2. Instructional Objectives
In this presentation, the students shall be able to
understand the principle of Signal Conditioning
focusing mainly on the following topics:
1. Signal Conditioning
2. Data Acquisition
3. Microprocessor
4. Microcontroller
5. Electric Drive
•
3. Signal conditioning:
Signal conditioning is a process of data acquisition, and an instrument
called a signal conditioner is used to perform this process. This
instrument converts one type of electrical or mechanical signal (input-
signal) into another (output-signal).
The purpose is to amplify and convert this signal into an easy to read
and compatible form for data-acquisition or machine-control.
A signal conditioner helps to provide precise measurements, which are
essential for accurate data acquisition and machine-control. These
instruments can perform an additional number of different functions.
4. Signal conditioning process:
Many applications require environment or structural measurements, such as
temperature and vibration, from sensors. These sensors, in turn, require
signal conditioning before a data acquisition device can effectively and
accurately measure the signal.
Key signal conditioning technologies provide distinct enhancements to both
the performance and accuracy of data acquisition systems.
5. General structure of measurement system:
The first component of a measurement system is the sensor that converts the physical
variable to be measured into an electrical quantity. However, the signal is usually in a
format that cannot be directly used: it requires ‘conditioning’.
6. Contd..
The second part of any measurement system is the signal
conditioning component that converts the electrical signal from
an unsuitable format to a suitable format. Signal processing
further modifies the signal to prepare it for transmission.
Signal conditioning element takes the output of the sensing
element and converts it into a form more suitable for further
processing, usually a d.c. voltage, d.c. current or frequency
signal.
8. Data Acquisition
Data acquisition is the process of sampling signals
that measure real world physical conditions and
converting the resulting samples into digital numeric
values that can be manipulated by a computer.
Data acquisition systems (abbreviated with the
acronym DAS or DAQ) typically convert analog
waveforms into digital values for processing.
9. Data Acquisition System
The collection of hardware and software components that
enable a computer to receive physical signals.
10. The components of data
acquisition systems include:
Sensors that convert physical parameters to electrical
signals.
Signal conditioning circuitry to convert sensor signals
into a form that can be converted to digital values.
Analog-to-digital converters, which convert
conditioned sensor signals to digital values.
13. The 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.
What is Microprocessor?
2
15. □ The application of microprocessor to metrology field has resulted in
an extensive range of digital measuring instruments combining
accuracy and ease of use
□ A micro-processor can remove the tedious work and risk of error.
□ Microprocessors can handle very complex measurements with no
reduction in accuracy
□ It provides process dimensional gauging with adaptive feedback
Why Micro-processor is necessary?
1
5
16. □ The processor improves set up procedures. For example, minimize
misalignment of the measuring system.
□ A microprocessor can log errors at high speed onthefly, and then
remove setup errors using mathematical techniques.
□ Automatic correction of systematic errors can be performed within a
measuring system in realtime.
□ The microprocessor also makes it possible to operate in realtime
within a machining process, providing inprocess dimensional gauging
1
6
Contd..
17. Hardware Required
•A processing system composed of a microprocessor, with a readonly
memory containing the operating system, and a memory containing the
application program and variables.
•An interface with the operator composed of a keyboard, screen display
signal lamps, etc.
•An interface to measure the lengths, etc.
•Interface with different peripherals such as a printer, another computer,
mass memory etc.
1
7
18. Softwares used
Basic software (operating software). It allows access to
different resources of the system by means of simple and
well defined orders. These orders constitute the part
accessible to the programmer who can also work in
high levellanguages.
Eg- PolyWorks - The Universal 3D Metrology
Software TM
1
8
21. Advantages:
□ High accuracy
□ Low measuring time
□ On-line monitoring
□ In-line monitoring
□ Error logging is possible
Disadvantages:
□ High initial investment
□ Skilled person is required
Advantages and Disadvantages
21
22. □ Rapid prototyping in plastic and metal for function,
fitment and visualization.
□ 3D surface modeling class A and class B.
□ CMM part programming.
