latest technology in control system.

1. MGM College of Engineering &MGM College of Engineering &
Technology, NoidaTechnology, Noida
Seminar Presentation
On
OBSERVER BASED SENSORLESS
CONTROL
• .Guided By:
Mr. A. K. Sinha
Presented By:
SAURABH RAI
Roll No. 1509540055

2. OBSERVER BASED
SENSORLESS CONTROL

3. INTRODUCTION
Definition Of Observer
:- An observer is an operator system which interprets available
measurement.
 Sometimes in generating mode drive is able to convert mechanical energy
into electric.
 The main function of any electrical drive is to ‘ operate in motoring mode’
to convert electrical energy into mechanical form .
 The resulting mechanical power of drive/motor is used to generate linear
or rotational motion of working machinery(load).

4. SENSOR
 A sensor is a device that detects and responds to some type of input from
the physical environment. The specific input could be light, heat, motion,
moisture, pressure, or any one of a great number of other environmental
phenomena.Sometimes in generating mode drive is able to convert
mechanical energy into electric.
TYPES OF SENSOR
1.Electric sensor
2.Mechanical sensor
3.Electromagnetic sensor
4.Wave sensor
5.Thermal and temperature sensor

5. EXAMPLES/APPLICATION OF SENSORS
Speedometer( electromechincal )
Hydrophone.
Radar Gun.
Fuel ratio meter.
Sonar.

6. Speed Sensor
System Speed Sensor is an analog/digital device which is used to measure
speed.
 In controlling AC Machine Drives Speed Transducers such as Tacho-
Generators, Resolvers or Digital Encoders are commonly used to obtain
speed information.

7. DISADVANTAGE OF COMMONLY
USED SENSORS
Speed Sensors has some disadvantages-
•They are usually expensive
•The speed sensor and the corresponding wires will
take up space
•The Efficiency of these Speed Sensors decreases
•Frequently maintenance required
•In defective and aggressive environments, the speed
sensor might be the weakest part of the system

8. What is Sensorless Control?
• Usually Sensorless control is defined as a control scheme where
no mechanical parameters like, speed and torque, are measured.
• Traditional vector control systems use the method of flux and slip
Estimations based on measurements of the phase currents and DC
link voltage of the inverter but this has a large error in speed
estimation particularly in the low-speed range.
• The model reference adaptive system (MRAS) techniques are
also used to estimate the speed of an induction motor. These also
have a speed error in low-speed range and settle to an incorrect
steady-state value.
• In recent years, non-linear observers are used to estimate
induction motor parameters and states.

9. What is Obsever?
• All states are not available for feedback in many cases and one needs
to estimate unavailable state variables.
• Estimation of unmeasurable state variables is commonly called
observation. A device (or a computer program) that estimates or
observes the states is called a state-observer or simply an observer. If
the state-observer observes all state variables of the system,
regardless of whether some state variables are available for direct
measurement, it is called a full-order state-observer.
• An observer that estimates fewer than the dimension of the state-
vector is called reduced-order state-observer or simply a reduced-
order observer.
• If the order of the reduced-order state observer is the minimum
possible, the observer is called minimum-order state observer.

10. Speed Observer System
Estimation of the rotor speed of an induction motor without the use
of speed sensors is the main focus.
 Estimation of rotor speed is done by using the two-phase vector
model of the induction motor in d-q and α-β reference frames.
 The rotor speed estimated by the speed observer system is used to
estimate the parameters of the induction motor.
 The whole work of Speed Observer System is done by MATLAB
7.12

11. Basic Block Diagram of Speed
Observer System

12. This Fig shows two reference
frames :
The first frame, at rest, is fixed
to the stator. The current
vector is is defined by the
instantaneous magnitude is
and phase angle α.
The real axis of the rotating
reference frame includes an
angle ‘x’ with the real axis of
the coordinate system at
rest.
Coordinate Transformation

13. Simulation Block Diagram of Speed
Observer System

14. APPLICATION OF OBSERVER BASED
CONTROL SYSTEM
• Fault detection and vibration control of elastic
mechanical structure .
• Modeling and control of dynamic of electro
mechanical system.
• Polyphase induction motor control.
• Sliding mode control in electro mechanical system.
• Electromechanical break.
• Corrected velocity signal are estimated in order to
state vector control.
• In induction motor vector and speed control.

15. SLIDING MODE OBSERVER
Introduction
Most recent and efficient development in the field of
observer is sliding mode observer.

16. SLIDING MODE OBSERVER
History
2000:-Edward And spurgeon in the induction motors.
2005:-Developed sliding mode observer for
mechanical system based on super twisting algorithm.
2006:-A second order sliding mode observer is
implemented to reconstruct state vector at mechanical
system in presence of uncertainty.
2011:-Problem of continues and discrete state
reconstruction for non liner system.
Now:- a simple sliding mode observer is proposed to
reconstruct velocity signal for mechanical system with
uncertainty.

17. KALMAN FILTER
Kalman filtering, also known as linear quadratic estimation (LQE), is
an algorithm that uses a series of measurements observed over time,
containing statistical noise and other inaccuracies, and produces estimates
of unknown variables that tend to be more accurate than those based on a
single measurement alone, by using Bayesian inference and estimating
a joint probability distribution over the variables for each timeframe. The filter
is named after Rudolf E. Kálmán, one of the primary developers of its theory.

18. APPLICATION
• Detecting range can be predicated.
• Object tracking.
• A real time target tracking
• Drones.
• Satellites.

19. Thank You