with the electrical grid. It is conceived to control the instantaneous energy stored in the passive components of the system and its rate of change, as well as the instantaneous reactive energy and power exchanged with the grid. The stability of the resulting closed-loop system is analyzed, and tuning of the designed SMC algorithm is also tackled. In addition, the design and tuning of a nonlinear observer estimating the renewable power supplied to the DC link are addressed. The overall control scheme obtained by combining the proposed complex-variable SMC algorithm with such observer is assessed in simulation, demonstrating its outstanding tracking performance and high robustness in presence of large parameter variations.Co-financed by the MICIN/AEI/10.13039/501100011033 (project code PID2020-115484RA-I00), by the Basque Government under research grant IT1644-22, by the Universidad Nacional del Sur (UNS), and by the Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)

Advances and Trends in Mathematical Modelling, Control and Identification of Vibrating Systems

This book introduces novel results on mathematical modelling, parameter identification, and automatic control for a wide range of applications of mechanical, electric, and mechatronic systems, where undesirable oscillations or vibrations are manifested. The six chapters of the book written by experts from international scientific community cover a wide range of interesting research topics related to: algebraic identification of rotordynamic parameters in rotor-bearing system using finite element models; model predictive control for active automotive suspension systems by means of hydraulic actuators; model-free data-driven-based control for a Voltage Source Converter-based Static Synchronous Compensator to improve the dynamic power grid performance under transient scenarios; an exact elasto-dynamics theory for bending vibrations for a class of flexible structures; motion profile tracking control and vibrating disturbance suppression for quadrotor aerial vehicles using artificial neural networks and particle swarm optimization; and multiple adaptive controllers based on B-Spline artificial neural networks for regulation and attenuation of low frequency oscillations for large-scale power systems. The book is addressed for both academic and industrial researchers and practitioners, as well as for postgraduate and undergraduate engineering students and other experts in a wide variety of disciplines seeking to know more about the advances and trends in mathematical modelling, control and identification of engineering systems in which undesirable oscillations or vibrations could be presented during their operation

Modeling and Feedback Control of a MEMS Electrostatic Actuator

This thesis describes the mathematical modeling and closed-loop voltage control of a MEMS electrostatic actuator. The control goal is to extend the travel range of the actuator beyond the open-loop pull-in limit of one third of the initial gap. Three controller designs are presented to reach the control goal. The first controller design utilizes a regular fourth order Active Disturbance Rejection Controller (ADRC) and is able to achieve 97 of the maximum travel range. The second design also uses a fourth order ADRC, while additional modeling information is included in an Extended State Observer (ESO), which is part of the ADRC, to improve control performance. This controller achieved 99 of the travel range. The third design is a multi-loop controller with a second order ADRC in an inner loop and a Proportional-Integral (PI) controller in an outer loop. This design achieved 100 of the travel range. Transfer function representations of the three controller designs are developed. The controllers are successfully applied and simulated in a parallel-plate electrostatic actuator model. The simulation results and frequency domain analyses verified the effectiveness of the controllers in extending the travel range of the actuator and in noise attenuatio

A unified approach for proportional-integral-derivative controller design for time delay processes

Abstract−An analytical design method for PI/PID controller tuning is proposed for several types of processes with time delay. A single tuning formula gives enhanced disturbance rejection performance. The design method is based on the IMC approach, which has a single tuning parameter to adjust the performance and robustness of the controller. A simple tuning formula gives consistently better performance as compared to several well-known methods at the same degree of robustness for stable and integrating process. The performance of the unstable process has been compared with other recently published methods which also show significant improvement in the proposed method. Furthermore, the robustness of the controller is investigated by inserting a perturbation uncertainty in all parameters simultaneously, again showing comparable results with other methods. An analysis has been performed for the uncertainty margin in the different process parameters for the robust controller design. It gives the guidelines of the M s setting for the PI controller design based on the process parameters uncertainty. For the selection of the closed-loop time constant, (τ c ), a guideline is provided over a broad range of θ/τ ratios on the basis of the peak of maximum uncertainty (M s ). A comparison of the IAE has been conducted for the wide range of θ/τ ratio for the first order time delay process. The proposed method shows minimum IAE in compared to SIMC, while Lee et al. shows poor disturbance rejection in the lag dominant process. In the simulation study, the controllers were tuned to have the same degree of robustness by measuring the M s , to obtain a reasonable comparison

Improving Closed-Loop Signal Shaping of Flexible Systems with Smith Predictor and Quantitative Feedback

Input shaping is a technique used to move flexible systems from point to point rapidly by suppressing the residual vibration at the destination. The vibration suppression is obtained from the principle of destruction of impulse responses. The input shaper, when placed before the flexible system inside the control loop, proves to deliver several benefits. However, this so-called closed-loop signal shaping has one major disadvantage that it adds time delays to the closed-loop system. Being a transcendental function, the time delays cause difficulty in analysis and design of the feedback controller. In most cases, the time delays also limit the maximum achievable bandwidth. In this paper, for the very first time, Smith predictors were applied to the closed-loop signal shaping to remove the time delay from the loop. It was shown in simulation result that the detrimental effect of the time delays was completely removed in the case of perfect plant model. The quantitative feedback control was used in the study to quantify the amount of achievable bandwidth and to suppress vibrations from the plant-input disturbance

Modeling and Feedback Control of a MEMS Electrostatic Actuator

This thesis describes the mathematical modeling and closed-loop voltage control of a MEMS electrostatic actuator. The control goal is to extend the travel range of the actuator beyond the open-loop pull-in limit of one third of the initial gap. Three controller designs are presented to reach the control goal. The first controller design utilizes a regular fourth order Active Disturbance Rejection Controller (ADRC) and is able to achieve 97 of the maximum travel range. The second design also uses a fourth order ADRC, while additional modeling information is included in an Extended State Observer (ESO), which is part of the ADRC, to improve control performance. This controller achieved 99 of the travel range. The third design is a multi-loop controller with a second order ADRC in an inner loop and a Proportional-Integral (PI) controller in an outer loop. This design achieved 100 of the travel range. Transfer function representations of the three controller designs are developed. The controllers are successfully applied and simulated in a parallel-plate electrostatic actuator model. The simulation results and frequency domain analyses verified the effectiveness of the controllers in extending the travel range of the actuator and in noise attenuatio