Control of a Class of Manipulators With a Single Flexible Link: Part I—Feedback Linearization

1991 ◽  
Vol 113 (4) ◽  
pp. 655-661 ◽  
Author(s):  
D. Wang ◽  
M. Vidyasagar
Keyword(s):  
Feedback Linearization ◽  
Degrees Of Freedom ◽  
Input State ◽  
Asymptotically Stable ◽  
Input Output ◽  
Flexible Link ◽  
State Equations ◽  
The Subject ◽  
Three Degrees Of Freedom ◽  
Linearization Techniques

The subject of this paper is the feedback linearization of the input-output and input-state equations for a class of multi-link, three degrees-of-freedom manipulators with the last link flexible. This class includes the 5-bar-linkage and the elbow manipulator. It is shown that the input-output equations are only feedback linearizable if the output variables are chosen appropriately. However, the nonlinear dynamics made unobservable by this feedback are not asymptotically stable which is a severe drawback. It is then shown that the input-state equations are not feedback linearizable. These results indicate that feedback linearization techniques are not appropriate for this class of manipulators. Thus, alternate methodologies should be explored. That issue is tackled in Part II.

scholarly journals Recent Developments on Modeling for a 3-DOF Micro-Hand Based on AI Methods

Micromachines ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 792
Author(s):  
Shuhei Kawamura ◽  
Mingcong Deng
Keyword(s):  
Artificial Intelligence ◽  
Degrees Of Freedom ◽  
Air Pressure ◽  
Support Vector ◽  
Input Output ◽  
Soft Actuator ◽  
Flexible Materials ◽  
Recent Developments ◽  
Soft Actuators ◽  
Three Degrees Of Freedom

Recently, soft actuators have been expected to have many applications in various fields. Most of the actuators are composed of flexible materials and driven by air pressure. The 3-DOF micro-hand, which is a kind of soft actuator, can realize a three degrees of freedom motion by changing the applied air pressure pattern. However, the input–output relation is nonlinear and complicated. In previous research, a model of the micro-hand was proposed, but an error between the model and the experimental results was large. In this paper, modeling for the micro-hand is proposed by using multi-output support vector regression (MSVR) and ant colony optimization (ACO), which is one of the artificial intelligence (AI) methods. MSVR estimates the input–output relation of the micro-hand. ACO optimizes the parameters of the MSVR model.

Trajectory Control of an Automated Guided Vehicle Using Feedback Linearization

2006 ◽  
Author(s):  
S. M. Mehdi Ansarey M. ◽  
M. J. Mahjoob
Keyword(s):  
Control System ◽  
Feedback Linearization ◽  
Degrees Of Freedom ◽  
Automated Guided Vehicle ◽  
State Variables ◽  
Discrete Curvatures ◽  
Steering Mechanism ◽  
Dynamics And Control ◽  
And Control ◽  
Three Degrees Of Freedom

In this paper, the dynamics and control of an automated guided vehicle (AGV) is described. The objective is to control the vehicle direction and location with respect to a prescribed trajectory. This is accomplished based on an optimum control strategy using vehicle state variables. A four-wheel vehicle with three degrees of freedom including longitudinal, lateral and yaw motion is considered. The nonlinearity of the tire and steering mechanism is also included. The control system design for circular, straight forward and composite path is presented based on feedback linearization. Some trajectory simulation for discrete curvatures is carried out. The controller was implemented within MATLAB environment. The design was also evaluated using ADAMS full vehicle assembly. The results demonstrated the accuracy of the model and the effectiveness of the developed control system.

Design and Implementation of a Binary Redundant Manipulator With Cascaded Modules1

2015 ◽  
Vol 8 (1) ◽  
Author(s):  
Emmanouil Tzorakoleftherakis ◽  
Anastasia Mavrommati ◽  
Anthony Tzes
Keyword(s):  
Computational Complexity ◽  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Redundant Manipulator ◽  
Stable States ◽  
Design And Implementation ◽  
Serial Robot ◽  
The Subject ◽  
Forward And Inverse Kinematics ◽  
Three Degrees Of Freedom

The subject of this paper is the design and implementation of a prototype snakelike redundant manipulator. The manipulator consists of cascaded modules eventually forming a macroscopically serial robot and is powered by shape memory alloy (SMA) wires. The SMAs (NiTi) act as binary actuators with two stable states and as a result, the repeatability of the manipulator's movement is ensured, alleviating the need for complex feedback sensing. Each module is composed of a customized spring and three SMA wires which form a tripod with three degrees of freedom (DOFs). Embedded microcontrollers networked with the I2C protocol activate the actuators of each module individually. In addition, we discuss certain design aspects and propose a solution that deals with the limited absolute stroke achieved by SMA wires. The forward and inverse kinematics of the binary manipulator are also presented and the tradeoff between maneuverability and computational complexity is specifically addressed. Finally, the functionality and maneuverability of this design are verified in simulation and experimentally.

