Chapter 3 - Introduction to Automation Flashcards
It is the technology by which a process or procedure is accomplished without human assistance.
Automation
3 Basic Elements of an automated system
- Power
- Program Instructions
- Control Systems
it is to accomplish the process and operate the automated system
Power
It is to direct the process
Program of instructions
It is to actuate the instructions
Control Systems
Power for the process
▪To drive the process itself
▪To load and unload the work unit (proper position and orientation
▪Transport between operations
Power for automation
▪Controller unit
▪Power to actuate the control signals
▪Data acquisition and information processing
It is the Principal Power Source
Electricity
Widely available at moderate cost
Electricity
Can be readily converted to alternative forms, e.g. Mechanical, thermal, light, etc.
Electricity
Low level power can be used for signal transmission, data processing, and communication
Electricity
Can be stored in long-life batteries
Electricity
Set of commands that specify the sequence of steps in the work cycle and the details of each step
Program of Instructions
The actions performed by an automated process are defined by a
Program of Instructions
The particular processing steps for the work cycle are specified in a ______ (part programs).
Work Cycle Program
What the following are examples of automated work cycles in which decision making is required:
▪Operator interaction
▪Different part or product styles processed by the system
▪Variations in the starting work units
The Control element of the automated system executes the program of instructions.
Control System
The ______ causes the process to accomplish its defined function, to carry out some manufacturing operation.
Control System
Two types of Control System
- Open-loop control system
2. Closed-loop (feedback) control system
operates without the feedback loop ▪Simpler and less expensive ▪Risk that the actuator will not have the intended effect
Open-loop control system
a system in
which the output variable is compared with an input
parameter, and any difference between the two is used
to drive the output into agreement with the input
Closed-loop (feedback) control system
It represents the desired value of
the output
Input Parameter (set point)
It is the operation or function being controlled
output value
The process
A _____ is used to measure the output variable and close
the loop between input and output.
Sensor
The ______ compares the output with the input and makes the required adjustment in the process to reduce
the difference between them.
Controller
The ______ is accomplished using one or more
actuators which are the hardware devices that physically
carry out the control actions.
Adjustment
Advanced Automation Functions
- Safety monitoring
- Maintenance and repair diagnostics
- Error detection and recovery
Use of sensors to track the system’s operation and
identify conditions that are unsafe or potentially unsafe
Safety Monitoring
Safety monitoring - Examples
▪Temperature sensors
▪Heat or smoke detectors
▪Pressure sensitive floor pads
▪Vision systems
It refers to the
capabilities of an automated system to assist in identifying
the source of potential or actual malfunctions and failures
of the system.
Maintenance and Repair Diagnostics
Monitors and records status of key sensors and
parameters during system operation
Status monitoring
▪Invoked when a malfunction occurs
▪Purpose: analyze recorded values so the cause of
the malfunction can be identified
Failure diagnostics
Provides recommended procedure for the repair crew to effect repairs
Recommendation of repair procedure
_____ are those that result from some
assignable cause such as a change in raw material
properties
Systematic errors
result from either an equipment failure or a human mistake
Aberrations (disorders)
– functions:
▪Use the system’s available sensors to determine when a deviation or malfunction has occurred
▪Correctly interpret the sensor signal
▪Classify the error
Error detection
possible strategies:
▪Make adjustments at end of work cycle
▪Make adjustments during current work cycle
▪Stop the process to invoke corrective action
▪Stop the process and call for help
Error recovery
What are the Levels of Automation?
- Device level
- Machine level
- Cell or system level
- Plant level
- Enterprise level
A level of Automation where actuators, sensors, and other hardware components to form individual control loops for the next level
Device level
A level of automation where CNC machine tools and similar production equipment, industrial robots, material handling equipment
Machine level
A level of automation which is manufacturing cell or system
Cell or system level
A level of automation which is factory or production systems level
Plant level
A level of automation which is corporate information system
Enterprise level
Benefits of Automation
- Increased capacity
- Improved Quality
- Reduced Cost
- Skilled Trade Gap
- Reduced Lead Time
