Dynamic model and force control of the redundantly actuated parallel manipulator of a 5-DOF hybrid machine tool

Robotica ◽  
2009 ◽  
Vol 27 (1) ◽  
pp. 59-65 ◽  
Author(s):  
Jun Wu ◽  
Jinsong Wang ◽  
Liping Wang ◽  
Tiemin Li

SUMMARYThis paper deals with the dynamic model and force control of the redundantly actuated parallel manipulator of a 5-DOF hybrid machine tool. The inverse dynamic model is derived by using the Newton–Euler method. The driving force is optimized by the least-square method. Based on the kinematic and dynamic models, the redundant chain is controlled by force mode and other chains by position mode. The redundantly actuated parallel manipulator is incorporated into a 5-DOF hybrid machine tool which also includes a worktable with a translational DOF and a rotational DOF. The experiments wherein the machine moves along a straight-line trajectory and a circular trajectory show that the machine has a good contouring performance.

2007 ◽  
Vol 2 (4) ◽  
pp. 344-350 ◽  
Author(s):  
Jun Wu ◽  
Jinsong Wang ◽  
Liping Wang ◽  
Tiemin Li ◽  
Yue Liu

This paper focuses on the dynamic modeling and counterweight optimization of the two degree of freedom planar parallel manipulator, which is a subpart of a hybrid machine tool. Based on a kinematic analysis, the dynamic equation is derived by using the Newton-Euler approach. Then, three counterweight modes are presented for the parallel manipulator. According to the cutting force model and motion planning of the cutting tool, the dynamic simulations with three counterweight modes are performed, and the mass of counterweight in each counterweight mode is optimized by minimizing the sum of mean square values of actuator forces. The simulations show that the optimal mass of counterweights does not equal the total mass of moving parts of the parallel manipulator, and each counterweight mode has its advantage and disadvantage. Considering the ease in which a counterweight can be implemented, the counterweight mode where two counterweights are connected to two sliders is adopted for the parallel manipulator.


2008 ◽  
Vol 130 (5) ◽  
Author(s):  
Jun Wu ◽  
Jinsong Wang ◽  
Liping Wang

This paper addresses optimal kinematic design and application of a redundantly actuated parallel manipulator with 3DOFs. Based on the kinematic model, the Jacobian matrix is derived and then transferred to a uniform form such that the conditioning index has explicit physical meaning. Based on the task workspace, the width between two columns is determined. Then, a comprehensive performance index, which compromises the conflict between workspace utilization performance measure and conditioning index, is proposed for the optimum design. The parallel manipulator is incorporated into a 4DOF hybrid machine tool, which also includes a feed worktable. Furthermore, a 5DOF machine tool is created by combining the parallel manipulator with a 2DOF worktable to machine blades of gas turbines.


Author(s):  
L-P Wang ◽  
J-S Wang ◽  
Y-W Li ◽  
Y Lu

This paper presents an inverse dynamic formulation using the Newton-Euler approach for a planar parallel manipulator, which is used in a new five-axis hybrid machine tool. The inverse kinematics of the manipulator is given and the velocity and the acceleration formulae are derived. The driving forces acting on the legs are determined according to the dynamic formulation. The formulation has been implemented in a program and has been used for some typical trajectories planned for a numerical simulation experiment. The simulation results reveal the nature of the variation of the driving forces in the hybrid machine tool and justify the dynamic control model. The dynamic modelling approach presented in this paper can also be applied to other parallel manipulators with less than six degrees of freedom.


Sign in / Sign up

Export Citation Format

Share Document