2. UNIT 1
Mechatronic system components
Concept of mechatronics
Introduction to Mechatronics: Introduction to mechatronics systems, Evolution of Mechatronics, Need and classification of
mechatronics system, Basic Elements and components, measurement and control systems. Proportional, Integral and
derivative (PI, PD and PID) controls.
3. UNIT 2
Sensors & Signal Conditioning: Performance terminologies. Displacement, position, velocity, force, pressure, flow,
temperature and light sensors. Signal conditioning, Operational amplifier. Digital signals, ADC, DAC. Digital logic, logic gates
and its application.
Potentiometer
Strain Gauge Encoder
Strain Gauge Load Cell
Signal Conditioning
4. UNIT 3
Actuators & Microprocessor: Actuation systems- Pneumatic, hydraulic, mechanical and electrical actuation systems. Types
of Stepper and Servo motors – Construction – Working Principle – Advantages and Disadvantages. Microprocessor: Buses.
Architecture of 8085. Programming of developmental board (ARDUINO).
Hydraulic System
Pneumatic System
Valve
Electric Actuators Arduino
5. UNIT 4
Introduction to programmable logic controller: Basic structure, Programming units and Memory of Programmable logic
controller, Input and Output Modules, Mnemonics for programming, Latching and Internal relays, Timers, Counters and
Shift Registers, Master relay and Jump Controls.
PLC
Relays and Switches
6. UNIT 5
System modelling & Case study: Mathematical modelling and dynamic response of mechanical, electrical, fluid and
thermal systems. Transfer functions of first and second order systems. Root locus and frequency response of dynamical
systems. Case studies of Mechatronics systems - Pick and place Robot, Engine Management system, Automatic car park
barrier.
Mechanical components
Electrical components
Response
Case Study-Robot
7. Contents: Unit-1
• Introduction to mechatronics systems
• Evolution of Mechatronics
• Need and classification of mechatronics system
• Basic Elements and components
• Measurement and control systems
• Proportional, Integral and derivative (PI, PD and PID) controls
8. What is MECHATRONICS?
• Synergistic integration of sensors, actuators, signal
conditioning, power electronics, decision and control
algorithms, and computer hardware and software to
manage complexity, uncertainty, and communication in
engineered systems.
• Multidisciplinary field that refers to the skill sets
needed in the contemporary, advanced automated
manufacturing industry.
• At the intersection of mechanics, electronics, and
computing, mechatronics specialists create simpler,
smarter systems.
10. cont..
• PRIMARY LEVEL:
Integrates electrical signaling with mechanical action at the basic
control level e.g. fluid valves and relay switches
• SECONDARY LEVEL:
Integrates microelectronics into electrically controlled devices
e.g. cassette tape player
11. cont..
• TERTIARY LEVEL:
Incorporates advanced control strategy using microelectronics,
microprocessors and other application specific integrated circuits e.g.
microprocessor based electrical motor used for actuation purpose in
robots
• QUATERNARY LEVEL:
Attempts to improve smartness of the system by introducing –
intelligence (ANN, Fuzzy logics, etc.) ability
Fault detection and isolation capability
16. Benefits of the mechatronic design of a
system
• Optimality and better component matching
• Ease of system integration and enhancement
• Compatibility and ease of cooperation with other systems
• Increased efficiency and cost effectiveness
• Improved controllability
• Improved maintainability
• Improved reliability and product life
• Reduced environmental impact
17. Advantages of Mechatronics systems
• Cost effective and good quality products are developed
• High degree of flexibility
• Greater extent of machine utilization
• High productivity
• Longer life subjected to higher maintenance expenses
• Integration of sensors and control system, in a complex system,
reduces capital expenses
18. Classification
• For conventional mechatronic systems
and MEMS, the operational principles
and basic fundaments are same.
• In a peculiar, electromagnetics and
classical mechanics apply the designer
to study conventional mechatronic
systems and MEMS.
• NEMS are constructed using Quantum
theory and nanoelectromechanics.
19. cont..
In the late 1970s, the Japan Society for the Promotion of Machine Industry (JSPMI)
classified mechatronics products into four categories:
• Class I: This includes mechanical products with electronics integrated to improve the practicality.
The numerically controlled machine tools and variable speed drives in manufacturing machines
are the examples.
• Class II: This class includes the traditional mechanical systems with significantly updated internal
devices incorporating electronics. The external user interfaces are unaltered. Examples include
the modern sewing machine and automated manufacturing systems.
• Class III: Systems that retain the functionality of the traditional mechanical system, but the
internal mechanisms are replaced by electronics. An example is a digital watch.
• Class IV: Products designed with mechanical and electronic technologies through synergistic
integration. Examples include photocopiers, intelligent washers and dryers, rice cookers, and
automatic ovens.
21. Physical Systems Modeling
• It includes mechanics of solids, translational and rotational systems, fluid
systems, electrical systems, thermal systems, micro, and nano-systems.
• Mechatronics applications are described by controlled motion of mechanical
systems conjugated to sensors and actuators.
• The purpose of the physical systems modeling is to empathize how attributes and
performance of mechanical components affect the overall mechatronic systems.
• Mechanical systems are rigid or elastic bodies these are moving relative to one
another, the movement depends on upon how these bodies are completed by
ingredients via joints, dampers, and other passive devices.
22. Sensors
• A sensor is a device that receives a stimulus and responds with an electrical
signal. The sensor responds to an input physical quantity and converts it into an
electrical signal.
• In other words, we can say senor converts non-electrical quantity into electrical
quantity. For example, a chemical sensor initially converts the energy of a
chemical reaction into heat (transducer) and then thermopile, converts heat into
electrical signals. In this example a chemical sensor is a complex sensor; it is
composed of transducer and sensor (heat).