A Methodology for Automatically Deriving Simple Electromechanical Equivalent Models from FEM-Models

2006 ◽  
Vol 113 ◽  
pp. 1-6
Author(s):  
Rafal Król ◽  
Michael Brökelmann ◽  
Jörg Wallaschek
Keyword(s):  
Equivalent Circuit ◽  
Degrees Of Freedom ◽  
State Space Model ◽  
Structural Response ◽  
Input Output ◽  
Element Analysis ◽  
Limited Bandwidth ◽  
Numeric Solution ◽  
The Subject ◽  
Dynamics Problems

FEM is a very important tool for getting the numerical solution of many engineering problems. It has been widely used in solving structural, mechanical, heat transfer, and fluid dynamics’ problems as well as problems of other disciplines such as piezoelectricity. Since the complexity of many problems leads to the formation of models of large dimension, which are described with many degrees of freedom, their numeric solution makes for the highest demands. The number of degrees of freedom is often unnecessarily large to represent the structural response in a limited bandwidth and therefore, in such a case, a reduction should be conducted. The systematic reduction of complex FE models on simple electromechanical equivalent circuit models (with less mechanical degrees of freedom) is the subject of this paper. The aim of the work is to make the reduction in such a way that the characteristics of the systems input/output descriptions are approximated within a pre-selectable frequency range with sufficient accuracy. A transducerwedge- system is used as an example for the method, to extract a state space model of the systems piezoelectric input/output description and to derive the parameters of the electromechanical equivalent circuit directly from the modal finite element analysis. In the present paper we describe the general methodology as well as its application to piezoelectric transducers as used in ultrasonic engineering.

Approximate Input-Output Feedback Linearization of Non-Minimum Phase System using Vanishing Perturbation Theory

2015 ◽  
pp. 173-201
Author(s):  
Monia Charfeddine ◽  
Khalil Jouili ◽  
Naceur Benhadj Braiek
Keyword(s):  
Perturbation Theory ◽  
Output Feedback ◽  
Feedback Linearization ◽  
Main Idea ◽  
Input State ◽  
Phase System ◽  
Minimum Phase ◽  
Input Output ◽  
Approximate System ◽  
System Input

The inverse of a non-minimum-phase system being unstable, standard input-output feedback linearization is not effective to control such systems. In this chapter is a presentation of a new tracking control method for the nonlinear non-minimum-phase system. Indeed, the main idea here is to dismiss a part of system dynamics in order to make the approximate system input-state feedback linearizable. The neglected part is then considered as a perturbation part that vanishes at the origin. Finally, a linear controller is designed to control the approximate system. Stability is analyzed using the vanishing perturbation theory. The efficacy and usage of the proposed approach is evaluated in an illustrative inverted cart-pendulum example.

Mobility and singularity analyses of a symmetric multi-loop mechanism for space applications

2021 ◽  
pp. 095440622199555
Author(s):  
Chuanyang Li ◽  
Jorge Angeles ◽  
Hongwei Guo ◽  
Huiyin Yan ◽  
Dewei Tang ◽  
...  
Keyword(s):  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Singularity Analysis ◽  
Space Applications ◽  
Aerospace Applications ◽  
Constraint Analysis ◽  
Multi Stage ◽  
Prismatic Joints ◽  
The Subject ◽  
Three Degrees Of Freedom

A symmetric, double-tripod multi-loop mechanism (DTMLM), for aerospace applications, is the subject of this paper. Its mobility and singularity are analyzed, while introducing a novel tool, the cell-division method for singularity analysis, applicable to multi-loop mechanisms. The key principle of this method lies in replacing the singularity analysis of the original multi-loop mechanism with: (1) that of an equivalent simpler parallel mechanism; (2) the constraint analysis between loops; and (3) the singularity analysis of simpler kinematic subchains. Then, the mechanism is transformed into a simpler, equivalent parallel mechanism with three identical kinematic subchains. Its mobility and singularity are analyzed based on screw algebra, which leads to a key conclusion about the geometric properties of this mechanism. Results show that: (a) the DTMLM has three degrees of freedom (dof), i.e., two rotational dof around two intersecting axes lying in the middle plane of the mechanism, and one translational dof along the normal to the said plane (2R1T); and (b) the singularities of the 3-RSR parallel mechanism are avoided in the DTMLM by means of prismatic joints, singularities in the DTMLM occurring on the boundary of its workspace. Thus, the DTMLM has a 2R1T mobility everywhere within its workspace. When a set of multi-loop mechanisms of this kind are stacked as modules to assemble a multi-stage manipulator for space applications, the modules can be designed so that, under paradigm operations, all individual loops operate within their workspace, safe from singularities.

scholarly journals Active Disturbance Rejection for a Three Degrees of Freedom Gyroscope

2018 ◽  
Vol 51 (13) ◽  
pp. 372-377 ◽  
Author(s):  
Juan E. Andrade García ◽  
Alejandra Ferreira de Loza ◽  
Luis T. Aguilar ◽  
Ramón I. Verdés
Keyword(s):  
Disturbance Rejection ◽  
Degrees Of Freedom ◽  
Active Disturbance Rejection ◽  
Three Degrees Of Freedom
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