2010

University of Engineering and Technology Lahore

Prepared by: Mr. Shariq Riaz

[CONTROL LAB MANUAL] Hardware Manual First Set of Experiments

Control Lab Manual

Session 2007 University of Engineering and Technology Page 2

Experiment Speed control of DC motor

Procedure

Make sure there is no offset voltage in op-amp unit or in pre-amp. unit.

Make connections given in figure 3.7.8, but for open loop system do not connect the tacho generator signal to pre-amp. unit.

Set no load speed of motor between 900 to 1100 and fill out table 1 for different loads

Now convert your system to feedback system by giving feedback signal from tacho gen. to pre-amp. unit. and now fill table 2 (make gain min.)

Now modify your circuit in such a way that you use a controller. (See fig 3.7.5) but you have to connect controller output to pre-amp. and then to servo amp.

Draw block diagram of system and answer (Q#1,Q#2)

Now apply disturbance signals by signal generator and note output for change in different parameters by simultaneously viewing input and its effect on motor speed i.e. output is the voltage of tacho generator.(Q#3)

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Session 2007 University of Engineering and Technology Page 3

Reversible speed control System

Fig 3.7.8

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Experiment Position control system of DC motor

Procedure

Make sure there is no offset voltage in op-amp unit or in pre-amp. unit.

Connect open loop position control shown in fig 3.5.3.Note that we are only checking error signal not providing it to run the motor. You can connect pre-amp. unit between attenuation unit and servo amplifier. Complete table 1. (gain of system should be minimum)

Adjust motor position to 0o attach signal gen. and provide it periodic square wave of 5Vpp DC-

offset of 2.5V and 50% duty cycle. You can observe output at terminal 3 of o/p potentiometer. Write your comments (C#1). ( Signal generator should be connected b/w GND and input terminal of either op amp unit or pre amp unit)

Now convert your system to close loop system as shown in fig 3.6.5 and draw its block diagram also complete table 2.

Add disturbance with help of toggle switch on i/p potentiometer and observe its effect on output settling time, overshoot and steady state error for both P and PI controller and write is as comment 2.(C#2),(Q#2)

Now apply disturbance signals by signal generator and note output for change in different parameters by simultaneously viewing input and its effect on motor position(Q#3,Q#4,Q#5)

Control Lab Manual

Session 2007 University of Engineering and Technology Page 5

Figure 3.5.3

Open Loop Position Control System

Figure 3.6.5

Close Loop Position Control System

Control Lab Manual

Session 2007 University of Engineering and Technology Page 6

Experiment Position Control system for AC Induction motor.

Procedure

Connect circuit as shown in fig 3.14.7

Adjust motor position to 0o.

Connect CH1 of oscilloscope to control phase and CH2 to AC tacho output and note the wave forms.

Add AC disturbance with signal generator to AC pre amp unit and observe its effect as(C#1).

Now connect circuit of AC position control shown in fig 13.16.2 and Draw its block diagram. (speed knob of synchro transmitter must on off condition)

Now draw wave forms between 1) position error velocity 2) feedback signal 3) input signal 4) disturbance signal and 5) control monitor for any disturbance signal.

If time permits connect following circuit and see input and output simultaneously.

Control Lab Manual

Session 2007 University of Engineering and Technology Page 7

Figure 3.14.7

Open Loop Position Control System

Figure 3.16.2

Close Loop Position Control System

Control Lab Manual

Session 2007 University of Engineering and Technology Page 8

Experiment To investigate characteristics of Magnetic Levitation System

Procedure

Connect circuit as shown in figure.

Stabilize the ball; floating in the air, try stabilizing the system with minimum gain.

Connect the oscilloscope to the ball position node with its ground connected to systems ground.

To add disturbances in the system attach the output of the signal generator to input disturbance terminal with ground attached to system ground, while connecting the signal generator its frequency and amplitude of disturbance must be as low as possible

Simulation

In simulation you have to see the step response of your system for changes in o M Mass of ball o Beta o L Inductance o R Resistance o g gravitational constant

Effect of different controllers (P, PD,PI)

Effect of disturbances o Frequency o Amplitude o Shape o DC offset

Control Lab Manual

Session 2007 University of Engineering and Technology Page 9

The magnetic levitation system (MAGLEV) experiment represented by following figure.

Control Lab Manual

Session 2007 University of Engineering and Technology Page 10

Experiment To investigate characteristics of Inverted Pendulum System

Procedure

Start Matlab.

Open Simulink file of inverted pendulum experiment.

This file is a real time simulation file, so instead of normal we are going to use external type of simulation.

First you have to connect your system by pressing connect icon adjacent to simulate icon.

Press Start button (Green Colour) on control unit if system exhibits random actions immediately press stop button (Red Colour).

Press simulate icon and then press start button.

Note the various wave forms on your screen and explain your results. o Caution: always be ready to press stop button.

