The Application Of Computer Algebra In Modelling And Vibration Control Of A Flexible Manipulator

2012 ◽  
Author(s):  
Z. Mohamed ◽  
A. A. Mohd Faudzi ◽  
M. N. Ahmad ◽  
Z. M Zain ◽  
A. W. I. Mohd Hashim
Keyword(s):  
Finite Element ◽  
Transfer Function ◽  
Vibration Control ◽  
Computer Algebra ◽  
Flexible Manipulator ◽  
Input Shaping ◽  
Control Scheme ◽  
Simulation Results ◽  
And Control ◽  
Symbolic Algorithm

Kertas kerja ini membentangkan aplikasi algebra computer utk pemodelan dan kawalan getaran sistem manipulator boleh ubah (flexible manipulator). Sebuah model berasaskan simbol menspesifikasikan sifat manipulator telah dibina menggunakan bahasa simbolik berasaskan finite element dan Lagrange. Menggunakan pendekatan ini, transfer function diperoleh dalam bentuk simbolik. Analisis dilaksanakan untuk mengkaji signifikan dan relasi pemboleh ubah fizikal manipulator boleh ubah tersebut dengan sistem tertentu termasuk poles, zeros, kestabilan, frekuensi getaran dan tertentu fasa non minimum sistem tersebut. Hasil akhir simbolik tersebut kemudian digunakan untuk mereka cipta input shaping getaran skema kawalan. Hasil akhir simulasi dari respons manipulator dibentangkan untuk mendemontrasi aplikasi algorithm dalam pemodelan dan kawalan sesebuah manipulator boleh ubah. Kata kunci: Algebra computer, manipulator boleh ubah, pemodelan, kawalan getaran This paper presents the application of computer algebra to modelling and vibration control of a flexible manipulator system. A symbolic–based model characterising the behaviour of the manipulator is developed using a symbolic language based on finite element and Lagrange methods. In this approach, the system transfer function is obtained in symbolic form. Analyses are carried out to investigate the significance and relations of the physical parameters of the flexible manipulator with the system characteristics including poles, zeros, stability, vibration frequencies and non-minimum phase characteristics of the system. The symbolic results are then used to design an effective input shaping vibration control scheme. Simulation results of the response of the manipulator are presented to demonstrate the application of the symbolic algorithm in modelling and control of a flexible manipulator. The symbolic results are then used to design an effective input shaping vibration control scheme. Simulation results of the response of the manipulator are presented to demonstrate the application of the symbolic algorithm in modelling and control of a flexible manipulator. Key words: Computer algebra; flexible manipulator; modelling; vibration control

Model development and control of an auto-refrigerated polystyrene polymerization reactor

2021 ◽  
pp. 014233122110251
Author(s):  
Reyhane Mokhtarname ◽  
Ali Akbar Safavi ◽  
Leonhard Urbas ◽  
Fabienne Salimi ◽  
Mohammad M Zerafat ◽  
...  
Keyword(s):  
Temperature Control ◽  
Model Development ◽  
Heat Removal ◽  
Superior Performance ◽  
Polymerization Process ◽  
Vacuum System ◽  
Control Scheme ◽  
Simulation Results ◽  
And Control ◽  
Operating Plant

Dynamic model development and control of an existing operating industrial continuous bulk free radical styrene polymerization process are carried out to evaluate the performance of auto-refrigerated CSTRs (continuous stirred tank reactors). One of the most difficult tasks in polymerization processes is to control the high viscosity reactor contents and heat removal. In this study, temperature control of an auto-refrigerated CSTR is carried out using an alternative control scheme which makes use of a vacuum system connected to the condenser and has not been addressed in the literature (i.e. to the best of our knowledge). The developed model is then verified using some experimental data of the real operating plant. To show the heat removal potential of this control scheme, a common control strategy used in some previous studies is also simulated. Simulation results show a faster dynamics and superior performance of the first control scheme which is already implemented in our operating plant. Besides, a nonlinear model predictive control (NMPC) is developed for the polymerization process under study to provide a better temperature control while satisfying the input/output and the heat exchanger capacity constraints on the heat removal. Then, a comparison has been also made with the conventional proportional-integral (PI) controller utilizing some common tuning rules. Some robustness and stability analyses of the control schemes investigated are also provided through some simulations. Simulation results clearly show the superiority of the NMPC strategy from all aspects.

A Robust Trajectory Tracking Control Scheme of Two-Link Flexible Manipulator

2011 ◽  
Vol 328-330 ◽  
pp. 2108-2112
Author(s):  
Jing Shuang Lu ◽  
Chun Mei Du ◽  
Rui Zhou ◽  
Na Li
Keyword(s):  
Trajectory Tracking ◽  
Tracking Control ◽  
Vertical Plane ◽  
Flexible Manipulator ◽  
System Model ◽  
Error Signal ◽  
Dynamics Model ◽  
Trajectory Tracking Control ◽  
Control Scheme ◽  
Simulation Results

A simple dynamics model is established based on the two-link flexible manipulator moving within the vertical plane, and a robust simple control scheme is put forward. The advantages of this scheme are simple and good robustness. Only the error signal is needed when designing the control scheme and the acquirement of control signal does not depend on the system model. The simulation results show that this method has a good robustness and stability.

scholarly journals Numerical and Experimental Study on Integration of Control Actions into the Finite Element Solutions in Smart Structures

2009 ◽  
Vol 16 (4) ◽  
pp. 401-415 ◽  
Author(s):  
L. Malgaca ◽  
H. Karagülle
Keyword(s):  
Finite Element ◽  
Vibration Control ◽  
Lead Zirconate Titanate ◽  
Smart Structures ◽  
Harmonic Excitation ◽  
Smart Structure ◽  
Displacement Sensor ◽  
Control Actions ◽  
First Case ◽  
Simulation Results

Piezoelectric smart structures can be modeled using commercial finite element packages. Integration of control actions into the finite element model solutions (ICFES) can be done in ANSYS by using parametric design language. Simulation results can be obtained easily in smart structures by this method. In this work, cantilever smart structures consisting of aluminum beams and lead-zirconate-titanate (PZT) patches are considered. Two cases are studied numerically and experimentally in parallel. In the first case, a smart structure with a single PZT patch is used for the free vibration control under an initial tip displacement. In the second case, a smart structure with two PZT patches is used for the forced vibration control under harmonic excitation, where one of the PZT patches is used as vibration generating shaker while the other is used as vibration controlling actuator. For the two cases, modal analyses are done using chirp signals; Control OFF and Control ON responses in the time domain are obtained for various controller gains. A non-contact laser displacement sensor and strain gauges are utilized for the feedback signals. It is observed that all the simulation results agree with the experimental results.

scholarly journals MIMO Active Vibration Control of Magnetically Suspended Flywheels for Satellite IPAC Service

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
Junyoung Park ◽  
Alan Palazzolo ◽  
Raymond Beach
Keyword(s):  
Vibration Control ◽  
Attitude Control ◽  
High Frequency ◽  
Active Vibration Control ◽  
Control Algorithms ◽  
Control Law ◽  
Frequency Noise ◽  
Active Vibration ◽  
Simulation Results ◽  
And Control

Theory and simulation results have demonstrated that four, variable speed flywheels could potentially provide the energy storage and attitude control functions of existing batteries and control moment gyros on a satellite. Past modeling and control algorithms were based on the assumption of rigidity in the flywheel’s bearings and the satellite structure. This paper provides simulation results and theory, which eliminates this assumption utilizing control algorithms for active vibration control (AVC), flywheel shaft levitation, and integrated power transfer and attitude control (IPAC), that are effective even with low stiffness active magnetic bearings (AMBs) and flexible satellite appendages. The flywheel AVC and levitation tasks are provided by a multiple input–multiple output control law that enhances stability by reducing the dependence of the forward and backward gyroscopic poles with changes in flywheel speed. The control law is shown to be effective even for (1) large polar to transverse inertia ratios, which increases the stored energy density while causing the poles to become more speed dependent, and for (2) low bandwidth controllers shaped to suppress high frequency noise. Passive vibration dampers are designed to reduce the vibrations of flexible appendages of the satellite. Notch, low-pass, and bandpass filters are implemented in the AMB system to reduce and cancel high frequency, dynamic bearing forces and motor torques due to flywheel mass imbalance. Successful IPAC simulation results are presented with a 12% initial attitude error, large polar to transverse inertia ratio (IP∕IT), structural flexibility, and unbalance mass disturbance.

scholarly journals Performance Of Hybrid Learning Control With Input Shaping For Input Tracking And Vibration Suppression Of A Flexible Manipulator

2012 ◽  
Author(s):  
M. Z. Md. Zain ◽  
M. O. Tokhi ◽  
Z. Mohamed
Keyword(s):  
Iterative Learning Control ◽  
Vibration Suppression ◽  
Hybrid Learning ◽  
Learning Control ◽  
Iterative Learning ◽  
Body Motion ◽  
Flexible Manipulator ◽  
Input Shaping ◽  
Control Input ◽  
Control Scheme

Objektif kertas kerja ini ialah untuk mengkaji keberkesanan gabungan pengawal pembelajaran berulang cerdik dan teknik pembentuk masukan bagi penjejakan masukan dan pengurangan getaran pada hujung suatu pengolah fleksibel. Model dinamik sistem tersebut diterbitkan menggunakan kaedah unsur terhingga. Pada permulaan, pengawal kadaran–kebezaan (PD) menggunakan sudut dan halaju hub direka bentuk untuk kawalan pergerakan badan tegar sistem. Kemudian, pengawal pembelajaran berulang dengan algoritma genetik dan pengawal suap hadapan berasaskan teknik pembentuk masukan ditambahkan untuk kawalan getaran sistem. Keputusan simulasi dalam domain masa dan frekuensi diberikan. Keberkesanan pengawal yang direka bentuk ini dikaji berasaskan penjejakan masukan dan kadar pengurangan getaran sistem. Keberkesanan pengawal ini untuk sistem pengolah fleksibel berbagai beban juga dikaji. Kata kunci: Pengolah fleksibel, algoritma genetik, kawalan cerdik, kawalan pembelajaran berulang, pembentukan masukan The objective of the work reported in this paper is to investigate the performance of an intelligent hybrid iterative learning control scheme with input shaping for input tracking and end–point vibration suppression of a flexible manipulator. The dynamic model of the system is derived using finite element method. Initially, a collocated proportional–derivative (PD) controller utilizing hub–angle and hub–velocity feedback is developed for control of rigid–body motion of the system. This is then extended to incorporate iterative learning control with genetic algorithm (GA) to optimize the learning parameters and a feedforward controller based on input shaping techniques for control of vibration (flexible motion) of the system. Simulation results of the response of the manipulator with the controllers are presented in time and frequency domains. The performance of hybrid learning control with input shaping scheme is assessed in terms of input tracking and level of vibration reduction. The effectiveness of the control schemes in handling various payloads is also studied. Key words: Flexible manipulator, genetic algorithms, intelligent control, iterative learning control, input shaping

Dynamic Analysis of Sandwich Beams Filled with ER Elastomers

2011 ◽  
Vol 50-51 ◽  
pp. 843-848 ◽  
Author(s):  
Quan Bai ◽  
Ke Xiang Wei ◽  
Wen Ming Zhang
Keyword(s):  
Finite Element ◽  
Electric Field ◽  
Vibration Control ◽  
Natural Frequencies ◽  
Flexible Structures ◽  
Sandwich Beam ◽  
Element Model ◽  
Sandwich Beams ◽  
Simulation Results ◽  
Er Fluids

Considered electrorheological (ER) elastomers as the visco-elasticity material, a finite element model of a sandwich beam filled with ER elastomers was developed based on Hamilton’s principle and sandwich beam’s theory. Then its dynamic characteristics were analyzed. Simulation results show that natural frequencies of the sandwich beam increase and vibration amplitudes of the beam decrease as the intensity of applied electric field increases. Increased the thickness of the ER elastomers layer, natural frequencies of the beam decrease and loss factors increase. Those indicate that the dynamic characteristic of ER elastomers sandwich beams is similar as that of ER fluids beam, which can be used for vibration control of flexible structures by applied a electric field.

