Kineto-static analysis of a novel high-speed parallel manipulator with rigid-flexible coupled links

Abstract

A novel high-speed parallel kinematic machine (PKM) named Delta-S parallel manipulator is proposed, which consists of a fixed base connected to a moving platform through three limbs with identical topology. Each limb is composed of one driving arm and one follower arm, herein, the latter includes two strings and one middle rod, all located in a same plane. Compared with similar manipulators with uniform parameters, the novel and unique topology as well as the addition of two strings of Delta-S manipulator can remove the clearance of the spherical joints, reduce the inertial load of components further, improve the positioning accuracy and dynamic performance, and so on. In order to formulate the kineto-static model of Delta-S manipulator, the kineto-static analyses and models of the driving arm, the generalized follower and the moving platform can be carried out by the D'ALEMBERT principle. For the sake of obtaining the force analytic results of strings, the deformation compatibility condition of strings and the middle rod are determined. Furthermore, in virtue of the assumption of small deformation and the linear superposition principle, the minimal pre-tightening force of the strings is calculated. The main results include that the loads of the strings and the middle rod must be larger than "zero" and the pre-tightening force over the workspace must be larger than the minimal pre-tightening force at any time within the workspace, which lay the foundation for the dynamic analysis and the prototype manufacture of the Delta-S manipulator.

Dynamic model and input shaping control of a flexible link parallel manipulator considering the exact boundary conditions

“…[38], an approach is proposed to estimate the tracking error of the moving platform using the output voltages of PZT sensors mounted on flexible links and feedback signals of a linear grating sensor. Equation (19) is used to estimate the tracking error along x-and y-axes. The modal coordinatesq in Eq.…”

“…The modal coordinatesq in Eq. (19) are calculated using the output voltages of PZT sensors through a modal filter, 38 and the variablesq andq in Eq. (19) can be obtained by differentiatingq twice and once, respectively.…”

“…Hu et al 18 conducted the experiments of active vibration control of a five-bar flexible PPM with PZT actuators and strain gauges. Sun et al 19 investigated a high-speed parallel Delta-S manipulator based on kinetostatic analysis. However, to obtain an accurate dynamic model of a PPM for vibration analysis, exact boundary conditions, which accurately model the linkage dynamic behavior, must be considered.…”

Elastodynamic modeling and parameter sensitivity analysis of a parallel manipulator with articulated traveling plate

“…The commonly concerned performance indices of parallel mechanisms include workspace [26], singularity avoidance [27,28], stiffness [29,30], and dynamic [31][32][33]. Since the studied PM-ATP is targeted for assembling large components, elastodynamic performance [34,35] catering on large loadcarrying, lightweight structure and small deflections is of importance.…”

Static and dynamic optimization of a pose adjusting mechanism considering parameter changes during construction

“…Having several kinematic chains to support the same end-effector, PMs have the advantages in terms of high stiffness, large load-weight ratio and good dynamic response [11][12][13]. Correspondingly, they suffer from smaller workspace and more complex control system comparing with their serial counterparts.…”