Understanding Industrial Automation

• The objectives are to define industrial automation, distinguish types of automation, classify elements of automation, and define the reasons for automation.

Automation Definition

• Automation uses control systems for operating equipment like machinery and boilers with minimal human intervention.
• Automation saves energy, materials, and improves quality, accuracy, and precision.
• Automation is technology accomplishing processes without human assistance.
• Mechanization assists or replaces manual labor for physical tasks while still requiring human cognitive and sensory input.
• Automation uses mechanized equipment to perform physical tasks with no need for human oversight.

Overview of Industrial Automation

• Manufacturing in the 1950s used traditional machinery lacking flexibility and skilled labor. Complex parts necessitated trial and error, and processes were time-consuming with high labor and production costs.
• Mechanization improves productivity using mechanical, hydraulic, pneumatic, or electrical devices.
• Mechanization still requires operators to control the process, so automating improves efficiency.
• An automated system is a device collection accomplishing tasks or producing products.
• An industrial automated system can be a single machine or a machine group called a cell.
• Programmable automation technology includes computer numerical control (CNC), robotics, and programmable logic control (PLC).

Realities of Modern Manufacturing

• Globalization has led to countries like China, India, and Mexico becoming major manufacturing players.
• International outsourcing involves American companies making parts and products offshore or near-shore.
• Local outsourcing is using U.S. suppliers for parts and services.
• Contract manufacturing involves companies specializing in entire products, not just parts, under contract.
• There is a trend toward the service sector in the economy.
• Customers demand products of the highest quality; manufacturers need operational efficiency to overcome labor cost advantages from international competitors.

Modern Manufacturing Approaches & Technologies

• Automation uses automated equipment instead of labor.
• Material handling technologies are essential because manufacturing usually involves a sequence of activities.
• Manufacturing systems integrate and coordinate multiple automated or manual workstations.
• Flexible manufacturing competes in low-volume/high-mix product categories.
• Quality programs help achieve the high quality expected by today's customers.
• CIM integrates design, production, and logistics.
• Lean production does more work with fewer resources.

Manual Labor in Production

• Manual labor has a place in modern production systems in factory operations and manufacturing support systems.

Manual Labor in Factory Operations

• The long-term trend moves to automated systems substituting for manual labor.
• Manual labor is justified when labor rates are low, a task is technologically difficult to automate, there is a short product life cycle, or a customized product requires human flexibility.
• Manual labor is also justified to cope with demand fluctuations, reduce the risk of failure, or due to lack of capital.

Labor in Manufacturing Support Systems

• Product designers bring creativity to the design.
• Manufacturing engineers design production equipment/tooling and plan production methods/routings.
• Equipment maintenance, programming and computer operation, engineering project work, and plant management are manufacturing support systems.

Production System Defined

• A production system is a collection of people, equipment, and procedures organized to accomplish manufacturing operations.
• Two categories are facilities and manufacturing support systems.
• Facilities are factories/equipment and how the facility is organized (plant layout).
• Manufacturing support systems are managing production and solving technical and logistic problems.

Production System Facilities

• Facilities include the factory, production machines and tooling, material handling equipment, inspection equipment, and computer systems that control operations.
• Plant layout is how equipment is physically arranged in the factory.
• Manufacturing systems are logical groupings of equipment and workers in the factory.
• Production Lines are complex manufacturing systems with machine and worker collections.
• Stand-alone workstations are facilities with just a worker and tooling.

Manufacturing Systems

• Manual work systems use a worker performing tasks with or without the aid of hand tools.
• Worker-machine systems use a worker operating powered equipment.
• Automated systems involve machines performing processes without human participation, implemented with a program, control system, and power.
• Two levels of automation are identified: semiautomated and fully automated.

Manufacturing Support Systems

• They involve a cycle of information-processing activities in four functions:
• Business functions includes sales and marketing, order entry, cost accounting, and customer billing.
• Product design includes research and development, design engineering, and prototype shop.
• Manufacturing planning is the information and documentation that constitutes the product design. It includes process planning, master scheduling, material requirements planning, and capacity planning.
• Manufacturing control manages and controls physical operations in the factory to implement manufacturing plans. It includes shop floor control, inventory control, and quality control.

Automation in Production Systems

• In an industrial context, automation is a technology applying mechanical, electronic, and computer-based systems to operate and control production processes.
• Examples of automation are in manufacturing, services, transport, process control, and offices.
• Automation, dealing with mechatronics and computers, and robots are related technologies used in production.
• Examples of this include:
  • Transfer lines that perform a series of machining operations
  • Mechanical assembly machines
  • Feedback control systems
  • Numerically controlled machine tools
  • Logistic support tools
  • Automated inspection system for quality control
  • Automated material handling system and storage system to integrate manufacturing operation
  • CAD/CAM is a system with robots that are mechatronic devices assisting industrial automation.

