Prepared by

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MECHATRONICS U5MEA22

• Prepared by
• Mr. S Riyaz Ahammed Mr. Hushein
• Assistant Professor, Mechanical Department
• VelTech Dr.RR Dr.SR Technical University

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Unit 1
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• Mechatronics-

• Mechatronics basically refers to mechanical
  electrical systems and is centered on mechanics,
  electronics, computing and control which,
  combined, make possible the generation of
  simpler, more economical, reliable and versatile
  systems.
• The term "mechatronics" was first assigned by
  Mr.Tetsuro Mori, a senior engineer of the
  Japanese company Yaskawa, in 1969.
• Mechatronics is the combination of mechanical,
  electronic, computer,control engineering's and
  system engineering to design and manufacture
  useful products.

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Key Elements
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Measurement system
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Control Systems

• Control Systems are mainly of Two Types
• Open Loop Control Systems
• Closed Loop control Systems
• An open-loop controller, also called
  a non-feedback controller.
• Basic difference between two types of systems
  is closed loop systems have feed back which makes
  them to be good precise control systems or
  automated systems.
• PID controller, a commonly used closed-loop
  controller

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Water Level Controller
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• Controlled variable- water level in tank
• Reference value- initial setting of float, lever
  position
• Comparison element- Lever
• Error signal- Difference between the actual
  and initial settings of lever
  position
• Control unit- Pivoted lever
• Correction unit- Flap opening or closing water
  supply
• Process- water level in the tank

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Shaft speed control systems
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Description

• Potentiometer is used to set the voltage to be
  supplied to the power amplifier.
• Differential amplifier is used to amplify and
  compare the feed back value and reference value.
• Amplified error signal is fed to the motor to
  adjust the speed of rotating shaft.
• Tachometer is used to measure the speed of
  rotating shaft and speed is fed to amplifier.

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Washing Machine control

• Example of an event based sequential control
  system is washing machine. Each event of washing
  machine may consist of number of sub events or
  steps. For example pre wash cycle, rinse cycle,
  main cycle, spinning cycle.
• Following figures represent the various events of
  washing machine system.

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During Pre wash cycle operation, the inlet valve
is opened when the machine is switched ON and the
valve is closed when the required level of water
is filled in the drum.Main wash cycle is then
started by micro processor by operating the inlet
valve to allow the water in to the drum.Water
level sensor senses the water level in the drum
and it closes the inlet valve after reaching
certain level, Micro processor switches ON the
heating coil in the drum.
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AUTOMATIC CAMERA

• Basic elements of control systems used in
  automatic camera are body, lenses and flash.
• Depending up on mode selected, the required
  combination of aperture and shutter speed and
  focus are automatically taken care by the camera.
• A typical camera system comprises drives and
  sensors, interfaces for lenses, flash and the
  user.

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• Micro processor systems for lenses, user and
  flash are incorporated for controlling various
  operations. Micro processor takes input from
  range sensor and sends output to lens.
• Position is fed back to micro processor and it
  modifies the same.
• Light sensor gives input to micro processor, When
  photographer selects shutter controller, shutter
  opens up for photograph to be taken.

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Engine Management System

• System consists of sensors for supplying, after
  suitable signal conditioning, the input signals
  to micro controller, and its providing output
  signals via drivers to actuate actuators.
• Engine speed sensor is an inductive sensor and
  consists of a coil for which inductance changes
  as the teeth of the sensor wheel pass it and so
  gives oscillating output.