Vibration Control of a Space Flexible Robot Manipulator Using PZT Actuators

2011 ◽  
Vol 66-68 ◽  
pp. 1142-1148 ◽  
Author(s):  
Jun Qiang Lou ◽  
Yan Ding Wei
Keyword(s):  
Control Strategy ◽  
Vibration Suppression ◽  
Robot Manipulator ◽  
Equations Of Motion ◽  
System Stability ◽  
Flexible Manipulator ◽  
Flexible Robot ◽  
Simulation Results ◽  
And Control ◽  
And Robotics

The dynamic analysis and control of flexible robot manipulators have been the main concerns of many recent studies in aeronautics and robotics. Moreover, the complexity of this problem increases when a flexible manipulator carries a payload. In this paper, we proposed a space two-link flexible manipulator with tip payload featuring surface-bonded piezoelectric torsional actuator and shear actuator. The equations of motion for the system are obtained using Hamilton’s principle. A Lyapunov-based controller is proposed to suppress the vibration of the system. Stability of the system is also investigated. The simulation results demonstrate the proposed control strategy is well suited for active control of vibration suppression on flexible manipulators.

Complementary data fusion in vision-guide and control of robotic tracking

Robotica ◽  
2001 ◽  
Vol 19 (1) ◽  
pp. 53-58 ◽  
Author(s):  
Y.M. Chen ◽  
C.S. Hsueh
Keyword(s):  
Neural Networks ◽  
Data Fusion ◽  
Moving Target ◽  
Robot Arm ◽  
End Effector ◽  
Robotic Tracking ◽  
Control Scheme ◽  
Simulation Results ◽  
And Control ◽  
Tracking Module

We present a data fusion control scheme for the hand-held camera of the SCORBOT-ER VII robot arm for learning visual tracking and interception. The control scheme consists of two modules: The first one generates candidate actions to drive the end-effector as accurate as possible directly above a moving target, so that the second module can handily take over to intercept it. The desired camera-joint coordinate mappings are generalized by Elman neural networks for a tracking module. The intercept module then determines a suitable intercept trajectory for the robot within the required conditions. The simulation results support the claim that it could be successfully applied to track and intercept a moving target.

On Aero Control Law Joined Compensatory PID for Glide down to Fixed Low Altitude System and Simulation Researches

2012 ◽  
Vol 198-199 ◽  
pp. 1021-1024
Author(s):  
De Hai Yu ◽  
Dong Cai Qu ◽  
Jian Hua Lu ◽  
Bin Wen Lu
Keyword(s):  
Control Law ◽  
Simple Analysis ◽  
Control Laws ◽  
Control Scheme ◽  
Improve Accuracy ◽  
Working Principle ◽  
Simulation Results ◽  
Low Altitude ◽  
Constant Altitude ◽  
And Control

In order to improve accuracy of constant altitude fly at low altitude and fly track of glide down to fixed altitude, aeroplane’s control scheme of glide down to fixed low altitude with PID compensatory link were designed. At the same time, the corresponding control laws had been designed. After simple analysis about working principle of the aeroplane’s control system, simulation researches were done to optimize designed control laws, so that achieving expectant requirement. Simulation results show that designed control scheme and control law were accurate and effective.

Distributed Modal Identification and Vibration Control of Continua: Piezoelectric Finite Element Formulation and Analysis

1991 ◽  
Vol 113 (3) ◽  
pp. 500-505 ◽  
Author(s):  
H. S. Tzou ◽  
C. I. Tseng
Keyword(s):  
Finite Element ◽  
Vibration Control ◽  
Rapid Development ◽  
Structural Identification ◽  
Modal Identification ◽  
Element Formulation ◽  
Sensors And Actuators ◽  
Integrated Sensor ◽  
Sensor Actuator ◽  
And Control

“Smart” continua with integrated sensor/actuator for structural identification and control have drawn much attention in recent years due to the rapid development of high-performance “smart” structures. The continua are distributed and flexible in nature. Thus, distributed dynamic measurement and active vibration control are of importance to their high-demanding performance. In this paper, continua (shells or plates) integrated with distributed piezoelectric sensors and actuators are studied using a finite element technique. A new piezoelectric finite element with internal degrees of freedom is derived. Two control algorithms, namely, constant gain feedback control and Lyapunov control, are implemented. Structural identification and control of a plate model with distributed piezoelectric sensor/actuator is studied. Distributed modal voltage and control effectiveness of mono and biaxially polarized piezoelectric actuators are evaluated.

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