Automation Divisions

• The automated elements of a production system can be separated into the automation of manufacturing systems in the factory and the computerization of the manufacturing support systems.
• The two categories overlap in modern manufacturing due to computer systems operating on factory floors, connected to computerized manufacturing support, and management information operating at a plant level.
• Computer-Integrated Manufacturing (CIM) is related.
• In an industrial context, we can define automation as a technology that is concerned with the use of mechanical, electrical /electronic and computer based system to control production process.
• Examples of technology include transfer lines to perform a series of machining operations, automated assembly systems, feedback control systems, numerically controlled machine tools, logistics support tools.
• Automated technology also is used in automated inspection system for quality control, automated material handling system and storage system to integrate manufacturing operations, and industrial robots (CAD/CAM system and robots- robots) that perform processing or assembly operations.

Objectives of Computerized Manufacturing Support Systems

• To reduce the amount of manual and clerical effort in product design, manufacturing planning and control, and the business functions.
• Computer technology is used to implement automation of the manufacturing systems in the factory.
• CIM (computer integrated manufacturing) denotes the pervasive use of computer systems to design the products, plan the production, control the operations, and perform the various business-related functions in one system that operates throughout the enterprise.
• CIM includes CAD/CAM and the business functions of the firm
• CAD/CAM integrates computer designs (CAD) and manufacturing (CAM). CAD uses computer systems to support product design, while CAM uses computer systems to perform manufacturing engineering functions like process planning and numerical control part programming.

Fixed Automation

• It is a manufacturing system with a sequence of processing, or assembly, operations fixed by the equipment configuration. It uses simple operation with high demand rates and inflexible product design.
• It is suited to high production quantities, high initial investment for custom-engineered equipment, and high production rates. It is appropriate to design specialized equipment to process products at high production rates and low cost (custom engineered with special-purpose equipment to automate fixed sequence of operation).
• It is relatively inflexible in accommodating product variety.
• A good example of fixed automation can be found in the automobile industry, where highly integrated transfer lines are used to perform machining operation on engine and transmission component.
• The economics of fixed automation is such that the cost of the special equipment can be divided over a large number of units produced, so that the resulting units cost can be lower relative to an alternative method of production.
• The risk with fixed automation is that the initial investment cost is high. If the volume of production is lower than anticipated, then the unit costs become greater.
• The other problem with fixed automation is that the equipment is specially designed to produce only one product. After that product's life cycle is finished, the equipment is likely to become obsolete. Therefore, for products with short life cycles, fixed automation is not economical.

Programmable Automation

• is a manufacturing system designed with the capability to change the sequence of operations to accommodate different product configurations.
• The operation sequence is controlled by a program, which is a instruction set coded for the system to read and interpreted. New programs can be prepared and entered into the equipment to produce new products.
• The physical setup of the machine must also be changed; tools must be loaded. Fixtures must be attached to the machine table, and the required machine setting must be entered.
• High investment in general purpose equipment has the production equipment designed to be adaptable to variations in a product configuration.
• It has lower production rates than fixed automation, has flexibility to deal with variations and changes in product configuration, and is most suitable for batch production.
• Physical setup and part program must be changed between jobs, or batches.
• Physical setup must be changed with tools loaded, fixtures attached, and machine setting entered.
• The cost of programmable equipment can be spread over many different products, even though they are different. Many different and unique products can be processed economically in small batches (batches production and medium volume).

Flexible Automation

• It is an extension of programmable automation in which the system can change over from one job to the next with no lost time between jobs.
• There is no lost production time while reprogramming the system and altering the physical combination and schedules of parts or products instead of requiring that they be made in batches.
• This automation is designed to manufacture a variety of a part with low production rates, varying product design and demand.
• It includes High investment for custom-engineered system, continuous production of variable mixes of products, and medium production rates.
• This type of automation is suitable for the mid-volume production range.
• Flexible automation often consists of a series of workstations interconnected by material handling and storage equipment to process different product configurations on the same manufacturing system.
• A central computer is used to control various activities that occur in the system.
• One of the features that distinguish programmable automation from flexible automation is that with programmable automation the products are made in batches, while flexible automation can produce one of a kind.

Advantages of Flexible Automation

• Increased speed and productivity.
• Reduced manual labor.
• Improved consistency.
• Greater reliability.
• Greater accuracy and consistency.
• Reduced cost of assembly

Automation Comparison

• Fixed automation maximizes efficiency and minimizes unit cost when used for high-volume, long-life cycle products, though it has a large initial investment and inflexibility.
• Programmable automation provides flexibility, accommodates product design changes, and minimizes unit costs for large batches, but this leads to a long setup time and high unit costs relative to fixed automation.
• Flexible automation deals with the most design variations, resulting in customized products. However, it does require a large initial investment and causes high unit costs.

Basic Elements of Automated System

• Power to accomplish the automated process needs power to drive the process and controls, and is typically electrical.
• The power is used for actuation and transmission, with mechanical, thermal, light, acoustic, hydraulic, and pneumatic conversion.
• Low-level power is used for signal transmission, information processing, and data storage.
• Power can be stored in batteries for use in remote locations.
• Terms of automation include, controller units, actuator signals, data acquisitions and information processing.

