Page 53 - Kaleidoscope Academic Conference Proceedings 2020

4.2 Geometric data in a STEP file

The geometric information of the machine model is exported
into a STEP file using the standard interface provided by
Creo. The export functionality automatically generates a .stp
file; a portion of the exported STEP file is shown in Figure
6. The STEP file (.stp) contains all the geometric data
starting from the line defining DATA. The schema used for
defining the model is CONFIG_CONTROL_DESIGN from
AP203. Figure 8 – An example of a complete STEP file (.stp file)
generated by the STEP generator

5. DISCUSSION
This work contributes to the field of system interoperability
and information reuse for machine modeling. During this
study, challenges and issues have been identified, and more
research and development efforts are required to address
them. The challenges are elaborated in the following
Figure 6 – A snap view of the STEP file that is exported subsections from different perspectives: (1) challenges with
from Creo and contains all the geometric information of the the applications of STEP, JSDAI, and J-link, (2) challenges
machine tool model with converting the machine models and kinematics
information including aspects of verification and validation
4.3 The STEP Generator using JSDAI and J-Link of the developed approach, and (3) challenges with the
commercial software and data reuse for end users.
The Java development environment used in this study is
Eclipse. JSDAI provides plug-ins that are compatible with 5.1 Challenges with the applications of STEP,
Eclipse. JSDAI also provides an EXPRESS compiler for JSDAI, and J-Link
compiling the EXPRESS files and creating .jar files for use
in Java programs to represent the data model. The STEP standard has been a work in progress since its
introduction in 1994 and there are continuous improvements
The STEP Generator uses an iterative process to evaluate the and new additions to it. One of the latest developments is the
characteristics of the kinematics information and add it AP 242 edition 2 that integrates the definitions from both AP
accordingly to the STEP file. To allow JSDAI to manipulate 203 and AP 214, which are originally developed for different
the model data, the read-and-write access is used for manufacturing industries. The new AP becomes more
accessing the data in the generated STEP file with geometric complex and is harder for users to understand and use.
data and for writing kinematics data to the STEP file to create Because the STEP definitions are cumbersome, it requires a
a complete STEP model according to the AP 242 EXPRESS specific software for editing and manipulating a STEP file.
model. A repository is created for JSDAI to store the
temporary kinematics data. JSDAI covers most definitions that are needed for writing,
reading, and modifying STEP models. This makes JSDAI
The kinematics information in the Hurco machine model is applicable to the development of the kind of STEP
defined as constraints. For each constraint, an array will be generators we described in this paper. However, the
created to store the data. This data is written to the STEP complication of the STEP definitions has also added more
model according to the EXPRESS schema used, i.e., AP 242, complexity to the JSDAI applications. Since JSDAI is an
and an example is shown in Figure 7. open source API, there are few examples demonstrating real
use cases of where JSDAI has been used. The technical
support from the developer of JSDAI is hard to get and the
documentation of JSDAI is not up to date. With better
documentation, more examples, and further developments,
JSDAI can facilitate the implementation of the STEP
Figure 7 – An example of code where the kinematic data of standard more efficiently. The effort required for this
model feature is extracted for conversion to the STEP format implementation was about 4 months for a person with basic
programming skills. By referring the approach proposed and
After going through all the kinematics constraints, a STEP the lessons learned in this paper, an industry application
model representing both geometrical and kinematics data is could be implemented in a shorter time. More JSDAI
generated from JSDAI as a .stp-file and a section of such a implementations would also motivate the enhancement and
model is shown in Figure 8. the support of technology.

– xlix –