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• Temperature sensor is usually a thermistor.
• Mass air flow sensor may be a hot wire sensor, as
  air passes over heated wire it will be cooled,
  the amount of cooling will depend on the mass
  rate of flow.
• Oxygen sensor is generally closed end tube made
  of zirconium oxide with porous platinum
  electrodes on inner and outer surfaces.
• Following figure represents an engine management
  system

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Unit 2

• MICROPROCESOR
• IN
• MECHATRONICS

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MICROPROCESSOR

• A microprocessor incorporates the functions of
  a computer's central processing unit (CPU) on a
  single integrated circuit (IC),or at most a few
  integrated circuits. Microprocessor is a
  multipurpose, programmable device that
  accepts digital data as input, processes it
  according to instructions stored in its memory,
  and provides results as output

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8085 ARCHITECTURE
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INPUT AND OUTPUT PERIPHERAL CIRCUITS

• A peripheral is a device that is connected to a
  host computer, but not part of it. It expands the
  host's capabilities but does not form part of the
  core computer architecture. It is often, but not
  always, partially or completely dependent on the
  host.
• There are three different types of peripherals
• Input, used to interact with, or send data to the
  computer (mouse, keyboards, etc.)
• Output, which provides output to the user from
  the computer (monitors, printers, etc.)
• Storage, which stores data processed by the
  computer (hard drives, flash drives, etc.)

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COMMUNICATIONS-INPUT,OUTPUT AND MEMORY WITH
TIMING DIAGRAM

• Input/output (I/O) scheduling is the method
  that computer operating systems use to decide
  which order block I/O operations will be
  submitted to storage volumes. I/O Scheduling is
  sometimes called 'disk scheduling'.

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PURPOSE

• I/O schedulers can have many purposes depending
  on the goal of the I/O scheduler. Some common
  ones are
• To minimize time wasted by hard disk seeks
• To prioritize a certain processes' I/O requests
• To give a share of the disk bandwidth to each
  running process
• To guarantee that certain requests will be issued
  before a particular deadline

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A/D CONVERTER

• An analog-to-digital converter (abbreviated ADC, A
  /D or A to D) is a device that converts a
  continuous physical quantity (usually voltage) to
  a digital number that represents the quantity's
  amplitude.

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• The conversion involves quantization of the
  input, so it necessarily introduces a small
  amount of error. Instead of doing a single
  conversion, an ADC often performs the conversions
  ("samples" the input) periodically. The result is
  a sequence of digital values that have converted
  a continuous-time and continuous-amplitude analog
  signal to a discrete-time and discrete-amplitude d
  igital signal.

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• An ADC may also provide an isolated measurement
  such as an electronic device that converts an
  input analog voltage or current to a digital
  number proportional to the magnitude of the
  voltage or current. However, some non-electronic
  or only partially electronic devices, such
  as rotary encoders, can also be considered ADCs.
  The digital output may use different coding
  schemes. Typically the digital output will be
  a two's complement binary number that is
  proportional to the input, but there are other
  possibilities. An encoder, for example, might
  output a Gray code.
• The inverse operation is performed by
  a digital-to-analog converter (DAC).

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ELECTRICAL SYMBOL
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• The key parameters to test a SAR ADC are
  following
• DC Offset Error
• DC Gain Error
• Signal to Noise Ratio (SNR)
• Total Harmonic Distortion (THD)
• Integral Non Linearity (INL)
• Differential Non Linearity (DNL)
• Spurious Free Dynamic Range
• Power Dissipation

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D/A CONVERTER

• a digital-to-analog converter (DAC or D-to-A) is
  a device that converts a digital (usually binary)
  code to an analog signal (current, voltage,
  or electric charge). An analog-to-digital
  converter (ADC) performs the reverse operation.
  Signals are easily stored and transmitted
  in digital form, but a DAC is needed for the
  signal to be recognized by human senses or other
  non-digital systems.

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• A common use of digital-to-analog converters is
  generation of audio signals from digital
  information in music players. Digital video
  signals are converted to analog
  in televisions and mobile phones to display
  colors and shades. Digital-to-analog conversion
  can degrade a signal, so conversion details are
  normally chosen so that the errors are negligible.

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• Due to cost and the need for matched components,
  DACs are almost exclusively manufactured
  on integrated circuits (ICs). There are many
  DACarchitectures which have different advantages
  and disadvantages. The suitability of a
  particular DAC for an application is determined
  by a variety of measurements including speed
  and resolution.

