Dynamic modeling of the Stewart platform for the NanShan Radio Telescope

2020 ◽  
Vol 12 (7) ◽  
pp. 168781402094007
Author(s):  
Guljaina Kazezkhan ◽  
Binbin Xiang ◽  
Na Wang ◽  
Aili Yusup
Keyword(s):  
Radio Telescope ◽  
Driving Forces ◽  
Virtual Work ◽  
Dynamic Performance ◽  
Stewart Platform ◽  
Dynamic Simulations ◽  
Inverse Dynamic ◽  
Passive Rotation ◽  
Precise Analysis ◽  
And Control

The NanShan Radio Telescope is a 26-m fully steerable radio telescope, and it adopts a 6-UPU Stewart platform with electric motors to adjust and align the position of the subreflector. In order to analyze the actual dynamic performance and control the Stewart platform of the NanShan Radio Telescope, this article models the inverse dynamic of the Stewart platform using the virtual work approach. The model improves the accuracy of the dynamic equations and considered the pitching motion of the base platform in the practical application of the radio telescope. Dynamic simulations of the Stewart platform are implemented, the conditions of the passive rotation of the piston of actuators are considered, and the results show that the effect of the passive rotation of the pistons of the actuators is important to obtain more accurate result. The conditions of the system under the different elevation angles of the radio telescope are also considered, and the results show that the change of the elevation angles of the radio telescope has a great impact on the driving forces of the Stewart platform. It is known from the analysis that the passive rotation of pistons of actuators and the elevation movement of the primary reflector of the radio telescope are not ignorable for the precise analysis and control of the Stewart platform of the NanShan Radio Telescope.

Dynamic Formulation and Performance Comparison of the 3-DOF Modules of Two Reconfigurable PKM—the Tricept and the TriVariant

2005 ◽  
Vol 127 (6) ◽  
pp. 1129-1136 ◽  
Author(s):  
Meng Li ◽  
Tian Huang ◽  
Jiangping Mei ◽  
Xueman Zhao ◽  
Derek G. Chetwynd ◽  
...  
Keyword(s):  
Virtual Work ◽  
Dynamic Performance ◽  
Performance Comparison ◽  
Inverse Dynamic ◽  
Virtual Work Principle ◽  
Joint Force ◽  
Inertial Parameters ◽  
Dynamic Formulation ◽  
Performance Evaluation And Comparison ◽  
And Performance

Utilizing the virtual work principle, this paper presents a method for the inverse dynamic formulation of the 3-degree-of-freedom (DOF) modules of the well-known Tricept robot and a newly invented hybrid robot named TriVariant. The TriVariant is a modified version of the Tricept, achieved by integrating one of the three active limbs into the passive one. Both local and global conditioning indices are proposed for the dynamic performance evaluation and comparison of these two robots. These indices are designed on the basis of the maximum actuated joint force required for producing a unit acceleration of the mobile platform. For a given set of geometrical and inertial parameters, it has been shown that the TriVariant has a similar overall dynamic performance compared with that of the Tricept.

Dynamic analysis and simulation of a six degree of freedom Stewart platform manipulator

2006 ◽  
Vol 220 (1) ◽  
pp. 61-72 ◽  
Author(s):  
H B Guo ◽  
H R Li
Keyword(s):  
Driving Forces ◽  
Complete System ◽  
Stewart Platform ◽  
Euler Method ◽  
Dynamic Equations ◽  
Task Space ◽  
Inverse Dynamic ◽  
Lagrange Formulation ◽  
Dynamic Formulation ◽  
Six Degree Of Freedom

This article presents the explicit compact closed-form dynamic equations in the task-space by applying the combination of the Newton—Euler method with the Lagrange formulation including the dynamics of the legs for the Stewart platform manipulator. The kinematics analysis of the manipulator is given and the velocity and the acceleration formulae needed to derive the dynamic equations are also derived. The driving forces acting on the legs are determined according to the dynamic formulation. The formulation has been implemented in routines and has been used for studying a few inverse dynamic problems of a specific Stewart platform manipulator. Simulation results reveal the effect of the leg inertia and that of its parts, respectively, on the dynamics of the complete system, and numerical examples show the effectiveness of the proposed method and the dynamic equations of the Stewart platform manipulator.

