Abstract
This chapter describes the development of a robotic CAM system for six-DOFs articulated industrial robot to generate online motion supported by cutter location source (CLS) data and numerical control (NC) data. The robotic CAM system realizes a practical data interface between industrial robots with open architecture controllers and commercially available CAD/CAM systems, and it includes functions that generate minute position and orientation components for real time motion control from CLS data and NC data without the need for teaching. The design principles of the developed robotic CAM system, and the experimental results on three real robots, RV1A, VS068, and FANUC R2000iC, are presented and demonstrated using both CLS and NC data generated through the developed CAM system.
Top1. Introduction
Mechatronics deals with development, design, practice and applications associated with modern systems, control techniques and intelligence aiming to solve engineering problems and fulfilling needs. Habib (2007) showed time line evolution of interdisciplinary mechatronics as a field of synergy since 1970s. In addition, he introduced the knowledge space paradigm of mechatronics, while exploring the importance and the prospect of the future development of mechatronics both at the research development and education levels.
One of representative mechatronics systems is the industrial robotics. Robotics represents a well-developed example of interdisciplinary class of mechatronic systems, which has been remarkably advanced and applied to several tasks such as welding, handling, painting, polishing, etc. In addition, due to improvement of robot accuracy, load handling, repeatability and speed, the robotics integrated with artificial intelligence and learning capabilities is evolving to play a key role in our current manufacturing and future industry and in human life as well.
It is important to mention that the relation between the current CAD/CAM systems and the NC machine tools are well established and widely adopted in manufacturing industries compared to that between the CAD/CAM systems and the industrial robots that is not well established yet. A model generated using CAD and verified through computer aided engineering (CAE) can be introduced to the CAM software in which its outcome controls the machine tool. Generally, the CAD/CAM system main-processor generates CLS data according to each model’s shape and machining conditions. Then, the post-processor produces the NC data that match the target actual NC machine tool that will use this data. The controller of the NC machine tool will use the generated NC date sequentially and accurately controls the positions of main head and the angles of other axes. On the other hand, however, the CAM system for industrial robots has not been sufficiently considered and as such it is not well developed yet. Due to this circumstance, generally a teaching pendant is used to obtain sequence of positions and orientations data of the arm tip through teaching before going to execute the trajectory connecting the taught points. Hence, it is necessary to develop innovative software that can integrate the simulation at the design level and the manufacturing at the robot level to increase flexibility and utilizes robotics capabilities effectively in solving problems. In addition, such software should be capable to receive the output of a CAM system and generate the suitable machining data code understandable by the robot side. Having the capability to share and exchange data between different CAD/CAM systems and different robot controllers will lead to fulfil the standardization demand is such evolution. The demand to develop innovative software that can integrate the design process and the manufacturing requirements increases. As a result of this many researchers in the field started their research toward achieving such goal developing software that realizes a robot driven machining process by having CAM robotics programing solution.
Key Terms in this Chapter
Robotic Teaching: Robotic teaching is the well-known process to make a desired trajectory by using a teaching pendant. The robotic teaching is a time-consuming task.
Robot Language: An industrial robot has an original robot language provided by the robot maker to describe a program for a robotic application. The drawback is that it is not well standardized among various types of industrial robots.
Industrial Robot: Articulated-type industrial robot RV1A with six degree-of-freedoms. The servo system and communication interface are technically opened to users.
Servo Controller: Six servo motors are built in the corresponding six joint of the industrial robot RV1A. The joint angles can be controlled to follow reference values by the servo controller.
CAD/CAM: Computer-aided design and computer-aided manufacturing. Here, CAD/CAM is used to make a desired trajectory of the robot arm without a robotic teaching process.
NC Data: Numerical control data according to the type of machine tool are converted from CLS data. The tool for this process is called the post-processor.
Reverse Post-Processor: Reverse post-processor is the online conversion tool from NC data to CLS data in the proposed robotic CAM system.
CLS Data: Cutter location source data are generated from the main-processor of CAM, which are written with multi-lined “GOTO” statements including position and orientation vectors.