Dynamic Modeling of Planar Flexible Multi-Link Manipulators with Accounting for both Link Foreshortening and Link Material Damping

2011 ◽  
Vol 199-200 ◽  
pp. 19-24
Author(s):  
Jin Fu Zhang
Keyword(s):  
Dynamic Model ◽  
Dynamic Modeling ◽  
Dynamic Performance ◽  
Material Damping ◽  
Motion Responses ◽  
Case Simulation ◽  
Tip Mass ◽  
Lagrange Approach

In order to investigate dynamic performance of flexible multi-link manipulators more exactly, establishing the dynamic model with accounting for link foreshortening and link material damping is needed. In this paper, a new dynamic model for planar flexible multi-link manipulators is established by using Lagrange approach. Both link foreshortening and link material damping are accounted for in this model. As a case simulation, this model is applied to a planar flexible two-link manipulator with a tip mass, and the motion responses of the manipulator are obtained using Gear method.

Dynamic Modeling and Optimal Design of a 2R Compliant Mechanism

2017 ◽  
Author(s):  
Wenshuo Ma ◽  
Yan Xie ◽  
Jingjun Yu ◽  
Xu Pei
Keyword(s):  
Optimal Design ◽  
Dynamic Model ◽  
Dynamic Modeling ◽  
Dynamic Characteristics ◽  
Natural Frequencies ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Dynamic Performance ◽  
Dynamic Problems ◽  
Numerical Result

Dynamic performance is of great importance to compliant mechanisms which are employed in dynamic applications, especially if the dynamic problems in DOC (degree of constraint) directions are to be met. An investigation on the dynamic characteristics of a 2R compliant mechanism is presented. Based on the substructure techniques, the in-plane dynamic model of the preceding compliant mechanisms is developed. The natural frequencies and sensitivities are then analyzed. The numerical result verifies the validity of the proposed method. Finally, optimal design of compliant mechanism is investigated.

scholarly journals Integrating Dynamics into Design and Motion Optimization of a 3-PRR Planar Parallel Manipulator with Discrete Time Transfer Matrix Method

2020 ◽  
Vol 2020 ◽  
pp. 1-23 ◽  
Author(s):  
Guoning Si ◽  
Mengqiu Chu ◽  
Zhuo Zhang ◽  
Haijie Li ◽  
Xuping Zhang
Keyword(s):  
Dynamic Model ◽  
Dynamic Modeling ◽  
Discrete Time ◽  
Parallel Manipulator ◽  
Robot Manipulators ◽  
Dynamic Performance ◽  
Parallel Robot ◽  
Time Transfer ◽  
Performance Indices ◽  
Planar Parallel Manipulator

This paper presents a novel method of dynamic modeling and design optimization integrated with dynamics for parallel robot manipulators. Firstly, a computationally efficient modeling method, the discrete time transfer matrix method (DT-TMM), is proposed to establish the dynamic model of a 3-PRR planar parallel manipulator (PPM) for the first time. The numerical simulations are performed with both the proposed DT-TMM dynamic modeling and the ADAMS modeling. The applicability and effectiveness of DT-TMM in parallel manipulators are verified by comparing the numerical results. Secondly, the design parameters of the 3-PRR parallel manipulator are optimized using the kinematic performance indices, such as global workspace conditioning index (GWCI), global condition index (GCI), and global gradient index (GGI). Finally, a dynamic performance index, namely, driving force index (DFI), is proposed based on the established dynamic model. The described motion trajectory of the moving platform is placed into the optimized workspace and the initial position is determined to finalize the end-effector trajectory of the parallel manipulator by the further optimization with the integrated kinematic and dynamic performance indices. The novelty of this work includes (1) developing a new dynamic model method with high computation efficiency for parallel robot manipulators using DT-TMM and (2) proposing a new dynamic performance index and integrating the dynamic index into the motion and design optimization of parallel robot manipulators.

Dynamic Modeling of Single-Wheeled Robot

2011 ◽  
Vol 383-390 ◽  
pp. 447-452
Author(s):  
Xiao Gang Ruan ◽  
Qi Yuan Wang
Keyword(s):  
Dynamic Model ◽  
Dynamic Modeling ◽  
Theoretical Basis ◽  
Model Simulation ◽  
Wheeled Robot ◽  
Lagrange Approach

This paper presents a kind of single-wheeled robot (SWR, unicycle robot). Lagrange approach is used to formulate the dynamic model of the robot moving in 3 dimensions. The result of model simulation is consistent with the physical. The proposed dynamic model provides some theoretical basis for designing and controlling SWR.

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 Numerical Investigation on Hydrodynamic Performance of a Portable AUV

2021 ◽  
Vol 9 (8) ◽  
pp. 812
Author(s):  
Lin Hong ◽  
Renjie Fang ◽  
Xiaotian Cai ◽  
Xin Wang
Keyword(s):  
Numerical Investigation ◽  
Dynamic Model ◽  
Autonomous Underwater Vehicle ◽  
Dynamic Performance ◽  
Plane Motion ◽  
Hydrodynamic Performance ◽  
Wave Forces ◽  
Modeling And Control ◽  
Experiment Platform ◽  
Cfd Method

This paper conducts a numerical investigation on the hydrodynamic performance of a portable autonomous underwater vehicle (AUV). The portable AUV is designed to cruise and perform some tasks autonomously in the underwater world. However, its dynamic performance is strongly affected by hydrodynamic effects. Therefore, it is crucial to investigate the hydrodynamic performance of the portable AUV for its accurate dynamic modeling and control. In this work, based on the designed portable AUV, a comprehensive hydrodynamic performance investigation was conducted by adopting the computational fluid dynamics (CFD) method. Firstly, the mechanical structure of the portable AUV was briefly introduced, and the dynamic model of the AUV, including the hydrodynamic term, was established. Then, the unknown hydrodynamic coefficients in the dynamic model were estimated through the towing experiment and the plane-motion-mechanism (PMM) experiment simulation. In addition, considering that the portable AUV was affected by wave forces when cruising near the water surface, the influence of surface waves on the hydrodynamic performance of the AUV under different wave conditions and submerged depths was analyzed. Finally, the effectiveness of our method was verified by experiments on the standard models, and a physical experiment platform was built in this work to facilitate hydrodynamic performance investigations of some portable small-size AUVs.