Analytical mechanics approaches in the dynamic modelling of Delta mechanism

Robotica ◽  
2014 ◽  
Vol 33 (4) ◽  
pp. 953-973 ◽  
Author(s):  
Renato Maia Matarazzo Orsino ◽  
Tarcisio Antonio Hess Coelho ◽  
Celso Pupo Pesce
Keyword(s):  
Computational Models ◽  
Virtual Work ◽  
Mechanical Systems ◽  
Dynamic Modelling ◽  
Point Of View ◽  
Analytical Mechanics ◽  
Dynamic Simulations ◽  
Inverse Dynamic ◽  
Complex Mechanical Systems ◽  
Multi Body

SUMMARYThe increasing importance of computational models for the design of complex mechanical systems raises a discussion on defining some criteria for the selection of adequate modelling methods. This paper aims to contribute to such discussion from an educational point of view. By choosing the Delta parallel mechanism as a typical representative of multi-body mechanical systems, four approaches – one based on the Principle of Virtual Work, two based on Lagrange's formalism, and one based on Kane's formalism – are analysed from the perspective of modelling procedures. Finally, inverse dynamic simulations are carried out along with qualitative comparisons of the considered approaches.

Inverse Kinematic and Dynamic Analyses of the 6-UCU Parallel Manipulator

2011 ◽  
Vol 127 ◽  
pp. 172-180 ◽  
Author(s):  
Guo Jun Liu ◽  
Shu Tao Zheng ◽  
Peter O. Ogbobe ◽  
Jun Wei Han
Keyword(s):  
Inverse Kinematics ◽  
Parallel Manipulator ◽  
Driving Forces ◽  
Stewart Platform ◽  
Inverse Kinematic ◽  
Euler Method ◽  
Kinematics And Dynamics ◽  
Precise Analysis ◽  
Dynamic Analyses ◽  
Reaction Forces

From the practical viewpoint, the inverse kinematics and dynamics of a practical Stewart platform, the 6-UCU parallel manipulator, are established in this paper. The velocities and accelerations of the manipulator are derived with the consideration of the attachments of the joints, and then the driving forces actuated by the actuators and the reaction forces applied to the joints are derived based on the Newton Euler method. In the last, the correctness of the equations established in this paper is confirmed by the study of a case. These equations can be used as the base for the precise analysis of the 6-UCU parallel manipulator.

Inverse Dynamics Analysis of a 2-DOF Planar Parallel Manipulator

2010 ◽  
Vol 44-47 ◽  
pp. 1848-1852
Author(s):  
Xiao Rong Zhu ◽  
Hui Ping Shen ◽  
Wei Zhu ◽  
Lan Cai
Keyword(s):  
Parallel Manipulator ◽  
Inverse Dynamics ◽  
Driving Forces ◽  
Dynamic Performance ◽  
Operating Mode ◽  
Moment Of Inertia ◽  
Inverse Dynamic ◽  
Operating Modes ◽  
Inverse Solutions ◽  
Dynamic Performance Analysis

The dynamic characteristics of the parallel mechanism depend strongly on the operating modes corresponding to different inverse solutions, but few of them have been involved with. In this paper, a new kind of 2-DOF parallel manipulator actuated horizontally by two parallel linear actuators is investigated. Firstly, the four inverse solutions of this manipulator are derived and analyzed; Secondly, the closed form inverse dynamic model is presented using the Lagrange approach based on the generalized system coordinates. An explicit formula of the equivalent moment of inertia, driving forces and consumed energy of the mechanism are investigated; Finally, the changes of equivalent moment of inertia, actuator force and energy consumption of the mechanism in different operating mode are analyzed through the dynamic numerical simulation. The results show that, for a given motion, the configuration and the operating modes have a significant influence on the equivalent moment of inertia and actuator force. The analysis provides necessary information for dynamic performance analysis and control of this parallel manipulator.

