Page 384 - Mechatronics for Safety, Security and Dependability in a New Era

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shown in Figure 4. The rotary motions around Xaxis as well as 7 axis and the Z axis are designated as
A, C (as B) and C |S respectively. The inclination and rotation of the work piece is executed by A and C
axis respectively, while the C s axis controls laser device direction for realizing high measurement
accuracy.

Figure 4: 5-axis machining center

MEASUREMENT SOFTWARE

In this system, commercial CAD/CAM system: Pro/ENGINEER is used for modeling as well as
machining and measurement. Additionally we use versatile post processor setup application: GPOST
which is collaborated with Pro/NC. The post processor setup application can change parameters and
add a routine macro easily. Thus, we setup two post processors for simultaneous 5-axis control
machining and measurement with laser displacement sensor. On CAM section (cutter location
generation support system) generates CL data both for machining and for measurement. CL for
machining has an inclination to normal vector of a free form surface for enhanced machining
efficiency as shown in Figure 5. As opposed to it, CL for measurement may always suit normal of a
free form surface as shown in Figure 5. CAM software can easily set up parameter of the inclination
angle to the normal direction of curved surface. NC data for machining center is created by post
processor. NC data is composed of the coordinate value of cutting point and angle expression of the
tool orientation. Post processor for the measurement generates NC data for the measurement. NC data
for the measurement has some special routine macro (called 'switch motion') in order to arrange
measurement data with a personal computer easily. Carrying out pick feed, measurement is performed
so that the whole surface may be traced. Therefore, plunging operation which does not trace the
measurement surface, retraction operation, and rapid traverse positioning operation follows as an
additional operation. It is necessary to notify PC about these non-measurement times in order to hold
down consumption of a useless memory. Then, operation which notifies the switch of measurement (:
switch motion) was introduced. The switch motion is the specific motion for notifying software about
the joint of measurement by changing coordinate value. The motion consists of Z-axis movement and
dwell. Secondary, we have developed PC software for the measurement on 5-axis machining center
because both coordinate values and laser data are required in measurement with high accuracy.
Furthermore, it is necessary to convert the 3-dimensional form data of a measured model from the
acquired coordinates which include angular position of rotary table and displacement from the laser
sensor. Then we developed software with these function. The main functions of the software is as
follows; inputting CL and NC data which were generated from commercial CAM for measurement,
reading machine coordinates and laser displacement sensor value. And the software monitors start and