Control of a Flexibly Mounted Stabilized Platform

1977 ◽  
Vol 99 (3) ◽  
pp. 174-182
Author(s):  
C. R. Burrows ◽  
T. P. Adams
Keyword(s):  
Control System ◽  
Steady State ◽  
Dynamic Performance ◽  
Digital Simulation ◽  
Experimental Results ◽  
Governing Equations ◽  
Positional Accuracy ◽  
Theoretical Predictions ◽  
Stabilized Platform ◽  
Improve Stability

The governing equations for a flexibly mounted stabilized platform are derived and solved using digital simulation. Theoretical predictions for the static and dynamic performance are compared with experimental results. This leads to a study of the effects of modifying the control system to improve stability and steady-state positional accuracy.

A Different View on Dynamic Recrystallization

2012 ◽  
Vol 715-716 ◽  
pp. 235-242 ◽  
Author(s):  
Günter Gottstein
Keyword(s):  
Grain Size ◽  
Steady State ◽  
Dynamic Recrystallization ◽  
Grain Boundaries ◽  
Experimental Results ◽  
Critical Conditions ◽  
New Approach ◽  
Theoretical Predictions

A new approach to dynamic recrystallization (DRX) is introduced. It is based on the assumption that the critical conditions for DRX and the arrest of DRX grain boundaries are related to the development of mobile subboundaries. The theoretical predictions are compared to experimental results during incipient and steady-state DRX. The grain size sensitivity of the DRX grains establishes the desired link between deformation and DRX microstructure.

Experimental Validation of Towed Underwater Cable Model

2019 ◽  
Author(s):  
Jan Vidar Grindheim ◽  
Antonio Carlos Fernandes ◽  
Joel Sena Sales Junior ◽  
Inge Revhaug
Keyword(s):  
Steady State ◽  
Experimental Validation ◽  
Experimental Results ◽  
Experimental Setup ◽  
Two Dimensional ◽  
Cable Model ◽  
Governing Equations ◽  
Current Channel ◽  
Steady State Condition ◽  
Wet Weight

Abstract Towed underwater cable models have been validated using experimental results performed in the current channel at Laboratório de Ondas e Correntes (LOC) at COPPE/UFRJ, Rio de Janeiro. The numerical simulators utilize a Finite Difference Method to solve the Partial Differential Equations describing the dynamics of a towed underwater cable under tension. A non-dimensional analysis of the system dynamics for the two-dimensional case has been performed, with non-dimensional governing equations being presented. The experimental setup consists of two cable sections of ∼1.5 m length each, the first having 3 mm diameter and slightly positive wet weight while the second section has 2.5 mm diameter and slight negative wet weight. With the cable in steady-state condition, the towpoint is moved 0.50 m sideways and the time for the cable to return to straight tow is measured. Further, the cable depths at midpoint and tail are measured in steady-state. Experiments are performed at currents ranging from 0.17 to 0.47 m/s. The presented experimental results are compared to the numerical results. Reasonable agreements are obtained.

Simulation of Yarn Tension Control System Based on Simulink

2010 ◽  
Vol 426-427 ◽  
pp. 106-108 ◽  
Author(s):  
De Gong Chang ◽  
Zhi Juan Xiao ◽  
Y.H. Liu ◽  
H. Li
Keyword(s):  
Control System ◽  
Dynamic Performance ◽  
Digital Simulation ◽  
Tension Control ◽  
Structure Parameters ◽  
Yarn Tension ◽  
Magnetic Powder Brake ◽  
Tension Control System ◽  
The Mathematical Model ◽  
The Relationship

Based on the analyses of the yarn tension and the mathematical model of the magnetic powder brake, the digital simulation of the yarn tension fuzzy control system was performed by using MATLAB Simulink. The relationship between the structure parameters and the system dynamic performance was then obtained, and the system scheme was justified.

scholarly journals Evaluation of SIPIC01 and SIPIC02 on Motor Speed Control

2018 ◽  
Vol 152 ◽  
pp. 02010
Author(s):  
Kah Kit Wong ◽  
Choon Lih Hoo ◽  
Mohd Hardie Hidayat Mohyi
Keyword(s):  
Control System ◽  
Steady State ◽  
Dynamic Performance ◽  
Pi Controller ◽  
Settling Time ◽  
Motor Speed ◽  
Proportional Integral ◽  
Integral Controller ◽  
Proportional Integral Controller ◽  
Decoupling Effect

Due to its simplicity, Proportional-Integral (PI) controller still remains as the widely used controller for motor speed control system. However, PI controller exhibits windup phenomenon when the motor operates in a saturated state, which may cause degradation to the control system. In order to overcome the windup phenomenon, many researches have introduced various types of anti-windup methods such as the Conditioning Technique (CI), Tracking Back Calculation (TBC), Integral State Prediction (ISP), Steady-state Integral Proportional Integral Controller-01 (SIPIC01) and Steady-state Integral Proportional Integral Controller-02 (SIPIC02). These are anti-windup techniques with integral control switching mechanism, coupling of proportional gain, kp, and integral gain, ki. Due to the coupled kp and ki, tuning motor performance is a difficult task with short settling time without experiencing overshoot. SIPIC01 and SIPIC02 are robust anti-windup methods without a switching mechanism and exhibit decoupling feature. SIPIC01 and SIPIC02 have shown better dynamic performance compared to CI, TBC and ISP. However, SIPIC01 has not been compared to SIPIC02 in terms of their decoupling effect flexibility and dynamic performance. The decoupling effect was verified using MATLAB simulation, while the performance analysis was verified through hardware simulation and testing by using Scilab. The results obtained from the simulation showed that both SIPIC01 and SIPIC02 consist of decoupling features that allow a performance with coexistence of zero or minimum overshoot with short settling time. However, SIPIC02 consists of longer rise and settling time as compared to SIPIC01. Therefore, it can be concluded that SIPIC01 is better than SIPIC02 in term of dynamic performance.

