scholarly journals ROBUST AND FEEDFORWARD CONTROL FOR A NONLINEAR PNEUMATIC SERVOMECHANISM SYSTEM

2021 ◽  
Vol 56 (5) ◽  
pp. 362-369
Author(s):  
Lafta E. J. Alkurawy ◽  
Adham H. Saleh ◽  
Ibraheem S. Fatah
Keyword(s):  
Robust Control ◽  
Pid Controller ◽  
Feedforward Control ◽  
Setting Time ◽  
Guidance System ◽  
Design Parameters ◽  
Feedback Controllers ◽  
Servo Actuator ◽  
The Stability ◽  
The Mathematical Model

The actuator of the vane servo unit epitomizes the control operator of force in systems of missile control, where the character of its dynamic and static plays a significant role in the missile behavior. Therefore, improving the dynamic behavior for the vane servo actuator is of main interest for designing control and guidance system. The article describes a new method of analyzing the mathematical model of the nonlinear pneumatic servo with different design parameters and designing a controller with these parameters. The robust control regulates the system with different parameters, and it is the first controller to attempt this technique. A servo actuator of nonlinear and linear simulators was constructed by MATLAB software package. Feedback controllers with PI and PID were designed and tested theoretically. The setting time and the behavior of the dynamic will be improved. The robust feedforward control was applied to the system to improve the stability and zero steady-state error and compare the results with PI and PID controller. Their tests showed that robust control is the best control for stability among the others.

Simulation Technologies for Tamper System of Asphalt-Paver Based on AMESim

2010 ◽  
Vol 129-131 ◽  
pp. 1098-1103 ◽  
Author(s):  
Tian Hong Luo ◽  
Xin Fu Gan ◽  
Wen Jun Luo
Keyword(s):  
Mathematical Model ◽  
Simulation Model ◽  
Pid Controller ◽  
Dynamic Performance ◽  
Operating Principle ◽  
Simulation Results ◽  
The Stability ◽  
The Mathematical Model

Tamper mechanism is one of the most important parts in all of Asphalt-pavers. In this article, the mathematical model of the tamper system has been established and the stability of the system has been analyzed by using Matlab. According to the operating principle of tamper system of Asphalt-paver, the simulation model of tamper system of Asphalt-paver has been established by using AMESim. The main parameters of the model were set, and then, the simulation results were analyzed, which show that the system is stable and the dynamic performance of system will be improved, when accumulator and PID controller were equipped. Besides, the tamping frequency of hammer is very important to the performance of system. When tamping frequency of hammer over 20HZ, the performance of system will go bad.

Design of a wheeled wall climbing robot based on the performance of bio-inspired dry adhesive material

Robotica ◽  
2021 ◽  
pp. 1-14
Author(s):  
Hongkai Li ◽  
Xianfei Sun ◽  
Zishuo Chen ◽  
Lei Zhang ◽  
Hongchao Wang ◽  
...  
Keyword(s):  
Flat Surface ◽  
Thrust Force ◽  
Adhesion Force ◽  
Structure Design ◽  
Design Parameters ◽  
Climbing Robot ◽  
Adhesive Material ◽  
Ducted Fan ◽  
The Stability ◽  
Belt System

Abstract Inspired by gecko’s adhesive feet, a wheeled wall climbing robot is designed in this paper with the synchronized gears and belt system acting as the wheels by considering both motion efficiency and adhesive capability. Adhesion of wheels is obtained by the bio-inspired adhesive material wrapping on the outer surface of wheels. A ducted fan mounted on the back of the robot supplies thrust force for the adhesive material to generate normal and shear adhesion force whilemoving on vertical surfaces. Experimental verification of robot climbing on vertical flat surface was carried out. The stability and the effect of structure design parameters were analyzed.

A computationally efficient adaptive robust control scheme for a quad-rotor transporting cable-suspended payloads

2021 ◽  
pp. 095441002110136
Author(s):  
Nasim Ullah ◽  
Irfan Sami ◽  
Wang Shaoping ◽  
Hamid Mukhtar ◽  
Xingjian Wang ◽  
...  
Keyword(s):  
Robust Control ◽  
Fractional Order ◽  
Sliding Mode ◽  
Adaptive Robust Control ◽  
Computationally Efficient ◽  
Control Scheme ◽  
Control Schemes ◽  
Adaptive Laws ◽  
Unknown Disturbances ◽  
The Stability

This article proposes a computationally efficient adaptive robust control scheme for a quad-rotor with cable-suspended payloads. Motion of payload introduces unknown disturbances that affect the performance of the quad-rotor controlled with conventional schemes, thus novel adaptive robust controllers with both integer- and fractional-order dynamics are proposed for the trajectory tracking of quad-rotor with cable-suspended payload. The disturbances acting on quad-rotor due to the payload motion are estimated by utilizing adaptive laws derived from integer- and fractional-order Lyapunov functions. The stability of the proposed control systems is guaranteed using integer- and fractional-order Lyapunov theorems. Overall, three variants of the control schemes, namely adaptive fractional-order sliding mode (AFSMC), adaptive sliding mode (ASMC), and classical Sliding mode controllers (SMC)s) are tested using processor in the loop experiments, and based on the two performance indicators, namely robustness and computational resource utilization, the best control scheme is evaluated. From the results presented, it is verified that ASMC scheme exhibits comparable robustness as of SMC and AFSMC, while it utilizes less sources as compared to AFSMC.

