Research on the Inverse Dynamics of the Flexible Multi-Body Systems for the Hybrid Polishing Kinematics Machine Tool

2006 ◽  
Vol 532-533 ◽  
pp. 53-56 ◽  
Author(s):  
Miao Yu ◽  
Ji Zhao
Keyword(s):  
Machine Tool ◽  
Parallel Mechanism ◽  
Inverse Dynamics ◽  
Dynamic Control ◽  
Free Form ◽  
Constraint Force ◽  
Body Dynamics ◽  
Multi Body ◽  
Free Form Surfaces ◽  
Polishing Tool

The hybrid polishing kinematics machine tool (HPKMT) which is made up of “3 axes parallel + 2 axes series” is developed with the specially designed elastic polishing tool system for the polishing operation on the free-form surfaces by using the characteristic of the elastic polishing adequately by the authors. In order to control the HPKMT effectively, its characteristic of the kinematics and dynamics need be known deeply. Moreover, the problem of inverse dynamics is the theory foundation to apply dynamic control of the HPKMT. The analysis of the inverse of mechanism is the important part in the research of dynamics. On the basis of the differential equations of flexible multi-body dynamics, this paper discusses on the condition of knowing the trace, posture and velocity for the end of bodies how to solve the constraint force and constraint moment of each joint on the 3- PTT parallel mechanism and two-joint series mechanism.

Experiment on Dynamics of the Hybrid Polishing Kinematics Machine Tool with Clearance Based on the Flexible Multi-Body Systems

2007 ◽  
Vol 359-360 ◽  
pp. 533-537
Author(s):  
Miao Yu ◽  
Yuan Ming Zhang
Keyword(s):  
Machine Tool ◽  
Parallel Mechanism ◽  
Influence Factor ◽  
Free Form ◽  
Body System ◽  
Shock Effect ◽  
Kinematics Model ◽  
Body Dynamics ◽  
Multi Body ◽  
Free Form Surfaces

This paper develops a novel five DOF hybrid polishing kinematics machine tool in order to obtain more stable machining result in the elastic polishing on the free-form surfaces. Because the machine tool is a complex multi-body system that comprises many close-loop structures, jointing clearance becomes the important influence factor to its moving stability. The unified rigid multi-body and flexible multi-body dynamics equation of for the parallel mechanism of hybrid polishing kinematics machine tool is respectively built, which considers the influence of joint with clearance and applies the kinematics model of Newton second state. The result of analysis shows that the moving stability of the hybrid polishing kinematics machine tool is reduced due to the existing jointing clearance. However, the interior flexibility of the mechanism can reduce the shock effect of collision in the part of motion pair. It can improve the working stability of mechanism.

Study on the Fuzzy-PID Policy for Force Control in Free-Form Surfaces Polishing by Robots

2011 ◽  
Vol 101-102 ◽  
pp. 422-426
Author(s):  
Xiao Ling Su ◽  
Jian Ming Zhan
Keyword(s):  
Force Control ◽  
Normal Direction ◽  
Curved Surface ◽  
Free Form ◽  
Work Piece ◽  
Fuzzy Pid ◽  
Polishing Force ◽  
The Right ◽  
Free Form Surfaces ◽  
Polishing Tool

When a robot is used to polish or finish a curved surface, both feed movement and contact force have to be controlled at the same time so that the polishing tool would machine its work-piece at the right position in right posture with required force. In this paper, a passive wrist system is developed to adapt the shape of the machining curved surface by changing its posture along with the surface. And under the Fuzzy-PID policy, polishing force is controlled at a stable value in the normal direction of the named machining point while the polishing tool moving along the curved surface by multi-point machining. It means that the passive wrist system and the model of the surroundings could be used in force controlling when robots polish free-form surfaces with multi-point machining by a grinding ring.

Development of Polishing Tool Capable of Self-Adaptive to Processing Site Using Steel Balls and Magnetic Force

2016 ◽  
Vol 1136 ◽  
pp. 466-471
Author(s):  
Lei Ma ◽  
Tatsuya Furuki ◽  
Takashi Kure ◽  
Toshiki Hirogaki ◽  
Eiichi Aoyama
Keyword(s):  
Magnetic Force ◽  
Free Form ◽  
Machining Center ◽  
Abrasive Finishing ◽  
Processing Site ◽  
Free Form Surface ◽  
Steel Balls ◽  
Free Form Surfaces ◽  
Polishing Tool ◽  
Self Adaptive

There has been the requirement in recent times for environmentally friendly methods for finishing free-form surfaces such as those of molding dies [1]. This has led to interest in the development of a new polishing technology that utilizes less abrasive slurry and magnetic abrasive finishing. However, it is well known that the traditional magnetic polishing method is unstable and produces insufficient surface smoothness. In the present paper, we discuss the causes of the instability of conventional magnetic polishing. We also propose a self-adaptive polishing tool comprising a brush with steel balls and a coating of thin slurry and present the results of its use to polish various incline surfaces on a three-axis machining center. The proposed self-adaptive polishing tool was found to be effective for polishing a free-form surface using less abrasive slurry.