scholarly journals Voltage Balancing of Multiphase FCML Converters with Coupled Inductors

2021 ◽  
Author(s):  
Daniel H. Zhou ◽  
Minjie Chen
Keyword(s):  
Steady State ◽  
Dynamic Model ◽  
Experimental Results ◽  
Voltage Balancing ◽  
Coupled Inductors ◽  
Periodic Disturbances ◽  
Capacitor Voltage ◽  
Theoretical Predictions ◽  
Flying Capacitors ◽  
Time Required

<div>Flying capacitor voltage balancing is critical for the performance of flying capacitor multilevel (FCML) converters. This paper investigates the intrinsic capacitor voltage balancing of multiphase FCML converters with coupled inductors. It is shown that the coupled inductor provides flying capacitor voltage balancing that minimizes steady-state imbalances due to periodic disturbances compared to converters with uncoupled inductors. A dynamic model of natural balancing of the converter is derived and used to estimate the time required for the flying capacitors to settle from an initial imbalance. The theoretical predictions are verified with analytical derivations, SPICE simulations, and experimental results.</div>

scholarly journals Current PIλ Control of the Single-Phase Grid Inverter

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Xueqin Yang ◽  
Xingyu Liu ◽  
Jichao Li ◽  
Binbin Zhang
Keyword(s):  
Control System ◽  
Steady State ◽  
Fractional Order ◽  
Single Phase ◽  
Dynamic Performance ◽  
Harmonic Distortion ◽  
Pi Controller ◽  
Fractional Order Pi Controller ◽  
Control System Model ◽  
Steady State Performance

In a grid-connected power generation system, the grid-connected current of the inverter is sensitive to nonlinear factors such as periodic disturbance of grid voltage, which results in grid-connected current waveform distortion. By establishing a single-phase photovoltaic grid-connected inverter control system model, designing an inverse current fractional-order PI (PIλ or FO-PI) controller and the dynamic and steady-state performance, antidisturbance and grid connection inversion characteristics of the system are simulated and compared under the action of the integer-order PI controller and fractional-order PI controller. The quality of the inverter grid-connected current is analyzed by using the fast Fourier transform (FFT). The simulation results show that the fractional-order control system can reduce the total harmonic distortion (THD) of the grid-connected current and dynamic performance and antidisturbance ability of the improving system while satisfying the steady-state performance indexes.

scholarly journals Voltage Balancing of Multiphase FCML Converters with Coupled Inductors

2021 ◽  
Author(s):  
Daniel H. Zhou ◽  
Minjie Chen
Keyword(s):  
Steady State ◽  
Dynamic Model ◽  
Experimental Results ◽  
Voltage Balancing ◽  
Coupled Inductors ◽  
Periodic Disturbances ◽  
Capacitor Voltage ◽  
Theoretical Predictions ◽  
Flying Capacitors ◽  
Time Required

<div>Flying capacitor voltage balancing is critical for the performance of flying capacitor multilevel (FCML) converters. This paper investigates the intrinsic capacitor voltage balancing of multiphase FCML converters with coupled inductors. It is shown that the coupled inductor provides flying capacitor voltage balancing that minimizes steady-state imbalances due to periodic disturbances compared to converters with uncoupled inductors. A dynamic model of natural balancing of the converter is derived and used to estimate the time required for the flying capacitors to settle from an initial imbalance. The theoretical predictions are verified with analytical derivations, SPICE simulations, and experimental results.</div>

Angular Position Control of Fluid-Driven Spindle

2009 ◽  
Author(s):  
Yohichi Nakao ◽  
Naoya Asaoka
Keyword(s):  
Mathematical Model ◽  
Control System ◽  
Steady State ◽  
Disturbance Observer ◽  
Position Control ◽  
Angular Position ◽  
Experimental Results ◽  
The Mathematical Model ◽  
Position Control System ◽  
State Error

A precise spindle is essential to achieve precision machining, such as diamond turning. A fluid driven spindle supported by hydrostatic bearings was thus designed and tested. A feature of the spindle is that several flow channels are designed in its rotor so that driving torque can be generated by supplying pressurized flow into the channels. Rotational speed of the spindle can be controlled by the flow rate. In addition, the rotational direction of the spindle can be controlled by switching supply ports. Thus angular position control of the spindle is achieved by designing appropriate feedback controller. In the present paper, mathematical model of the spindle was thus derived in order for designing an angular position control system. Then spindle characteristics calculated by the mathematical model were compared with experimental results. Furthermore, the angular position control system that has a disturbance observer in its feedback loop was designed based on the mathematical model. The performance of the designed control system was experimentally investigated through the step response. Experimental results verified that the designed controller minimizes the steady state error of angular position of the spindle. Consequently, the steady state error was comparable with the resolution of the rotary encoder, 0.018 degree. In particular, the experimental results indicated that the disturbance observer effectively reduced the influence of various load torque on the angular position of the spindle.

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