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RECENT DEVELOPMENTS IN MICROPROCESSORS AND
CONTROLLERS

• The recent development In microprocessor
  technology makes Implementation of advanced
  control strategies feasible at the generating
  level. A self-tuning (ST) proportional-plus-lntegr
  al-plus-derivative (PID) digital automatic
  voltage regulator (DAVR) for a large synchronous
  machine is proposed and the influence of this
  regulator on the generator dynamic and transient
  stability is investigated. The algorithm for this
  regulator combines a least-square estimator with
  a digital PID control algorithm. The parameters
  of the PID control algorithm are computed and
  updated according to the estimated model. The
  dynamic performance of the machine when equipped
  with a digital PID governor is also presented. A
  comparison of the computer results as obtained
  from the simulation study are compared with the
  available experimental results.

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Unit 3

• ELECTRICAL DRIVES
• AND
• CONTROLLERS

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Electromagnetic principles

• "When a conductor is exposed to a changing
  magnetic field, an electric current will flow in
  the conductor."
• This principle is the basis for the generation of
  electricity. In a typical large-scale operating
  electrical generator, an armature coil (a coil of
  wire of many turns) is wrapped around a soft iron
  armature and forced to spin in a powerful
  electromagnetic field. The spinning is achieved
  by forcing high-pressure steam (in a thermal
  generator), fast-flowing water (in a hydro
  generator), or wind (in a wind generator) across
  a turbine (similar to a propeller blade) attached
  to the end of the armature. As the armature
  spins, an electric current is induced (forced) to
  flow in the armature coil where it is extracted
  and sent to the electricity grid that supplies
  electricity across a broad area (the province of
  Ontario and beyond, for example). It is the
  direction of flow of this induced current that is
  addressed by Lenz's law.

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SOLENOIDS

• In physics, the term refers specifically to a
  long, thin loop of wire, often wrapped around
  a metallic core, which produces a
  uniform magnetic field in a volume of space
  (where some experiment might be carried out) when
  an electric current is passed through it.
  Solenoids are important because they can create
  controlled magnetic fields and can be used
  as electromagnets.

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• In engineering, the term may also refer to a
  variety of transducer devices that
  convert energy into linear motion. The term is
  also often used to refer to asolenoid valve,
  which is an integrated device containing an
  electromechanical solenoid which actuates either
  a pneumatic or hydraulic valve, or a solenoid
  switch, which is a specific type of relay that
  internally uses an electromechanical solenoid to
  operate an electrical switch for example,
  an automobile starter solenoid, or a linear
  solenoid, which is an electromechanical solenoid.

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SOLENOID
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RELAYS

• A relay is an electrically operated switch. Many
  relays use an electromagnet to operate a
  switching mechanism mechanically, but other
  operating principles are also used. Relays are
  used where it is necessary to control a circuit
  by a low-power signal (with complete electrical
  isolation between control and controlled
  circuits), or where several circuits must be
  controlled by one signal. The first relays were
  used in long distance telegraph circuits,
  repeating the signal coming in from one circuit
  and re-transmitting it to another. Relays were
  used extensively in telephone exchanges and early
  computers to perform logical operations.

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ELECTROMECHANICAL RELAY
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• A type of relay that can handle the high power
  required to directly control an electric motor or
  other loads is called a contactor. Solid-state
  relays control power circuits with no moving
  parts, instead using a semiconductor device to
  perform switching. Relays with calibrated
  operating characteristics and sometimes multiple
  operating coils are used to protect electrical
  circuits from overload or faults in modern
  electric power systems these functions are
  performed by digital instruments still called
  "protective relays".

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STEPPER MOTORS

• A stepper motor (or step motor) is a brushless DC
  electric motor that divides a full rotation into
  a number of equal steps. The motor's position can
  then be commanded to move and hold at one of
  these steps without any feedback sensor
  (an open-loop controller), as long as the motor
  is carefully sized to the application.

