Abstract:
We are in the process of developing a laboratory for automated manufacturing. As would be expected, this laboratory contains robotic manipulators and CNC machine tools. But, the backbone of the laboratory is a collection of computers that allow access and programming of all the equipment using the World Wide Web (http://www.aml.gvsu.edu). This allows student access to virtual and real equipment 24 hours a day from any location (including home) with a web browser. The architecture of the laboratory will be discussed along with examples of planned student use.
1. Introduction
As part of our expanding curriculum, we are adding a course in integrated manufacturing. This course (EGR 474: Integrated Manufacturing) will include topics such as robotics, CNC machining, networking, databases and integration. This course will require that students are taught to use a number of basic pieces of equipment, and then combine these into a complex system. Safety concerns would normally cause us to teach the programming techniques and then allow students to use the scheduled lab time. To overcome this problem we are developing a laboratory that would remove many of the access barriers for this type of laboratory including open hours and physical presence.
The Internet is a naturally flexible tool that can be adapted to overcome the access problem. We have been writing programs that allow a user to access various devices in the laboratory to just ‘play’ or to test programs. These allow the student to directly access the equipment, and vary parameters. A video link allows visual verification of commands. All of these services are available using the Netscape Web browser with no special additions. The software technologies used include HTML, VRML, Java, and various other languages.
2. The Lab
The laboratory usage is planned to involve a prelab step where programs are developed. When the students arrive at the laboratory they will try their programs, and analyze the results for correctness. This model requires that the students have access to the information and equipment before the lab session to learn how the equipment operates. Figure 1 shows how a student might use the virtual laboratory to experiment with the equipment before the scheduled lab time. The interfaces to the lab have been developed with this approach in mind.
Figure 1: Prelab Preparation for Robot Usage
At present the laboratory contains,
2 robots (RS-232)
1 lamp (parallel port and special circuitry)
video camera (parallel port)
data acquisition card (installed in computer)
1 CNC lathe (RS-422)
These are connected by various computers running Linux and Windows NT. The student can access one of the machines and view the workcell with the camera as shown in Figure 2. Before trying the actual robot (or if it is in use) the students will be able to run a simulated robot to become familiar with the basic structure of the robot, or to run simulated programs. The robot simulator window is seen below in Figure 3. The robot simulator has been developed with a combination of Java and VRML.
Figure 2: The Video Link
Figure 3: The Virtual Robot Using Java and VRML
The student will use a Java applet to get control of the workcell. An applet for the robot is shown in Figure 4. To use this applet the student clicks on appropriate buttons to direct motions and change settings. Feedback of position is also possible.
Figure 4: Java Applet for Robot Control
Figure 5: Java Applet for a Robot Program Simulation
6. Conclusions
We have described our current progress on an Internet accessible laboratory for Integrated Manufacturing. At the time of writing (January 1998) we are four months away from the first course offering, but we have already tested and developed most of the major components as outlined in the paper. By the summer of 1998 the laboratory will support a number of fundamental laboratories in robotics, remote data monitoring and CNC machining. In addition we will be able to incorporate other applications such as a database.
