Research on Nonlinear Dynamic Control Method of Two Degree of Freedom Redundantly Actuated Parallel Robot

In this work, a new control method for uncertain processes is developed based on two-degree-of-freedom control structure. The setpoint tracking controller designed by input/output linearization technique is used to regulate the disturbance-free output and the disturbance rejection controller designed is designed by high-gain technique. The advantage of two-degree-of-freedom control structure is that setpoint tracking and load disturbance rejection controllers can be designed separately. Open-loop observer is applied to provide disturbance-free response for setpoint tracking controller. The process/disturbance-free model mismatches are fed to the disturbance rejection controller for reducing effect of disturbance. To evaluate the control performance, the proposed control method is applied through the example of a continuous stirred tank reactor with unmeasured input disturbances and random noise kinetic parametric uncertainties. The simulation results show that both types of disturbances can be effectively compensated by the proposed control method.

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Performance Evaluation of a Two Degree of Freedom Micro Parallel Robot

2007 IEEE International Conference on Automation and Logistics ◽

10.1109/ical.2007.4339092 ◽

2007 ◽

Author(s):

Sergiu-Dan Stan ◽

Vistrian Maties ◽

Radu Balan

Keyword(s):

Performance Evaluation ◽

Parallel Robot ◽

Degree Of Freedom ◽

Two Degree Of Freedom

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IRSBot-2: A Novel Two-DOF Parallel Robot for High-Speed Operations

Volume 6: 35th Mechanisms and Robotics Conference, Parts A and B ◽

10.1115/detc2011-47564 ◽

2011 ◽

Cited By ~ 4

Author(s):

Coralie Germain ◽

Se´bastien Briot ◽

Victor Glazunov ◽

Ste´phane Caro ◽

Philippe Wenger

Keyword(s):

High Speed ◽

Parallel Robot ◽

Degree Of Freedom ◽

Kinematic Chains ◽

Robot Architecture ◽

Intrinsic Stiffness ◽

Two Degree Of Freedom

This paper presents a novel two-degree-of-freedom (DOF) translational parallel robot for high-speed applications named the IRSBot-2 (acronym for IRCCyN Spatial Robot with 2 DOF). Unlike most two-DOF robots dedicated to planar translational motions, this robot has two spatial kinematic chains which confers a very good intrinsic stiffness. First, the robot architecture is described. Then, its actuation and constraint singularities are analyzed. Finally, the IRSBot-2 is compared to its two-DOF counterparts based on elastostatic performances.

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Nonlinear Dynamic of Cantilever Functionally Graded Plates Under the Thermalmechanical Loads

Volume 15: Sound, Vibration and Design ◽

10.1115/imece2009-12382 ◽

2009 ◽

Author(s):

Yu-xin Hao ◽

Wei Zhang ◽

Jian-hua Wang

Keyword(s):

Nonlinear System ◽

Functionally Graded Materials ◽

Nonlinear Dynamic ◽

Equations Of Motion ◽

Functionally Graded ◽

Degree Of Freedom ◽

Mode Shapes ◽

Governing Equations ◽

Graded Materials ◽

Two Degree Of Freedom

An analysis on nonlinear dynamic of a cantilevered functionally graded materials (FGM) plate which subjected to the transverse excitation in the uniform thermal environment is presented for the first time. Materials properties of the constituents are graded in the thickness direction according to a power-law distribution and assumed to be temperature dependent. In the framework of the Third-order shear deformation plate theory, the nonlinear governing equations of motion for the functionally graded materials plate are derived by using the Hamilton’s principle. For cantilever rectangular plate, the first two vibration mode shapes that satisfy the boundary conditions is given. The Galerkin’s method is utilized to discretize the governing equations of motion to a two-degree-of-freedom nonlinear system under combined thermal and external excitations. By using the numerical method, the two-degree-of-freedom nonlinear system is analyzed to find the nonlinear responses of the cantilever FGMs plate. The influences of the thermal environments on the nonlinear dynamic response of the cantilevered FGM plate are discussed in detail through a parametric study.

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The Research of Damping Adjustable Isolators Control Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.774-776.44 ◽

2013 ◽

Vol 774-776 ◽

pp. 44-47

Author(s):

Bo Jiang

Keyword(s):

Fuzzy Control ◽

Mechanical Model ◽

Control Method ◽

Simulation Analysis ◽

Degree Of Freedom ◽

Matlab Software ◽

Fluid Damping ◽

Two Degree Of Freedom

The mechanical model of the electro-rheological fluid damping adjustable isolator is established. Then the two degree of freedom vibration adjusting system of engine and car frame is built. The PD fuzzy control method is used to control the damping characteristic of the damping adjustable isolator. Simulation analysis is executed by using Matlab software. The datum of simulation analysis indicates that the isolation capability of the PD fuzzy control electro-rheological fluid damping adjustable isolator is well.

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Control of Near-Grazing Dynamics in the Two-Degree-of-Freedom Vibroimpact System with Symmetrical Constraints

Complexity ◽

10.1155/2020/7893451 ◽

2020 ◽

Vol 2020 ◽

pp. 1-12

Author(s):

Zihan Wang ◽

Jieqiong Xu ◽

Shuai Wu ◽

Quan Yuan

Keyword(s):

Control Strategy ◽

Stability Criterion ◽

Control Method ◽

Degree Of Freedom ◽

Local Analysis ◽

Grazing Bifurcation ◽

Vibroimpact System ◽

The Stability ◽

Two Parameters ◽

Two Degree Of Freedom

The stability of grazing bifurcation is lost in three ways through the local analysis of the near-grazing dynamics using the classical concept of discontinuity mappings in the two-degree-of-freedom vibroimpact system with symmetrical constraints. For this instability problem, a control strategy for the stability of grazing bifurcation is presented by controlling the persistence of local attractors near the grazing trajectory in this vibroimpact system with symmetrical constraints. Discrete-in-time feedback controllers designed on two Poincare sections are employed to retain the existence of an attractor near the grazing trajectory. The implementation relies on the stability criterion under which a local attractor persists near a grazing trajectory. Based on the stability criterion, the control region of the two parameters is obtained and the control strategy for the persistence of near-grazing attractors is designed accordingly. Especially, the chaos near codimension-two grazing bifurcation points was controlled by the control strategy. In the end, the results of numerical simulation are used to verify the feasibility of the control method.

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