□ Conversion of 2D drawing into 3D CAD model.
□ CMM retrofit and calibration services.
□ Product designing.
□ 3D Solid Modeling
□ Tool and die designing
Applications
22
23. Лектор:
Розробники:
Для студентів напрямів підготовки:
Доступне для завантаження на сайті кафедри:
Fundamentals of electric drive
Electrotechnic faculty
Electric drive department
24. Basic concepts and
determinations
1. Electric drive and its basic
elements
2. Classification of electric drives
3. Basic directions of electric drive
development
26. Electric drive and its basic elements
Feedback signals
Motor
Three-phase transmission line
Controller
Convertor Gear box
Transducer Transducer
Transducer
Reference
signals
Reference
signals
Feedback
signals
Feedback
signals
27. Types of electric motors
ac motor
dc motor
Synchronous
motor
Function: transformation of electric energy into mechanical
28. Types of Servo Motors
Servo motors are classified into different types based on their application, such as AC servo
motor, DC servo motor, brushless DC servo motor, positional rotation, continuous rotation and
linear servo motor etc.
Typical servo motors comprise of three wires namely, power control and ground.
The shape and size of these motors depend on their applications.
Servo motor is the most common type which is used in hobby applications, robotics due to
their simplicity, affordability and reliability of control by microprocessors.
30. Servo Motor:
The servo motor is most commonly used for high technology devices in the industrial
application like automation technology.
It is a self contained electrical device, that rotate parts of a machine with high efficiency and
great precision.
The output shaft of this motor can be moved to a particular angle.
Servo motors are mainly used in home electronics, toys, cars, airplanes, etc.
31. AC Servo Motor
AC servo motor is an AC motor that includes
encoder is used with controllers for giving
closed loop control and feedback.
This motor can be placed to high accuracy and
also controlled precisely as compulsory for the
applications.
Frequently these motors have higher designs of tolerance or better bearings and some simple
designs also use higher voltages in order to accomplish greater torque.
Applications of an AC motor mainly involve in automation, robotics, CNC machinery, and other
applications a high level of precision and needful versatility.
32. DC motor
Stator Armature
S N
Br
2
Br
1
C1
C2
F2
F1
S
N
T
𝑭 = 𝑩𝑰𝑳
𝑩 - induction
𝑰 - current
𝑳 – length of
the conductor
T= 𝑭𝑫
T - torque
𝑭 - force
𝑫 - diamete
33. DC Servo Motor
The motor which is used as a DC servo motor generally have a separate DC source in the field
of winding & armature winding.
The control can be archived either by controlling the armature current or field current.
Field control includes some particular advantages over armature control.
In the same way armature control includes some
advantages over field control.
Based on the applications the control should be applied to
the DC servo motor.
DC servo motor provides very accurate and also fast
respond to start or stop command signals due to the low
armature inductive reactance.
DC servo motors are used in similar equipment's and
computerized numerically controlled machines.
35. Stepper Motor:
A stepper motor is an electromechanical device it converts electrical power into mechanical
power.
Also it is a brushless, synchronous electric motor that can divide a full rotation into an
expansive number of steps.
The motor’s position can be controlled accurately without any feedback mechanism, as long as
the motor is carefully sized to the application.
Stepper motors are similar to switched reluctance motors.
36. The stepper motor uses the theory of operation for magnets to make the motor shaft turn a
precise distance when a pulse of electricity is provided.
The stator has eight poles, and the rotor has six poles. The rotor will require 24 pulses of
electricity to move the 24 steps to make one complete revolution.
Another way to say this is that the rotor will move precisely 15° for each pulse of electricity
that the motor receives.
37. Working Principle:
Stepper motors operate differently from DC brush motors, which rotate when voltage is
applied to their terminals.
Stepper motors, on the other hand, effectively have multiple toothed electromagnets arranged
around a central gear-shaped piece of iron.
The electromagnets are energized by an external control circuit, for example a microcontroller.
To make the motor shaft turn, first one electromagnet is given power, which makes the gear’s
teeth magnetically attracted to the electromagnet’s teeth.