Stability Analysis of the MRT-Based Compliant Polishing Tool System

2012 ◽  
Vol 201-202 ◽  
pp. 473-476
Author(s):  
Chong Yang Yuan ◽  
Di Zheng ◽  
Jian Ming Zhan ◽  
Li Yong Hu
Keyword(s):  
Geometric Modeling ◽  
Mixed Model ◽  
Simulation Software ◽  
Free Form ◽  
Cnc Milling ◽  
Element Analysis ◽  
Compliant Polishing ◽  
The Stability ◽  
Free Form Surfaces ◽  
Polishing Tool

In order to meet the needs for the precise polishing of free-form surfaces, a new compliant polishing tool system was designed based on a magnetorheological torque servo (MRT), and integrated into a CNC milling machine. Through analysis, it was pointed out that the key factor affecting the polishing quality of this system is the stability of the system. By means of the 3D geometric modeling software ProE, the finite element analysis software ANSYS, and the dynamic simulation software ADAMS, the rigid-flexible mixed model of the system was established and the stability of the polishing pressure and tool position was numerically analyzed.

The Series-Parallel Robot Coordinates Polishing System Based on the Multi-Agent

2010 ◽  
Vol 97-101 ◽  
pp. 2682-2685
Author(s):  
Miao Yu ◽  
Shi Qiang Ma
Keyword(s):  
Optimal Path ◽  
Parallel Robot ◽  
Free Form ◽  
Multi Agent System ◽  
Control Parameters ◽  
Optimal Parameters ◽  
Point Curve ◽  
Multi Agent ◽  
Multi Body ◽  
Polishing Tool

This paper puts forward a multi-Agent alliance control model that is made up of the series robot Agent, the parallel moving platform Agent and the polishing tool system Agent and so on by organically introducing the MAS (Multi-Agent System) theory into the polishing. Through the introduction of point-curve constraint, the dynamics equation of the constraint multi-body for the polishing system is established in order to accurately program the moving track of the robots. Meanwhile, the control parameters during the polishing can be optimized and the foundation can be afforded for carrying out the collocation of the optimal parameters with the series-parallel coordinates polishing and programming the optimal path on the free-form surface.

The Dynamics Analysis of the Robot Polishing System by the Multi-Agent System

2009 ◽  
Vol 419-420 ◽  
pp. 601-604
Author(s):  
Miao Yu ◽  
Zhi Cai
Keyword(s):  
Optimal Path ◽  
Free Form ◽  
Multi Agent System ◽  
Control Parameters ◽  
Agent System ◽  
Working Space ◽  
Point Curve ◽  
Multi Agent ◽  
Multi Body ◽  
Polishing Tool

In order to solve the confliction among the working space, precision and stiffness on the free-form surface, this paper puts forward a Multi-Agent alliance control model that is made up of the series robot Agent, the parallel moving platform Agent and the polishing tool system Agent and so on by organically introducing the MAS (Multi-Agent System) theory into the polishing. Through the introduction of virtual point-curve constraint, the dynamics of the constraint multi-body equation for the polishing system is established in order to accurately program the moving track of the robots. Meanwhile, the control parameters and the optimal path during the polishing can be optimized.

A Comprehensive Inverse Dynamics Problem of a Stewart Platform by Means of Lagrangian Formulation

2017 ◽  
Author(s):  
Naser Mostashiri ◽  
Alireza Akbarzadeh ◽  
Jaspreet Dhupia ◽  
Alexander Verl ◽  
Weiliang Xu
Keyword(s):  
Inverse Dynamics ◽  
Virtual Work ◽  
Stewart Platform ◽  
Joint Torques ◽  
Body Dynamics ◽  
Inverse Kinematics Problem ◽  
Simplifying Assumptions ◽  
Inverse Dynamics Problem ◽  
Multi Body ◽  
Lagrange’S Method

In this paper, using the Lagrange’s method a comprehensive inverse dynamics problem of a 6-3 UPS Stewart platform is investigated. First, the inverse kinematics problem is solved and the Jacobian matrix is derived. Next, the full inverse dynamics problem of the robot, taking into account the mass of links and inertia, is investigated and its governing equations are derived. The correctness of the dynamics equations are verified in two ways, first, using the results of the virtual work method and second using the results of a commercial multi-body dynamics software. Because the dynamic calculation is time consuming, two simplifying assumptions are considered. First, the link is assumed to have a zero mass and next it is assumed as a point mass. Studying the former assumption is rather straightforward. However, more complex equations are needed and derived in the present paper for the latter assumption. Required actuator forces for the two assumptions are compared with the case where the mass and link inertial is fully considered. It is shown that the first simplifying assumption significantly affects the accuracy of the required joint torques.

Sign in / Sign up

Export Citation Format

Share Document