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TYPES OF STEPPER MOTORS

• There are four main types of stepper motors1
• Permanent magnet stepper (can be subdivided into
  'tin-can' and 'hybrid', tin-can being a cheaper
  product, and hybrid with higher quality bearings,
  smaller step angle, higher power density)
• Hybrid synchronous stepper
• Variable reluctance stepper
• Lavet type stepping motor

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SERVO MOTORS

• A servomotor is a rotary actuator that allows for
  precise control of angular position, velocity and
  acceleration. It consists of a suitable motor
  coupled to a sensor for position feedback. It
  also requires a relatively sophisticated
  controller, often a dedicated module designed
  specifically for use with servomotors.
• Servomotors are not a different class of motor,
  on the basis of fundamental operating principle,
  but uses servomechanism to achieve closed loop
  control with a generic open loop motor.
• Servomotors are used in applications such
  as robotics, CNC machinery or automated
  manufacturing.

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PROGRAMMABLE LOGIC CONTROLLER

• A Programmable Logic Controller, PLC or Programmab
  le Controller is a digital computer used
  for automation of electromechanical processes,
  such as control of machinery on factory assembly
  lines, amusement rides, or light fixtures. The
  abbreviation "PLC" and the term "Programmable
  Logic Controller" are registered trademarks of
  the Allen-Bradley Company (Rockwell Automation).

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• PLCs are used in many industries and machines.
  Unlike general-purpose computers, the PLC is
  designed for multiple inputs and output
  arrangements, extended temperature ranges,
  immunity to electrical noise, and resistance to
  vibration and impact. Programs to control machine
  operation are typically stored in
  battery-backed-up or non-volatile memory. A PLC
  is an example of a hard real time system since
  output results must be produced in response to
  input conditions within a limited time, otherwise
  unintended operation will result.

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MEMORY- INPUT , OUTPUT MODULES

• In computer architecture, the combination of
  the CPU and main memory (i.e. memory that the CPU
  can read and write to directly, with
  individual instructions) is considered the brain
  of a computer, and from that point of view any
  transfer of information from or to that
  combination, for example to or from a disk drive,
  is considered I/O. The CPU and its supporting
  circuitry providememory-mapped I/O that is used
  in low-level computer programming, such as the
  implementation of device drivers. An I/O
  algorithm is one designed to exploit locality and
  perform efficiently when data reside on secondary
  storage, such as a disk drive.

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TIMERS- INTERNAL RELAYS

• A timer is a clock that controls the sequence of
  an event while counting in fixed intervals of
  time
• A timer is a specialised type of clock for
  measuring time intervals

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Counters shift registers

• In digital circuits a shift register is a
  cascade of flip-flops , sharing the same clock,
  in which the output of each flip flop is
  connected to the data input of next flip flop in
  the chain resulting in the circuit that shifts by
  one position the bit array stored in it,shifting
  in the data present at its input and shifting out
  the last bit in the array, at each transition of
  clock input.

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Counter- timing
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PLC- USING LADDER DIAGRAM

• A ladder diagram represents a program in LADDER
  LOGIC
• A ladder logic is a method of drawing electrical
  logic schematics.

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PLC WITH LADDER LOGIC
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PLC - APPLICATIONS
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Unit 4
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Limit Switch

• A limit switch is an electromechanical device
  that consists of an actuator mechanically linked
  to a set of contacts.
• When an object comes into contact with the
  actuator, the device operates the contacts to
  make or break an electrical connection.
• It can determine the presence or absence of an
  object. It was first used to define the limit of
  travel of an object hence the name "Limit
  Switch."

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Basic Components

• Actuator The portion of the switch that comes in
  contact with the object being sensed.
• Head It houses the mechanism that translates
  actuator movement into contact movement. When the
  actuator is moved as intended, the mechanism
  operates the switch contacts.
• Contact Block It houses the electrical contact
  elements of the switch. It typically contains
  either two or four contact pairs.

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Basic Components (contd.)

• Terminal Block The terminal block contains the
  screw terminations. This is where the electrical
  (wire) connection between the switch and the rest
  of the control circuit is made.
• Switch Body The switch body houses the contact
  block in a plug-in switch. It and terminal block
  in the nonplug-in switch.
• Base The base houses the terminal block in a
  plug-in switch. Nonplug-in switches do not have a
  separate base.

