Dynamic Modeling of a Quadruped With a Robotic Tail Using Virtual Work Principle

2018 ◽  
Author(s):  
Yujiong Liu ◽  
Pinhas Ben-Tzvi
Keyword(s):  
Numerical Simulations ◽  
Dynamic Model ◽  
Dynamic Modeling ◽  
Virtual Work ◽  
Inverse Model ◽  
Virtual Work Principle ◽  
Alternative Approach ◽  
Systematic Methodology ◽  
Methods Numerical

For utilizing robotic tail to stabilize and maneuver a quadruped, it is important to understand the mechanism of how the tail motion influences the quadruped motion which requires obtaining an analytic dynamic model. This paper presents a systematic methodology for modeling the dynamics of a general quadruped (capable of all 6 DOF motions) with a robotic pendulum tail based on the virtual work principle. The formulation of this model is motivated by robotic tail research, it can also be used as an alternative approach to model the quadruped dynamics other than using Lagrangian and Newton-Euler based methods. Numerical simulations are also conducted to verify both the forward and the inverse model.

A Measure for Evaluation of Maximum Acceleration of Redundant and Nonredundant Parallel Manipulators

2015 ◽  
Vol 8 (2) ◽  
Author(s):  
Jun Wu ◽  
Binbin Zhang ◽  
Liping Wang
Keyword(s):  
Dynamic Model ◽  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Virtual Work ◽  
Parallel Manipulators ◽  
Maximum Acceleration ◽  
Virtual Work Principle ◽  
Joint Force ◽  
Joint Forces ◽  
Three Degrees Of Freedom

The paper deals with the evaluation of acceleration of redundant and nonredundant parallel manipulators. The dynamic model of three degrees-of-freedom (3DOF) parallel manipulator is derived by using the virtual work principle. Based on the dynamic model, a measure is proposed for the acceleration evaluation of the redundant parallel manipulator and its nonredundant counterpart. The measure is designed on the basis of the maximum acceleration of the mobile platform when one actuated joint force is unit and other actuated joint forces are less than or equal to a unit force. The measure for evaluation of acceleration can be used to evaluate the acceleration of both redundant parallel manipulators and nonredundant parallel manipulators. Furthermore, the acceleration of the 4-PSS-PU parallel manipulator and its nonredundant counterpart are compared.

Dynamic performances analysis of hybrid press based on dependent generalized coordinates

2014 ◽  
Vol 229 (12) ◽  
pp. 2187-2194
Author(s):  
Jinliang Gong ◽  
Xiaoming Wang ◽  
Fengan Huang ◽  
Yanfei Zhang
Keyword(s):  
Dynamic Model ◽  
Virtual Work ◽  
Single Degree Of Freedom ◽  
Virtual Work Principle ◽  
Generalized Coordinates ◽  
Hybrid Mechanism ◽  
Adams Simulation ◽  
Angular Velocities ◽  
Dynamic Performances ◽  
Angular Displacements

A kind of multi-link hybrid press mechanism is brought forth. It adopts three motors as actuations to fulfill the single degree of freedom output of end effector. For hybrid press mechanism, the forward kinematics is usually complicated and its numerical solution is computation-intensive and time-consuming. Therefore, the dynamic model is difficult to build up when it needs to analyze the input function’s effect on system dynamic performances. Concept of dependent generalized coordinates is adpoted here and a kind of dynamic modeling method of multi-link hybrid mechanism is presented based on the virtual work principle. The linear and angular displacements of every component can be expressed concisely in the form of dependent generalized coordinates. They are much simpler than that of independent generalized coordinates. Accordingly, linear and angular velocities will be derived by differentiating with respect to displacements. Velocity Jacobian matrix will be simplified under dependent generalized coordinates system and the virtual work principle-based dynamic model will also be simplified accordingly. Then it needs to introduce constraint conditions and multiplier in order to acquire actuation forces. Introduction of the constraints guarantees the real kinetic characteristics of mechanism. In the end, the curves of actuation forces and spherical joints’ inner forces variations are presented using Matlab. By comparing with Adams simulation results, validity of the method has been proved.

scholarly journals Modeling and Simulation for Multi-Rotor Fixed-Wing UAV Based on Multibody Dynamics

2019 ◽  
Vol 37 (5) ◽  
pp. 928-934 ◽  
Author(s):  
Han Wu ◽  
Zhengping Wang ◽  
Zhou Zhou ◽  
Rui Wang
Keyword(s):  
Dynamic Model ◽  
Multibody Dynamics ◽  
Dynamic Modeling ◽  
Virtual Work ◽  
Lagrange Equation ◽  
Dynamic Change ◽  
Lagrangian Multiplier ◽  
And Control ◽  
Control Surfaces ◽  
Generalized Coordinate

Accurate dynamic modeling lays foundation for design and control of UAV. The dynamic model for the multi-rotor fixed-wing UAV was looked into and it was divided into fuselage, air-body, multi-rotors, vertical fin, vertical tail and control surfaces, based on the multibody dynamics. The force and moment model for each body was established and derived into the Lagrange equation of the second king by virtual work. By electing quaternion as generalized coordinate and introducing Lagrangian multiplier, the dynamic modeling was deduced and established. Finally, the comparison between the simulation results and the experimental can be found that the present dynamic model accurately describes the process of dynamic change of this UAV and lay foundation for the control of UAV.

