Small Overshoot Research Articles

CONTROLLING THE MEAN ARTERIAL PRESSURE BY MODIFIED MODEL REFERENCE ADAPTIVE CONTROLLER BASED ON TWO OPTIMIZATION ALGORITHMS

This paper Presents Modified Model Reference Adaptive Controller (MRAC) to regulate the hight blood pressure. It is based on slate model that represent the mathematical equation that clarifies relationship between blood pressure and vasoactive drug injection. In this work Squirrel Search Algorithm (SSA) and Grey Wolf Optimizer (GWO)algorithms are considered to optimize the controller parameters. the results showed that the suggested controller has good performance and stabilize the mean arterial pressure with small settling time (below than 400s) and small overshoot (below than 1 mmHg) with low amount of error.

Hierarchical sliding mode attitude control of a spherical underwater exploring robot

Aiming at the attitude control of the spherical underwater robot, the kinematics and dynamics of the underactuated attitude control adjusting system are analyzed, and its dynamics model is established. By using the differential homeomorphism transformation, the model was divided into two subsystems. Based on the advantages of sliding mode variable structure control, this paper adopts the hierarchical sliding mode variable structure method to design the sliding mode of different variables respectively, and then designs the sliding mode of the whole system. The presented control scheme can solve the coupling problem well. The controller has small overshoot and can well suppress chattering phenomenon. The simulation results show that the designed control law can make the system converge quickly and control the attitude of the underwater spherical robot effectively.

Control optimization of electromechanical systems by fractional-integral controllers

The object of research in the work is electromechanical systems, a characteristic feature of which is the presence of significant power dependence in the mathematical description. Because of this, problems arise when choosing the structure and parameters of controllers. In particular, in a DC motor with series excitation, a switched reluctance motor and electromagnetic retarders, saturation of the magnetic system in static and dynamic modes can occur. The apparatus of fractional-integral calculus used in the work allows us to describe such nonlinear objects with high accuracy by linear transfer functions of fractional order. So, when approximating the anchor circuit of a DC motor with series excitation by a fractional transfer function, the smallest standard error was obtained. The combination of a conventional PID controller with fractional integral components of the order of 0.35 and 1.35 ensured the best quality of the transient process - the current reaches the set value as quickly as possible without overshoot. Secondly, the switched reluctance motor, in the model of which it is necessary to take into account the power dependences, is described by the aperiodic function of the order of 0.7 when describing the transient processes of the speed during a voltage jump. From the family of controllers studied, the traditional PI controller with additional fractional-integral components of the order of 0.7 and 1.7 ensured the astaticism of the speed loop of the order of 1.7 and the smallest overshoot. Thirdly, the electromagnetic retarders of the driving wheels of a car, used to tune the internal combustion engine, are also most accurately described after testing by the fractional transfer function. Using the PIDIγIµ controller, which ensured closed loop astaticism of the order of 1.63, stabilization of the rotation speed of two wheels without out-of-phase oscillations and the accurate development of a triangular tachogram were achieved. Thus, thanks to the apparatus of fractional-integral calculus, a more accurate identification of object parameters is provided, the mathematical description is reduced to linear transfer functions of fractional order. And in closed systems it is possible to ensure astaticism of fractional order 1.3–1.7 and to achieve a better quality of transient processes than using classical methods.

Research on temperature control system of distillation column based on ABC-PID

The existence of non-linearity and variable parameters in distillation column system makes it difficult to tune the parameters of PID controller in its control system. The artificial bee colony algorithm is applied to the temperature control system of distillation column to optimize the PID parameters. The specific process of optimizing PID parameters based on artificial bee colony algorithm is put forward. PID controller optimized by artificial bee colony algorithm and traditional PID controller are separately used to control temperature coupling system of distillation column. The performance comparison and analysis are carried out by simulation. The results show that the temperature response curve of the PID controller based on artificial bee colony algorithm has smaller overshoot and the system has better robustness, verified the superiority of the artificial bee colony algorithm in optimizing the PID controller of distillation column.

Study on the non-equilibrium temperature behavior of normal shock waves and the bulk viscosity

The abnormality of small overshoot in the temperature profile of strong normal shock waves has been resolved, and the bulk viscosity of dilute monatomic gases cannot be ignored. By introducing the total energy conservation equation rather than the internal energy equation, an equation for the non-equilibrium temperature has been suggested. The postulated temperature equation gives a monotonically increasing profile of Monte Carlo data. The Navier–Stokes approximation derives shock equations in one differential equation and one algebraic equation and gives that the ratio of the bulk viscosity to the shear viscosity is equal to 1/15 for dilute monatomic gases.

Static pressure set-point reset smoothing scheme based-on improved iterative learning control and variable trajectory for air-conditioning system

Variable static pressure is the main strategy for air volume adjustment in variable air volume air-conditioning system and can offer huge energy savings compared with constant air volume systems. When parameter set-points reset with load, dynamic processes are excited. Some processes take a long time to reach a new stable state with large overshoots. Improved iterative learning control (ILC) algorithm is studied to ameliorate transition processes of the static pressure reset control loop. A mathematical model of the static pressure control loop is established, and a new desired trajectory is given to improve the system tracking performance. Simulation and experimental studies are performed on traditional Proportion Integration Differentiation (PID) control, Proportion Differentiation (PD) type ILC, fuzzy gain PD type ILC and variable speed-integral PID type ILC. Results show that the system has the smallest overshoot and the shortest adjustment time with the fuzzy gain PD type ILC. Meanwhile the system can be betterly stabilized near the set-point with smallest evaluation index and the desired trajectory can be tracked with better dynamic performance. Studies show that the dynamic process is smoothed by improved ILC and variable trajectory. It is of great significance to enhance the whole system stability.

An Offset-Free Composite Model Predictive Control Strategy for DC/DC Buck Converter Feeding Constant Power Loads

The high penetration of power electronic converters into dc microgrids may cause the constant power load stability issues, which could lead to large voltage oscillations or even system collapse. On the other hand, dynamic performance should be satisfied in the control of power electronic converter systems with small overshoot, less oscillations, and smooth transient performance. This article proposes an offset-free model predictive controller for a dc/dc buck converter feeding constant power loads with guaranteed dynamic performance and stability. First, a receding horizon optimization problem is formulated for optimal voltage tracking. To deal with the unknown load variation and system uncertainties, a higher order sliding mode observer is designed and integrated into the optimization problem. Then an explicit closed-loop solution is obtained by solving the receding horizon optimization problem offline. A rigorous stability analysis is performed to ensure the system large signal stability. The proposed controller achieves optimized transient dynamics and accurate tracking with simple implementation. The effectiveness of the proposed controller is validated by simulation and experimental results.

Nonlinear rheology and dynamics of supramolecular polymer networks formed by associative telechelic chains under shear and extensional flows

Nonequilibrium computer simulations have been applied to study the shear and extensional flow behavior of supramolecular polymer networks (SPNs) formed by unentangled and weakly entangled associative telechelic chains and their nonassociative polymer melt counterparts. The reversible bonding of the associative end monomers or stickers leads to the formation of percolated transient networks and consequently stronger mechanical properties of the SPNs than their melt counterparts. In startup shear, the transient shear viscosities η ( t ) and first normal stress coefficients Ψ 1 ( t ) of both the SPN and melt systems show overshoot behavior, but only the SPNs demonstrate transient strain hardening at high shear rates. In startup planar extensional flows, all systems demonstrate the characteristic extensional strain hardening behavior. The transient extensional viscosities η E ( t ) of the SPNs undergo a small overshoot before entering the steady state, which was not observed in the nonassociative polymer melts. For both types of polymer systems with unentangled and weakly entangled chain lengths, the steady-state shear viscosities show typical shear-thinning behavior, while the steady-state extensional viscosities demonstrate extension hardening, which are consistent with published simulation and experimental works. The observed flow behavior can be well understood from the flow-induced non-Gaussian chain stretching and segment orientation in all polymer systems studied, as well as the additional relaxation mechanisms in the SPNs, including the flow-induced reduction in the density of elastically active strands, the increment in the probability for the stickers to exchange their associated partners, and the reduction in the average sticky bond lifetimes at high strain rates.

Optimasi Pengaturan Kecepatan Motor Shunt Berbasis Imperalist Competitive Algorithm (ICA)

Imperalist Competitive Algorithm (ICA) is one method of artificial intelligence inspired by competition for power. In system optimization this method gets better results than other artificial intelligence methods. DC shunt motors do not need a lot of space because of the small wire diameter, but the output power is very small because the amplifier current is small. A good shunt motor setting is needed to produce the desired motor speed. In this study PID controls were tuned using ICA. This good PID guide will get a good system optimization. As a comparison, the control of the shunt motor speed without control, with PID control, with detuning ICA PID control (PID-ICA). The results showed that the results of PID-ICA had the smallest overshot and undershot, with a speed of 500.00 rpm and the fastest settling time : 1201 s. This research will be developed using other artificial intelligence methods.

SIMULASI PEREDAMAN GETARAN PADA PEGAS KATUP (VALVE SPRING) SISTEM HIDROLIK DENGAN METODE PID MEMANFAATKAN SIMULINK MATLAB

A simulation of damping vibration on valve spring hydraulic system has been done. This research is a study of the simulation that aims to control excess vibration on valve spring hydraulic system as a result of excitation force that is affected by the changes of pressure periodically, to produce a stable system. The simulation performed by using Matlab simulink with applying a PID method (P, PD, PI and PID) and noticed to variations of proportional constant (Kp), integral constant (Ki) and the derivative constant (Kd).
 The simulation results obtained show that by combining these three constants Ki, Kp and Kd can dampen the vibration better. For the total excitation force, using the value of Kp = 106, Ki = 7 x 106 and Kd = 6 x 104 can provide damping vibration system response on valve spring with a rise time of 1.2119 s, settling time of 1.2792 s, stable at setpoint 1, error steady state 0% and a small maximum overshoot of 0.3309. This is the result of a stable system response and best compared to the other combinations of the constant values.
 
 Keywords : vibration, damper, valve spring, hydraulic system, PID method.

Kontrol Frekuensi Wind-Diesel Menggunakan Hibrid Kontroller PID-BA-ANFIS

The wind diesel system is greatly influenced by the wind speed and which is then combined with the diesel engine. Optimization of wind-diesel systems is needed to get good frequency quality and optimal power. The optimal setting of the gain and time constant on the Load Frequency Control (LFC) causes the frequency stability to be weak. In practice, the wind-diesel system is controlled by a PID controller and Fuzzy Logic Controller. At present the gain value setting of the PID is still in the conventional method, so it is difficult to get the optimal value. In this study the control design is applied by using the Smart Method in finding the optimum Proportional Integral Derivative (PID) based on Bat Algorithm (BA). For comparison, the method is used without a control method, conventional PID method, PID auto tune matlab method, PID-BA method, and PID-BA-ANFIS. Wind-diesel modeling uses the transfer function of wind turbine and diesel diagrams. From the results of research that has been done shows that the smallest undershoot on PID-BA-ANFIS, the smallest overshot on PID-BA-ANFIS, and the fastest settling time is equal to PID-BA-ANFIS. This research can later be continued using other artificial intelligence methods.

The fuzzy adaptive PID control of brushless DC motor

Brushless direct current motor (BLDCM) is a complicated system with multivariable, nonlinear and strong coupled. The present work devotes to design a fuzzy adaptive PID algorithm based on the speed loop so that it could crack the traditional PID problems which include bad parameter setting, poor adaptability, imprecise control and weak anti-interference so on. In this paper, the mathematical model and operating characteristics of BLDCM are analyzed. Then, the simulation platform is built by MATLAB/Simulink. Finally, the control effects of PI, PID and fuzzy adaptive PID are compared and analyzed. The results indicate that the fuzzy adaptive PID is better robustness, faster response, smaller overshoot and more stable operation than others.

