Advanced Automation function
In addition to executing work
cycle programs, an automated system may be capable of executing advanced
functions that are specific to a particular work unit. In general, the
functions are concerned with enhancing the safety and performance of the
equipment. Advanced automation functions include the following
(1) Safety
monitoring,
(2) Maintenance
and repair diagnostics, and
(3) Error
detection and recovery.
automation functions are made
possible by special subroutines included in the program of instructions. In
some cases, the functions provide information only and do not involve any
physical actions by the control systems, for example reporting a list of
preventive maintenance tasks that should be accomplished. Any actions taken on
the basis of this report are decided by the human operations and managers of
the systems and not by the system itself. In other cases, the program of
instructions must be physically executed by the control system using available
actuators. A simple example of this case is a safety monitoring system that
sounds an alarm when a human worker gets dangerously close to the automated
equipment.
One of the significant reasons
for automating a manufacturing operation is to remove workers from a hazardous
working environment. An automated system is often installed to perform a
potentially dangerous operation that would otherwise be accomplished manfully by
human workers. However, even in automated systems, workers are still needed to
service the system at periodic intervals if not full-time, accordingly, it is
important that the automated system be designed to operate safety when workers
are in attendance. In addition, it is essential that the automated system carry
out it is process in a way that is not self-destructive. Thus, there are two
reasons for providing an automated system with a safety monitoring capability:
(1) to
product human workers in the vicinity of the system and
(2) to
product the equipment associated with the system.
Safety monitoring means more than
the conventional safety measures taken in a manufacturing operation, such a
productive shield around the operation or the kinds of manual devices that
might be utilized by human workers such as emergency stop buttons. Safety
monitoring in an automated system involves the uses of sensors to track the
systems operation and identify conditions and events that are unsafe or
potentially unsafe. The safety monitoring system is programmed to respond to
unsafe conditions in some appropriate way
.Possible responses to various hazards might include one more
of the following:
1. completely
stopping the automated system,
2. sounding
an alarm
3. reducing
the operating speed of the process,
4. Tacking
corrective actions to recover from the safety violation.
This last response is the most
sophisticated and is suggestive of an intelligent machine performing some
advanced strategy. This kind of response is applicable to a variety of possible
mishaps, not necessarily confined to safety issues, and is called error
detection and recovery
Sensors for safety monitoring
range from very simple devices to highly sophisticated systems. The following
list suggests some of the possible sensors and their applications for safety
monitoring:
·
Limit switches to detect proper positioning of a
part in a work holding devices so that the processing cycle can begin.
·
Photoelectric sensors trigged by the interruption
of a light beam; this could be used to indicate that a part is in the proper
positions or to detect the pressure of a human intruder in the work cell.
·
Temperature sensors to indicate the metal work
part is hot enough to proceed with hot forging operations. if the work part is
not sufficiently heated, then the metals ductility might be too low, and the
forging dies might be damaged during the operations.
Related Topics
Privacy Policy, Terms and Conditions, DMCA Policy and Compliant
Copyright © 2018-2024 BrainKart.com; All Rights Reserved. Developed by Therithal info, Chennai.