Simple PID Controller Research Articles

Fuzzy Logic based PID Controller for pH Neutralization Process

automation of a Water treatment plant involves monitoring and control of various parameters like Temperature, Pressure, Level, Flow and Vibration in the plant. Process Control plays a major role in the automation industry. The intricacy of any control mechanism has only increased due to an unprecedented increase in the requirements, instrumentation and various control loops. Therefore a simple PID control mechanism is not a practical option for efficient control of any real - time process, let alone automation of an entire plant. This paper presents an improved version of the classic PID control mechanism that is the use of Fuzzy control logic along with the PID control for the pH neutralization process in a water treatment plant. The implementation of this procedure will be relevant for any multivariable process. General Terms Automation, Industrial multivariable process Keywordsater treatment plant, classic PID, Fuzzy logic control, pH neutralization process, multivariable process

A neutron poison tritium breeding controller applied to a water cooled fusion reactor model

The generation of tritium in sufficient quantities is an absolute requirement for a next step fusion device such as DEMO due to the scarcity of tritium sources. Although the production of sufficient quantities of tritium will be one of the main challenges for DEMO, within an energy economy featuring several fusion power plants the active control of tritium production may be required in order to manage surplus tritium inventories at power plant sites. The primary reason for controlling the tritium inventory in such an economy would therefore be to minimise the risk and storage costs associated with large quantities of surplus tritium. In order to ensure that enough tritium will be produced in a reactor which contains a solid tritium breeder, over the reactor's lifetime, the tritium breeding rate at the beginning of its lifetime is relatively high and reduces over time. This causes a large surplus tritium inventory to build up until approximately halfway through the lifetime of the blanket, when the inventory begins to decrease. This surplus tritium inventory could exceed several tens of kilograms of tritium, impacting on possible safety and licensing conditions that may exist.This paper describes a possible solution to the surplus tritium inventory problem that involves neutron poison injection into the coolant, which is managed with a tritium breeding controller. A simple PID controller and is used to manage the injection of the neutron absorbing compounds into the water coolant of a stratified blanket model, depending on the difference between the required tritium excess inventory and the measured tritium excess inventory. The compounds effectively reduce the amount of low energy neutrons available to react with lithium compounds, thus reducing the tritium breeding ratio. This controller reduces the amount of tritium being produced at the start of the reactor's lifetime and increases the rate of tritium production towards the end of its lifetime. Thus, a relatively stable tritium production level may be maintained, allowing the control system to minimize the stored tritium with obvious safety benefits. The FATI code (Fusion Activation and Transport Interface) will be used to perform the tritium breeding and controller calculations.

The Design of Bending Force Shape Control System Based on Fuzzy Adaptive Control

This paper presents a fuzzy adaptive shape control system, which overcomes the shortcoming of simple PID controller and simple fuzzy controller. The PID parameters can be adjusted on-line in this system. The simulation result shows that the control system can improve the control performance and control quality of steel shape control.

PD-SVM Integrated Controller for Robotic Manipulator Tracking Control

Highly precise tracking of a robotic manipulator in presence of uncertainties like noise, disturbances, and friction has been addressed in this particular paper. An integrated proportional derivative and support vector machine (SVMPD) controller has been proposed for manipulator tracking. To illustrate the efficiency of the proposed controller, simulations have been done on a 2-DOF manipulator system. Performance of the proposed controller has been checked and verified with respect to to a simple PID controller and the radial bias neural network proportional integral derivative (RBNNPD) controller. It has been proved that the proposed controller can achieve better tracking performance as compared to other controllers as the range of errors is less and the time taken by the controller has reduced up to 14 times as compared to RBNN.

Linear control of the flywheel inverted pendulum

The flywheel inverted pendulum is an underactuated mechanical system with a nonlinear model but admitting a linear approximation around the unstable equilibrium point in the upper position. Although underactuated systems usually require nonlinear controllers, the easy tuning and understanding of linear controllers make them more attractive for designers and final users. In a recent paper, a simple PID controller was proposed by the authors, leading to an internally unstable controlled plant. To achieve global stability, two options are developed here: first by introducing an internal stabilizing controller and second by replacing the PID controller by an observer-based state feedback control. Simulation and experimental results show the effectiveness of the design.