Dynamic Modeling of a Rolling Flexible Sphere

2015 ◽  
Author(s):  
François Robert Hogan ◽  
James Richard Forbes ◽  
Alex Walsh
Keyword(s):  
Spherical Shell ◽  
Numerical Simulations ◽  
Dynamic Model ◽  
Dynamic Modeling ◽  
Flat Surface ◽  
Free Vibrations ◽  
Lagrangian Formulation ◽  
Discretization Method ◽  
Motion Equations

The motion equations of a rolling flexible spherical shell are derived using a Lagrangian formulation. The motion equations developed capture the nonholonomic nature of the flexible sphere rolling without slip on a flat surface. The free vibrations of the spherical shell are modeled using the Rayleigh-Ritz discretization method. Numerical simulations are performed to validate the dynamic model developed and to investigate the effect of the flexibility of the spherical shell on its trajectory.

RESEARCH ON RIGID BODY INVERSE DYNAMICS OF A NOVEL 6-PRRS PARALLEL ROBOT

2018 ◽  
Vol 18 (08) ◽  
pp. 1840037
Author(s):  
YUBIN LIU ◽  
GANGFENG LIU
Keyword(s):  
Dynamic Model ◽  
Inverse Dynamics ◽  
Virtual Work ◽  
Equations Of Motion ◽  
Parallel Robot ◽  
Simulation Software ◽  
Real Time Control ◽  
Dynamical Equations ◽  
Time Control ◽  
Systematic Methodology

A systematic methodology for solving the inverse dynamics of a 6-PRRS parallel robot is presented. Based on the principle of virtual work and the Lagrange approach, a methodology for deriving the dynamical equations of motion is developed. To resolve the inconsistency between complications of established dynamic model and real-time control, a simplifying strategy of the dynamic model is presented. The dynamic character of the 6-PRRS parallel robot is analyzed by example calculation, and a full and precise dynamic model using simulation software is established. Verification results show the validity of the presented algorithm, and the simplifying strategies are practical and efficient.

Dynamic Modelling of a 3DOF Medical Parallel Robot with One Decoupled Motion

2013 ◽  
Vol 837 ◽  
pp. 594-599 ◽  
Author(s):  
Mircea Neagoe ◽  
Nadia Cretescu ◽  
Radu Saulescu
Keyword(s):  
Numerical Simulations ◽  
Dynamic Model ◽  
Dynamic Modeling ◽  
Lagrange Multipliers ◽  
Dynamic Modelling ◽  
Parallel Robot ◽  
Multipliers Method ◽  
Adams Software ◽  
Decoupled Motion ◽  
Analytical Dynamic

The paper presents the dynamic modeling of a 3DOF parallel robot of 1PRRR+2PRPaR type using the Lagrange multipliers method in the rigid link assumption. Numerical simulations of the analytical dynamic model, developed using Maple software, on representative trajectories are carried out and these results are finally validated trough numerical simulations in the MBS ADAMS software. Final conclusions are drawn, useful for researchers and practitioners in the robotic field.

A PD Computed Torque Control Method with Online Self-gain Tuning for a 3UPS-PS Parallel Robot

Robotica ◽  
2021 ◽  
pp. 1-13
Author(s):  
Xiaogang Song ◽  
Yongjie Zhao ◽  
Chengwei Chen ◽  
Liang’an Zhang ◽  
Xinjian Lu
Keyword(s):  
Feedback Loop ◽  
Control Method ◽  
Virtual Work ◽  
Parallel Robot ◽  
Torque Control ◽  
Virtual Work Principle ◽  
Tuning Method ◽  
Computed Torque Control ◽  
Control Feedback ◽  
Computed Torque

SUMMARY In this paper, an online self-gain tuning method of a PD computed torque control (CTC) is used for a 3UPS-PS parallel robot. The CTC is applied to the 3UPS-PS parallel robot based on the robot dynamic model which is established via a virtual work principle. The control system of the robot comprises a nonlinear feed-forward loop and a PD control feedback loop. To implement real-time online self-gain tuning, an adjustment method based on the genetic algorithm (GA) is proposed. Compared with the traditional CTC, the simulation results indicate that the control algorithm proposed in this study can not only enhance the anti-interference ability of the system but also improve the trajectory tracking speed and the accuracy of the 3UPS-PS parallel robot.

scholarly journals Application of the virtual work principle to compute magnetic forces with a volume integral method

2013 ◽  
Vol 27 (3) ◽  
pp. 418-432 ◽  
Author(s):  
Anthony Carpentier ◽  
Nicolas Galopin ◽  
Olivier Chadebec ◽  
Gérard Meunier ◽  
Christophe Guérin
Keyword(s):  
Integral Method ◽  
Virtual Work ◽  
Volume Integral ◽  
Virtual Work Principle ◽  
Magnetic Forces

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.

Sign in / Sign up

Export Citation Format

Share Document