Program of Instructions

• Program of instructions defines automated process action with details of each step and the sequence of steps.
• In programmed instructions, set point is the value of the process parameter or desired a controlled variable in process.
• In work cycle programs, simplest automated process are work cycles consisting of 1 step and complex systems are work cycles with steps
• A process parameter is an input to the process, whereas a process variable is the corresponding output of the process.
• In a programmed work cycle, each work cycle is made up of continuous steps and operator interactions.

Work Cycle Programs

• In the simplest automated processes, the work cycle consists of one step, to maintain a process parameter at a level. Loading and unloading work units into a furnace is performed manually, so it's not part of the cycle.
• A process parameter is an input to the process.
• A process variable is an output of the process.
• Activities in each step involves changes in process parameters.
• Examples of process parameters include desired coordinate axis value (positioning system), valve open/closed (fluid flow system), and motor on/off.
• Examples of process variables include actual position of the coordinate axis, fluid flow rate, and motor rotational speed.

Five Categories of Work Cycle Programs

• Set-point control maintains a constant process parameter value.
• Logic control values depend on the values of others.
• Sequence control process values change as function of time, either discrete or continuous.
• Interaction program interaction occurs between a human operator and the control system during workload..
• Intelligent program the control system exhibits aspects of human intelligence.

Automated Operations

• An automated turning operation generates a cone-shaped product. A robot loads/unloads work. -Steps: (1) load starting work piece, (2) position cutting tool prior to turning, (3) turn, (4) reposition tool to a safe location at end of turning, and (5) unload finished workpiece.
• Activities: reaching, lifting, and positioning the raw work part, then retreating to safe position.
• Process Parameters: X values, gripper value (open or closed)
• Activities: Movement to a "ready" position.
• Process Parameters: X And Z axis position of tool
• Activities: Workpiece rotation, cutting tool feed & position, cut conical shape, finishing operation
• Process Parameters: Speed, radial distance rotated

Decision Making

• Two features of the work cycle are the number and sequence of processing steps and the process parameter changes in each step.
• Examples of automated work cycles are operator interactions (input data), automobile teller machine, different system styles, variations in starting work unit units and machining.

Features of a Work Cycle Program

• The following summarizes the features of work cycle programs (part programs) to direct operations of an automated system:
• Number of steps in the work cycle: A general sequence in discrete production operations is (1) load, (2) process, (3) unload, but the process may include multiple steps.
• Manual participation in the work cycle includes loading and unloading workparts.
• Process parameters focus on how many process parameters must be controlled during each step.
• It includes continuous and discrete parameters.
• Operator interaction factors in whether the operator enter processing data.
• It covers variations in part or product styles, and in starting work units, some adjustments in process parameters may be required to compensate for differences in starting units.

Control Systems

• Control System - Definition of the control system is that it causes the process to accomplish something
• 1.Closed feedback control systems: is a parameter that is based on any difference between those.
• 2.Open control loop, a parameter that operates without feedback.

Closed and Open Loop Systems

• In closed loop system, the input parameter set point represents the desired value of output
• The process is the operation that is controlled
• The output is the loop performance.
• Sensor is used to measure the operation.
• The adjustment is accomplished by using the hardware.

Open Loop Systems

• In this case, the controls operate without measuring the output variable.
• The controller relies on accurate mode of affector on process
• The effect of the processor is an open -loop systems.
• Advantage: is generally simple and less expansive.

Open-Loop Systems

• Open Loop Control Systems are most accurate when actions are simple and if all connections are functional; if these connections are non functional, then closed loop systems.

Safety Monitoring

• Safety Monitoring of equipment uses sensors to track conditions that are unsafe or potentially unsafe.
• Possible responses to hazards: Complete stoppage of the system, Sounding an alarm, Reducing operating speed of process.

More on Automated Safety

• Automation is installed to perform difficult operations that may not be possible to operate manually.
• Limit switches, photoelectric sensors, Emergency stop buttons have been installed.

Maintenance

• Monitor records and statuses that are monitored
• Failure Diagnostic: What happens when the parts fail
• Recommendation: procedure to assist operators with repairs.

Error Detection

• Errors are classified in three steps :
• Random: Large Variations
• Systemic assignable change
• Abbreviated: Human Failure
• It Uses sensors to determine what has failed
• Correctly interpret the signal (Sensor Signal)

Error Recovery

• It is Applying all the required actions to recover and correct the error.

Strategies for Error Recovery

• Adjustments at the end of the shift
• Stop the process, and inform the shift.

Some Automated Machining Errors

• Machine and Processes: Loss of control, power output
• Cutting Tools: Not correct tooling, breakage
• Work Holding tool: Error
• Part Storage : None

Possible Error Solutions

• Parts are deviating in size.
• Part is not being held properly at location.
• Call Operator for assistance.

Reasons for Automation

• To Increase labor productivity.
• To Reduce Labor costs and shortages.
• To Remove people out of harms ways.
• To Avoid High costs of the system.

Reasons for Automated Processes

• Automation performs the manufacturing processes with greater uniformity and conformity to quality specifications.
• Operation cannot be accomplished with CAD or with a machine
• Value of output per person increases with labor.