Machine automation
SKILLS / MAIN GOALS
At the end of this module the students will be capable of developing automation systems for small machines with PLCs, using interlocks, sequencing and other approaches.
CONTENTS
Historical context of automation
Main concepts related to logic control
Programmable logic controllers: hardware and software structure, technical characteristics and specifications, programming languages, main ladder instructions, data handling, numeric formats, maths, comparisons, timers and analog interfaces
State machine (SFC) approach
Electric diagram interpretation
Electric commands for motor engines and pneumatic systems and their interfaces to PLCs
GAMIFIED CONTEXT
In this module the student is a trainee at the virtual factory. He/she is welcome to and learns that the factory is an industrial enterprise with businesses in many sectors, and is investing in industrial automation systems to increase its competitiveness.
So the trainee(student) is required to develop automation projects and receives all guidance, instructions and contents to study, in order to learn what is necessary to get the jobs done.
MATERIALS AND METHODS
Students will learn the contents by developing automation systems for machines and processes in the virtual environments. They will be provided with all the instructions, theory and contents required.
PLC TECHNOLOGY OPTIONS
In this module, the teacher may use tools such as Codesys Development, that is free, WinPCL7 that has demo and lite free versions, Simatic Manager, TIA Portal or Logix 5000. If the school decides to use a Rockwell or Siemens system, it will be necessary to provide licenses to the students.
Important note: TIA Portal can be downloaded and used fully operational for 21 days in trial mode, and it is possible for a student to do all the module in that time period if the student is dedicated exclusively to the module.
MODULE STRUCTURE IN CHALLENGES
CHALLENGE 1
AUTOMATING THE GATE OF FACTORY ACCOMODATIONS BUILDING
Project: the student is required to automate the door gate of the factory’s accommodation. The reason is that the factory has plans to implement remote control for all its accesses
Tasks:
Open/Close while pressing 2 buttons
Using the end switches to avoid collision
Open/Close by pushing(impulse) 2 buttons
Interlocking to avoid short-circuit
Using the wall-button
Automation contents: automation and PLC basics, input and outputs, sensors and actuators, ladder language, basic ladder Boolean instructions: NO/NC contacts and simple coil, direct engine start and interlocks.
Electricity contents: basic electric automation panel, electric motor protection and command.
CHALLENGE 2
MANUAL OPERATION OF THE GYPSUM DOSING AND MIXING LINE
Project: the student receives a line from another factory but the PLC program is lost. Therefore, it is necessary to study the electric diagram and the description of how the machine works in order to develop a new system.
The student is required to work on the project in 2 phases: phase 1, manual operation, and phase 2, automatic operation. This challenge is phase 1.
Tasks:
Manual operations
3 conveyors with 1 button
Adding water
Adjusting the conveyors
New automation contents: memory and image memory, PLC scan cycle, interlocks, retentive command instructions, sequencing techniques using interlocks and memories.
New electricity contents: complete automation and motor command electric panel, interpretation of the whole electric diagram, mapping the IO from the electric diagram.
CHALLENGE 3
AUTOMATION OF THE GYPSUM DOSING AND MIXING LINE
Project: the student is guided on the automation of the whole line using interlocks, memory, timers and dealing with the analog input to read the scale signal. He automates the sequencing step-by step in 8 tasks.
Tasks:
Transporting the recipient to the dosing station
Transporting the recipient to the mixing station
Filling the recipient
Moving the mixer up
Moving the mixer down
Turning the mixer on
Almost there (just a few adjusts)
Line 100% in automated
New automation contents: timers, counters, analog input signal reading and scaling, guidance on the use of memories and retentive commands. New electricity contents: analog signal
CHALLENGE 4
IMPROVE THE AUTOMATION SYSTEM OF THE GATE
Project: In this project the student must implement the automation of the gate so it can be opened, stopped or closed using a single push-button.
Tasks:
Opening and closing with 1 button
Adding the stop command
Adding the revert after stop feature
New automation contents: edge detection instructions, implement commands from impulse/pushes.
CHALLENGE 5
AUTOMATING THE LINE USING STATE MACHINES (SFC)
Project: the student is required to implement a new PLC software for the line but this time using SFC or state machine approach, in order to make it more flexible and easy to maintain. Final instructions are to split the machine in 2 different state machines in order to allow simultaneous dosing and mixing operations, to increase the machine’s performance.
Tasks:
Designing an SFC Part 1: Steps and transitions
Designing an SFC Part 2: Actions
Improving the machine’s performance
Implementing the SFC in Ladder
SFC solution to the dosing station
SFC solution to the mixing station
Machine 100% automated with SFC
New automation contents: state machines, SFC, implementation of SFC in ladder logic.
CHALLENGE 6
AUTOMATING THE FACTORY’S ELEVATOR
Project: the factory has vertical operation and needs to increase the number of elevators but instead of buying a new one, the factory decided to build it. The student is required to develop the elevator’s PLC software.
Tasks:
Designing a state machine for 2 floors
Addint the 3° floor
Using origin-destiny approach instead of SFC
New automation contents: when not to use state machines, linear movement with origin and destiny memory approach. New electric contents: safety relays and circuit, interface between PLC and frequency inverters.
CHALLENGE 7
AUTOMATING THE INK COLORING PROCESS
Project: the student is required to develop a solution to automate color formulation in its ink factory. The student must use all the knowledge and skills developed to get this job done.
Tasks:
Creating a function block
Semi-automatic operation
Automatic operation
Automation contents: organization and function blocks, modularizing the project in small blocks, calling various instances of the same function block.
Eletric component
ELECTRIC PANEL
The image below shows an electric panel of one of the machines in the module. You may see that it’s very similar to a real electric automation and motor command panel. It has the energy supply and protection, circuit breakers, contactors, safety relay, 24Vdc power supply, PLC, interface relays, connectors, contactors, frequency inverters and so on.
ELECTRIC DIAGRAM SIMPLES
As well as the electric panel, the electric diagrams are also presented to the students in industrial standard. The following images are samples of the electric diagram pages. The left column regards the electric motor command panel(forward/reverse motor direct start, frequency inverter start, safety relay), and the right column regards to the PLC panel(digital input page, analog input page, output page).
TROUBLESHOOTING
Solving problems on machinery quickly and effectively to reduce downtime is one of the most valued skills in industries. That’s why our solution includes a resource(right image) to let the student activate a defect without knowing which defect it is. When the student does that, some component will be damaged and the machine will behave in some strange way.
The student’s job is to find out the root cause of the problem and replace the damaged component by using the replacement console (image below)
In order to find out what the problem is, the student may use the virtual multimeter(left picture) to make measurements in the electric panel as well as force signal (right picture) to relay’s coils in order to verify if actuators are working fine.
CHALLENGE/TASK VALIDATION
In the automation module the tasks are validated automatically by verifying if the machine’s sequential behavior is accordingly to the requirements. The screenshot below shows a student’s interface opened with DL VFA4.0(right) and Codesys Development System(left)
