scholarly journals Series pid pitch controller of large wind turbines generator

2015 ◽  
Vol 12 (2) ◽  
pp. 183-196
Author(s):  
Aleksandar Micic ◽  
Miroslav Matausek
Keyword(s):  
Damping Ratio ◽  
Stable Process ◽  
Control Variable ◽  
Open Loop ◽  
Step Response ◽  
Process Step ◽  
Transport Delay ◽  
Oscillatory Dynamics ◽  
Natural Mechanism ◽  
Order Butterworth Filter

For this stable process with oscillatory dynamics, characterized with small damping ratio and dominant transport delay, design of the series PID pitch controller is based on the model obtained from the open-loop process step response, filtered with the second-order Butterworth filter Fbw. Performance of the series PID pitch controller, with the filter Fbw, is analyzed by simulations of the set-point and input/output disturbance responses, including simulations with a colored noise added to the control variable. Excellent performance/robustness tradeoff is obtained, compared to the recently proposed PI pitch controllers and to the modified internal model pitch controller, developed here, which has a natural mechanism to compensate effect of dominant transport delay.

scholarly journals Carotid and aortic baroreflexes of the rat: II. Open-loop frequency response and the blood pressure spectrum

2000 ◽  
Vol 279 (5) ◽  
pp. R1922-R1933 ◽  
Author(s):  
Barry R. Dworkin ◽  
Xiaorui Tang ◽  
Alan J. Snyder ◽  
Susan Dworkin
Keyword(s):  
Blood Pressure ◽  
Venous Pressure ◽  
Low Frequency ◽  
Noise Spectrum ◽  
Open Loop ◽  
Step Response ◽  
Algebraic Solution ◽  
Noise Power ◽  
Vascular Conductance ◽  
Aortic Depressor Nerve

To determine the relationship between blood pressure (BP) variability and the open-loop frequency domain transfer function (TF) of the baroreflexes, we measured the pre- and postsinoaortic denervation (SAD) spectra and the effects of periodic and step inputs to the aortic depressor nerve and isolated carotid sinus of central nervous system-intact, neuromuscular-blocked (NMB) rats. Similar to previous results in freely moving rats, SAD greatly increased very low frequency (VLF) (0.01–0.2 Hz) systolic blood pressure (SBP) noise power. Step response-frequency measurements for SBP; interbeat interval (IBI); venous pressure; mesenteric, femoral, and skin blood flow; and direct modulation analyses of SBP showed that only VLF variability could be substantially attenuated by an intact baroreflex. The −3-dB frequency for SBP is 0.035–0.056 Hz; femoral vascular conductance is similar to SBP, but mesenteric vascular conductance has a reliably lower and IBI has a reliably higher −3-dB point. The overall open-loop transportation lag, of which ≤0.1 s is neural, is ≈1.07 s. Constrained algebraic solution, over a range of frequencies, of the pre- and postSAD endogenous noise spectra and the independently determined relative frequency and absolute lag measurements was used to calculate the absolute gain for the open-loop TF. The average gain at 0.02 Hz, the frequency of maximum sensitivity, was 1.47 (95% confidence interval = ±0.48), which agrees well with estimates for the dog reversible sinus. We found that, in the NMB rat, the effects of SAD on the BP noise spectrum were accounted for by the open-loop properties of the baroreflex.

scholarly journals Parameter Identification of Nonlinear System on Combustion Engine Based MVEM using PEM

2018 ◽  
Vol 1 (4) ◽  
Author(s):  
Trigas Badmianto ◽  
Eka Firmansyah ◽  
Adha Imam Cahyadi
Keyword(s):  
Combustion Engine ◽  
Mean Value ◽  
Open Loop ◽  
Injection System ◽  
High Price ◽  
Opening Angle ◽  
Virtual Sensors ◽  
Transport Delay ◽  
Lambda Sensor ◽  
Non Linear System

In four-stroke engine injection system, often called spark ignition (SI) engine, the air-fuel ratio (AFR) is taken from the measurement of lambda sensor in the exhaust. This sensor does not directly describe how much AFR in the combustion chamber due to the large transport delay. Therefore, the lambda sensor is used only as a feedback in AFR control "correction", not as the "main" control. The purpose of this research is to identify the parameters of the non-linear system in SI engines to produce AFR estimator. The AFR estimator is expected to be used as a feedback of the main "AFR" control system. The process of identifying the parameters using the Gauss-Newton method, due to its rapid computation to Achieve convergence, is based on prediction error minimization (PEM). The models of AFR estimator is an open-loop system without a universal exhaust gas oxygen (UEGO) sensors as feedback, called a virtual AFR sensor. The high price of UEGO sensors makes the virtual AFR sensor can be a practical solution to be applied in AFR control. The model in this research is based on the mean value engine models (MVEM) with some modifications. The research dataset was taken from a Hyundai Verna 2002 with the additional UEGO type of lambda sensors. The throttle opening angle (input) is played by stepping on the gas pedal and the signal to the injector (input) is set to a certain quantity to produce the AFR (output) value read by the UEGO sensor. This research produces an open loop estimator model or AFR virtual sensors with normalized root mean square error (NRMSE) = 0.06831 = 6.831%.