Quadrotor: Design, Control and Vision Based Localization

Abstract Modelling and control of Unmanned Aerial Vehicles (UAV) is a challenging problem owing to the inherent non-linearity. They demand ideal control for generating precise motion. This work aims at designing and building a light-weight quadrotor with improved on-board computational power and a diverse set of applications. Computer Aided Design (CAD) has been used to estimate mass and inertia parameters of the system. We briefly describe the functionality of various hardware components used in the fabrication process. Our work also describes dynamics of the system and state-space formulation for the controller design. We discuss two control strategies and evaluate their performance: (i) a simple PID controller and (ii) a back- stepping controller. A Simulator is designed to easily verify the control strategies and evaluate their effectiveness. We also incorporated vision based localization using a simple monochrome camera output. In the end, we describe the future work and the possible applications of our system. All the simulation and the field test results are shown where and when they are necessary.

Optimal Design, Fabrication, and Control of an $XY$ Micropositioning Stage Driven by Electromagnetic Actuators

This paper presents the optimal design, fabrication, and control of a novel compliant flexure-based totally decoupled XY micropositioning stage driven by electromagnetic actuators. The stage is constructed with a simple structure by employing double four-bar parallelogram flexures and four noncontact types of electromagnetic actuators to realize the kinematic decoupling and force decoupling, respectively. The kinematics and dynamics modeling of the stage are conducted by resorting to compliance and stiffness analysis based on matrix method, and the parameters are obtained by multiobjective genetic algorithm (GA) optimization method. The analytical models for electromagnetic forces are also established, and both mechanical structure and electromagnetic models are validated by finite-element analysis via ANSYS software. It is found that the system is with hysteresis and nonlinear characteristics when a preliminary open-loop test is conducted; thereafter, a simple PID controller is applied. Therefore, an inverse Preisach model-based feedforward sliding-mode controller is exploited to control the micromanipulator system. Experiments show that the moving range can achieve 1 mm t 1 mm and the resolution can reach ±0.4 μm. Moreover, the designed micromanipulator can bear a heavy load because of its optimal mechanical structure.

Self-Tuning Fuzzy Adaptive PID Pitch Control of Wind Power Systems

A large variable speed constant frequency (VSCF) wind power system usually adopts the variable pitch control technology to ensure the output power is steady to ensure the safety of the wind power system above the rated wind speed. But the strong nonlinear and large moment of inertia of wind turbine result in the difficulty of variable pitch control, both simple fuzzy control and conventional PID control can not achieve a good control effect. Concerning this issue, variable pitch control algorithm is proposed based on self-tuning fuzzy adaptive PID control strategy. According to the dynamic model of VSCF, a simulation model of wind turbine control system is built in this paper with Matlab/Simulink. When the wind speed is random variable above the rated speed, the simulation results show that the proposed control strategy can keep the output power of the system around the rated power.

Simple Analytic PID Controller Tuning Rules Revisited

The SIMC method by Skogestad (J. Process Control 2003, 13, 291–309) to tune the PID controller is revisited, and a new method (K-SIMC) is proposed. The proposed K-SIMC method includes modifications of model reduction techniques and suggestions of new tuning rules and set point filters. Effects of such modifications are illustrated through simulations for a wide variety of process models. The proposed modifications permit the SIMC method to be applied with more confidence.

A High Accurate Adaptive Temperature Control Algorithm Based on Fuzzy Reasoning and PID Control

A high accurate adaptive temperature control algorithm is proposed and implemented for a thermostatic chemical detecting device. The proposed algorithm combines the advantages of PID control and Fuzzy control which are high accuracy and easy control. The algorithm flow chart and fuzzy reasoning rules are presented. The experiment results and actual operation show that the algorithm has much better performance on adaptability, stability, accuracy than simple PID control and has a great application prospect on the field of constant-temperature chemical apparatus.

Time-slicing control strategy for rotary SMA actuators

A new control strategy that can be applied efficiently to rotary SMA actuators was investigated. This type of controller primarily focuses on adjusting the amount of time to apply a voltage or current to actuators while the traditional controllers have been widely used to compute amplitude of signals fed to the actuators. To prove the effectiveness as well as the capability of the proposed strategy in controlling rotary SMA actuators, a simple time-slicing PID controller was developed. The experimental results showed that the proposed time-slicing PID controller attained a better tracking performance compared to the traditional one.

A No-Nonsense Control Engineering Approach to Anaesthesia Control during Induction Phase

Abstract This paper introduces a strategy for patient-individualized control of induction phase during general anaesthesia. A down-to-earth, pragmatic (and possibly provocative) approach has been used. The core of the paper is the idea to avoid the direct use of the Bispectral Index signal (BIS) as a feedback signal, since it introduces artificial delays, it is noisy and in the initial stage of the induction it contains no useful information for control purposes because it hardly varies and it introduces nonlinearity. The effect site concentration ( C e ) of the drug in the patient is instead used as the controller's feedback signal. Of course the BIS measurement is still indirectly used in our proposed control strategy, in order to adapt the parameters of the Hill curve - which relates BIS to C e - resulting in a patient-individualized closed loop control of anesthesia. These ideas are validated on 12 virtually generated patients varying significantly in sensitivity to the drug effect, using a simple PID control. The control of the induction phase is split into two phases: the initial phase where no useful BIS feedback signal is available, hence target controlled infusion (TCI) with a fixed setpoint is temporarily applied; and the secondary phase when a useful BIS feedback signal becomes available and the TCI setpoint is adapted based on the estimated Hill-curve steepness. The approach is simple and excellent simulation results combined with theoretical insights indicate that the strategy looks promising for future clinical practice.

模糊控制在直流无刷电机控制系统中的应用<br>The Application of Fuzzy Control to Brushless DC Motor Control System

直流无刷电机控制系统是多变量、时变和非线性的复杂大系统，本文针对简单PID控制方法在电机启动阶段具有较大超调以及在负载跳变时抗负载扰动能力不足的问题，提出了改进方案：电机控制系统的速度环采用参数自整定模糊PID控制。在Matlab/Simulink环境下搭建直流无刷电机矢量控制的仿真模型，通过仿真结果验证了所选控制方案的可行性。将该控制方案的仿真结果与简单PID控制的仿真结果相比较可得响应时间缩短了40%、超调量降低了3.5%、转矩扰动减小了30%，表明模糊PID控制可有效地提高控制系统的精确度、灵敏度和鲁棒性。 The brushless direct current motor control system is a complex one with multi-variables, time-variability and non-linear. Regarding to the problems of large overshoot of simple PID control method in the motor start-up phase and insufficiency of anti-load disturbance ability when the load fluctuates suddenly, this thesis proposes an improved program. Parameter self-tuning fuzzy-PID control method is used for the speed loop of the motor control system. The brushless direct current motor’s vector control simulation model is built by using Matlab/Simulink, and the results of simulation verified the selected control scheme’s feasibility. Compared with the simulation result of this control program and that of simple PID, which has demonstrated that the system response time was reduced 40%, the overshoot was decreased 3.5% and the torque disturbance was dropped 30%. This shows that the fuzzy PID control is effective to improve the accuracy, sensitivity and robustness of the control system.

Model-free robot joint position regulation and tracking with prescribed performance guarantees

The problem of robot joint position control with prescribed performance guarantees is considered; the control objective is the error evolution within prescribed performance bounds in both problems of regulation and tracking. The proposed controllers do not utilize either the robot dynamic model or any approximation structures and are composed by simple PID or PD controllers enhanced by a proportional term of a transformed error through a transformation related gain. Under a sufficient condition for the damping gain, the proposed controllers are able to guarantee (i) predefined minimum speed of convergence, maximum steady state error and overshoot concerning the position error and (ii) uniformly ultimate boundedness (UUB) of the velocity error. The use of the integral term reduces residual errors allowing the proof of asymptotic convergence of both velocity and position errors to zero for the regulation problem under constant disturbances. Performance is a priori guaranteed irrespective of the selection of the control gain values. Simulation results of a three dof spatial robotic manipulator and experimental results of one dof manipulator are given to confirm the theoretical findings.

High Performance Control of Stewart Platform Manipulator Using Sliding Mode Control with Synchronization Error

This paper presents the design and analysis of a high performance robust controller for the Stewart platform manipulator. The controller is a variable structure controller that uses a linear sliding surface which is designed to drive both tracking and synchronization errors to zero. In the controller the model based equivalent control part of the sliding mode controller is computed in task space and the discontinuous switching controller part is computed in joint space and hence it is a hybrid of the two approaches. The hybrid implementation helps to reduce computation time and to achieve high performance in task space without the need to measure or estimate 6DOF task space positions. Effect of actuator friction, backlash and parameter variation due to loading have been studied and simulation results confirmed that the controller is robust and achieves better tracking accuracy than other types of sliding mode controllers and simple PID controller.

Path Tracking Control of a Motorcycle Based on System Identification

This study investigates the roll angle tracking and path tracking controls of a motorcycle. For the control design, a required linear model is obtained from the system identification method. The roll angle is controlled at a specific speed via a simple PID controller to generate input-output data, including steering torque, as well as roll and steering angles. The collected data are then used to identify a one-input two-output linear model by a prediction error identification method using parameterization in a canonical state-space form derived as a Whipple model. With the obtained linear model, full-state feedback (FSF) is designed for roll angle tracking control. Simulations and comparisons with a PID controller show that this FSF is robust against changes in speed as well as external disturbances. On the basis of the roll angle tracking controller, a path tracking controller by path preview is developed with consideration of disturbance rejection. The simulations show the effectiveness of the proposed control scheme.

Behavior of a small diffusion flame as an electrically active component in a high-voltage circuit

Active control of combustion is challenging because there are few actuators with sufficient power to overcome the effects associated with the significant energy release associated with flames. The control leverage afforded by adjusting the fuel stream has so far been the most effective for this purpose. Naturally occurring flame ions allow an alternative control option via external electric fields, and this mechanism has been investigated, in experimental analysis of small non-premixed flame acted on by a high-voltage grid. During the course of these studies, the voltage–current characteristics of air–methane flames has been identified. This article describes how electric fields acting on flame ions affect the local convective environment and produce a very characteristic electrical behavior that can be analyzed as part of an electrical circuit for control in order to produce a desired flame response, using the ion production as a sensor for overall reaction intensity and a fairly simple PID control algorithm to effect the desired flame response.

Differential Drag as a Means of Spacecraft Formation Control

This paper investigates the feasibility of using differential drag as a means of nano-satellite formation control. Differential drag is caused when the ballistic coefficients of the spacecraft in a formation are not equal. The magnitude of differential drag depends on the difference in ballistic coefficients and also the altitude of the spacecraft formation. AGI's Satellite Tool Kit (STK) is used initially to assess the magnitude of drifts caused due to differential drag for different altitudes. This information is then used to show that it is feasible to use differential drag for spacecraft formation control. A simple PID controller is then implemented that adjusts the cross- sectional areas of the satellites such that the energies of the orbits remain equal. Results are presented that show that the control law can maintain the formation separation with reasonable accuracy.

A Design of a PID Self-Tuning Controller Using LabVIEW

In this paper a trial has been made to design a simple self-tuning LabVIEW-based PID controller. The controller uses an open-loop relay test, calculates the tuned parameters in an open loop mode of operation before it updates controller parameters and runs the process as a closed-loop system. The controller reacts on a persistent offset error value as a result of load disturbance or a set point change. Practical results show that such a controller may be recommended to control a variety of industrial processes. A GUI was developed to facilitate control-mode selection, the setting of controller parameters, and the display of control system variables. GUI makes it possible to put the controller in manual or self-tuning mode.

Beam vibration control using cellulose-based Electro-Active Paper sensor

Cellulose based Electro-Active Paper (EAPap) has recently shown a great potential as an environment-friendly smart material due to its biodegradability, biocompatibility and flexibility. Lots of studies have been conducted to investigate the basic smart characteristics of EAPap, but its application has not yet developed well. In this paper, the possibility of cellulose-based Electro-Active Paper (EAPap) as a piezoelectric sensor was investigated by the vibration control of the cantilevered beam. The EAPap sample was attached at the root of the cantilevered beam and used as a vibration sensor. The piezoceramic patch was also attached at the root of the beam and played as an actuator. The voltage output of EAPap showed exact dynamic characteristics of the cantilevered beam. The frequency bandwidth and quality factor of EAPap were similar to those of piezoceramic patch, which results EAPap has similar sensing capability of piezoceramic patch. To find the application of EAPap sensor, beam vibration control was performed. EAPap sensor output was considered as a position error of the cantilevered beam and a simple PID controller was designed to suppress the vibration of the beam. The EAPap sensor output provided clear time response of the beam. The controlled system showed good vibration control performance of the beam. The results provided that the piezoelectric characteristic of EAPap has a great potential as a sensor and also as a new smart material.