The main menu is iconized and displayed in VP2 as shown in Fig. 2;
the user can choose the type of mechanism to be synthesized by clicking
these icons with the mouse. Thus, VP2 is divided into seven sections called
POSi, for , as described below:
Figure 2:Icons of the main menu.
POS0: When this area is selected, VP2 changes from passive mode
to active mode.
POS1: The mechanism can comprise either three links or four
links. The option selected is highlighted to let the user know which one
is active.
POS2: Similar to POS1, except that, in this case, the user chooses
either an oscillating or an indexing mechanism.
POS3: The input kinematic pair can be revolute or prismatic;
the user selects the type here.
POS4: Similar to POS3, but, in this case, the kinematic pair
is chosen for the output.
POS5: This icon is used to define the input-output function
with the aid of a submenu displayed in VP4.
POS6: The user can exit VP2 any time by selecting this icon,
VP2 thus switching into passive mode.
In order to identify the type of mechanism under synthesis, we introduce
a suitable labelling, namely, x_xxx_xx, the meaning of each of
the three fields being
x:
The number of links of the mechanism, three (3) or four (4).
xxx:
The type of the follower motion, indexing (ind) or oscillating
( osc).
xx:
Two characters are reserved for this field, p and r,
which stand for prismatic and revolute, respectively. Thus, if we read
from left to right, the first character tells us the input pair, while
the second, the output pair.
For example, 4_osc_rr indicates a four-link mechanism with
oscillating follower, revolute input and revolute output.
Table 1:Design Parameters of VP3
The two square icons at the top of VP3 allow the user to animate
the motion of the mechanism. Here, the user can choose the sense of the
input motion. With the six icons below these two, it is possible to modify
the distance and the angle of three pairs of axes, namely,
The distance between the input and output axes;
the angle between the above two axes;
the distance between the output and roller axes;
the angle between the above two axes;
the distance between the roller axis and its generatrix; and
the angle between the above two axes.
With the eighth and ninth icons of VP3, the user can modify the
thickness of the contact surfaces, , , which do not affect the kinematics
of the mechanism, but have to be specified for manufacturing purposes.
The design parameters vary depending on the type of mechanism selected.
The parameters pertaining to a given mechanism type are marked with in
Table 1.
Figure 3:Flowchart of a) the
select_vp1 procedure; b) VP1 procedures.