Pre-Bending Motion Strategy Analysis of a 3-DOF UACT Robotic Finger

2021 ◽  
Author(s):  
Shangling Qiao ◽  
Yichen Wang ◽  
Hongwei Guo ◽  
Hong Xiao ◽  
Zongquan Deng
Keyword(s):  
Driving Force ◽  
Driving Forces ◽  
Virtual Work ◽  
Linkage Mechanism ◽  
Strategy Analysis ◽  
Single Motor ◽  
Motion Models ◽  
And Control ◽  
Underactuated Finger ◽  
Motion Strategy

Abstract Motion strategy analysis at the pre-bending stage is a fundamental component of underactuated finger grasp research. This study presents the pre-bending motion strategy and corresponding analysis of cable driving forces a 3-DOF underactuated finger comprising cable truss units. This robotic finger uses a tendon-pulley transmission and parallel four-linkage mechanism to realize the grasp capability. The structure and four motion strategies at the pre-bending stage are illustrated. The equivalent joint-driven and quasi-static motion models are established in the case where one or two cable driving forces drive the finger. In accordance with the virtual work principle, the tendon-pulley transmission is transformed into an equivalent joint-driven system. On the basis of the constraints of maximum motion space of the finger, the joint spring stiffness distributions are discussed and the finger quasi-static motion space is analyzed under the condition of single motor driving force. The unique coupled motion process and corresponding cable driving force of the finger driven by a single motor are assessed. Furthermore, three other typical quasi-static motion strategies and their corresponding cable driving forces are discussed. Valid simulation experiments are conducted to verify the accuracy of the quasi-static motion strategy. The analysis of this study can provide guidance and a theoretical reference for the design of cable-driven underactuated hands and control of the couple-driven underactuated mechanism.

Revisiting the inverse dynamics of the Gough–Stewart platform manipulator with special emphasis on universal–prismatic–spherical leg and internal singularity

2012 ◽  
Vol 226 (10) ◽  
pp. 2422-2439 ◽  
Author(s):  
Mohamed Afroun ◽  
Antoine Dequidt ◽  
Laurent Vermeiren
Keyword(s):  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Dynamic Models ◽  
Inverse Dynamics ◽  
Driving Forces ◽  
Stewart Platform ◽  
Inverse Dynamic ◽  
Computational Burden ◽  
Six Degrees Of Freedom ◽  
Leg Kinematics

This article discusses the dynamic modeling for control of Gough–Stewart platform manipulator with special emphasis on universal–prismatic–spherical leg kinematics. Inverse dynamic model of these six degrees of freedom parallel manipulator robots is reviewed, while complete dynamics with true kinematics of universal–prismatic–spherical legs is compared with several models found in the literature. Most existing models have not taken into account some of the legs kinematical effects, namely the legs angular velocity around their axes and the internal singularities due to passive joints; some other used a simplified parameterization to describe the leg kinematics. Furthermore, some kinetic assumption can be used to reduce the computational burden. This article shows the effect of all these simplifications on the driving forces by simulating the different dynamic models for a commercial manipulator and for different sets of geometric and dynamic parameters of manipulator.