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Type-1 Nonplug-in Housing

• They are box shaped with a separate cover.
• Seals between the head, body, and cover are
  maintained by an O-ring and a flat gasket.

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Type-2 Plug-in Housing

• Developed to ease replacement of the switch if
  needed.
• Plug-in housing splits in half to allow access to
  the terminal block for wiring.
• A set of stabs in the switch body plugs into
  sockets in the base to make electrical
  connections between the contact block and the
  terminal block.

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Encoders

• What is an encoder?
• An encoder is a sensor for converting rotary
  motion or position to a series of electronic
  pulses
• Advantages
• Simplicity of construction (low cost)
• High sensitivity (depending upon the supply
  voltage)
• Disadvantages
• It includes the familiar drawbacks related to
  contacting and communicating devices like
  friction, wear, brush bounce due to vibration,
  signal glitches and metal oxidation due to
  electrical arcing.

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The types of encoders

• Absolute encoders
• Absolute encoders have a unique code that can
  be detected for each angular position
• Absolute encoders are much more complex and
  expensive than incremental encoders

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The types of encoders

• Incremental encoders
• Pulses from LEDS are counted to provide rotary
  position
• Two detectors are used to determine direction
  (quadrature)
• Index pulse used to denote start point
• Otherwise pulses are not unique

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Temperature Sensor

• Temperature sensors appear in building, chemical
  process plants, engines, appliances, computers,
  and many other devices that require temperature
  monitoring
• Many physical phenomena depend on temperature, so
  we can often measure temperature indirectly by
  measuring pressure, volume, electrical
  resistance, and strain

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Temperature Sensor

• Bimetallic Strip
• Application
• Thermostat (makes or breaks electrical connection
  with deflection)

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Temperature Sensor

• Resistance temperature device.

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Position Sensors
Position Sensors is a device that provides the
position measurement of a component. A position
sensor can be 1.Linear 2.Angular 3.Multi-axis
Some of the well-known position sensors
are Linear Variable Differential Transformer
(LVDT) Hall Effect Sensor Proximity Sensor
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LDVT-Configuration

• An alternating current is driven through the
  primary, causing a voltage to be induced in each
  secondary proportional to its mutual inductance
  with the primary. The frequency is usually in the
  range 1 to 10 kHz.

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Hall Effect Sensor

• The Hall effect was discovered by Edwin Hall in
  1879 electron was not experimentally
  discovered had to wait until quantum mechanics
  came
• Development of semiconductor compoundsin 1950's
  led to first useful Hall effect
  magneticinstrument
• In the 1960's, first combinations of Hall
  elements and integrated amplifiers
• Resulted to classic digital output Hall switch
• In 1965, first low-cost solid state sensor

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Theory of the Hall Effect
Hall effect principle, no magnetic field
Hall effect principle, magnetic field present
Potential Difference (voltage) across output V
I B
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Basic Hall Effect Sensor

• Hall element is the basic magnetic field sensor
• Differential Amplifier amplifies the potential
  difference (Hall voltage)
• Regulator holds current value so that the output
  of the sensor only reflects the intensity of the
  magnetic field
• Types
• 1. Unipolar
• 2.Latching
• 3.Bipolar

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Proximity Sensor

• A proximity sensor is a sensor able to detect the
  presence of nearby objects without any physical
  contact.
• These sensors use mutual inductance between a
  known inductor and a conductive material
• Commonly referred to as eddy current probes
• Mutual inductance is a function of the distance
  between the inductor and the material

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How Eddy Currents Work

• An inductive coil is placed near a conductive
  surface
• An AC voltage (typically around 2Mhz) is applied
  to the coil
• Mutual inductance begins to occur
• The coil generates a magnetic field
• Circular or Eddy Currents begin to flow in the
  conductive material
• These currents resemble an eddy in a stream of
  water

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How Eddy Currents Work

• The Eddy Currents generate their own magnetic
  field
• These fields have interaction with the coil
  through mutual inductance
• This leads to a measurable result

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What can be measured?

