Automation

Definition of Automation

Automation: The technology by which a process or procedure is performed with minimal human assistance.

Manufacturing Automation: The use of control systems and information technologies to reduce the need for human work in the production of goods and services.

Evolution of Automation

Historical Development:

1. Manual Production (Pre-Industrial Revolution)

   • Hand tools
   • Skilled craftsmen
   • Low volume production

2. Mechanization (Industrial Revolution - 1760s-1840s)

   • Power-driven machines
   • Water and steam power
   • Increased production capacity

3. Mass Production (Early 1900s)

   • Assembly lines
   • Standardization
   • Division of labor
   • Henry Ford's Model T

4. Automated Production (Mid-1900s)

   • Numerical control machines
   • Transfer lines
   • Feedback control systems

5. Computer-Integrated Manufacturing (1970s-1990s)

   • CNC machines
   • Industrial robots
   • Computer control systems

6. Smart Manufacturing/Industry 4.0 (2010s-Present)

   • IoT (Internet of Things)
   • AI and Machine Learning
   • Cyber-physical systems
   • Big data analytics

Types of Automation

1. Fixed Automation (Hard Automation)

Characteristics:

• Designed for high production volumes
• Fixed sequence of operations
• Difficult to change or reconfigure
• High initial investment
• Low unit cost at high volumes

Examples:

• Transfer lines
• Automated assembly lines
• Continuous process plants (refineries, chemical plants)

Advantages:

• High production rates
• Low unit cost
• Consistent quality
• Efficient use of materials

Disadvantages:

• Inflexible
• High initial cost
• Difficult to modify
• Product changes require major retooling

Applications:

• Mass production of standardized products
• Automotive assembly
• Bottling and canning
• Paper production

2. Programmable Automation

Characteristics:

• Equipment can be reprogrammed for different products
• Suitable for batch production
• Changeover time required between batches
• Medium production volumes
• Moderate flexibility

Examples:

• CNC machine tools
• Industrial robots
• Programmable Logic Controllers (PLCs)

Advantages:

• Flexibility for product variety
• Reprogrammable
• Suitable for batch production
• Lower investment than fixed automation

Disadvantages:

• Lower production rates than fixed automation
• Changeover time required
• Programming complexity
• Higher unit cost than fixed automation

Applications:

• Batch manufacturing
• Job shop production
• Medium-volume production with product variety

3. Flexible Automation (Soft Automation)

Characteristics:

• Can produce variety of products with minimal changeover
• Computer-controlled
• Quick changeover between products
• Medium to high production volumes
• High flexibility

Examples:

• Flexible Manufacturing Systems (FMS)
• Automated Guided Vehicles (AGVs)
• Robotic work cells

Advantages:

• High flexibility
• Minimal changeover time
• Can handle product mix
• Efficient production
• Quick response to demand changes

Disadvantages:

• High initial investment
• Complex to design and implement
• Requires sophisticated control systems
• Maintenance complexity

Applications:

• Mixed-model production
• Mass customization
• Automotive manufacturing
• Electronics assembly

Levels of Automation

1. Device Level

• Individual machines and equipment
• Sensors and actuators
• Basic control functions

2. Machine Level

• CNC machines
• Industrial robots
• Automated equipment

3. Cell/System Level

• Manufacturing cells
• Automated work stations
• Coordinated equipment groups

4. Plant Level

• Factory-wide systems
• Production planning
• Material flow control

5. Enterprise Level

• Business systems
• Supply chain management
• Customer relationship management

Components of Automated Systems

1. Power Source

• Provides energy for system operation
• Types: Electric, hydraulic, pneumatic

2. Control System

• Directs and regulates system operation
• Types: Open-loop, closed-loop (feedback)

3. Actuators

• Convert control signals to physical action
• Examples: Motors, cylinders, solenoids

4. Sensors

• Detect system state and environment
• Provide feedback to control system
• Types: Position, temperature, pressure, flow, vision

5. Processing Equipment

• Performs the actual manufacturing operations
• Machine tools, assembly equipment, etc.

6. Material Handling

• Moves materials and parts
• Conveyors, robots, AGVs

Control Systems

Open-Loop Control

Characteristics:

• No feedback
• Output not measured
• Simple and inexpensive
• Less accurate

Example: Timer-based systems, stepper motors

Closed-Loop Control (Feedback Control)

Characteristics:

• Output is measured
• Compared to desired value
• Error signal used for correction
• More accurate and stable

Components:

1. Input/Reference: Desired value (setpoint)
2. Controller: Processes error signal
3. Actuator: Implements control action
4. Process: System being controlled
5. Sensor: Measures output
6. Feedback: Returns output information to controller

Example: Temperature control, position control, speed control

Control System Types:

1. On-Off Control

• Simple two-position control
• Output either fully on or fully off
• Example: Thermostat

2. Proportional Control (P)

• Output proportional to error
• Faster response than on-off
• May have steady-state error

3. Proportional-Integral (PI) Control

• Eliminates steady-state error
• Integral action accumulates error over time

4. Proportional-Integral-Derivative (PID) Control

• Most common industrial controller
• P: Responds to current error
• I: Responds to accumulated error
• D: Responds to rate of error change
• Provides fast response with minimal overshoot

Programmable Logic Controllers (PLCs)

PLC: A digital computer used for automation of industrial processes.

