Kinematic Reliability Analysis of 3-PSS manipulator based on the explicit solution and design of experiment method

Document Type : Research Article

Authors

1 صنعتی امیرکبیر*مهندسی مکانیک

2 دانشگاه صنعتی امیرکبیر

3 دانشگاه صنعتی امیرکبیر، دانشکده مهندسی مکانیک

Abstract

This paper aims at the kinematic reliability analysis of a 3D printer
with parallel architecture. Parallel mechanisms bear many advantages like higher
stiffness, more accuracy and speed compared to the serial counterparts. Generally,
the moving platform (MP) of a robot is demanded to follow a desired trajectory
with a certain accuracy to reach a defined position. Because of several uncertainty
factors such as actuators error, links flexibility, joints clearance and etc. a robot
cannot follow a desired trajectory without an error. Hence, it is crucial to evaluate
the level of kinematic accuracy and reliability of a robot to perform a task. In
this study, at first, among many uncertain parameters, eight are selected. Next,
the probability distribution of the MP position is conducted by means of the
closed-form kinematic relation of robot and the Monte Carlo Simulation (MCS),
and then, the kinematic reliability is calculated for different levels of accuracy.
In the second part, the number of uncertain parameters are increased to 12. In
this regard, the closed-form kinematic relation between the actuators rate and
the MP position cannot be obtained. Hence, a polynomial algebraic equation is
fitted via the design of experiments (DOE) method. With the fitted polynomial
kinematic equation at hand, the reliability analysis is conducted and evaluated for
different levels of accuracy. Also, an experimental reliability analysis is performed
to evaluate the results which are obtained numerically. At the end, a sensitivity
analysis is conducted to determine the influence of each uncertain parameter on
the accuracy.

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