Simulation

In simulation you have to see the step response of your system for changes in o M Mass of cart o m mass of pendulum o B friction between rails and wheels of cart o L length of pendulum from C.G (center of gravity) to joining point o g gravitational constant

Effect of different controllers (P, PD,PI)

Effect of disturbances o Frequency o Amplitude o Shape o Dc offset

Different responses o Step o Sin o Impulse o Ramp o Pulses

Control Lab Manual

Session 2007 University of Engineering and Technology Page 11

Experiment Introduction to Hydraulic System.

Procedure

Identify each and every component on your hydraulic plant.

Identify the transducers of your plant and their signal in control unit. Indicate them on the figure

Connect the circuit of your control unit as given in fig 4.1.1

Turn ON your control unit first.

Now attach a voltmeter between signal going to e-h servo valve and GND. Note the effect of change of att’r1 and att’r2 as comment 1(C#1) and draw equivalent circuit diagram

Now make sure that the orifice calibration on return line is fully open (This is open on extreme right position).

Now turn on the induction motor attached to pump and complete table 1. o Caution: No pressure dial should be on extreme right position. This is very dangerous

condition done to high pressure.

See the effect on motor direction and speed of voltage given to e-h valve.(Q#1)

Now turn off your induction motor and power supply to control unit.

Now connect circuit given in fig 4.7.4 and turn on your control unit first and then your IM and fill table2.

Now connect input 1 to -15V and complete table 3.

Now connect circuit given in fig. 4.8.4 and observe the system response due to position and velocity feedback.(Q#2)

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Session 2007 University of Engineering and Technology Page 12

Figure 4.1.1

Control Lab Manual

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Figure 4.7.4

Figure 4.8.4

Control Lab Manual

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OBSERVATIONS

Speed control of DC motor

Q#1 What is effect of using P and PI controller in close loop configuration?

Q#2 What is effect of increase in gain to the system in close loop?

Q#3 What is the effect of disturbance, frequency, amplitude, shape, dc offset and duty?

Load in degrees

Tacho meter voltage Speed

Load in degrees

Tacho meter voltage Speed

0

0

10

10

20

20

30

30

40

40

50

50

60

60

70

70

80

80

90

90

Table 1 Table 2

Block Diagram of your Close Loop System

Control Lab Manual

Session 2007 University of Engineering and Technology Page 15

OBSERVATIONS

Position control system of DC motor

C#1

C#2

Q#1 What is control signal of motor in open and close loop configuration?

Q#2 What is effect of increase in gain to the system in close loop?

Q#3 What is the effect of disturbance given to pre-amp unit or op-amp unit?

Q#4 What is effect of disturbance’s frequency, amplitude and shape on output?

Q#5 What is effect of DC offset disturbance on output especially in case of PI controller?

Output at 0o degree

Input degrees Error

Input degrees

Output degrees Error

0

0

45

45

90

90

135

135

180

180

225

225

270

270

315

315

360

360

Table 1 Table 2

Control Lab Manual

Session 2007 University of Engineering and Technology Page 16

OBSERVATIONS

Position Control system for AC Induction motor.

C#1

Q#1 What is the effect of disturbance applied to same gain of 0o and90o phases of pre amp?

Q#2 What is the effect of load on close loop position control?

Wave Forms

Control Lab Manual

Session 2007 University of Engineering and Technology Page 17

OBSERVATIONS

To investigate characteristics of Magnetic Levitation System

For Sine wave of 20mVpp

For Sine wave of 40Hz

Input Freq.

Output voltage Vpp

Output Freq.

Input Volts mVpp

Output voltage Vpp

Output Freq.

10

10

20

20

30

30

40

40

50

50

60

60

70

70

Table1 Table 2

Input 50Hz Vpp 30mV

Shape Output

voltage Vpp Output Freq.

sine

square

triangle

Table 3

Q#1 What is maximum frequency of input for stability give reason?

Q#2 What maximum input voltage for stability give reason?

Q#3 What is the effect of frequency of disturbance on ball position?

Q#4 What is the effect of dc offset in disturbance on ball position?

Q#5 What is the effect of amplitude of disturbance on ball position?

Control Lab Manual

Session 2007 University of Engineering and Technology Page 18

OBSERVATIONS

To investigate characteristics of Inverted Pendulum System

Draw all wave forms obtained from matlab and explain your results

Control Lab Manual

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OBSERVATIONS

Introduction to Hydraulic System.

C#1

C#2

Q#1 What is the direction of rotation of motor for +ive and –ive voltages supplied to e-h valve?

Q#2 After demodulation what is the type of electrical signal is it AC or DC signal.

Att’r1 Att’r2 Supply Pressure

Return Pressure

P1 Pressure P2 Pressure

0 0

0 10

0 20

0 40

0 80

10 10

20 10

40 10

80 10

100 10

120 10

TABLE 1

Control Lab Manual

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Att’r1 Vrv Vx

Att’r1 Vrv Vx

10

10

20

20

30

30

40

40

60

60

80

80

100

100

TABLE 2 TABLE 3

Diagrams

Control Lab Manual

Session 2007 University of Engineering and Technology Page 21