Kinematic calibration of gantry hybrid machine tool based on estimation error and local measurement information

Abstract

This paper presents the kinematic calibration of a four degrees-of-freedom (DOF) hybrid machine tool based on a novel planar 3-DOFs parallel mechanism and a long movement of the worktable. Closed-form solutions are developed for both the inverse and direct kinematics about the parallel mechanism. The error model is built and the mechanism accuracy is investigated. Two types of kinematic calibration method are proposed by a simple measurement device. The first type of calibration method is based on estimation error, and can easy improve the machine tool accuracy quickly by estimating the error trends. The second type of kinematic calibration method is based on local measurement information, which includes the position errors and does not include the pose errors of the machine tool. The calibration tests showed the effectiveness of the calibration methods, which can be useful for the similar types of parallel machine tool.

Optimum Design of 3-3 Stewart Platform Considering Inertia Property

“…Considering (4) and (6) together gives the relation between the end-effector velocity and the limb velocity aṡ…”

“…Compared with conventional serial manipulators, parallel manipulators possess some inherent potential advantages [1], such as high accuracy, improved stiffness, increased dynamics, compact structure with multiple degree of freedoms (DOF), and so on. As a result, parallel manipulators attract great academic attentions and are more and more widely adopted in industrial applications, namely, flight simulators [2], telescopes [3][4][5], and machine tools [6].…”

Calibration of Parallel Manipulators and their Application to Machine Tools. A State of the Art Survey

“…For a Gantry hybrid machine tool, based on a 3 dof parallel mechanism and a long motion of the working table, the kinematic calibration methods based on estimation error and local measurement information is presented in (Tang et al, 2005). The first type of calibration method can easily improve the PKM accuracy quickly by estimating the errors trends.…”

Dynamics Verification Experiment of the Stewart Parallel Manipulator

“…It has been acknowledged that parallel manipulators possess advantages in terms of accuracy, rigidity, large load-to-weight ratio and high acceleration, compared to traditional serial manipulators [2, 3]. This statement can be verified by their wide application as machine tools [4, 5], positioning devices [6, 7], motion simulators [8, 9] and high-speed pick-and-place robots [10, 11]. An accurate dynamic model and parameters function as a closely related whole and are important for the parallel manipulator in several aspects, including dynamic control, optimization analysis and driver selection, since parallel manipulators are generally preferred in applications where high load and good dynamics are required.…”