20142015 sem2 mechatronics labsheet

7/24/2019 20142015 Sem2 Mechatronics Labsheet

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Fakulti: FAKULTI KEJURUTERAAN ELEKTRIK

Nama Matapelajaran: MAKMAL KEJ. ELEKTRIK

Kod Matapelajaran : SKEM 3742

Semakan

Tarikh Keluaran

Pindaan Terakhir

No. Prosedur

: 2

: 2013

: 2015

:

SKEM3742

FAKULTIKEJURUTERAANELEKTRIK

UNIVERSITITEKNOLOGIMALAYSIA

KAMPUSSKUDAI

JOHOR

MECHATRONICSLABORATORY

Disediakan oleh : Dr. Salinda Buyamin Disahkan oleh : Ketua Jabatan

Nama : Ir. Dr. Kumeresan

En. Mohd Ariffanan

Mohd Basri

PM Dr. Rosbi Mamat

Nama : PM Dr. Zaharuddin Bin

Mohamed

ELECTROHYDRAULIC

&

ELECTROPNEUMATIC


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1. THEORY

i. Definition

Electro-hydraulic (electro-pneumatic) term is defined from words of electro, which mean electrical

and hydraulic (pneumatic) which mean hydro/liquid (air) pressure. The electro-hydraulic (electro-

pneumatic) equipment and system is an integration of electrical and mechanical components withcompressed liquid (air) source.

ii. Components

Electro-hydraulic (electro-pneumatic) controllers have a hydraulic (pneumatic) power section. In an

electro-hydraulic (electro-pneumatic) control, the signal control section is made up of electrical

components, for example, the proximity switches, and relays. The directional control valves

behaves as a medium between the electrical signal control section and the hydraulic (pneumatic)

power section in the controller (refer Figure 1.1).

Figure 1.1: Signal flow and components of an electro-hydraulic/electro-pneumatic control

system

Signal flow Electro-hydraulic/electro-pneumaticComponents

Commandexecution

Signaloutput

Signalprocessing

Power components- Cylinder- Optical displays

Final Control Elements- Electro hydraulically/pneumatically operateddirectional control valves

Processing Elements

- Relays- Contactors

Hydraulic/pneumaticpower section

Input Elements- Pushbuttons- Limit switches- Reed switches- Ind. proximity sensors- Cap. proximity switches

Electrical signalcontrol sectionSignal

input


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iii. Switch

There are 3 types of electrical switches used in the design of electro-hydraulic (electro-pneumatic)

circuit. They are:

i) Normally-opened (NO) contact switch (refer Figure 1.2(a)).ii) Normally-closed (NC) contact switch (refer Figure 1.2(b)).

iii) Changeover contact switch (refer Figure 1.2(c)).

Figure 1.2(a): Normally-opened contact switches

Figure 1.2(b): Normally-closed contact switches

Figure 1.2(c): Changeover contact switches


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iv. Relay

Relay is an electrical device that contains a coil and a contactor switch. Relay also can consist of a

coil and multiple contactors. Figure 1.3 shows a coil (K) with 4 contactor switches. If the coil is

activated, the Changeover Contact will change its state. A NO switch will change its state from ON

to OFF state.

Figure 1.3: Relay with a coil and multiple contactor switches

v. Solenoid Valve

Solenoid valve is an electro-mechanical device that built-in with a coil (solenoid) and a

hydraulic/pneumatic directional control valve (DCV). There are many types of built-in solenoid

directional control valve. A few of them are:

4/2 Way DCV single solenoid with spring return

4/3 Way DCV double solenoid with spring return

2/2 Way DCV single solenoid with spring return

5/2 Way DCV double solenoid

a. Basic Electro-Hydraulic Operation Using the 4/2 Way DCV Single Solenoid

The 4/2 way DCV single solenoid or monostable valve consists of a built-in solenoid at the left hand

side and a built-in spring at the right hand side of the valve. Figure 1.4 shows the hydraulic and

electrical circuits (electro-hydraulic circuits) for actuating a double acting cylinder using 4/2 DCV

single solenoid.

When pushbutton S1 is pressed, coil R1 is activated. Activation of R1 will turn ON the NO

K1switch. Once, K1 is ON, it will activate Y1. Solenoid Y1 will change the position of the valve

from the original position (right dominant) to the new position (left dominant). The liquid will start to

flow into the left side of the cylinder. This will cause the rod of the cylinder to extend.


