scholarly journals A contribution to the dynamic simulation of robot manipulator with the software RobotDyn

2004 ◽  
Vol 26 (4) ◽  
pp. 215-225
Author(s):  
Nguyen Van Khang ◽  
Do Thanh Tung

Robots manipulators are multibody systems with tree structures. In this paper the theoretical background of the computer program RobotDyn is presented. The program is developed using Lagrange's equations and Denavit-Hartenberg matrix. The dynamic simulation of the Robot SCARA with four degrees of freedom is considered as an example of application of the program RobotDyn.

1987 ◽  
Vol 54 (2) ◽  
pp. 424-429 ◽  
Author(s):  
J. T. Wang ◽  
R. L. Huston

A procedure for automated analysis of constrained multibody systems is presented. The procedure is based upon Kane’s equations and the concept of undetermined multipliers. It is applicable with both free and controlled systems. As with Lagrange’s equations, the multipliers are identified as scalar components of constraining forces and moments. The advantage of using Kane’s equations is that they are ideally suited for development of algorithms for numerical analyses. Also, generalized speeds and quasi-coordinates are readily accommodated. A simple example illustrating the concepts is presented.


1989 ◽  
Vol 111 (4) ◽  
pp. 559-566 ◽  
Author(s):  
Chang-Jin Li

In this paper, a new Lagrangian formulation of dynamics for robot manipulators is developed. The formulation results in well structured form equations of motion for robot manipulators. The equations are an explicit set of closed form second order highly nonlinear and coupling differential equations, which can be used for both the design of the control system (or dynamic simulation) and the computation of the joint generalized forces/torques. The mathematical operations of the formulation are so few that it is possible to realize the computation of the Lagrangian dynamics for robot manipulators in real-time on a micro/mini-computer. For a robot manipulator with n degrees-of-freedom, the number of operations of the formulation is at most (6n2 + 107n − 81) multiplications and (4n2 + 102n − 86) additions; for n = 6, about 780 multiplications and 670 additions.


Mathematics ◽  
2022 ◽  
Vol 10 (2) ◽  
pp. 257
Author(s):  
Sorin Vlase ◽  
Marin Marin ◽  
Negrean Iuliu

This paper presents the main analytical methods, in the context of current developments in the study of complex multibody systems, to obtain evolution equations for a multibody system with deformable elements. The method used for analysis is the finite element method. To write the equations of motion, the most used methods are presented, namely the Lagrange equations method, the Gibbs–Appell equations, Maggi’s formalism and Hamilton’s equations. While the method of Lagrange’s equations is well documented, other methods have only begun to show their potential in recent times, when complex technical applications have revealed some of their advantages. This paper aims to present, in parallel, all these methods, which are more often used together with some of their engineering applications. The main advantages and disadvantages are comparatively presented. For a mechanical system that has certain peculiarities, it is possible that the alternative methods offered by analytical mechanics such as Lagrange’s equations have some advantages. These advantages can lead to computer time savings for concrete engineering applications. All these methods are alternative ways to obtain the equations of motion and response time of the studied systems. The difference between them consists only in the way of describing the systems and the application of the fundamental theorems of mechanics. However, this difference can be used to save time in modeling and analyzing systems, which is important in designing current engineering complex systems. The specifics of the analyzed mechanical system can guide us to use one of the methods presented in order to benefit from the advantages offered.


Author(s):  
Claudio Braccesi ◽  
Filippo Cianetti ◽  
Luca Landi

Dynamic simulation through Multibody Systems is more and more used for the design of new industrial products to avoid long and expensive experimental tests on them. The research presented in this paper deals with the realization of an actively controlled virtual test-rig, functional for comfort and durability tests of entire vehicles. The virtual test rig, is capable to impose any experimental acceleration to the centers of the four vehicle wheels through four imposed displacements to the actuators. The active control is implemented with four independent degrees of freedom, one for every actuator. In the paper the active controller logic and its automatic setup will be fully explained. Moreover it will be also explained how to avoid the aliasing and the so called “random signal drift” problems. Finally the results of some virtual pave road experiments to an existing vehicle will be presented.


1993 ◽  
Vol 1 (2) ◽  
pp. 107-119 ◽  
Author(s):  
L. Meirovitch

Early derivations of the equations of motion for single rigid bodies, single flexible bodies, and flexible multibody systems in terms of quasi-coordinates have been carried out in two stages. The first consists of the use of the extended Hamilton’s principle to derive standard Lagrange’s equations in terms of generalized coordinates and the second represents a transformation of the Lagrange’s equations to equations in terms of quasi-coordinates. In this article, hybrid (ordinary and partial) differential equations for flexible multibody systems are derived in terms of quasi-coordinates directly from the extended Hamilton's principle. The approach has beneficial implications in an eventual spatial discretization of the problem.


2021 ◽  
Vol 11 (12) ◽  
pp. 5398
Author(s):  
Tomáš Kot ◽  
Zdenko Bobovský ◽  
Aleš Vysocký ◽  
Václav Krys ◽  
Jakub Šafařík ◽  
...  

We describe a method for robotic cell optimization by changing the placement of the robot manipulator within the cell in applications with a fixed end-point trajectory. The goal is to reduce the overall robot joint wear and to prevent uneven joint wear when one or several joints are stressed more than the other joints. Joint wear is approximated by calculating the integral of the mechanical work of each joint during the whole trajectory, which depends on the joint angular velocity and torque. The method relies on using a dynamic simulation for the evaluation of the torques and velocities in robot joints for individual robot positions. Verification of the method was performed using CoppeliaSim and a laboratory robotic cell with the collaborative robot UR3. The results confirmed that, with proper robot base placement, the overall wear of the joints of a robotic arm could be reduced from 22% to 53% depending on the trajectory.


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