Application of Dynamic Input Shaping for a Dual-Mirror System

2021 ◽  
Author(s):  
Alicia Dautt-Silva ◽  
Raymond de Callafon
Keyword(s):  
Input Signal ◽  
Inverse Kinematic ◽  
Open Loop ◽  
Mirror System ◽  
Image Motion ◽  
Step Response ◽  
Input Shaping ◽  
Input Signals ◽  
Compensation Device ◽  
Operating Constraints

Abstract The task of trajectory planning for a dual-mirror optical pointing system greatly benefits from carefully designed dynamic input signals. This paper summarizes the application of multivariable input shaping (IS) for a dual-mirror system, starting from initial open-loop step-response data. The optical pointing system presented consists of two Fast Steering Mirrors (FSM) for which dynamically coupled input signals are designed, while adhering to mechanical and input signal constraints. For the solution, the planned trajectories for the dual-mirrors are determined via (inverse) kinematic analysis. A linear program (LP) problem is used to compute the dynamic input signal for each of the FSMs, with one of the mirrors acting as an image motion compensation device that guarantees tracking of a planned trajectory within a specified accuracy and the operating constraints of the FSMs.

Modeling of a Dynamic Mirror With Antagonistic Piezoelectric Stack Actuation

2013 ◽  
Vol 136 (2) ◽  
Author(s):  
James A. Mynderse ◽  
George T. C. Chiu
Keyword(s):  
Constitutive Models ◽  
Open Loop ◽  
Step Response ◽  
Experimental Frequency ◽  
Loop Control ◽  
Response Data ◽  
Input Control ◽  
Proposed Model ◽  
Single Input ◽  
Charging Dynamics

A dynamic mirror actuator utilizing antagonistic piezoelectric stack actuators is presented for use in laser printers. Exhibiting hysteresis and other nonlinearities in open-loop operation, the dynamic mirror actuator (DMA) requires a control structure to achieve accurate mirror positioning. A linear DMA model is developed for extending operational bandwidth under closed-loop control, employing explicit piezoelectric stack actuator (PESA) charging dynamics and incorporating two modes for single input control of opposing PESA drives. Compared to constitutive models from literature, the proposed model displays a comparable fit with experimental frequency response data while retaining a lower model order. As further validation, simulated step response data are shown to agree with experimental data.

Efficient Linear Approach for the Closed-Loop Control of a Ionic Polymer Bending Actuator

2016 ◽  
Vol 97 ◽  
pp. 75-80 ◽  
Author(s):  
Bertrand Tondu ◽  
Aiva Simaite ◽  
Ganesh Kumar Hari Shankar Lal Das ◽  
Philippe Soueres ◽  
Christian Bergaud
Keyword(s):  
Closed Loop ◽  
Open Loop ◽  
Step Response ◽  
Order System ◽  
Initial Slope ◽  
Vertical Position ◽  
Control Voltage ◽  
Closed Loop Control ◽  
Loop Control ◽  
Bending Actuator

Tri-layer electroactive bending polymeric artificial muscles generally exhibit no overshoot during open-loop step response with a non-zero initial slope when the output is the vertical position of the bending sample tip. We propose to identify such a bending step contraction by a nonlinear system derived from a linear first order system in the form: where the parameters k, T and r depend on the u-control voltage. We show the relevance of this approach for identifying the step-response of a PEDOT:PSS/PVDF/ionic liquid actuator developed at the laboratory. As a consequence, we try to show that a linear PI-controller, including voltage constraints, is a simple and an efficient approach for a closed-loop control of the bending actuator.

Comparison of Buck–Boost and Ćuk Converters Based on Time Domain Response

2018 ◽  
Vol 27 (14) ◽  
pp. 1850222
Author(s):  
J. Leema Rose ◽  
B. Sankaragomathi
Keyword(s):  
Pid Controller ◽  
Closed Loop ◽  
State Equation ◽  
Power Converter ◽  
Open Loop ◽  
Step Response ◽  
State Equations ◽  
Loop Control ◽  
Time Domain Response ◽  
Response Method