• The direct sensors are those which convert physical properties into direct
electrical signals. Examples of modern sensors for mechatronic systems are
Disposable blood pressure sensors, Pressure sensors for automotive manifold air
pressure, Accelerometers for airbag systems.
23. Actuators
• Actuators may work opposite to that of sensors
• It converts the electrical signal into non-electrical energy. For example, an electric
motor (actuator) converts the electrical signal into mechanical energy.
• Modern actuators used in mechatronics applications are electro-mechanical
actuators, motors: AC motors, DC motors, and stepper motors, pneumatic and
hydraulic actuators.
24. Signals and Systems
• Signals and systems play a vital role in mechatronic systems. Anything that carries
the information is the signal.
• Signals are important because by realizing them we can make sure that they can
be transmitted faithfully and by interpreting the signal and their structure, we can
determine more about an instrument that is generating them.
• Easily measured quantities, current and voltage are the form of electrical signals,
thus sensors and transducers used to converts physical quantities into electrical
signals.
• These signals must be processed by appropriate techniques if desirable results
are to be obtained.
25. Computers and Logic Systems
• In mechatronic systems, computers are used to model, analyze, and simulate
mechatronic systems and useful for control design.
• As a part of measurement systems, computers are used in mechatronic systems
to measure the performance of the mechatronic systems. Also, computers or
microprocessors form central component in digital control systems for the design
of mechatronic systems.
• Mechatronics is the synergistic combination of mechanical engineering,
electronics, control systems, and computers and the key element in mechatronics
is the integration of these areas through the design process.
• A successful design will be produced if computers and logic elements are used in
mechatronic systems, only if this synergy is achieved.
26. Software and Data Acquisition
• Data acquisition systems and software includes transducers and measurement
systems, A/D and D/A converter, amplifiers and signal conditioning, data
recording and software engineering.
• A data acquisition system captures and analyzes some form of physical properties
from the real world. Some physical properties like pressure, light, temperature
that can interface to a data acquisition system.
• At the same time, data acquisition system produces electrical signals. These
signals provide stimulus so that the data acquisition system can measure the
response.
27. Concepts and Technologies of a Mechatronic
System
The study of mechatronic engineering should
include all stages of modeling, design,
development, integration, instrumentation,
control, testing, operation, and maintenance of
a mechatronic system.
32. Control systems
Control system can be thought of as a system which can be used to:
• Control some variable to some particular value, e.g. a central heating
system where the temperature is controlled to a particular value;
• Control the sequence of events, e.g. a washing machine where when
the dials are set to, say, ‘white’ and the machine is then controlled to
a particular washing cycle, i.e. sequence of events, appropriate to
that type of clothing;
• Control whether an event occurs or not, e.g. a safety lock on a
machine where it cannot be operated until a guard is in position.
36. Uses of the controllers
• Controllers improve the steady-state accuracy by decreasing the
steady state error.
• As the steady-state accuracy improves, the stability also improves.
• Controllers also help in reducing the unwanted offsets produced by
the system.
• Controllers can control the maximum overshoot of the system.
• Controllers can help in reducing the noise signals produced by the
system.
• Controllers can help to speed up the slow response of an overdamped
system.
39. Controller
• The purpose of a controller is to compare the actual output of the plant with the
input command and to provide a control signal which will reduce the error to zero
or as close to zero as possible.
• Controller generally consists of:
• Summing junction, where input and output signals are compared
• A control device which determines the control action
• Necessary power amplifiers
• Associated hardware
• We will look at some common controllers
40. Controller
On-Off Control
• Only two level of control
• Full-on or full-off
• If the error present at the controller is e(t) and the control signal which is
produced by the controller is m(t), then the on-off controller is represented by:
• In most cases, either M1 or M2 is zero
41. Controller
Proportional Control
• Used where a smoother control action is required
• Proportional control provides a control signal that is proportional to the error
• It acts as an amplifier with a gain Kp
• Controller action is represented by:
42.
43. Controller
Integral Control
• In a controller employing an integral control action the control signal is changed
at a rate proportional to the error signal.
• That is if the error signal is large, the control signal increases rapidly
• Represented by:
• Ki is the integrator gain
44.
45. Controller
Derivative Control
• We never use derivative controllers alone.
• It should be used in combinations with other modes of controllers because of its
few disadvantages which are written below:
It never improves the steady-state error.
It produces saturation effects and also amplifies the noise signals produced in the system.
46. Controller
Proportional-plus-Integral Control
• A proportional controller is incapable of counteracting a load on the system
without an error
• An integral controller can provide zero error but usually provides slow response
• PI controller is thus used and represented by:
• Ti adjusts the integrator gain
47. Controller
• Proportional-plus-Derivative Control
• Derivative control action provides a control signal proportional to the rate of
change of the error signal.
• Since it would not generate any output unless error is changing differently, it is
less used
• A PD controller is however used and represented by:
48. Controller
• Proportional-plus-Integral-plus-Derivative Control
• Three control actions can be combined to form a PID controller represented by:
• PID control is very common
• It provides quick response, good control of system stability and low steady-state
error.
• Computations are performed in micro-computers of the robot
50. Open- vs closed-loop systems
Heating a room: (a) an open-loop system, (b) a closed-loop system
51. Advantages and Limitations
Open-loop systems
• Relatively simple
• Consequently low cost
• Good reliability
• Often inaccurate since there is no correction for error
Closed-loop systems
• Relatively accurate in matching the actual to the required values
• More complex
• More costly with
• Greater chance of breakdown as a consequence of the greater number of
components.
52. Basic elements of a closed-loop system
• Comparison element
• Control element
• Correction element
• Process element
• Measurement element
