EMC311: Mechatronics (2014/15)Course Outcomes1. Able to describe a typical mechatronic system.2. Able to formulate logic function digitally.3. Able to operate PLC and program ladder diagram.4. Able tooperate raspberry pi and program python.5. Able to design pneumatic and hydraulic circuits using various actuation and control elements.6. Able to identify the basic element used in an electrical actuation system and explain their underlying principles of operation.7. Able to integrate the various sensor and actuation systems using PLC in developing a typical mechatronic system

Learning Outcomes:

At the end of this topic, you should be able to:Able to describe a typical mechatronic system.Explain the term mechatronicsAble to describe a typical mechatronic system.Identify the basic elements of a closed loop system

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What is mechatronics?

The term mechatronics is used for the integration of microprocessor control systems, electrical systems and mechanical systems:

"Mechatronics represents more than mechanical and electronics, according to Craig, a professor of mechanical engineering at Marquette University.

"Mechatronics is really all about design of any physical system, where you integrate controls, electronics, and computers from the very start of the design process."

Control systemsMechanical systemsElectronic systemsComputersMechatronics

Control systemsMechanical systemsElectronic systemsComputersMechatronics1

Mechatronics integrates other areas, such as:Sensors and measurement systems MEMsDrive and actuation systemsMicroprocessor systemsControl systems

Examples of mechatronics systemsAutofocus cameraHard disk drive*Washing machinehttp://www.memagazine.org/contents/current/features/rightthe/rightthe.html

Lets see how autofocus camera works

Lego Mindstorms

Complex mechatronics enable the Nexans Spider remotely operated underwater vehicle to prepare the sea floor for pipelines running 3,000 feet under the ocean. http://www.memagazine.org/contents/current/features/rightthe/rightthe.html

Embedded systems Embedded system where microprocessors are embedded into systems Microprocessor can be considered as being a collection of logic gates and memory elements whose logic functions are implemented by means of a software. Microcontrollers microprocessors used in control system that is equipped with additional chips for data storage and input/output ports

What is the difference between a microprocessor and a microcontroller? (Self-reading)

Systems

A system can be considered as a box which has an input and an output:

Measurement SystemsA measurement system can be considered as a black box used for making measurements.

Measurement systems can be considered to be made up of three elements:

Please identify three main elements of an altitude measurement systems?Please identify the three main elements of a tensile measurement systems?2

Control SystemsA control system can be considered as a black box that uses the input to regulate the the output.

Control systems use to:Control some variable to some particular values.Control the sequence of events.Control the logics. In feedback control, signals are fed back from the output and compared to what is required, and the output is adjusted accordingly.

Two basic forms of control system: Open loop and closed loop. Example of an open loop system: A manually controlled heating system:Open-loop systems: Relatively simple, low cost but inaccurate, no correction for error

Automatically controlled heating system:Closed-loop systems: Accurate in matching the actual to the required values, but more complex, more costly, greater chance of breakdown.

Basic elements of a closed-loop systemComparison element: Compares the required or reference value of the variable condition being controlled with the measured value of what is being achieved and produces an error signal.

Control element: Decides what action to take when it receives an error signal. Control plans may be hard-wired systems or programmable systems

Correction element: Produces a change in the process to correct or change the controlled condition.

Process element: What is being controlled.Measurement element: Produces a signal related to the variable condition of the process that is being controlled.

Identify all the elements of the feedback control system shown in the block diagram.?????????3

Identify the various elements of the closed loop system shownExample of a simple control system used to maintain a constant water level in a tank: 5

A simple automatic control system for the speed of rotation of a shaft:

6

Controlled variable:Reference value:Comparison element:Error signal:

Control unit: Correction unit:Process:Measuring device:

Learning points1. Name the FIVE basic elements of a control system2. Draw the block diagram of a closed loop control system and label all the elements.

Analog and digital control systems Basic elements of a digital closed-loop control system.

Sequential controllers The term sequential control is used when control is such that actions are strictly ordered in a time or event driven sequence. Such control could be obtained by an electrical circuit with sets of relays or cam-operated switches which are wired up in such a way as to give the required sequence.

Sequential control example: consider domestic washing machine:

PLC microprocessor based controller which uses programmable memory to store instructions and to implement functions such as logic, sequence, timing counting and arithmetic to control events. Programmable logic controller (PLC)

Example of control sequence using PLC:Switch on pump to move liquid into tank.Switch off pump when a level detector gives the on signal.Switch on the heater.Switch off the heater when temperature sensor given the on signal to indicate required temperature is reached.Switch on pump to empty liquid from container.Switch off pump when level detector gives on signal.

Examples of mechatronic systems The digital camera and autofocus. No feedback control

Examples of mechatronic systems The digital camera and autofocus With feedback control:

The engine management system Synchronized by Hard-wired system via a timing belt

http://en.wikipedia.org/wiki/Engine_control_unitAn engine control unit (ECU), also known as power-train control module (PCM), or engine control module (ECM) is a type of electronic control unit that determines the amount of fuel, ignition timing and other parameters an internal combustion engine needs to keep running. It does this by reading values from multidimensional performance maps (so called LUTs), using input values (e.g. engine speed) calculated from signals coming from sensor devices monitoring the engine. Before ECU's, air/fuel mixture, ignition timing, and idle speed were directly controlled by mechanical and pneumatic sensors and actuators.

LEARNING POINTSName the four main components of Mechatronics.What is meant by an embedded system?Name the three main elements of a measurement system.What is the main difference between open-loop and closed-loop systems?List the five basic elements of a closed-loop system.

LEARNING POINTSName the four main components of Mechatronics.What is meant by an embedded system?3. Name the three main elements of a measurement system.

4.What is the main difference between open-loop and closed-loop systems?5. List the five basic elements of a closed-loop system.

Replace the mechanical control system with an electrical/electronic control system for the tank filling system shown: