An Underactuated Manipulation Method Using a Mechanical Gravity Canceller

2004 ◽  
Vol 16 (6) ◽  
pp. 563-569 ◽  
Author(s):  
Yoshiki Ono ◽  
◽  
Toshio Morita
Keyword(s):  
Equilibrium Points ◽  
Experimental Results ◽  
Active Joint ◽  
Underactuated Manipulator ◽  
Active Base

This paper propose a method, to stabilize the arbitrary posture of a distal link by generating and erasing equilibrium points in passive joints of a vertical planar underactuated manipulator with an active joint in the base. A vertical planar three-DOF manipulator combining a passive two-DOF mechanical gravity canceller and an active base joint was developed. Experimental results demonstrate the effectiveness of this method.

Vertical Planar Underactuated Manipulation Using a Gravity Compensation Mechanism

2005 ◽  
Vol 17 (5) ◽  
pp. 553-559 ◽  
Author(s):  
Yoshiki Ono ◽  
◽  
Toshio Morita ◽  
Keyword(s):  
Degrees Of Freedom ◽  
Position Control ◽  
Equilibrium Points ◽  
Gravity Compensation ◽  
Compensation Mechanism ◽  
Angular Variation ◽  
Underactuated Manipulator ◽  
Zero Equilibrium ◽  
Three Degrees Of Freedom ◽  
Active Base

We propose generating and erasing equilibrium points for passive joints, together with an underactuated manipulator having both vertical and horizontal planar type. This manipulator implements three degrees of freedom (DOF) by combining a passive two-DOF mechanical gravity canceller and an active base joint. Equilibrium points are erased and adjusted by angular variation of the base joint so equilibrium points are erased when gravity torque is zero. If gravity torque is not zero, equilibrium points depend on angular variation of the base joint. Experimental results show position control of the distal link through the mechanical gravity canceller is effective for underactuated manipulation.

scholarly journals Hyperchaotic Circuit Based on Memristor Feedback with Multistability and Symmetries

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Xiaoyuan Wang ◽  
Xiaotao Min ◽  
Pengfei Zhou ◽  
Dongsheng Yu
Keyword(s):  
Theoretical Analysis ◽  
Dynamic Analysis ◽  
Chaotic System ◽  
Equilibrium Points ◽  
Experimental Results ◽  
System Dynamic ◽  
Hyperchaotic System ◽  
Analogue Circuits

A novel hyperchaotic circuit is proposed by introducing a memristor feedback in a simple Lorenz-like chaotic system. Dynamic analysis shows that it has infinite equilibrium points and multistability. Additionally, the symmetrical coexistent attractors are investigated. Further, the hyperchaotic system is implemented by analogue circuits. Corresponding experimental results are completely consistent with the theoretical analysis.

Trajectory Tracking of Underactuated Manipulator Using Fuzzy Method

2013 ◽  
Vol 791-793 ◽  
pp. 643-646
Author(s):  
Qi Xiao Xia ◽  
Yue Qing Yu ◽  
Zhang Yu
Keyword(s):  
Numerical Simulation ◽  
Trajectory Tracking ◽  
Control Method ◽  
Fuzzy Controller ◽  
Membership Functions ◽  
Active Joint ◽  
Motion Error ◽  
Passive Joint ◽  
Underactuated Manipulator ◽  
Joint Dynamics

Control of Underactuate manipulator is a challenge. A fuzzy control method is presented to control a three DOFs underactuated manipulator with the last joint passive. Using the redundancy DOF, the base joint was assigned a motion plan. The second active joint is planed and controlled to compose the base joint dynamics to drive the last passive joint moving. So, the motion error of the joint 1 neednt be cared about. The fuzzy controller was designed based on measures errors between the tracked trajectory and desired trajectory. Gaussian membership functions are used for fuzzification of the error inputs and defuzzification of reasoning results. Numerical simulation on tracking of circle arc was implemented for verification of the presented fuzzy controller.

Design of Grid Multiscroll Chaotic Attractors via Transformations

2015 ◽  
Vol 25 (10) ◽  
pp. 1530027 ◽  
Author(s):  
Xingxing Ai ◽  
Kehui Sun ◽  
Shaobo He ◽  
Huihai Wang
Keyword(s):  
Numerical Simulation ◽  
Lyapunov Exponent ◽  
Theoretical Analysis ◽  
Experimental Verification ◽  
Equilibrium Points ◽  
Experimental Results ◽  
Chaotic Attractors ◽  
Largest Lyapunov Exponent ◽  
One Dimensional ◽  
Circular Grid

Three transformation approaches for generating grid multiscroll chaotic attractors are presented through theoretical analysis and numerical simulation. Three kinds of grid multiscroll chaotic attractors are generated based on one-dimensional multiscroll Chua system. The dynamics of the multiscroll chaotic attractors are analyzed by means of equilibrium points, eigenvalues, the largest Lyapunov exponent and complexity. As the experimental verification, we implemented the circular grid multiscroll attractor on DSP platform. The simulation and experimental results are consistent well with that of theoretical analysis, and it shows that the design approaches are effective.

