On the Vibration of a Translating String Coupled to Hydrodynamic Bearings

1990 ◽  
Vol 112 (3) ◽  
pp. 337-345 ◽  
Author(s):  
C. A. Tan ◽  
B. Yang ◽  
C. D. Mote
Keyword(s):  
Control System ◽  
Transfer Function ◽  
Spatial Location ◽  
System Response ◽  
Thickness Variation ◽  
Translation Speed ◽  
Impedance Function ◽  
Hydrodynamic Bearing ◽  
Loop Transfer Function ◽  
Bearing Force

The vibration of a translating string, controlled through hydrodynamic bearing forces, is analyzed by the transfer function method. Interactions between the string response and the bearing film are described by the bearing impedance function. This function depends on the string translation speed, the frequency of the film thickness variation, and the spatial location of the bearings. The control system consists of the translating string, bearings, actuators and sensors, and feedback elements. An integral formulation of the controlled system response is proposed that leads to the closed-loop transfer function. The frequency response of the control system is studied in the system parameter space. The feasibility of adding active control to improve the bearing force control is also considered.

Robust Feedback Control of a Baffled Plate via Open-Loop Optimization

2001 ◽  
Vol 124 (1) ◽  
pp. 154-157 ◽  
Author(s):  
P. De Man ◽  
A. Franc¸ois ◽  
A. Preumont
Keyword(s):  
Genetic Algorithm ◽  
Control System ◽  
Transfer Function ◽  
Open Loop ◽  
Displacement Sensor ◽  
Search Procedure ◽  
Loop Optimization ◽  
Loop Transfer Function ◽  
Poles And Zeros ◽  
Siso System

A SISO control system is built by using a volume displacement sensor and a set of actuators driven in parallel with a single amplifier. The actuators location is optimized to achieve an open-loop transfer function which exhibits alternating poles and zeros, as for systems with collocated actuators and sensors; the search procedure uses a genetic algorithm. The ability of a simple lead compensator to control this SISO system is numerically demonstrated.

Kinematics, Dynamics, and Control of Tendon-Driven Mechanisms Using Signal Flow Graphs

1998 ◽  
Author(s):  
Meng-Sang Chew ◽  
Theeraphong Wongratanaphisan
Keyword(s):  
Control System ◽  
Transfer Function ◽  
Closed Loop ◽  
Transfer Functions ◽  
Signal Flow ◽  
Signal Flow Graphs ◽  
Loop Transfer Function ◽  
Dynamics And Control ◽  
Flow Graphs ◽  
And Control

Abstract This paper presents the analysis of the kinematics, dynamics and controls of tendon-driven mechanism under the framework of signal flow graphs. For decades, the signal flow graphs have been applied in many areas, particularly in controls, for determining the closed-loop transfer function of a control system. The tendon-driven mechanism considered here consists of several subsystems including actuator-controller dynamics, mechanism kinematics and mechanism dynamics. Each subsystem will be derived and represented by signal flow graphs. The representation of the whole system can be carried out by connecting the graphs of subsystems at the corresponding nodes. Transfer functions can then be obtained by using Mason’s rules. A 3-DOF robot finger utilizing tendon-driven mechanism is used as an illustrative example.

scholarly journals Design of the Deadbeat Controller with Limited Output

1970 ◽  
Vol 110 (4) ◽  
pp. 93-96
Author(s):  
L. Balasevicius ◽  
G. Dervinis
Keyword(s):  
Control System ◽  
Transfer Function ◽  
Polynomial Coefficient ◽  
System Response ◽  
Third Order ◽  
The Third ◽  
The Family ◽  
Limited Output ◽  
One Step ◽  
Simulation Results

There is presented a method for finding the parameters of the deadbeat controller in Matlab environment. The method is based on the introduction of an additional polynomial into the transfer function of the controller. The method for determining the additional polynomial coefficient of a deadbeat controller is based on creating the family of the coefficient curves and defining the permissible selection area. The method was tested by using simulations in Matlab environment and realizing the deadbeat control system for the third order object in the PLC. Simulation results in Matlab show that even though the control increases by one-step, the settling time of the system response can be lower than that of the deadbeat controller without any modifications. Based on the obtained results it can be concluded that the results confirm the idea of defining the parameters of the transfer function of a deadbeat controller with a limited output. Ill. 9, bibl. 3 (in English; abstracts in English and Lithuanian).http://dx.doi.org/10.5755/j01.eee.110.4.296

Ramp Tracking in Systems With Nonminimum Phase Zeros: One-and-a-Half Integrator Approach

2016 ◽  
Vol 138 (3) ◽  
Author(s):  
Mohammad Saleh Tavazoei
Keyword(s):  
Control System ◽  
Dynamical Systems ◽  
Transfer Function ◽  
Fractional Calculus ◽  
Control Law ◽  
Nonminimum Phase ◽  
Numerical Examples ◽  
Loop Transfer Function ◽  
Asymptotic Tracking

In this paper, a simple fractional calculus-based control law is proposed for asymptotic tracking of ramp reference inputs in dynamical systems. Without need to add any zero to the loop transfer function, the proposed technique can guarantee asymptotic ramp tracking in plants having nonminimum phase zeros. The appropriate range for determining the parameters of the proposed control law is also specified. Moreover, the performance of the designed control system in tracking ramp reference inputs is illustrated by different numerical examples.

