Analysis of Reset Control Systems Consisting of a FORE and Second-Order Loop1

2001 ◽  
Vol 123 (2) ◽  
pp. 279-283 ◽  
Author(s):  
Qian Chen ◽  
Yossi Chait ◽  
C. V. Hollot
Keyword(s):  
Control Systems ◽  
Closed Loop ◽  
Second Order ◽  
Step Response ◽  
Steady State Response ◽  
First Order ◽  
State Response ◽  
Loop Transfer Function ◽  
Performance Specifications ◽  
Reset Control

Reset controllers consist of two parts—a linear compensator and a reset element. The linear compensator is designed, in the usual ways, to meet all closed-loop performance specifications while relaxing the overshoot constraint. Then, the reset element is chosen to meet this remaining step-response specification. In this paper, we consider the case when such linear compensation results in a second-order (loop) transfer function and where a first-order reset element (FORE) is employed. We analyze the closed-loop reset control system addressing performance issues such as stability, steady-state response, and transient performance.

scholarly journals Development of FOPDT and SOPDT model from arbitrary process identification data using the properties of orthonormal basis function

2018 ◽  
Vol 7 (2.21) ◽  
pp. 77 ◽  
Author(s):  
Lalu Seban ◽  
Namita Boruah ◽  
Binoy K. Roy
Keyword(s):  
Basis Function ◽  
Delay Time ◽  
Orthonormal Basis ◽  
Control Point ◽  
Second Order ◽  
Step Test ◽  
Step Response ◽  
Order System ◽  
Model Parameters ◽  
First Order

Most of industrial process can be approximately represented as first-order plus delay time (FOPDT) model or second-order plus delay time (FOPDT) model. From a control point of view, it is important to estimate the FOPDT or SOPDT model parameters from arbitrary process input as groomed test like step test is not always feasible. Orthonormal basis function (OBF) are class of model structure having many advantages, and its parameters can be estimated from arbitrary input data. The OBF model filters are functions of poles and hence accuracy of the model depends on the accuracy of the poles. In this paper, a simple and standard particle swarm optimisation technique is first employed to estimate the dominant discrete poles from arbitrary input and corresponding process output. Time constant of first order system or period of oscillation and damping ratio of second order system is calculated from the dominant poles. From the step response of the developed OBF model, time delay and steady state gain are estimated. The parameter accuracy is improved by employing an iterative scheme. Numerical examples are provided to show the accuracy of the proposed method. 

Design of Reset Control Systems: The PI + CI Compensator

2012 ◽  
Vol 134 (5) ◽  
Author(s):  
Alfonso Baños ◽  
Angel Vidal
Keyword(s):  
Control Systems ◽  
Dynamic Systems ◽  
Closed Loop ◽  
Dead Time ◽  
Nonlinear Characteristic ◽  
Integral Term ◽  
Wide Range ◽  
Reset Control ◽  
Time Invariant ◽  
Time Systems

Reset compensation has been used to overcome limitations of linear and time invariant (LTI) compensation. In this work, a new reset compensator, referred to as proportional and integral (PI) + CI (Clegg integrator), is introduced. It basically consists of adding a Clegg integrator to a PI compensator, with the goal of improving the closed loop response by using the nonlinear characteristic of this element. It turns out that by resetting a percentage of the integral term in a PI compensator, a significant improvement can be obtained over a well-tuned PI compensator in some relevant practical cases, such as systems with dominant lag and integrating systems. The work is devoted to the development of PI + CI tuning rules for basic dynamic systems in a wide range of applications, including first and higher order plus dead time systems.

A Digital Compensator Design for Electrohydraulic Single-Rod Cylinder Position Control Systems

1990 ◽  
Vol 112 (3) ◽  
pp. 403-409 ◽  
Author(s):  
J. Watton
Keyword(s):  
Control Systems ◽  
Closed Loop ◽  
Position Control ◽  
Open Loop ◽  
Closed Loop System ◽  
Forward Algorithm ◽  
Loop Transfer Function ◽  
Compensator Design ◽  
Feedback Algorithm ◽  
Position Control System

A digital compensator using a forward algorithm, F(z−1), and a feedback algorithm, H(z−1), is developed for an electrohydraulic position control system incorporating an underlapped servovalve and a single-rod cylinder. The main problems encountered with designing such a closed-loop system are discussed, and it is shown how the filter coefficients may be easily determined for a particular class of open-loop transfer function. An excellent comparison between theory and experiment is obtained and it is deduced that one coefficient only need be changed in the forward algorithm for such gain-change dominant systems.

Driver Modeling and Simulation Based on Improved Preview Follower Algorithm

2013 ◽  
Vol 321-324 ◽  
pp. 847-851
Author(s):  
Xi Chang Huang
Keyword(s):  
Steady State ◽  
Closed Loop ◽  
Search Algorithm ◽  
Driver Model ◽  
Steady State Response ◽  
State Response ◽  
Target Track ◽  
Simulation Based ◽  
Point Search ◽  
High Level

Described a driver modelbased on the improved preview follower algorithms.Proposed a new preview-point search algorithm to ensure that the preview point fall on theexpected track and avail on the large curvature road. Considered theimpact of the steady state response to improve the dynamics performance ofdriver model. Modeled and stimulated the driver-vehicle-road closed-loop modelby Dymola. The results indicate thatthe improved driver model perform a high level ofaccuracy on the target track following.

scholarly journals Stabilization of Unstable Second-Order Delay Plants under PID Control: A Nyquist Curve Analysis

Actuators ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 227
Author(s):  
Li Sun ◽  
Dan Ma
Keyword(s):  
Control Systems ◽  
Pid Control ◽  
Time Delays ◽  
Closed Loop ◽  
Second Order ◽  
Control Algorithms ◽  
Special Cases ◽  
Communication Links ◽  
Nyquist Stability ◽  
Real Poles

Time delays arise in various components of control systems, including actuators, sensors, control algorithms, and communication links. If not properly taken into consideration, time delays will degrade the closed-loop performance and may even result in instability. This paper studies the stabilization problem of the second-order delay plants with two unstable real poles. Stabilization conditions under PD and PID control are derived using the Nyquist stability criterion. Algorithms for computing feasible PD and PID parameter regions are proposed. In some special cases, the maximal range of delay for stabilization under PD control is also given.

Research on Triple-Loop Control of BLDCM Based on Fuzzy PID

2014 ◽  
Vol 615 ◽  
pp. 395-401
Author(s):  
Yang Hua Li ◽  
Bo Mo ◽  
Ying He ◽  
Wen Jing Zhang
Keyword(s):  
Pid Controller ◽  
Step Response ◽  
Brushless Dc Motor ◽  
Control Methods ◽  
Steady State Response ◽  
Fuzzy Pid ◽  
Loop Control ◽  
Brushless Dc ◽  
State Response ◽  
Better Than

The brushless DC motor (BLDCM) has many advantages. This paper first analyzes the work principle of BLDCM and the control methods of the fuzzy PID, then designs a triple-loop controller based on the fuzzy PID BLDCM, finally makes a comparison of the traditional PID method and this new method. The experiment result shows that the result of the PID controller based on the BLDCM is much better than the traditional PID controller, the BLDCM improves the performance both on the step response of the position and the sinusoidal steady state response.

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