Inductor Saturation Compensation in Three-Phase Three-Wire Voltage-Source Converters via Inverse System Dynamics-I

2020 ◽  
Author(s):  
Ziya Özkan ◽  
Ahmet Masum Hava
Keyword(s):  
Dynamic Model ◽  
Dynamic Performance ◽  
Current Control ◽  
Inverse System ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Two Phase ◽  
Inverse Dynamic ◽  
Three Phase ◽  
Steady State Current

In three-phase three-wire (3P3W) voltage-source converter (VSC) systems, utilization of filter inductors with deep saturation characteristics is often advantageous due to the improved size, cost, and efficiency. However, with the use of conventional synchronous frame current control (CSCC) methods, the inductor saturation results in significant dynamic performance loss and poor steady-state current waveform quality. This paper proposes an inverse dynamic model based compensation (IDMBC) method to overcome these performance issues. Accordingly, a review of inductor saturation and core materials is performed, and the motivation on the use of saturable inductors is clarified. Then, two-phase exact modelling of the 3P3W VSC control system is obtained and the drawbacks of CSCC have been demonstrated analytically. Based on the exact modelling, the inverse system dynamic model of the nonlinear system is obtained and employed such that the nonlinear plant is converted to a fictitious linear inductor system for linear current regulators to perform satisfactorily.

scholarly journals Fault Simulations in a Multiterminal High Voltage DC Network with Modular Multilevel Converters Using Full-Bridge Submodules

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1653
Author(s):  
Ioan-Cătălin Damian ◽  
Mircea Eremia ◽  
Lucian Toma
Keyword(s):  
High Voltage ◽  
Energy Resource ◽  
Fault Analysis ◽  
Renewable Energy Resource ◽  
Dynamic Simulations ◽  
Multilevel Converters ◽  
Strong Focus ◽  
Modular Multilevel Converters ◽  
Overhead Power Lines ◽  
And Control

The concept of high-voltage DC transmission using a multiterminal configuration is presently a central topic of research and investment due to rekindled interest in renewable energy resource integration. Moreover, great attention is given to fault analysis, which leads to the necessity of developing proper tools that enable proficient dynamic simulations. This paper leverages models and control system design techniques and demonstrates their appropriateness for scenarios in which faults are applied. Furthermore, this paper relies on full-bridge submodule topologies in order to underline the increase in resilience that such a configuration brings to the multiterminal DC network, after an unexpected disturbance. Therefore, strong focus is given to fault response, considering that converters use a full-bridge topology and that overhead power lines connect the terminals.

scholarly journals Multi-Objective Lightweight Optimization of Parameterized Suspension Components Based on NSGA-II Algorithm Coupling with Surrogate Model

Machines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 107
Author(s):  
Rongchao Jiang ◽  
Zhenchao Jin ◽  
Dawei Liu ◽  
Dengfeng Wang
Keyword(s):  
Ride Comfort ◽  
Lightweight Design ◽  
Dynamic Performance ◽  
Vehicle Dynamic ◽  
Multi Objective Optimization ◽  
Original Design ◽  
Dynamic Simulations ◽  
Nsga Ii ◽  
Torsion Beam ◽  
Multi Objective

In order to reduce the negative effect of lightweighting of suspension components on vehicle dynamic performance, the control arm and torsion beam widely used in front and rear suspensions were taken as research objects for studying the lightweight design method of suspension components. Mesh morphing technology was employed to define design variables. Meanwhile, the rigid–flexible coupling vehicle model with flexible control arm and torsion beam was built for vehicle dynamic simulations. The total weight of control arm and torsion beam was taken as optimization objective, as well as ride comfort and handling stability performance indexes. In addition, the fatigue life, stiffness, and modal frequency of control arm and torsion beam were taken as the constraints. Then, Kriging model and NSGA-II were adopted to perform the multi-objective optimization of control arm and torsion beam for determining the lightweight scheme. By comparing the optimized and original design, it indicates that the weight of the optimized control arm and torsion beam are reduced 0.505 kg and 1.189 kg, respectively, while structural performance and vehicle performance satisfy the design requirement. The proposed multi-objective optimization method achieves a remarkable mass reduction, and proves to be feasible and effective for lightweight design of suspension components.

Sign in / Sign up

Export Citation Format

Share Document