Structure about the Dual-Axis Speed Turntable and its’ Stability Analysis

2012 ◽  
Vol 235 ◽  
pp. 186-191
Author(s):  
Gui Ying Lu ◽  
Yuan Sheng Wang ◽  
Bo Li ◽  
Juan Yu
Keyword(s):  
Control System ◽  
Transfer Function ◽  
Block Diagram ◽  
Stability Margin ◽  
Open Loop ◽  
Digital Controller ◽  
Loop Control ◽  
Rate Table ◽  
Loop Transfer Function ◽  
Loop Control System

The structure and its function about a dual-axis rate turntable has been elaborated, its principle block diagram of control system is given. And its electromechanical system’s transfer function of the dual-axis rate table has been calculated and simplified reasonably based on experiments and practical situation, then a double loop control system constituted with a speed loop and a stabilization loop is got. Its’ correction link of the stabilization loop is calculated, which has a 2-order open loop transfer function. In order to achieve a suitable stability margin, the corresponding digital controller is designed, and its’ pulse transfer function response and the three-step iterative simulation results to a same sinusoidal excitation are got and compared, the same results verified the correctness of the design to the correction link.

scholarly journals Relative Stability of Electrical into Mechanical Conversion with BLDC Motor-Cascade Control

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 704
Author(s):  
Sylwester Sobieraj ◽  
Grzegorz Sieklucki ◽  
Józef Gromba
Keyword(s):  
Transfer Function ◽  
Relative Stability ◽  
Power Supply System ◽  
Theoretical Calculations ◽  
Electrical Energy ◽  
Cascade Control ◽  
Bldc Motor ◽  
Cascade System ◽  
Loop Transfer Function ◽  
Basic Parameters

The conversion of the electrical energy into the mechanical is usually realized by a motor, power electronics and cascade control. The relative stability (Θ-stability), i.e., the displacement of its eigenvalues of this system is analyzed for a drive with a BLDC motor. The influence of changing the basic parameters of the motor and power supply system on the drive operation is considered. 4th order closed-loop transfer-function of the cascade control is presented, where boundaries of the transfer-function coefficients are used. The cascade system which uncertainty of the resistance, inductance, flux and gain parameters is analyzed. Theoretical calculations for the cascade control, simulations and laboratory tests are included in the article.

scholarly journals Dynamic control of maximal ventricular elastance via the baroreflex and force-frequency relation in awake dogs before and after pacing-induced heart failure

2010 ◽  
Vol 299 (1) ◽  
pp. H62-H69 ◽  
Author(s):  
Xiaoxiao Chen ◽  
Javier A. Sala-Mercado ◽  
Robert L. Hammond ◽  
Masashi Ichinose ◽  
Soroor Soltani ◽  
...  
Keyword(s):  
Heart Failure ◽  
Transfer Function ◽  
Transfer Functions ◽  
Dynamic Properties ◽  
System Response ◽  
Force Frequency ◽  
Arterial Baroreflex ◽  
Ventricular Elastance ◽  
Arterial Blood ◽  
Frequency Relation

We investigated to what extent maximal ventricular elastance ( Emax) is dynamically controlled by the arterial baroreflex and force-frequency relation in conscious dogs and to what extent these mechanisms are attenuated after the induction of heart failure (HF). We mathematically analyzed spontaneous beat-to-beat hemodynamic variability. First, we estimated Emax for each beat during a baseline period using the ventricular unstressed volume determined with the traditional multiple beat method during vena cava occlusion. We then jointly identified the transfer functions (system gain value and time delay per frequency) relating beat-to-beat fluctuations in arterial blood pressure (ABP) to Emax (ABP→ Emax) and beat-to-beat fluctuations in heart rate (HR) to Emax (HR→ Emax) to characterize the dynamic properties of the arterial baroreflex and force-frequency relation, respectively. During the control condition, the ABP→ Emax transfer function revealed that ABP perturbations caused opposite direction Emax changes with a gain value of −0.023 ± 0.012 ml−1, whereas the HR→ Emax transfer function indicated that HR alterations caused same direction Emax changes with a gain value of 0.013 ± 0.005 mmHg·ml−1·(beats/min)−1. Both transfer functions behaved as low-pass filters. However, the ABP→ Emax transfer function was more sluggish than the HR→ Emax transfer function with overall time constants (indicator of full system response time to a sudden input change) of 11.2 ± 2.8 and 1.7 ± 0.5 s ( P < 0.05), respectively. During the HF condition, the ABP→ Emax and HR→ Emax transfer functions were markedly depressed with gain values reduced to −0.0002 ± 0.007 ml−1 and −0.001 ± 0.004 mmHg·ml−1·(beats/min)−1 ( P < 0.1). Emax is rapidly and significantly controlled at rest, but this modulation is virtually abolished in HF.

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