Characteristics:

• Rugged and reliable
• Designed for industrial environments
• Easy to program
• Modular design
• Real-time operation

Components:

1. CPU (Central Processing Unit): Executes control program
2. Input modules: Interface with sensors and switches
3. Output modules: Interface with actuators and indicators
4. Power supply: Provides power to PLC
5. Programming device: For creating and modifying programs
6. Communication interfaces: For networking

Programming Languages:

• Ladder Logic: Graphical, resembles relay logic
• Function Block Diagram (FBD): Graphical blocks
• Structured Text (ST): Text-based, like programming languages
• Instruction List (IL): Assembly-like language
• Sequential Function Chart (SFC): For sequential processes

Applications:

• Machine control
• Process control
• Assembly line control
• Material handling
• Packaging systems

Sensors in Automation

1. Position and Displacement Sensors

• Potentiometers: Variable resistance
• Linear Variable Differential Transformer (LVDT): Inductive
• Encoders: Digital position measurement
  • Incremental encoders
  • Absolute encoders
• Proximity sensors: Detect object presence
  • Inductive (for metals)
  • Capacitive (for all materials)
  • Optical (light-based)

2. Velocity and Acceleration Sensors

• Tachometers: Measure rotational speed
• Accelerometers: Measure acceleration

3. Force and Torque Sensors

• Load cells: Measure force/weight
• Strain gauges: Measure deformation
• Torque sensors: Measure rotational force

4. Temperature Sensors

• Thermocouples: Voltage-based
• RTDs (Resistance Temperature Detectors): Resistance-based
• Thermistors: Semiconductor-based
• Infrared sensors: Non-contact measurement

5. Pressure Sensors

• Bourdon tube: Mechanical
• Piezoelectric: Crystal-based
• Strain gauge: Deformation-based

6. Flow Sensors

• Turbine flowmeters: Rotating element
• Magnetic flowmeters: Electromagnetic induction
• Ultrasonic flowmeters: Sound waves

7. Vision Sensors

• Cameras: Image capture
• Image processing: Pattern recognition, measurement
• Applications: Inspection, guidance, identification

Material Handling Automation

1. Conveyors

• Belt conveyors: Continuous belt
• Roller conveyors: Series of rollers
• Chain conveyors: Chain-driven
• Overhead conveyors: Suspended from ceiling

2. Automated Guided Vehicles (AGVs)

• Characteristics:

  • Driverless vehicles
  • Follow predetermined paths
  • Computer-controlled
  • Flexible routing

• Guidance Systems:

  • Wire-guided: Follow buried wire
  • Laser-guided: Use laser scanners
  • Vision-guided: Use cameras
  • Magnetic tape: Follow magnetic strips
  • Natural navigation: Use environment features

• Applications:

  • Material transport
  • Warehouse operations
  • Assembly line feeding

3. Automated Storage and Retrieval Systems (AS/RS)

• Components:

  • Storage racks
  • Storage/retrieval machines
  • Control system
  • Input/output stations

• Advantages:

  • High storage density
  • Improved inventory control
  • Reduced labor costs
  • Better space utilization
  • Increased accuracy

4. Industrial Robots

• See Robotics chapter for details
• Used for material handling, assembly, processing

Flexible Manufacturing Systems (FMS)

FMS: A manufacturing system that can adapt to changes in the type and quantity of products being manufactured.

Components:

1. CNC machine tools: Perform machining operations
2. Material handling system: Move parts between machines
3. Central computer: Controls entire system
4. Load/unload stations: Interface with system
5. Tool storage and delivery: Automated tool management
6. Pallet fixtures: Hold workpieces

Characteristics:

• High flexibility
• Automated operation
• Computer-controlled
• Can handle variety of parts
• Efficient for medium volumes

Advantages:

• Reduced lead time
• Lower work-in-process inventory
• Better machine utilization
• Flexibility for product changes
• Consistent quality
• Reduced labor costs

Disadvantages:

• High initial investment
• Complex to plan and implement
• Requires skilled maintenance
• Limited to certain part families
• Potential for system-wide failures

Applications:

• Machining operations
• Sheet metal fabrication
• Assembly operations
• Inspection and testing

Computer-Integrated Manufacturing (CIM)

CIM: The integration of total manufacturing enterprise through the use of integrated systems and data communications.