Robust Control Theory Based Performance Investigation of an Inverted Pendulum System using Simulink

In this paper, the performance of inverted pendulum have been Investigated using robust control theory. The robust controllers used in this paper are H∞ Loop Shaping Design Using Glover McFarlane Method and mixed H∞ Loop Shaping Controllers. The mathematical model of Inverted Pendulum, a DC motor, Cart and Cart driving mechanism have been done successfully. Comparison of an inverted pendulum with H∞ Loop Shaping Design Using Glover McFarlane Method and H∞ Loop Shaping Controllers for a control target deviation of an angle from vertical of the inverted pendulum using two input signals (step and impulse). The simulation result shows that the inverted pendulum with mixed H∞ Loop Shaping Controller to have a small rise time, settling time and percentage overshoot in the step response and having a good response in the impulse response too. Finally the inverted pendulum with mixed H∞ Loop Shaping Controller shows the best performance in the overall simulation result. Keywords : Inverted pendulum, H∞ Loop Shaping Design Using Glover McFarlane, mixed H∞ Loop Shaping DOI: 10.7176/CTI/9-04 Publication date: April 30 th 2020

Modified active disturbance rejection control for fluidized bed combustor

As a widely-used technology, fluidized bed combustor (FBC) boiler is facing many control challenges such as coupling, high-order dynamics and nonlinearity. With more and more sustainable energy integrating into the bulk power system, the FBC boiler is obliged to speed up the respond to the automatic generation control command and this results in great challenges for keeping the bed temperature in the desired range. To this end, a modified active disturbance rejection control (MADRC) is put forward for high order systems with the type of K∕(Ts+1)n to enhance the control quality of the FBC boiler. Firstly, a simulation is carried out to discuss the estimation ability of the MADRC. A theorem about the stability analysis of the MADRC is provided and proofed theoretically. To help the field personnel to understand and use more easily, an effective tuning procedure is also concluded. Besides, a tuning toolbox based on the tuning procedure is established. Simulations and comparative experiments based on the Peltier temperature control platform validate the superiority of the MADRC, where the MADRC is able to enhance the control quality. Then the MADRC and other comparative controllers (the proportional integral controller and the regular ADRC) are designed for the FBC boiler. Simulation results illustrate that the MADRC can obtain the best performance. Statistical indices show that the MADRC has the smallest overshoot and shortest settling time. In addition, the MADRC still has the strongest ability to reject the input and coal quality variation disturbances. The advantages of the MADRC guarantee the high control quality and can be applied to industrial practice widely.

A Self-Adaptive Damping Control Strategy of Virtual Synchronous Generator to Improve Frequency Stability

In a microgrid, grid-connected inverters, as the interface between the distributed power supply and grid, cannot provide inertia support for the system. The control strategy of virtual synchronous generator (VSG) based on grid-connected inverters can enhance the stability of system frequency. In order to make the frequency response that has a smaller overshoot and a shorter settling time, a self-adaptive damping control strategy based on the relationship between the damping and the maximum frequency deviation for microgrid VSG is presented. The small-signal mathematical model of VSG is established, and the range of the damping coefficient is determined. Finally, simulation experiments are carried out with MATLAB/Simulink, and the effectiveness of the proposed control strategy is verified by comparing it with various damping control methods.

Comparing Composition Control Structures for Kaibel Distillation Columns

Although Kaibel distillation columns are superior to conventional distillation sequences owing to smaller equipment investment and operation cost, they display high nonlinearity and this greatly increases the difficulty of achieving their tight control. To overcome this problem, four decentralized composition control structures, i.e., the CSR/QR, CSR/B, CSD/QR, and CSD/B structures, are proposed and compared based on the control of a Kaibel distillation column fractionating a methanol/ethanol/propanol/butanol quaternary mixture. These four composition control structures all include five composition control loops. While the four of them are employed to maintain the purity of the top, upper sidestream, lower sidestream, and bottom products, the remaining one is employed to minimize the energy consumption of the Kaibel distillation column by maintaining the composition of propanol at the first stage of the prefractionator. Dynamic simulation results show the CSR/QR and CSR/B structures can tightly maintain the purity of the controlled products with a small overshoot and short settling time after facing various disturbances in feed conditions, but the CSD/QR and CSD/B structures lead to oscillatory responses (the latter even shows divergent responses under individual disturbances). At the end of the article, some effective guides for developing composition control systems are given.