Dynamic modeling of a rotating beam having a tip mass

2008 ◽  
Author(s):  
Shengjian Bai ◽  
Pinhas Ben-Tzvi ◽  
Qingkun Zhou ◽  
Xinsheng Huang
Keyword(s):  
Dynamic Modeling ◽  
Rotating Beam ◽  
Tip Mass

scholarly journals Planetary Gearbox Dynamic Modeling Considering Bearing Clearance and Sun Gear Tooth Crack

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2638
Author(s):  
Xianhua Chen ◽  
Xingkai Yang ◽  
Ming J. Zuo ◽  
Zhigang Tian
Keyword(s):  
Dynamic Model ◽  
Dynamic Modeling ◽  
Failure Modes ◽  
Gear Tooth ◽  
Working Environment ◽  
The Sun ◽  
Planetary Gearbox ◽  
Bearing Clearance ◽  
Vibration Responses ◽  
Planet Gear

Planetary gearbox systems are critical mechanical components in heavy machinery such as wind turbines. They may suffer from various failure modes, due to the harsh working environment. Dynamic modeling is a useful method to support early fault detection for enhancing reliability and reducing maintenance costs. However, reported studies have not considered the sun gear tooth crack and bearing clearance simultaneously to analyze their combined effect on vibration characteristics of planetary gearboxes. In this paper, a dynamic model is developed for planetary gearboxes considering the clearance of planet gear, sun gear, and carrier bearings, as well as sun gear tooth crack levels. Bearing forces are calculated considering bearing clearance, and the dynamic model equations are updated accordingly. The results reveal that the combination of bearing clearances can affect the vibration response with sun gear tooth crack by increasing the kurtosis. It is found that the effect of planet gear bearing clearance is very small, while the sun gear and carrier bearing clearance has clear impact on the vibration responses. These findings suggest that the incorporation of bearing clearance is important for planetary gearbox dynamic modeling.

Sensor Dynamic Modeling Based on LS-SVM and NGA

2008 ◽  
Vol 381-382 ◽  
pp. 439-442
Author(s):  
Qi Wang ◽  
Zhi Gang Feng ◽  
K. Shida
Keyword(s):  
Genetic Algorithm ◽  
Neural Networks ◽  
Support Vector Machine ◽  
Least Squares ◽  
Dynamic Model ◽  
Dynamic Modeling ◽  
Support Vector ◽  
Local Minima ◽  
Highly Nonlinear ◽  
Sharing Function

Least squares support vector machine (LS-SVM) combined with niche genetic algorithm (NGA) are proposed for nonlinear sensor dynamic modeling. Compared with neural networks, the LS-SVM can overcome the shortcomings of local minima and over fitting, and has higher generalization performance. The sharing function based niche genetic algorithm is used to select the LS-SVM parameters automatically. The effectiveness and reliability of this method are demonstrated in two examples. The results show that this approach can escape from the blindness of man-made choice of LS-SVM parameters. It is still effective even if the sensor dynamic model is highly nonlinear.

System-dynamic model of power redistribution among several subjects

2021 ◽  
pp. 52-57
Author(s):  
D.S. Zhukov
Keyword(s):  
Decision Making ◽  
Simple Model ◽  
Dynamic Model ◽  
Dynamic Modeling ◽  
Computer Experiments ◽  
System Dynamic ◽  
System Dynamic Model ◽  
Mathematical Apparatus ◽  
Stocks And Flows ◽  
Specialized Program

A simple model simulating the redistribution of decision-making functions between the state, business, bureaucracy and regional elites is presented. The methodological basis of the work is system-dynamic modeling. The model is implemented in the specialized program Powersim Studio 10. A diagram of stocks and flows is considered, all elements of which were compared with certain political science concepts. The mathematical apparatus of the model is described. Some results of computer experiments are presented: these results indicate the operability and interpretability of the model.

Dynamic Modeling of a Multi-Legged Robotic Vehicle: Part 2 — Dynamic Analysis

1987 ◽  
Author(s):  
R. A. Hart ◽  
N. D. Ebrahimi
Keyword(s):  
Dynamic Analysis ◽  
Dynamic Model ◽  
Dynamic Modeling ◽  
Kinetic Equations ◽  
Euler Method ◽  
Degree Of Freedom ◽  
Time Response ◽  
Robotic Vehicle

Abstract In Part 1 of this report, we described the overall objective of the investigation; that is, the formulation of a dynamic model for determining the time response of a multi-legged robotic vehicle traveling on a variable-topographic terrain. Specifically, we developed expressions for the joint variables, and their rates, which are essential for describing the system’s links orientations, velocities, and accelerations. This procedure enabled us to determine the kinematic quantities associated with the entire vehicular system in accordance with the Newton-Euler method. In the present paper, we formulate the kinetic equations for the multi-degree-of-freedom leg assemblies, the rigid wheels, and the platform of the vehicle to achieve the prescribed motion and corresponding configuration of the system.

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