Many of you have gained your impressions of robots from watching science fiction movies. Before reading the material on robots, you should first view some robotic animations .
From these videos it should be obvious to you that your hand has
much greater dexterity than a robot hand. Also, a great deal of effort
is required to get robots to perform tasks that humans consider very
boring.
Once programmed, however, a robot can perform a task repeatedly without
getting tired or bored.
An industrial robot is generally an arm with a gripper and some
capacity for movement such as straight lines and rotations. Japan has
been successful with robots capable of two straight movements and two
rotations; whereas, the US is going for all 6 degrees of freedom. More
advanced robots have microprocessors as brains. Sequences of motion for
the robot can be programmed into memory by leading the robot through
the desired sequences or programming the robot. Even more advanced
robots have artificial senses such as sight, touch, and force.
A fundamental problem in the assembly of industrial products is fitting
pieces with close tolerances together such as gears or placing a weld
in exactly the correct place. A human is an excellent assembler because
we automatically make minor adjustments in position to fit parts
together correctly. If a robot without sight tries to do the same it
must know exactly where the two parts are in space and the sequence of
motions to fit them together. Lacking the ability to make corrections,
the robot can easily jam or wedge the two parts together. The initial
progress in assembly automation was with robots without senses. These
initial successes required considerable effort to overcome the
orientation problem.
Robots without senses are currently used in painting and welding
automobiles. In painting, the robot is superior to the human because
the robot does not need a fresh air supply and protection from
dangerous chemicals. Moreover, painting is tolerant to deviations in
the positioning of the paint gun with respect to the automobile frame.
In welding auto frames together, the robot is also superior given the
strength required to handle the welders and the adverse conditions
under which the welds must be made. The equipment to have the frames
exactly aligned to make the welds costs much more than the robots.
Also, Kawasaki was able to program a robot without senses to assemble a
motorcycle gearbox by having the robot gripper vibrate slightly to
compensate for inaccurate positioning.
Advances in the use of robots in assembly have required the development
of robots with senses. When a human assembles a product or component of
a product, he or she can usually identify the component parts
instinctively without much thought. To create a program which gives a
robot the capacity to pick up randomly arranged parts is a major
undertaking. To provide a robot with a camera so that it can see is no
problem. What is a problem is providing the robot with the machine
intelligence to interpret the input from the camera. One solution is to
have the parts to be assembled arrive in exactly the right orientation.
This is expensive; thus, while acceptable for mass production, it is
inefficient for batch production. Some success is being achieved at
creating machine intelligence that can recognize parts in an arbitrary
setting. Work is progressing to give robots such senses as sight,
touch, and force. With these senses, a robot can be programmed to make
minor corrections to the sequences of steps it makes.
Much current success in assembly by robots with senses is achieved by
greatly simplifying the task of identifying alternatives. In production
this can be achieved by using bar codes similar to the ones used in
grocery stores. Bradly-Allen has a plant which automatically assembles
many kinds of controllers for electric motors on the same assembly
line. Robots know which sequence of operations to perform on each
product coming down the assembly line by reading the bar code on the
product. Robots with senses are also used for quality control checking
in this plant. A new alternative to reading bar codes is to install a
chip in each product with a radio transmitter. The advantage of this
technology is that numerous product identification ICs can be read at
the same time.
IBM created a plant here in Austin that employed robots with senses to
assemble laptop computers. The robots were controlled by PC-ATs. This
technology will probably be used to assemble all IBM personal computers
in the near future. Without significant labor costs, IBM can compete
with the clones. Robots, once programmed, put the right chip in the
right slot - something humans do not always do. As the number of
component parts in electronic goods is generally small, robotic
assembly in this area will proceed quickly.
Robots can currently assemble electronic products such as laptop
computers, gear boxes, electric motors, and other components. With each
new plant to assemble a product such as an auto, more and more of the
assembly will be automated. Since robots are not humans, the jobs that
they do best differ from jobs that humans do best. Furthermore, the
best assembly by robots frequently requires a complete redesign of the
product and manufacturing procedure to take advantage of the
capabilities of robots. This product redesign usually involves
simplification and reduction of the number of parts and consequently,
usually results in greater reliability.