The point when the gear’s teeth are thus aligned to the first electromagnet, they are slightly
offset from the next electromagnet.
So when the next electromagnet is turned ON and the first is turned OFF, the gear rotates
slightly to align with the next one and from there the process is repeated.
38. Each of those slight rotations is called a step, with an integer number of steps making a full
rotation.
In that way, the motor can be turned by a precise. Stepper motor doesn’t rotate continuously,
they rotate in steps.
There are 4 coils with 90o angle between each other fixed on the stator. The stepper motor
connections are determined by the way the coils are interconnected.
In stepper motor, the coils are not connected together. The motor has 90o rotation step with
the coils being energized in a cyclic order, determining the shaft rotation direction.
The working of this motor is shown by operating the switch. The coils are activated in series
in 1 sec intervals. The shaft rotates 90o each time the next coil is activated. Its low speed
torque will vary directly with current.
43. Classification of electric drives
By the sort of current of drive
engine:
direct current (DC)
alternating current (AC)
44. Classification of electric drives
By the sort of mechanical
transmission:
geared electric drive in
which an electric motor is
connected with a working
machine by means of one of
types of transmission
devices
gearless electric drive (direct
drive), when an electric
motor is connected directly
with a machine tool
Gear
box
Motor
46. Classification of electric drives
By the level of automation:
a) uncontrolled electric drive
b) automated electric drive in which a part of control operations is executed
without operator participation;
c) automatic electric drive, in which full control operations are executed
without operator participation.
TRANSDUC
ERS
TRANSDU
ERS
a)
b)
c)
47. Classification of electric drives
By the type of control system:
a) open-loop control. It is an electric drive control system in which a
feed-back of output coordinate absents;
b) closed-loop control. It is an electric drive control system in which
a feed-back of output coordinate presents;
c) electric shaft it is an interconnected electric drive which
provides synchronous motion two or more machine tools, not
having a mechanical connection.
TRANSDUC
ERS
a) b) c)
48. Classification of electric drives
a)
b)
d)
By principles of output coordinates control:
a) controllable electric drive which provides a
guided change of machine tool motion
coordinates in accordance with
requirements of a technological process;
b) positional electric drive which provides a
machine tool transferring to a set position;
c) follow-up electric drive which provides a
machine tool moving in accordance with an
arbitrarily changing reference signal;
d) software programmable electric drive
which provides a machine tool moving in
accordance with a set program;
e) adaptive electric drive which automatically
adapts to parameters changing and
disturbance influences, by a structure and
parameters changing of a control system.
ED MT
r
ED MT
r
ED MT
(t)
r(t)
ED MT
r,r
c)
ED MT
(t)
r
TL(t)
e)
49. Classification of electric drives
a)
b)
d)
ED MT
r
ED
M1
M2
M3
MT
r
c)
By a method of passing to mechanical energy:
a) individual electric drive only one
machine tool is operated by one engine;
b) group electric drive a few machine tools
are operated by one engine;
c) multimotor electric drive one machine
tool is operated by a few electric motors;
d) interconnected electric drive an electric
drive contains two or a few electric or
mechanically connected electric drives,
during working of which a set correlation
of their speeds, loadings or positions of
machine tools is supported.
ED
r
MT1
MT2
MT3
MT
r
ED1
ED2
ED3
51. Basic directions of electric drive development
Expansion of automated drives, mainly frequency controlled drives of
alternating current with a usage of the fully controlled semiconductor devices
Increase of requirements to accuracy indexes of dynamic and static modes of
operations
Expansion and complication of electric drives functions
Standardization of an element base and creation of a complete electric drive for
requirements satisfying of a wide class of production mechanisms
Expansion of power ratings to ten of thousands of kilowatts and considerable
variety of their design
Creation of powerful gearless drives of ball and autogenous mills, mine winder,
basic mechanisms of excavators and other mechanisms
Increase efficiency and power factor of all electric drive types
Usage of grouped electric drive systems with a common suppaly for flexible
control of electric power streams, energy storage, reactive power
compensation etc.
