Finite Element-Based Control of a Single-Link Flexible Hydraulic Manipulator

2017 ◽  
Author(s):  
Petri Mäkinen ◽  
Jouni Mattila
Keyword(s):  
Finite Element ◽  
Controller Design ◽  
Hydraulic Cylinder ◽  
Flexible Manipulator ◽  
Flexible Link ◽  
Hydraulic Actuator ◽  
Single Link ◽  
Dynamics And Control ◽  
The Stability ◽  
And Control

In this study, a stability-guaranteed, nonlinear, finite element-based control is presented for a single-link flexible manipulator with hydraulic actuation, subject to experimental validation. The strong, inherent nonlinearities of the hydraulic cylinder and fluid dynamics, coupled with flexible link dynamics, cause remarkable challenges in controlling the system effectively. In an attempt to cope with these challenges, a controller based on the Virtual Decomposition Control (VDC) approach is introduced. The VDC approach takes advantage of subsystem-dynamics-based control, enabling the handling of the dynamics and control of the hydraulic actuator and the flexible link separately, thus keeping the controller design relatively simple. The rigorous stability theory of the VDC approach guarantees the stability of the entire system. The experiments demonstrate the VDC controller’s performance in end-point control with built-in vibration dampening.

A Finite Element Approach for Single-Link Flexible Manipulator

2013 ◽  
Vol 347-350 ◽  
pp. 453-456
Author(s):  
Jing Yuan Shi ◽  
Kai Jun Ji ◽  
Yan Kun Tang ◽  
Kun Yang
Keyword(s):  
Finite Element ◽  
Equations Of Motion ◽  
Energy Approach ◽  
Flexible Manipulator ◽  
Flexible Link ◽  
Finite Element Approach ◽  
Single Link ◽  
Element Approach

Many researchers have studied the dynamics of the single-link flexible manipulator. A finite element approach is used in this study to describe the dynamics of the flexible link. The displacement of any point on the link is described in terms of modal displacements. Energy approach is used to formulate the equations of motion.

Vibration Control of a Flexible Link Manipulator Using an Array of Fiber-Optic Curvature Sensors and Piezoelectric Actuators

2007 ◽  
Author(s):  
Kerem Gurses ◽  
Bradley J. Buckman ◽  
Edward J. Park
Keyword(s):  
Motion Control ◽  
Sensor Array ◽  
Fiber Optic ◽  
Element Model ◽  
Flexible Manipulator ◽  
Flexible Link ◽  
Velocity Feedback ◽  
Lyapunov Approach ◽  
Single Link ◽  
Actuator Control

This paper presents a novel feedback sensing approach for actively suppressing vibrations of a single-link flexible manipulator. Slewing of the flexible link by a rotating hub induces vibrations in the link that persist long after the hub stops rotating. These vibrations are suppressed through a combined scheme of PD-based hub motion control and proposed piezoelectric (PZT) actuator control, which is a composite linear and velocity feedback controller. Lyapunov approach was used to synthesize the controller based on a finite element model of the system. Its realization was possible due to the availability of both linear and angular velocity feedback provided by a unique, commercially-available fiber optic curvature sensor array, called ShapeTape™. It is comprised of an array of fiber optic curvature sensors, laminated on a long, thin ribbon tape, geometrically arranged in such a way that, when it is embedded into the flexible link, the bend and twist of the link’s centerline can be measured. Experimental results show the effectiveness of the proposed approach.

Detailed Dynamic Modelling of an Integrated Hydraulic Actuator

2020 ◽  
Author(s):  
Dom Wilson ◽  
Ioannis Georgilas ◽  
Andrew Plummer ◽  
Pejman Iravani ◽  
Dhinesh Sangiah
Keyword(s):  
High Performance ◽  
Dynamic Modelling ◽  
Flow Characteristics ◽  
Hydraulic Cylinder ◽  
Theoretical Development ◽  
Hydraulic Actuator ◽  
Pressure Losses ◽  
Low Leakage ◽  
Smart Actuator ◽  
And Control

Abstract Hydraulic servos are characterised by their high-performance nature but due to their size and weight are not suitable for robotics where new legged applications require high power density and excellent dynamic behaviour in a small size. As an answer to this need a new class of integrated smart actuators is being developed. These systems consist of a servo valve, hydraulic cylinder, sensors and a controller all in a single device. This paper outlines the detailed modelling of the smart actuator for use in simulation and control design. The result is a model consisting of the dynamics of the novel ultra-low leakage servovalve, the valve flow characteristics considering the properties of each spool land, the single-ended cylinder with friction and the pressure losses in the supply and return lines to the actuator. The models are a combination of empirical and theoretical development, validated with experimental data. The smart actuator’s unique properties; compactness, weight and efficiency, combined with high-performance hydraulics make it well suited to mobile robot applications.

Electrospinning Nanofibers: Measurements, Dynamics, and Control Strategy Development

2014 ◽  
Author(s):  
Yunshen Cai ◽  
Michael Gevelber
Keyword(s):  
Controller Design ◽  
Fiber Diameter ◽  
Operating Regime ◽  
Strategy Development ◽  
Process Conditions ◽  
Control Approach ◽  
Process Dynamics ◽  
Wide Range ◽  
Dynamics And Control ◽  
And Control

Electrospinning produces submicron fibers for a variety of applications using a wide range of polymers. Achieving the desired fiber diameter, maximizing productivity, and minimizing variation are important production objectives. This paper addresses several important areas needed to develop a general electrospinning control approach including: developing a correlation between measurements, process conditions, and the resulting fiber diameter, developing a method to determine an operating regime that meets manufacturing objectives, and identifying process dynamics for controller design.

A Comparative, Experimental Study of Model Suitability to Describe Vehicle Rollover Dynamics for Control Design

2005 ◽  
Author(s):  
John T. Cameron ◽  
Sean Brennan
Keyword(s):  
Experimental Validation ◽  
Controller Design ◽  
Experimental Testing ◽  
Control Strategies ◽  
Control Design ◽  
Experimental Results ◽  
Dynamics And Control ◽  
Vehicle Rollover ◽  
And Control ◽  
Future Work

This work presents results of an initial investigation into models and control strategies suitable to prevent vehicle rollover due to untripped driving maneuvers. Outside of industry, the study of vehicle rollover inclusive of both experimental validation and practical controller design is limited. The researcher interested in initiating study on rollover dynamics and control is left with the challenging task of identifying suitable vehicle models from the literature, comparing these models with experimental results, and determining suitable parameters for the models. This work addresses these issues via experimental testing of published models. Parameter estimation data based on model fits is presented, with commentary given on the validity of different methods. Experimental results are then presented and compared to the output predicted by the various models in both the time and frequency domain in order to provide a foundation for future work.

scholarly journals A unified approach to rigid body rotational dynamics and control

2011 ◽  
Vol 468 (2138) ◽  
pp. 395-414 ◽  
Author(s):  
Firdaus E. Udwadia ◽  
Aaron D. Schutte
Keyword(s):  
Rigid Body ◽  
Closed Form ◽  
Equations Of Motion ◽  
Fundamental Equation ◽  
Rotational Dynamics ◽  
Constrained Motion ◽  
Dynamics And Control ◽  
Common Framework ◽  
The Stability ◽  
And Control

This paper develops a unified methodology for obtaining both the general equations of motion describing the rotational dynamics of a rigid body using quaternions as well as its control. This is achieved in a simple systematic manner using the so-called fundamental equation of constrained motion that permits both the dynamics and the control to be placed within a common framework. It is shown that a first application of this equation yields, in closed form, the equations of rotational dynamics, whereas a second application of the self-same equation yields two new methods for explicitly determining, in closed form, the nonlinear control torque needed to change the orientation of a rigid body. The stability of the controllers developed is analysed, and numerical examples showing the ease and efficacy of the unified methodology are provided.

Robust Stabilization of Large Amplitude Ship Rolling in Beam Seas

1997 ◽  
Vol 122 (1) ◽  
pp. 108-113 ◽  
Author(s):  
Shyh-Leh Chen ◽  
Steven W. Shaw ◽  
Hassan K. Khalil ◽  
Armin W. Troesch
Keyword(s):  
Large Amplitude ◽  
Controller Design ◽  
Sliding Mode ◽  
Robust Stabilization ◽  
Vertical Plane ◽  
Singularly Perturbed Systems ◽  
Strongly Nonlinear ◽  
Beam Seas ◽  
Dynamics And Control ◽  
And Control

The dynamics and control of a strongly nonlinear 3-DOF model for ship motion are investigated. The model describes the roll, sway, and heave motions occurring in a vertical plane when the vessel is subjected to beam seas. The ship is installed with active antiroll tanks as a means of preventing large amplitude roll motions. A robust state feedback controller for the pumps is designed that can handle model uncertainties, which arise primarily from unknown hydrodynamic loads. The approach for the controller design is a combination of sliding mode control and composite control for singularly perturbed systems, with the help of the backstepping technique. It is shown that this design can effectively control roll motions of large amplitude, including capsize prevention. Numerical simulation results for an existing fishing vessel, the twice-capsized Patti-B, are used to verify the analysis. [S0022-0434(00)02701-5]

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 Pid Controller Design for Multiple Time Delays System

2021 ◽  
Vol 15 ◽  
pp. 121-127
Author(s):  
Asma Karoui ◽  
Rihem Farkh ◽  
Moufida Ksouri
Keyword(s):  
Pid Controller ◽  
Time Delays ◽  
Controller Design ◽  
Multiple Time ◽  
Multiple Time Delays ◽  
Pid Controller Design ◽  
The Stability ◽  
And Control ◽  
Time Invariant

This paper presents an approach of stabilization and control of time invariant linear system of an arbitrary order that include several time delays. In this work, the stability is ensured by PI, PD and PID controller. The method is analytical and needs the knowledge of transfer function parameters of the plant. It permits to find stability region by the determination of p K , i K and d K gains.

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