Components:

1. Computer-Aided Design (CAD)

• Design product geometry
• Create engineering drawings
• Perform analysis and simulation

2. Computer-Aided Manufacturing (CAM)

• Generate NC programs
• Plan manufacturing processes
• Simulate machining operations

3. Computer-Aided Process Planning (CAPP)

• Generate process plans
• Select tools and machines
• Determine operation sequences

4. Manufacturing Execution System (MES)

• Track production in real-time
• Monitor equipment status
• Collect production data
• Manage quality

5. Enterprise Resource Planning (ERP)

• Manage business processes
• Integrate business functions
• Financial management
• Supply chain management

6. Product Data Management (PDM)

• Manage product information
• Control document versions
• Coordinate engineering changes

Benefits of CIM:

• Improved productivity
• Better quality
• Reduced lead times
• Lower inventory
• Better resource utilization
• Improved decision-making
• Enhanced competitiveness

Industry 4.0 and Smart Manufacturing

Industry 4.0: The fourth industrial revolution characterized by cyber-physical systems, IoT, and smart factories.

Key Technologies:

1. Internet of Things (IoT)

• Connected devices and sensors
• Real-time data collection
• Machine-to-machine communication

2. Cyber-Physical Systems (CPS)

• Integration of physical and computational elements
• Networked systems
• Autonomous operation

3. Big Data and Analytics

• Large-scale data collection
• Advanced analytics
• Predictive insights
• Data-driven decisions

4. Cloud Computing

• Distributed computing resources
• Scalable storage
• Remote access
• Collaboration platforms

5. Artificial Intelligence and Machine Learning

• Intelligent decision-making
• Pattern recognition
• Predictive maintenance
• Process optimization

6. Augmented Reality (AR)

• Overlay digital information on physical world
• Training and maintenance support
• Assembly guidance

7. Additive Manufacturing (3D Printing)

• On-demand production
• Complex geometries
• Customization
• Rapid prototyping

8. Simulation and Digital Twins

• Virtual models of physical systems
• Test scenarios without risk
• Optimize before implementation
• Monitor and predict performance

Benefits of Industry 4.0:

• Increased efficiency
• Mass customization
• Improved quality
• Predictive maintenance
• Reduced downtime
• Better resource utilization
• Enhanced flexibility
• Real-time visibility

Advantages of Manufacturing Automation

1. Increased Productivity

   • Higher production rates
   • 24/7 operation
   • Reduced cycle times

2. Improved Quality

   • Consistent performance
   • Reduced human error
   • Better process control

3. Reduced Labor Costs

   • Fewer operators needed
   • Lower long-term costs

4. Enhanced Safety

   • Reduced worker exposure to hazards
   • Automated handling of dangerous materials

5. Better Flexibility

   • Quick changeovers (flexible automation)
   • Adapt to product variations

6. Improved Accuracy

   • Precise positioning and control
   • Repeatable operations

7. Reduced Waste

   • Optimized material usage
   • Consistent processes

8. Better Information

   • Real-time monitoring
   • Data collection and analysis

9. Reduced Lead Times

   • Faster production
   • Better scheduling

10. Competitive Advantage

    • Lower costs
    • Better quality
    • Faster response

Disadvantages and Challenges

1. High Initial Investment

   • Expensive equipment
   • Installation costs
   • Integration expenses

2. Technical Complexity

   • Requires specialized knowledge
   • Complex troubleshooting
   • Integration challenges

3. Maintenance Requirements

   • Skilled maintenance personnel needed
   • Spare parts inventory
   • Downtime for repairs

4. Inflexibility (Fixed Automation)

   • Difficult to change
   • Product-specific equipment

5. Job Displacement

   • Reduced need for manual labor
   • Social and economic impacts

6. Dependence on Technology

   • System failures affect entire production
   • Cybersecurity risks

7. Obsolescence

   • Technology becomes outdated
   • Need for upgrades

8. Training Requirements

   • Operators need new skills
   • Ongoing training needed

Economic Justification of Automation

Factors to Consider:

1. Capital Investment

   • Equipment cost
   • Installation cost
   • Integration cost
   • Training cost

2. Operating Costs

   • Energy consumption
   • Maintenance
   • Spare parts
   • Labor (reduced but still needed)

3. Benefits

   • Labor savings
   • Increased production
   • Improved quality (reduced scrap and rework)
   • Reduced inventory
   • Better space utilization

4. Financial Metrics

   • Payback Period: Time to recover investment
   • Return on Investment (ROI): Profit relative to investment
   • Net Present Value (NPV): Present value of future cash flows
   • Internal Rate of Return (IRR): Discount rate for NPV = 0

Payback Period Formula:

Payback Period = Initial Investment / Annual Savings

ROI Formula:

ROI = (Net Profit / Investment) × 100%

Future Trends in Manufacturing Automation

1. Increased AI Integration

   • Smarter systems
   • Self-learning machines
   • Autonomous decision-making

2. Collaborative Automation

   • Humans and robots working together
   • Cobots becoming more common

3. Edge Computing

   • Processing at device level
   • Faster response times
   • Reduced network load

4. 5G Connectivity

   • Faster communication
   • More connected devices
   • Real-time control

5. Sustainable Manufacturing

   • Energy-efficient systems
   • Reduced waste
   • Circular economy

6. Mass Customization

   • Flexible systems for individual products
   • On-demand manufacturing

7. Autonomous Systems

   • Self-optimizing processes
   • Minimal human intervention

8. Blockchain in Manufacturing

   • Supply chain transparency
   • Quality traceability
   • Secure data sharing