Unraveling Interlimb Interactions Underlying Bimanual Coordination

2005 ◽  
Vol 94 (5) ◽  
pp. 3112-3125 ◽  
Author(s):  
Arne Ridderikhoff ◽  
C. (Lieke) E. Peper ◽  
Peter J. Beek
Keyword(s):  
Bimanual Coordination ◽  
Feedforward Control ◽  
Emg Activity ◽  
Minor Role ◽  
Error Corrections ◽  
Flexion Extension ◽  
Contralateral Hand ◽  
Phase Coordination ◽  
The Stability ◽  
Passive Movements

Three sources of interlimb interactions have been postulated to underlie the stability characteristics of bimanual coordination but have never been evaluated in conjunction: integrated timing of feedforward control signals, phase entrainment by contralateral afference, and timing corrections based on the perceived error of relative phase. In this study, the relative contributions of these interactions were discerned through systematic comparisons of five tasks involving rhythmic flexion–extension movements about the wrist, performed bimanually (in-phase and antiphase coordination) or unimanually with or without comparable passive movements of the contralateral hand. The main findings were the following. 1) Contralateral passive movements during unimanual active movements induced phase entrainment to interlimb phasing of either 0° (in-phase) or 180° (antiphase). 2) Entrainment strength increased with the passive movements' amplitude, but was similar for in-phase and antiphase movements. 3) Coordination of unimanual active movements with passive movements of the contralateral hand (kinesthetic tracking) was characterized by similar bilateral EMG activity as observed in active bimanual coordination. 4) During kinesthetic tracking the timing of the movements of the active hand was modulated by afference-based error corrections, which were more pronounced during in-phase coordination. 5) Indications of in-phase coordination being more stable than antiphase coordination were most prominent during active bimanual coordination and marginal during kinesthetic tracking. Together the results indicated that phase entrainment by contralateral afference contributed equally to the stability of in-phase and antiphase coordination, and that differential stability of these patterns depended predominantly on integrated timing of feedforward signals, with only a minor role for afference-based error corrections.

Investigation of sustainability of lubricated journal bearing under relevant design parameters

2018 ◽  
Vol 70 (4) ◽  
pp. 789-804 ◽  
Author(s):  
M.M. Shahin ◽  
Mohammad Asaduzzaman Chowdhury ◽  
Md. Arefin Kowser ◽  
Uttam Kumar Debnath ◽  
M.H. Monir
Keyword(s):  
Aspect Ratio ◽  
Elastic Strain ◽  
Journal Bearing ◽  
Design Parameters ◽  
Content Type ◽  
Computational Fluid Dynamics Cfd ◽  
Stress Formation ◽  
Bearing Design ◽  
The Stability ◽  
Bearing Friction

Purpose The purposes of the present study are to ensure higher sustainability of journal bearings under different applied loads and to observe bearing performances such as elastic strain, total deformation and stress formation. Design/methodology/approach A journal bearing test rig was used to determine the effect of the applied load on the bearing friction, film thickness, lubricant film pressure, etc. A steady-state analysis was performed to obtain the bearing performance. Findings An efficient aspect ratio (L/D) range was obtained to increase the durability or the stability of the bearing while the bearing is in the working condition by using SAE 5W-30 oil. The results from the study were compared with previous studies in which different types of oil and water, such as Newtonian fluid (NF), magnetorheological fluid (MRF) and nonmagnetorheological fluid (NMRF), were used as the lubricant. To ensure a preferable aspect ratio range (0.25-0.50), a computational fluid dynamics (CFD) analysis was conducted by ANSYS; the results show a lower elastic strain and deformation within the preferable aspect ratio (0.25-0.50) rather than a higher aspect ratio using the SAE 5W-30 oil. Originality/value It is expected that the findings of this study will contribute to the improvement of the bearing design and the bearing lubricating system.

Dynamic modeling and design of controller for the 2-DoF serial chain actuated by a cable-driven robot based on feedback linearization

2021 ◽  
pp. 095440622110279
Author(s):  
Vahid Bahrami ◽  
Ahmad Kalhor ◽  
Mehdi Tale Masouleh
Keyword(s):  
Dynamic Modeling ◽  
Pid Controller ◽  
Feedback Linearization ◽  
Tracking Error ◽  
Pid Controllers ◽  
Serial Chain ◽  
Simulation Results ◽  
The Stability ◽  
Feedback Linearization Approach ◽  
Bounded Disturbance

This study intends to investigate a dynamic modeling and design of controller for a planar serial chain, performing 2-DoF, in interaction with a cable-driven robot. The under study system can be used as a rehabilitation setup which is helpful for those with arm disability. The latter goal can be achieved by applying the positive tensions of the cable-driven robot which are designed based on feedback linearization approach. To this end, the system dynamics formulation is developed using Lagrange approach and then the so-called Wrench-Closure Workspace (WCW) analysis is performed. Moreover, in the feedback linearization approach, the PD and PID controllers are used as auxiliary controllers input and the stability of the system is guaranteed as a whole. From the simulation results it follows that, in the presence of bounded disturbance based on Roots Mean Square Error (RMSE) criteria, the PID controller has better performance and tracking error of the 2-DoF robot joints are improved 15.29% and 24.32%, respectively.

Energy Shaping Control of Electrostatic Membrane Vibrations

1999 ◽  
Author(s):  
Andreas Kugi ◽  
Kurt Schlacher ◽  
Manfred Kaltenbacher ◽  
Reinhard Lerch
Keyword(s):  
Nonlinear Distortion ◽  
Supply Voltage ◽  
Mathematical Formulation ◽  
Voltage Source ◽  
Membrane Electrode ◽  
Closed Loop System ◽  
Feedback Controllers ◽  
Electrostatic Transducers ◽  
Membrane Vibrations ◽  
The Mathematical Model

Abstract A strong analytical mathematical formulation of electrostatic transducers is the necessary prerequisite for the design of feedback controllers. Based on the theory of Hamiltonian systems the mathematical model of a typical electrostatic transducer configuration with a moving membrane electrode and a rigid backplate electrode is derived. It is a well known fact that an increase in the sensitivity of the transducer often brings about also an increase in the nonlinear distortion and may occur a sticking of the membrane to the backplate electrode. In this paper, we propose a concept that gives a possible solution for these undesirable effects by using a controlled voltage source for the supply voltage of the transducer. The controller is designed by shaping the potential energy of the closed loop system. The change of the capacity of the transducer due to the motion of the membrane is considered as the sensor output.

Three-dimensional adaptive fixed-time guidance law against maneuvering targets with impact angle constraints and control input saturation

2021 ◽  
pp. 014233122110598
Author(s):  
Fei Ma ◽  
Yunjie Wu ◽  
Siqi Wang ◽  
Xiaofei Yang ◽  
Yueyang Hua
Keyword(s):  
Sliding Mode ◽  
Input Saturation ◽  
Three Dimensional ◽  
Fixed Time ◽  
Impact Angle ◽  
Guidance System ◽  
Control Input ◽  
Guidance Law ◽  
The Stability ◽  
And Control

This paper presents an adaptive fixed-time guidance law for the three-dimensional interception guidance problem with impact angle constraints and control input saturation against a maneuvering target. First, a coupled guidance model formulated by the relative motion equation is established. On this basis, a fixed-time disturbance observer is employed to estimate the lumped disturbances. With the help of this estimation technique, the adaptive fixed-time sliding mode guidance law is designed to accomplish accurate interception. The stability of the closed-loop guidance system is proven by the Lyapunov method. Simulation results of different scenarios are executed to validate the effectiveness and superiority of the proposed guidance law.

scholarly journals Aeroelastic Behavior of Low Aspect Ratio Metal and Composite Blades

1986 ◽  
Author(s):  
James F. White ◽  
Oddvar O. Bendiksen
Keyword(s):  
Aspect Ratio ◽  
Opposite Effect ◽  
Design Parameters ◽  
Aeroelastic Stability ◽  
Low Aspect Ratio ◽  
Supersonic Flutter ◽  
Type Mode ◽  
The Stability ◽  
Composite Blades ◽  
Plate Type

The aeroelastic stability of titanium and composite blades of low aspect ratio is examined over a range of design parameters, using a Rayleigh-Ritz formulation. The blade modes include a plate-type mode to account for chordwise bending. Chordwise flexibility is found to have a significant effect on the unstalled supersonic flutter of low aspect ratio blades, and also on the stability of tip sections of shrouded fan blades. For blades with a thickness of less than approximately four percent of chord, the chordwise, second bending, and first torsion branches are all unstable at moderately high supersonic Mach numbers. For composite blades, the important structural coupling between bending and torsion cannot be modeled properly unless chordwise bending is accounted for. Typically, aft fiber sweep produces beneficial bending-torsion coupling that is stabilizing, whereas forward fiber sweep has the opposite effect. By using crossed-ply laminate configurations, critical aeroelastic modes can be stabilized.

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