In factory automation, software can be thought of as middleware, which facilitates communications between various applications. In the same way, standardization of software allows the various machines and robots involved in the manufacturing process to communicate with each other and with the firm’s central computers. This interconnectivity builds advanced analyses and forecasting abilities into the manufacturing process. RobotScript, a programming language for Robotics, is being developed based on VBScript (Visual Basic Script), which is already present on the Windows Platform. RobotScript enhances the existing VBScript with additional libraries necessary for programming robots and machines. The benefits a standardized programming language are economies of scale as the same code may now be reused for different robots and a decrease in labor costs since most programmers are already familiar with VBScripts intuitive syntax. Integrating RobotScript with VB also means that the Robot can be treated by Visual Basic as a Microsoft ActiveX component, which can then be easily interfaced with other programs on the Windows NT (networking) platform. This versatility allows companies to react rapidly to changes in the production process as well as equipment.
Robots are being built to provide self-diagnosis when they encounter errors or need maintenance. With these advanced intelligent features, companies do not need to hire specially trained/skilled technicians for general maintenance thereby making the process smoother and more efficient. Robots can provide instructions for repair and when more serious maintenance is required they can give detailed information about the errors involved and when they occurred.
This is the hard part of automation. Advances are taking place in
each of the steps of automation. Integration of all the steps is
currently impossible because the various types of machines are
incompatible. One step in the advance of automation and the integration
of steps is the creation of standards. Standards in the marketplace are
determined by professional groups or the dominant player. IBM, the
dominant player, set the standards for PCs. Standards have been
established for CAD graphics. GM has devised a language called MAP so
that all machines in manufacturing can talk to each other, and this
protocol has promoted the development of manufacturing communication
standards. Standards ensure compatibility between equipment, and small
players adopt the standards to ensure a market for their products.
Standards allow the small firm to specialize in a niche market knowing
its equipment will be compatible with whatever equipment comes along.
Currently (1995), there are several competing protocols for factory
LANs.
Standards for CAD drawings have been adopted industrywide and now CAD
is being integrated with FMS. In 1992 after a 5 year research program
costing $3.5M, a research group at a Dutch university created a startup
to market their program which would create the software to run a FMS to
create a part designed in a CAD program. Their software can be updated
and extended to accommodate different types of FMSs. This product is at
least 10 times faster than a human planner.
Advances in software to take CAD designs to create the software to run the machines to create the part is directly related to advances in 3D CAD software. Read Greco Systems's discussion of reusable software is this industry.One trend is upgrading older machines that were controlled by paper tapes with computers. Shop floor automations is active in this area.
Complete CIM must solve the data problem. A completely automated plant
from design to final assembly requires a massive data base with all the
designs, the programs to create the parts from the designs, the
programs to route the parts to the assembly line, and the programs to
assemble the final product. Moreover, this database must be integrated
into the office database for sales, accounting and so on. In a
completely automated factory, once the design is complete, a program
would take that design and automatically create all the sets of
instructions for all subsequent steps. The achievement of this goal is
some indefinite time in the future. However, more and more of the
paperwork associated with manufacturing is shifting to electronics.
A recent invention in software tools for manufacturing is the creation of digital factory software to simulate the production process and layout. We use this term generically even though Tecnomatix has a trade mark on the term, digital factory. The use of digital factory software has lead to innovations in manufacturing:
Leaders in the field:
New factory equipment now comes equipped with a built in Internet connection. This means that robots in several factories can be monitored from one central location. Using XML, robots can transfer data and information seamlessly between robots as well as between the robot and the company’s database. XML is particularly useful for storing configuration information such as the facilities in which it is working, input and output equipment, location, etc. This information can be stored and used for quick setup, which is particularly important in a Flexible Manufacturing System. XML can also be used to develop industry specifications for RoboML, a markup language for robotic applications. Entire factories may also be monitored by advanced Neural Networks, which yield startling accuracy with respect to quality control. Managers can drill down and analyze the production process as well as the effectiveness of particular robots, individual processes, or entire plants. This information can be used for tracking inventory, production, and quality control purposes. Norman: This project appears to have been abandoned. Nevertheless factory automation communication is being increasingly based on the Internet
Some interesting sites to surf for CIM are listed below. Remember, these are partial and not total solutions to CIM: