Research in Engineering Education Symposium 2011 - rees2009

Universidad Politécnica de Madrid (UPM) Página 327 de 957
Figure 2: Information provided by the ABB manufacturer used by the students to perform the first
practice and apply it to the robot ABB: (a) Manipulator axes, (b) working space, (c) ranges of
movement and (d) load diagram
Then they must decide if a series of combinations of axels angles are possible to be
applied or not and when possible apply it to the robot (Fig. 2c). Another task is to
define the maximum load allowable at a certain distance from the extreme element
applying the load diagram given by the manufacturer (Fig. 2d). Finally a
commentary about relevant technical information such as repeatability is given
and information about safety use of the robot. This practice is developed at the end
of the first unit of the subject when the students have general knowledge of the
components of the industrial robot, types of control, applications, etc.
• Practice 2: Analysis of position applied to the robot ABB IRB: In this practice
two different position problems (direct and inverse) are covered. Each one is
developed in two phases: firstly simulation and secondly the application to the
robot ABB IRB140. The direct position problem consists in obtaining the final
position of the robot´s extreme for a given set of axle angles. The simulation stage
is done with the computer simulation (student must have the knowledge of
movement simulation with Inventor® and Robostudio® so the seminars
Inventor® and Robostudio® must be done previously), obtaining the three
cartesian coordinates of the interest point of the terminal element. Also the
simulation provides an image of the robot at that position. Then, students move
the robot axle by axle until the desired axle angles are reached, and take a photo of
the final configuration of the robot. Next, a student checks the position of the
extreme element with a laser measurement device. These coordinates are read by
other student; laser device gives the z coordinate and laser spot gives the x and y
coordinates. In the practice report, students compare the two solutions, virtual
with simulation software and real with the ABB robot.
The second problem, the inverse position problem, consists in obtaining the values
of the set of angles which applied to each axle set the robot in a given position.
According to the theory, 8 different ways of raise a certain position are
mathematically possible (Fu, Gonzalez & Lee, 1988). First, the students use the
computer application in Mathcad® for obtaining the 8 possible solutions of the
manipulator and check if one is mechanically possible according to the technical
data of the robot (studied in practice 1). Then, students simulate the movement in
Inventor® to all the positions observing the possible collision between robot
elements for the non accessible mechanic solutions, and keeping an image of each
possible solution. Then, the students apply to the robot all the mechanical
Proceedings of Research in Engineering Education Symposium 2011
Madrid, 4 th - 7 th October 2011