Tunable Vibration Absorber Design for a High-Precision Cartesian Robot

Abstract

In metal sheet processing for automotive application, it is crucial to guarantee high robot dynamics for reduced cycle times and adequate components accuracy to be competitive in the market. Since the two aspects are closely and inversely related, the problem becomes challenging. After the first cutting tests, the Cartesian Robot prototype displayed insufficient dimensional accuracy when undergoing high accelerations. The solution hereby proposed is the design of a Tuned Mass Damper (TMD), working in shear mode, to reduce the robot vibration amplitude. To this end, an initial assessment of the robot frequency response and natural frequencies was performed both by using a Finite Element (FE) model of the machine and experimentally. Further, frequency response analyses were carried out to evaluate the TMD effectiveness and to highlight possible criticalities from the manufacturing point of view. On a numerical level, the proposed design can damp the machine resonant frequencies, also showing a certain grade of tunability before operation and in-plane orientation insensitiveness thanks to the use of cylindrically shaped springs.

Robotics and Aseptic Processing in View of Regulatory Requirements

“…It gets its name from the reference system introduced by the philosopher and mathematician Descartes using the coordinate method to highlight its movements along orthogonal axes. Its special distinction point is that it has only prismatic (linear) joints for principal movements; it can therefore move only in a straight line on the three axes [ 35 , 36 ].…”

Virtual Training System for the Teaching-Learning Process in the Area of Industrial Robotics

“…The IFR Robot Suppliers Committee classifies industrial manipulator robots according to the mechanical structure of the arm as follows: Cartesian robots corresponding to linear and gantry robots; Scara robots; articulated robots, which are anthropomorphic robots; parallel robots, which are delta robots; cylindrical robots; and among others [5]. (i) Cartesian robot: this type of robot has a limited working space, shows a serial configuration of the motors so it performs a linear movement, and cannot be subjected to high accelerations because there is an error in the position of the axis, reducing structural rigidity [7], are also used in specific applications for the handling of heavy loads [6]. (ii) Delta robot: they are mostly used for tasks of handling, sorting and classification of light materials where the development of this type of robots with high velocity and precision and light weight means that the links are made of flexible materials which cause vibrations as mentioned in the following table [8,9].…”