Effect of Payload on the Dynamics of a Flexible Manipulator—Modeling for Control

1991 ◽  
Vol 113 (3) ◽  
pp. 409-418 ◽  
Author(s):  
T. R. Parks ◽  
H. A. Pak
Keyword(s):  
Transfer Functions ◽  
Order Reduction ◽  
Qualitative Change ◽  
Flexible Manipulator ◽  
Flexible Beam ◽  
Model Order ◽  
Modeling And Control ◽  
Prior Literature ◽  
And Control ◽  
Substantial Change

The “exact” and pole/zero transfer functions are developed for a flexible beam-like single link arm with actuator on one end and payload on the other. This model represents a broader class of actuator hub and payload mass properties than is found in prior literature. The dependence of dynamics on the hub and payload inertia characteristics are studied and graphs are provided to facilitate estimation of poles and zeroes for any similar plant. It is shown that a 10:1 reduction in fundamental frequency and substantial change in the zeroes results from variations in payload through a practical range. Payload rotary inertia is shown to cause a qualitative change in the arm tip zeroes resulting in loss of observability/controllability in some cases. Results provide insight into the two-link problem and it is shown that complex values zeroes may result if the second arm is allowed to “fold back.” Implications to plant modeling and control design are discussed including sensor placement and model order reduction issues. Analytical results are compared to those measured on an experimental arm and show very good agreement in modal frequency and shape.

Three-state switching cell boost converter using H-inf controller

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Nivedita Pati ◽  
Babita Panda
Keyword(s):  
Model Order Reduction ◽  
Controller Design ◽  
Order Reduction ◽  
Boost Converter ◽  
Describing Function ◽  
Model Order ◽  
Modeling And Control ◽  
State Switching ◽  
Converter Topology ◽  
And Control

Abstract This paper presents the modeling and control of a non-minimum phase dc-dc boost converter based on the three - state switching cells. In any double stage grid-connected system the converter forms an interface between the photovoltaic source and the inverter. As the control and regulation of the converter output is a vital part of penetration of renewable to grid, therefore, this paper had attempted the control of a converter topology that can reduce the current stress across its switches. But the system becomes highly unstable and complex which has been validated by predicting the limit cycle with a describing function. The Controller design is implemented after reducing the complexity of the system using the Model order reduction principle. H-inf controller being robust in nature is applied for stable and regulated output.

scholarly journals A Generic Control-Oriented Model Order Reduction Approach for High Step-Up DC/DC Converters Based on Voltage Multiplier

Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1971
Author(s):  
Binxin Zhu ◽  
Qingdian Zeng ◽  
Mahinda Vilathgamuwa ◽  
Yang Li ◽  
Yao Chen
Keyword(s):  
Control System ◽  
System Design ◽  
Controller Design ◽  
Low Frequency ◽  
Order Reduction ◽  
Control System Design ◽  
Model Order ◽  
Modeling And Control ◽  
Simulation Results ◽  
And Control

The modeling and control system design of high step-up DC/DC converters based on voltage multipliers (VMs) are difficult, due to the various circuit topologies and the presence of large number of capacitors in VMs. This paper proposes a generic approach to reduce the model order of such converters by replacing the VM capacitors with voltage sources controlled by the output voltage of the converter. Theoretical analysis and simulation results show that the derived models can accurately represent the low frequency response of the converter which is valuable for obtaining a small-signal AC model for control system design. The detailed modeling and controller design process are demonstrated for the converter, and the obtained simulation results are verified experimentally on a 400 W prototype.

scholarly journals A Black-Box method for parametric model order reduction based on matrix interpolation with application to simulation and control

2016 ◽  
Vol 64 (9) ◽  
Author(s):  
Matthias Geuß
Keyword(s):  
Model Order Reduction ◽  
Order Reduction ◽  
Black Box ◽  
Design Parameters ◽  
Dimensional Parameter ◽  
Model Order ◽  
Parametric Model Order Reduction ◽  
Box Method ◽  
Matrix Interpolation ◽  
And Control

AbstractThis thesis deals with model order reduction of parameter-dependent systems based on interpolation of locally reduced system matrices. A Black-Box method is proposed that automatically determines the optimal design parameters and delivers a reduced system with desired accuracy. In addition, the method is extended to stability preservation and interpolation for high-dimensional parameter spaces.

Study on Variable Structure Vibration Control for Flexible Manipulator

2014 ◽  
Vol 875-877 ◽  
pp. 1961-1966
Author(s):  
Hui Jin Mu
Keyword(s):  
Variable Structure ◽  
Flexible Manipulator ◽  
Robot Arm ◽  
Dynamics Modeling ◽  
Space Robots ◽  
Modeling And Control ◽  
Depth Study ◽  
Operating Space ◽  
And Control ◽  
Dual Arm

In recent years, modeling and control of flexible space robots are extensively researched. Compared with traditional rigid robots, flexible robots have low energy consumption, wide operating space, high carrying capacity and other characteristics. However, due to its special structure, the robot arm will get deformation and vibration in motion, which brings a lot of problems to the positioning and tracking control of flexible space robots. Therefore, directing at the dynamics modeling and control issues of the free-floating flexible dual-arm space robots, this article carries out in-depth study. This paper first studies the elastic deformation and vibration of the flexible space manipulator and the robust control problem of the system trajectory tracking for free-floating flexible dual-arm space robots.

Influence of backlash in gear reducer on dynamic of single-link manipulator arm

Robotica ◽  
2014 ◽  
Vol 33 (08) ◽  
pp. 1671-1685 ◽  
Author(s):  
Jian-Wei Lu ◽  
Xiao-Ming Sun ◽  
Alexander F. Vakakis ◽  
Lawrence A. Bergman
Keyword(s):  
Dynamic Response ◽  
Dynamic Modeling ◽  
Excitation Frequency ◽  
Planetary Gear ◽  
Flexible Manipulator ◽  
Lumped Mass ◽  
Modeling And Control ◽  
Single Link ◽  
Manipulator Arm ◽  
And Control

SUMMARYThe dynamic modeling of a flexible single-link manipulator arm with consideration of backlash in the planetary gear reducer at the joint is presented, and the influence of backlash on the dynamic response of the system is evaluated. A 2K-H planetary gear reducer with backlash was employed as an example to discuss the dynamic modeling of the sub-model of the planetary gear reducer, and the sub-model of the planetary gear reducer was established based on the lumped mass method. The flexible manipulator was regarded as an Euler--Bernoulli beam, and the dynamic model of the flexible manipulator arm with backlash in the planetary gear reducer was determined from Lagrange's equations. Based on the this model, the influence of the backlash in the planetary gear reducer and excitation frequency on the dynamic response of the system were evaluated through simulation, and the results showed that the dynamic response of the system is sensitive to the backlash and the excitation frequency simultaneously, which provides a theoretical foundation for improvement of dynamic modeling and control of the flexible manipulator arm.

scholarly journals Behavioral Analysis of Various Techniques of Model Order Reduction Used in the Reduction of Large Scale Control System

2019 ◽  
Vol 9 (2) ◽  
pp. 4894-4899
Keyword(s):  
Transfer Function ◽  
Model Order Reduction ◽  
Large Scale ◽  
Transfer Functions ◽  
Order Approximation ◽  
Order Reduction ◽  
Higher Order ◽  
Reduction Technique ◽  
Order System ◽  
Model Order

It is very important task to study the behavior of the processes occurring in the industry. To attain this task, the knowledge of the transfer function of the system should be there. When working in robust environment, these transfer functions becomes so tedious that it becomes very difficult to obtain these transfer functions and hence affects the study of the behavior of these system. Due to this, the requirement for reduction of these transfer function becomes a necessity to analyze the behavior of foresaid systems and it becomes easy to do the desired modifications in the system i.e addition of any feature, desired changes in the behavior etc., furthermore the thing to be kept in consideration while doing the reduction in transfer function that the behavior viz. peak overshoot, settling time, steady state error of the two systems (reduced and the original system) should be approximately same, so it is prime importance that the applied model order reduction technique should provide a more accurate approximation of original higher order system. The paper presents here the different categories of model order reduction techniques that can be applied to achieve the motto of model order reduction of higher order systems. The techniques presented are categorized into the four different categories to understand them and their merits and demerits and these will help in proper selection of the model order reduction technique to obtain the most accurate reduced order approximation of large scale system.

Modeling and Control of a Novel Variable-Stiffness Regenerative Actuator

2018 ◽  
Author(s):  
Erivelton Gualter dos Santos ◽  
Hanz Richter
Keyword(s):  
Position Control ◽  
Lightweight Design ◽  
Variable Stiffness ◽  
Electrical Energy ◽  
Flexible Beam ◽  
Modeling And Control ◽  
Electromechanical Drive ◽  
Elastic Potential Energy ◽  
Mechanical Dynamics ◽  
And Control

This paper focuses on the design, modeling and basic control of a variable stiffness actuator to be used in combination with a regenerative electromechanical drive system. Due to the use of a flexible beam, the actuator has the ability to store and return elastic potential energy. Also, an ultracapacitor is used in the electromechanical drive, which allows electrical energy storage and return. Moreover, elastic and electrostatic energies can be exchanged, resulting in a highly efficient and lightweight design which will be beneficial for robotic prostheses, exoskeletons and other orthotic devices. The paper presents a model and calculation method for large beam deflections and the integrated electromechanical actuator model. A semiactive virtual control strategy is used to decouple the mechanical dynamics from the charge dynamics and achieve position control of the actuator. Simulation results are presented to illustrate the control system and the energy exchange features.

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