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Figure 1.4: 4/2 DCV single solenoid is used for actuating a double acting cylinder

b. Basic Electro-Hydraulic Operation Using the 4/3 Way DCV Double Solenoid

The 4/3 Way DCV double solenoids consists of two solenoids (Y1 and Y2) at the both sides of the

valve. It is also called bistable valve or memory valve. Basically, the 4/3 Way DCV are identical

with 4/2 way DCV. The difference is that a center section is added for 4/3 DCV. Figure 1.5 shows

the hydraulic and electrical circuits (electro-hydraulic circuits) for actuating a double acting cylinder

using 4/3 DCV single solenoid. Initially, the 4/3 DCV single solenoid is at a stable state (center

dominant).

When pushbutton S1 is pressed, coil R1 will be activated. Activation of R1 will turn ON the NO K1switch. Once, K1 is ON, it will leads to activation of solenoid Y1. Solenoid Y1 will change the

position of the valve from the original position (center dominant) to the new position (left dominant).

On the other hand, if pushbutton S2 is pressed, coil R2 will be activated. Activation of R2 will turn

ON the NO K2 switch. Once, K2 is ON, it will lead to activation of solenoid Y2. Solenoid Y2 will

push the position of the valve from the original position (center dominant) to the new position (right

dominant).

Figure 1.5: 4/3 DCV double solenoid is used for actuating a double acting cylinder


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c. Basic Electro-Pneumatic Operation Using 2/2 Way DCV Single Solenoid

The 2/2 way DCV single solenoid or monostable valve consists of a built-in solenoid at the left hand

side and a built-in spring at the right hand side of the valve. It is used to control the actuation of

double acting cylinder.

Figure 1.6 shows the electro-pneumatic circuit for actuating a single acting cylinder using 2/2 DCVsingle solenoid. When pushbutton S1 is pressed, coil R1 is activated. Activation of R1 will turn ON

the NO K1 switch. Once K1 is ON, it will leads to activation of solenoid Y1. Solenoid Y1 will

change the position of the valve from the original position (right dominant) to the new position (left

dominant). The air will start to flow into the left side of the cylinder. This will cause the rod of the

cylinder to extend.

Figure 1.6: Electro-pneumatic circuit for actuating a single acting cylinder

d. Basic Electro-Pneumatic Operation Using 5/2 Way DCV Double Solenoid

The 5/2 way DCV double solenoid consists of two solenoids (Y1 and Y2) at both sides of the valve.

It is also called bistable valve or memory valve. The 5/2 way DCV is used to control the actuation

of double acting cylinder. Figure 1.7 shows the electro-pneumatic circuit for actuating a double

acting cylinder using the 5/2 DCV double solenoids.

Initially, the 5/2 DCV double solenoid is at the initial state (right dominant). When pushbutton S1 is

pressed, coil R1 is activated. Activation of R1 will turn ON the NO K1 switch. Once K1 is ON, it

will leads to activation of solenoid Y1. Solenoid Y1 will change the position of the valve from the

original position (right dominant) to the new position (left dominant). The air will start to flow into

the left side of the cylinder. This will cause the rod of the cylinder to extend.

Then, if the pushbutton S1 is released and the pushbutton S2 is pressed, coil R2 is activated.

Activation of R2 will turn ON the NO K2 switch. Once, K2 is ON, it will lead to activation of

solenoid Y2. Solenoid Y2 will push the position of the valve from the current position (left dominant)

to the new position (right dominant). The air will start to flow into the right side of the cylinder. This

will cause the rod of the cylinder to retract.


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Figure 1.7: 5/2 DCV double solenoid is used for actuating a double acting cylinder

vi. Proximity Sensor

Proximity sensors, Figure 1.8, are commonly used to monitor a process condition in a machine. For

instance, sensor is used to ensure the raw part was placed on a fixture, height of raw material within

control, etc. There are three types of proximity sensors:

Inductive sensor able to detect metal, especially mild steel

Capacitive sensor able to detect most parts except low-density product

Optical sensor able to detect bright surface reflectively except black / rough surface

Figure 1.8: Proximity sensor (PS) is placed at the beginning of the actuator movement


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a. Operation of the self-holding (memory) electrical circuit for Electro-Hydraulic and

Electro Pneumatic

The self-holding electrical circuit is as shown in Figure 1.9. The function of this circuit is to

provide continuous electrical signal to the circuit even after the pushbutton S1 is released.