• Electrical conductivity and magnetic permeability
  of the target material
• The amount of material cutting through the coils
  of the magnetic field
• The condition of the material(whether it contains
  cracks or defects
• Lift-Off

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Pressure Sensor

• Two Main Types of Pressure Sensors
• Capacitive Sensors
• Work based on measurement of capacitance from two
  parallel plates.
• C eA/d , A area of plates d distance
  between.
• This implies that the response of a capacitive
  sensor is inherently non-linear. Worsened by
  diaphragm deflection.
• Must use external processor to compensate for
  non-linearity

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Pressure Sensor

• Piezoresistive Sensors
• Work based on the piezoresistive properties of
  silicon and other materials.
• Piezoresistivity is a response to stress.
• Some piezoresistive materials are Si, Ge, metals.
• In semiconductors, piezoresistivity is caused by
  2 factors geometry deformation and resistivity
  changes.

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Pressure Sensing
Pressure

• Pressure is sensed by mechanical elements such as
  plates, shells, and tubes that are designed and
  constructed to deflect when pressure is applied.
• This is the basic mechanism converting pressure
  to physical movement.
• Next, this movement must be transduced to obtain
  an electrical or other output.
• Finally, signal conditioning may be needed,
  depending on the type of sensor and the
  application. Figure 8 illustrates the three
  functional blocks.

Sensing Element
displacement
Transduction element
electric
Signal Conditioner
V or I output
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Sensing Elements

• The main types of sensing elements are Bourdon
  tubes, diaphragms, capsules, and bellows
• All except diaphragms provide a fairly large
  displacement that is useful in mechanical gauges
  and for electrical sensors that require a
  significant movement

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Potentiometric Pressure Sensors

• Potentiometric pressure sensors use a Bourdon
  tube, capsule, or bellows to drive a wiper arm on
  a resistive element.
• For reliable operation the wiper must bear on the
  element with some force, which leads to
  repeatability and hysteresis errors.
• These devices are very low cost, however, and are
  used in low-performance applications such as
  dashboard oil pressure gauges

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 Inductive Pressure Sensors

• Several configurations based on varying
  inductance or inductive coupling are used in
  pressure sensors. They all require AC excitation
  of the coil(s) and, if a DC output is desired,
  subsequent demodulation and filtering. The LVDT
  types have a fairly low frequency response due to
  the necessity of driving the moving core of the
  differential transformer
• The LVDT uses the moving core to vary the
  inductive coupling between the transformer
  primary and secondary.

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Capacitive Pressure Sensors.

• Capacitive pressure sensors typically use a thin
  diaphragm as one plate of a capacitor.
• Applied pressure causes the diaphragm to deflect
  and the capacitance to change.
• This change may or may not be linear and is
  typically on the order of several picofarads out
  of a total capacitance of 50-100 pF.
• The change in capacitance may be used to control
  the frequency of an oscillator or to vary the
  coupling of an AC signal through a network.
• The electronics for signal conditioning should be
  located close to the sensing element to prevent
  errors due to stray capacitance.

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INTRODUCTION OF TRANSDUCERS

• A transducer is a device that convert one form of
  energy to other form. It converts the measurand
  to a usable electrical signal.
• In other word it is a device that is capable of
  converting the physical quantity into a
  proportional electrical quantity such as voltage
  or current.

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BLOCK DIAGRAM OF TRANSDUCERS

• Transducer contains two parts that are closely
  related to each other i.e. the sensing element
  and transduction element.
• The sensing element is called as the sensor. It
  is device producing measurable response to change
  in physical conditions.
• The transduction element convert the sensor
  output to suitable electrical form.