Modeling and Identification of Inelastic Systems Using the Endochronic Model

1998 ◽  
Vol 65 (2) ◽  
pp. 513-518 ◽  
Author(s):  
Dar-Yun Chiang
Keyword(s):  
Parameter Estimation ◽  
Biaxial Tension ◽  
Equilibrium Points ◽  
Estimation Procedure ◽  
Experimental Results ◽  
Modeling Technique ◽  
Practical Applications ◽  
Modeling Process ◽  
Parameter Estimation Procedure ◽  
Systematic Optimization

An effective modeling method is proposed for the endochronic model based on the concept of plastic equilibrium points, which reduces the number of parameters involved and greatly simplifies the modeling process for practical applications. A systematic, optimization-based parameter estimation procedure for the proposed class of endochronic models is also presented for identification studies. Validity of the proposed modeling technique in both modeling and identification of inelastic systems is demonstrated by biaxial tension-torsion applications using experimental results available in the literature.

Motion Control of Three Link Underactuated Manipulator by Bifurcation Control

2014 ◽  
Author(s):  
Hiroshi Yabuno ◽  
Kazuya Endo
Keyword(s):  
Feedback Control ◽  
Motion Control ◽  
Multiple Scales ◽  
Equilibrium Points ◽  
Pitchfork Bifurcation ◽  
Upright Position ◽  
State Feedback Control ◽  
Vertical Excitation ◽  
Underactuated Manipulator ◽  
Pitchfork Bifurcations

Motion control of a three link underactuated manipulator, whose first joint has an actuator and a sensor and second and third joints do not have actuator or sensor, is theoretically proposed without feedback control with respect to the motion of the free links. By using high-frequency vertical excitation, so called Kapitza pendulum is stabilized at the upright position without state feedback control. The phenomenon can be regarded as a subcritical pitchfork bifurcation. On the other hand, it is known that the horizontal excitation causes supercritical pitchfork bifurcation in a pendulum. Also, the inclination of excitation from the horizontal and vertical directions produces the perturbation of the complete supercritical and subcritical pitchfork bifurcations, respectively. In this paper, we apply the method of multiple scales to obtain the averaged equations governing the motion of the free links. We perform the bifurcation analysis of the free links and clarify the equilibrium points in the free links and their stability. Then, we propose a strategy to swing up the free links and to stabilize them at the upright position by actuating the perturbation of the pitchfork bifurcations based on the change of the inclination of excitation.

Derivation and Experimental Validation of the Equations of Motion of Magnetic Pendulums

2021 ◽  
pp. 1-7
Author(s):  
Razieh Saeidi Hosseini ◽  
Glenn R. Heppler ◽  
Eihab Abdel-Rahman
Keyword(s):  
Social Networks ◽  
Experimental Validation ◽  
Equilibrium Points ◽  
Equations Of Motion ◽  
Experimental Results ◽  
Quantum Communications

Abstract A series of coaxial magnetic pendulums is studied as a simple physical surrogate for more general nonlinearly-coupled almost-identical resonators that arise in quantum communications and the dynamics of social networks. The equations of motion for a series of coaxial magnetic pendulums are derived and the solution is compared to experimental results. The equilibrium points and their stability are also determined.

Chaos Suppression Of An Underactuated Manipulator: Experimental Results

2004 ◽  
Vol 2 (1) ◽  
pp. 19-24 ◽  
Author(s):  
O.P. Mejia ◽  
Jaime A. Gallegos ◽  
Joaquin A. Gallegos
Keyword(s):  
Experimental Results ◽  
Chaos Suppression ◽  
Underactuated Manipulator

Swing-Up Control of a Three-Link Underactuated Manipulator by High-Frequency Horizontal Excitation

2012 ◽  
Vol 8 (1) ◽  
Author(s):  
Kazuya Endo ◽  
Hiroshi Yabuno
Keyword(s):  
High Frequency ◽  
Multiple Scales ◽  
Equilibrium Points ◽  
Equations Of Motion ◽  
Excitation Frequency ◽  
Averaged Equations ◽  
Underactuated Manipulator ◽  
High Frequency Excitation ◽  
Pitchfork Bifurcations ◽  
The Stability

In the present paper, we consider a three-link underactuated manipulator, the first joint of which is active and the second and third joints of which exhibit passive motion, on a plane inclined at slight angle from horizontal the plane. We analytically investigate changes in the stability of equilibrium points of the free links connected to the passive joints using high-frequency horizontal excitation of the first link. We derive autonomous averaged equations from the dimensionless equations of motion using the method of multiple scales. We clarify that the two free links can be swung up through pitchfork bifurcations and stabilized at some configurations by producing nontrivial and stable equilibrium points due to the high-frequency excitation. Furthermore, it is experimentally verified that increasing the excitation frequency multiplies stable and nontrivial equilibrium points.

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