Abstract
The present paper analyses the potential dynamic performance of a novel redundant SCARA robot, currently at the stage of a functional design proposed by a renowned robot manufacturer. The static and dynamic manipulability of the new concept is compared with the conventional model of the same manufacturer by means of computer simulation in typical pick and place tasks arising from industry. The introduction of a further revolute joint in the SCARA robot kinematics leads to some improvements in the kinematic and dynamic behaviour at the expense of a greater complexity. In this paper, the potential of a redundant SCARA architecture in cutting cycle-times is investigated for the first time in performing several tasks. It is shown that, in order to exploit the possible enhancements of the redundant structure, the whole manipulator, mechanics and control must be redesigned according to specific tasks aiming at the optimization of their cycle-time.
Highlights
The history of assembly technology has a milestone in 1980, when Hiroshi Makino filed the patent of a new concept of robot called SCARA, which stands for Selective Compliance Assembly Robot Arm [1], see Figure 1a; with four axes; it is able to develop a kind of motion, called Schönflies motion, which is very useful in many applications and consists of a linear displacement in three-dimensional space plus one orientation around an axis with fixed direction
Other parallel kinematic structures that assure fast pick-and-place operation have been derived from the Delta manipulator, e.g., the parallel kinematics machines (PKMs) proposed by Tosi et al [3] or from other similar concepts [4,5,6]
Some tests have shown that Coriolis and Centrifugal terms have a heavier weight for the redundant robot than for the conventional SCARA
Summary
The history of assembly technology has a milestone in 1980, when Hiroshi Makino filed the patent of a new concept of robot called SCARA, which stands for Selective Compliance Assembly Robot Arm [1], see Figure 1a; with four axes; it is able to develop a kind of motion, called Schönflies motion, which is very useful in many applications and consists of a linear displacement in three-dimensional space plus one orientation around an axis with fixed direction. The success of the SCARA kinematics is mainly due to the fact that this architecture can realise very high speed movements, unreachable at that time with previous robots like the three-axis R-theta Robot. Since the 1980s, many other efforts have been made to meet or even overcome the performance of that design, leading in recent years to the completely new concept of parallel kinematics machines (PKMs), like the Delta patented by Clavel [2].
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call