This paper presents the design and modeling of power electronic converters such as buck–boost and Ćuk operated under continuous conduction mode (CCM). The open-loop behavior of buck–boost and Ćuk converters needs modeling and simulation using modeled equations. The closed-loop control of these converters has a propositional–integral–derivative (PID) controller. PID controller parameters are obtained from Ziegler–Nichols step response method. These converters can be analyzed using the state equation. The MATLAB/SIMULINK tool is used for simulation of those state equations. Ćuk and buck–boost converters are designed and analyzed. The mathematical model of power Converter for simulation has been carried out using SIMULINK with/without any Sim Power System Elements. The open- and closed-loop results are compared.

scholarly journals Design of Identification Experiments for Step Response Models: Open Loop Case

2000 ◽  
Vol 33 (15) ◽  
pp. 1225-1230
Author(s):  
Dianne Smektala ◽  
William Cluett ◽  
Liuping Wang
Keyword(s):  
Open Loop ◽  
Step Response ◽  
Response Models

Adaptive Grinding Process—Prevention of Thermal Damage Using OPC-UA Technique and In Situ Metrology

2017 ◽  
Vol 139 (12) ◽  
Author(s):  
Matthias Steffan ◽  
Franz Haas ◽  
Alexander Pierer ◽  
Gentzen Jens
Keyword(s):  
Thermal Damage ◽  
Control Variable ◽  
Safety Margin ◽  
Value Added ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Production Chain ◽  
Process Step ◽  
Edge Zone ◽  
Control Concept

The production process grinding deals with finishing of hardened workpieces and is one of the last stages of the value-added production chain. Up to this process step, considerable costs and energy have been spent on the workpieces. In order to avoid production rejects, significant safety reserves are calculated according to the present state of the art. The authors introduce two approaches to minimize the safety margin, thus optimizing the process’ economic efficiency. Both control concepts use the feed rate override of the machining operation as regulating variable to eliminate thermal damage of the edge zone. The first control concept is developed to avoid thermal damage in cylindrical plunge grinding by controlling the cutting forces. Therefore, the industrial standard Open Platform Communications Unified Architecture (OPC-UA) is used for the communication between a proportional–integral–derivative (PID) controller and the SINUMERIK grinding machine tool control system. For noncircular workpieces, grinding conditions change over the circumference. Therefore, thermal damage cannot be ruled out at any time during the grinding process. The authors introduce a second novel control approach, which uses a micromagnetic measure that correlates with thermal damage as the main control variable. Hence, the cutting ability of the grinding wheel and thermal damage to the workpiece edge zone is quantified in the process. The result is a control concept for grinding of noncircular workpieces, which opens up fields for major efficiency enhancement. With these two approaches, grinding processes are raised on higher economic level, independently of circular and noncircular workpiece geometries.

Exact Deadbeat Controller Design From N Impulse Response Samples

1986 ◽  
Vol 108 (1) ◽  
pp. 65-68 ◽  
Author(s):  
R. E. Rink
Keyword(s):  
Steady State ◽  
Impulse Response ◽  
Controller Design ◽  
Open Loop ◽  
Step Response ◽  
Simple Method ◽  
Arbitrary Type ◽  
Pi Controllers ◽  
State Tracking ◽  
Time Invariant

A simple method is given for the design of exact deadbeat regulators and PI controllers when only N impulse or step response samples from the process are available. It is required that the process be linear, controllable, observable, time invariant, and that N≥2n, where n is the degree of the process. It is not required that the process be open-loop stable, in distinction with previously-given simple methods. This makes it easy to include any number of integrations in the controller to achieve steady-state tracking properties of arbitrary type.

Robust Design of a Micro-Electromechanical System in the Presence of Assembly Uncertainty

2010 ◽  
Author(s):  
Choong-Ho Rhee ◽  
Kenn Oldham
Keyword(s):  
Damping Ratio ◽  
Weight Bearing ◽  
Open Loop ◽  
Alignment Error ◽  
Wide Range ◽  
Loop Dynamics ◽  
Out Of Plane ◽  
Micro Electromechanical System ◽  
Stiffness And Damping ◽  
Function Models

Three methods of minimizing error between the transient response of a dynamic system with parameter variation and its nominal open-loop dynamics are tested on a second-order example system of a piezoelectric microactuator. The example system is a piezoelectrically actuated silicon flexure intended for use in micro-robotic systems. Polymer and silicon layers are to be stacked on top of the original flexure to increase out-of-plane weight-bearing capacity, but this process is subject to substantial alignment error. The procedures evaluated in this paper seek target stiffness and damping coefficients that minimize error in open-loop actuator motion. The first method is based on simple damping ratio and natural frequency calculations, while the second and third methods are based on state-space and transfer function models, respectively. All three approaches reduce error in transient dynamics compared to nominal designs based solely on static weight-bearing or fabrication considerations, with the state-based being identified as usable to a wide range of systems, although the ability to reduce sensitivity to model variation in purely open-loop operation is limited.

Sign in / Sign up

Export Citation Format

Share Document