Modeling identification and control of a 6-DOF active vibration isolation system driving by voice coil motors with a Halbach array magnet

The sheet current model considering the end effects is applied to design a six-degree-of-freedom (6-DOF) active vibration isolation system (AVIS) driving by the voice coil motors (VCMs). Compared with the charge model, the sheet current method represents higher calculation efficiency. Then, the hybrid functions (HFs) are employed to identify the multi-input and multi-output (MIMO) AVIS, and the identification parameters are used to design the controller. To promote the control performance, the composite nonlinear feedback (CNF) controller is designed based on the identification parameters. Consequently, the simulations and experiments are carried out, compared with PID controller, the CNF controller shows quicker response and smaller overshoot, i.e., the CNF controller achieves the dynamic damping ratio during the control. Thus, the experimental results demonstrate the better performance of the CNF controller.

Improved Iterative Learning Control Strategy for Surface-Mounted Permanent Magnet Synchronous Motor Drives

In this article, an improved iterative learning control (ILC), which significantly enhances the speed tracking performance in the transient and steady state for a surface-mounted permanent magnet synchronous motor (SPMSM) drive, is proposed. The proposed ILC encapsulates two control terms: the feedback linearization control terms force the speed error to approach zero, and the iterative learning control terms (ILCTs) improve the performance of the control inputs based on the stored data such as previous speed error and previous control input. Unlike the conventional feedback linearization control (FLC), the proposed ILC does not require the exact information of the SPMSM parameters, significantly rejects the periodic and nonperiodic disturbances, and efficiently provides an enhanced speed tracking performance owing to the included ILCTs. Besides, its stability is proven by showing that the speed tracking error asymptotically goes to zero. In comparative studies, the proposed method offers the better transient performance (e.g., faster transient response and smaller overshoot) and steady-state performance (i.e., smaller steady-state error) than the conventional FLC under load and speed step changes. To prove the practicability of the proposed scheme, the proposed ILC is simulated and implemented on a MATLAB/Simulink software and a prototype SPMSM test-bed using TI TMS320F28335 digital signal processor, respectively.

Speed Control of Direct Current Motor Using ANFIS Based Hybrid P-I-D Configuration Controller

Considering DC motor's non-linear characteristics, design challenges and mechanical variation due to the operation conditions, the precise controller cannot be performed using the traditional control alone. This study presents an innovative method to optimize the direct current motor speed by decreasing the transient response characteristics such as overshoot, settling time and rise time. In this study, several PID's configurations and ANFIS controllers have been performed for direct current motor speed control. The suggested techniques were compared to each other to validate the superiority of the highest controller performance. Training data for ANFIS was generated using standard configuration, cascade and dual configuration. The dual configuration is a hybrid of two controller's data manipulated using a special algorithm. The results obtained using Matlab Simulink tools demonstrated the efficiency of ANFIS based dual PID and ANFIS based PD methods for controlling the motor speed. The overall simulation results showed that the models have a rapid response, small overshoot, superior dynamics and robustness, and static performance. The techniques presented herein outperform the traditional control methods for obtaining highly accurate control.

A High-Bandwidth End-Effector With Active Force Control for Robotic Polishing

To promote operational intelligence, improve surface quality, and reduce manpower dependence, a novel high-bandwidth end-effector with active force control for robotic polishing was proposed. Using this end-effector as a mini robot, a macro-mini robot for polishing processing was constructed, in which the macro robot provides posture control during polishing operations, whereas the mini-robot provides constant force control. By minimizing the inertia along the spindle in this configuration, the end-effector obtains a force control bandwidth of 200 Hz. Through a series of comparative experiments with different contact forces and feed rates, the proposed design was proven to have a smaller overshoot, a faster response, and a shorter settling time than the conventional method based on macro robot (KUKA iiwa) controlled force. The roughness of the workpiece reached $0.4~\mu \text{m}$ after polishing with the macro-mini robot, indicating the efficiency of this end-effector in high-precision material removal and surface polishing operations.