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CHARACTERISTICS OF TRANSDUCERS

1. Ruggedness
2. Linearity
3. Repeatability
4. Accuracy
5. High stability and reliability
6. Speed of response
7. Sensitivity
8. Small size

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TRANSDUCERS SELECTION FACTORS

• Operating Principle The transducer are many
  times selected on the basis of operating
  principle used by them. The operating principle
  used may be resistive, inductive, capacitive ,
  optoelectronic, piezo electric etc.
• Sensitivity The transducer must be sensitive
  enough to produce detectable output.
• Operating Range The transducer should maintain
  the range requirement and have a good resolution
  over the entire range.
• Accuracy High accuracy is assured.
• Cross sensitivity It has to be taken into
  account when measuring mechanical quantities.
  There are situation where the actual quantity is
  being measured is in one plane and the transducer
  is subjected to variation in another plan.
• Errors The transducer should maintain the
  expected input-output relationship as described
  by the transfer function so as to avoid errors.

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Contd.

• Transient and frequency response The transducer
  should meet the desired time domain specification
  like peak overshoot, rise time, setting time and
  small dynamic error.
• Loading Effects The transducer should have a
  high input impedance and low output impedance to
  avoid loading effects.
• Environmental Compatibility It should be assured
  that the transducer selected to work under
  specified environmental conditions maintains its
  input- output relationship and does not break
  down.
• Insensitivity to unwanted signals The transducer
  should be minimally sensitive to unwanted signals
  and highly sensitive to desired signals.

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CLASSIFICATION OF TRANSDUCERS

• The transducers can be classified as
• Active and passive transducers.
• Analog and digital transducers.
• On the basis of transduction principle used.
• Primary and secondary transducer
• Transducers and inverse transducers.

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Unit 5
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Stages in designing Mechatronics Systems
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Traditional and Mechatronics Design

• system is partitioned into individual homogenous
  subsystems according to the disciplines,
• homogenous subsystems are designed by specialists
  from a design team,
• each homogenous subsystem is designed by
  traditional way,
• each product function is from the most part
  realized by only one homogenous subsystem,
• ¾ interactions are minimized, emphasis is mainly
  laid on common interfaces of the subsystems.

• more functions,
• higher efficiency and reliability,
• lower demands on energy,
• minimal size and weight,
• lower cost.

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Engine Management Systems

• 1.Throttle position
• sensor
• 2.EGO sensor
• 3.MAP Sensor
• 4.Temperature
• sensor
• 5.Speed/Timing
• Sensor
• 6.EGR diagnostic
• switch
• 7.EGR valve position sensor

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Sensors and actuators in EMS
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Pick and Place Robot

• The robot has three axis about which motion can
  occur.
• The following movements are required for this
  robot.
• 1. clockwise and anticlockwise rotation of the
  robot unit on its base.
• 2. Linear movement of the arm horizontally i.e.,
  extension or contraction of arm.
• 3. Up and down movement of the arm and

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• 4. Open and close movement of the gripper.
• The foresaid movements can be obtained by
  pneumatic cylinder which is operated by solenoid
  valves with limit switches.
• Limits switches are used to indicate when a
  motion is completed.
• The clockwise rotation of the robot unit on its
  base can be obtained from a piston and cylinder
  arrangement during pistons forward movement
• v Similarly counter clockwise rotation can be
  obtained during backward
• movement of the piston in cylinder.

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Control circuit diagram of the pick and place
robot
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Automatic car parking system

• Consider an automatic car park system with
  barriers operated by coin inserts.
• The system uses a PLC for its operation.
• There are two barriers used namely in barrier and
  out barrier. In barrier is used to open when the
  correct money is inserted while out barrier open
  when the car is detected in front of it.
• It shows a schematic arrangement of an automatic
  car park barrier. It consists of a barrier which
  is pivoted at one end, two Solenoid valves A and
  B and a piston cylinder arrangement
• A connecting rod connects piston and barrier as
  shown in fig below Solenoid valves are used to
  control the movement of the piston.
• Solenoid A is used to move the piston upward
  inturn barrier whereas solenoid B is used to move
  the piston downward.

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• Limit switches are used to detect the foremost
  position of the barrier. When current flows
  through solenoid A, the, piston in the cylinder
  moves upward and causes the barrier to rotate
  about its pivot and raises to let a car through

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