Figure 1.9: The self-holding electrical circuit

It is made up of:

1. A NO detent switch, S0.2. A NO pushbutton, S1.3. A NC pushbutton, S2.4. A relay, K1 (with a NO changeover contact switch K1).

The operation of the self-holding circuit is as follows: when the pushbutton S1 is pressed for a

short period of time, the coil of relay K1 is activated. The (changeover contact) switch K1 closes

and relay K1 remains activated even after the pushbutton, S1 is released. Pushbutton S2 is pressed

to cancel the self-holding effect. Detent switch S0 is use as a safety switch.

+24V

0

K1

K1

S1

0V

S2

1 2 3

4


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2. TASKS

2.1.Electro-Hydraulic

Task 1:Actuation of the 4/2 Way Directional Control Valve.

Practice ObjectiveAfter working through this practice, students are expected to be able to understand the basic

operation of the electro-hydraulic control circuits using a double-acting cylinder.

Procedure1. Connect the hydraulic circuit according to Figure 2.1(a).2. Connect the electric circuit as shown in Figure 2.1(b).3. Validate the hydraulic circuit and the electric circuit for any misconnection.4. Turn the hydraulic power unit ON. Adjust the pressure to 25 to 35 MPa at the

pressure- limiting valve.

5. Turn the DC Power Supply ON. Set the voltage to be 24V.

6. Turn S0 ON.7. Press and hold S1, verify if the piston rod continue to extend to its maximum limit.8. Release S1; verify if the piston rod retracts.9. Once you finish the practice, turn OFF of the Hydraulic Power Unit and DC Power

Supply.

(a)Hydrauliccircuit (b)Electricalcircuit

Figure 2.1: Circuit drawing of hydraulic and electrical circuits for Task 1

Assignment:Based on your observation, fill in Table 2.1.

Table 2.1

S1 Double-Acting Cylinder (Extend/Retract)

Pressed

Released

Based on your understanding, describes the expected result if the connection A and B to cylinder is

swapped.

P T

Ts

P

T

A B

P T

Y1

A

B

+24V

S1

K1

0V

Y1

K1

S0

34

1 2 3

4


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Task 2: Self-holding (Memory) Electro-Hydraulic Circuit Using Relay.

Practice ObjectiveAfter working through this practice, students are expected to understand the self-holding

concept in the electro-hydraulic control system.

Procedure1. Connect the hydraulic circuit according to Figure 2.2(a).2. Connect the electric circuit as shown in Figure 2.2(b).3. Validate the hydraulic circuit and the electric circuit for any misconnection.4. Turn the hydraulic power unit ON. Adjust the pressure to 25 to 35 MPa at the

pressure-limiting valve.

5. Turn the DC Power Supply ON. Set the voltage to be 24V.6. Turn S0 ON.7. Press S1; verify if the piston rod continue to extend to its maximum limit.8. Press S2; verify if the piston rod retracts.9. Once you finish the practice, turn OFF of the Hydraulic Power Unit and DC Power

Supply.

(a)HydraulicCircuit (b)ElectricalCircuit

Figure 2.2: Circuit drawing of hydraulic and electrical circuits for Task 2

Assignment

Based on your observation, explain the differences between Task 1and Task 2, in term of:

1. The operation and function of the electrical circuit.2. The operation and function of the hydraulic circuit

P T

Ts

P

T

A B

P T

Y1

+24V

S1

K1

0V

Y1

S0

34

K1K1

LS

1

2

A

B

1 2 3 4

4

5


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Task 3: Implementing Basic Logic Functions in Electro-hydraulic Circuit.

Practice ObjectiveAfter working through this practice, students are expected to be able to relate the installation of

parallel and serial electric circuit of with the basic logic functions (OR/AND/NOT).

AssignmentBy using hydraulic circuit shown in Figure 2.2(a), design electrical circuits to perform the

following tasks:

1. Task #1: Cylinder is extended whenever S1 and S2 are pressed.2. Task #2: Cylinder is extended whenever S1 or S2 are pressed.3. Task #3: Cylinder is extended whenever S1 is pressed and S2 is not pressed.

For each task (1 to 3), you are required to:

1. Write down the truth table of the operation.

2. Formulate the logic equations based on the truth table.3. Design the electrical circuit that you have designed.4. Validate (and record) the experiment observation.


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2.2.Electro-Pneumatic

Task 1: Actuation of the 5/2 Way Directional Control Valve (DCV).

Practice ObjectiveAfter working through this practice, students are expected to understand the basic operation of

the electro-pneumatic control circuit using a double-acting cylinder.

Procedure1. Connect the pneumatic circuit as shown in Figure 2.3(a).2. Connect the electric circuit as shown in Figure 2.3(b).3. Validate the pneumatic circuit and electric circuit for any misconnection.4. Turn the pneumatic power unit ON. Adjust the pressure to 2 to 5 bars at the pressure-

limiting valve.

5. Turn the electrical power unit ON.6. Press S1 and verify if the piston rod of the pneumatic cylinder extends.7. Press S2 and verify if the piston rod of the pneumatic cylinder retracts.

8. After you complete the experiment, turn OFF of the pneumatic power unit andelectric power unit.

(a)PneumaticCircuit (b)ElectricalCircuit

Figure 2.3: Circuit drawing of pneumatic and electrical circuits for Task 1

AssignmentBased on your observation, fill Table 2.2.

Table 2.2: Truth table for Task 1.

S1 S2 Double-Acting Cylinder

(Extend/Retract/No change)

Not pressed Not pressed

Not pressed Pressed

Pressed Not pressed

Pressed Pressed

Based on your understanding, describes the expected result if both solenoids (B1 and B2) in Figure

2.3(b) are swapped.

2

1 3

2

1 3

2

1

B1

2

1

B2

4 2

51

3

2

1 3

B1 B2

0V

+24V

S1

3

4

S2

3

4

S2

1

2

S1

1

2

1 2


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Task 2: Self-holding (Memory) Electro-Pneumatic Circuit Using Relay.

Practice ObjectiveAfter working through this practice, students are expected to understand the self-holding

concept in the electro-pneumatic control system.

Procedure1. Connect the pneumatic circuit and electric circuit as shown in Figure 2.4(a) and(b).2. Validate the pneumatic circuit and electric circuit for any misconnection.3. Turn the pneumatic power unit ON. Adjust the pressure to 2 to 5 bars at the pressure-

limiting valve.

4. Turn the electrical power unit ON.5. Press and hold S1. Verify if the piston rod of the pneumatic cylinder extends.6. Release S1. Verify if the piston rod of the pneumatic cylinder extends.7. Record your observation.8. Press the switch S2 and verify if the piston rod of the pneumatic cylinder retracts.9. Replace the current electric circuit to the electrical circuit shown in Figure 2.5.

Repeat procedure #3 to #7. Based on your observation, explain the differencesobserved between these two electrical circuits.

10.After you complete the experiment, turn OFF of the pneumatic power unit andelectrical power unit.

(a)PneumaticCircuit (b)ElectricalCircuit

Figure 2.4: Circuit drawing of pneumatic and electrical circuits for Task 2

2

1 3

2

1 3

2

1

B1

4 2

51

3

2

1 3

B1

0V

+24V

S1

3

4

1


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Figure 2.5: Self-holding electrical circuit

0V

+24V

Z

3

4

Z

A1

A2

B1

Z

3

4

S2

1

2

S1

3

4

1 2 3

2

3


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Task 3: Implementing Basic Logic Functions in Electro-pneumatic Circuit.

Practice ObjectiveAfter working through this practice, students are expected to be able to relate the installation of

parallel and serial electric circuit with the basic logic functions (OR/AND/NOT).

AssignmentBy using the pneumatic circuit as shown in Figure 2.6, try out different electrical circuits as

shown in Figure 2.7(a)to Figure 2.7(c).

Figure 2.6: Pneumatic circuit for Task 3

2

1 3

2

1 3

2

1

B1

4 2

51

3

2

1 3


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(a) (b) (c)

Figure 2.7: Electrical Circuits for Task 3

For each scenario (Figure 2.7(a)to Figure 2.7(c)), you are required to:

1. Write down the truth table of the observed result.

2. Formulate the logic equation based on the truth table.3. Identify which logic function is used.

Based on what you have learned in the previous section, design an electro-pneumatic circuit that

fulfill the following truth table (refer Table 2.3).

Table 2.3: Truth Table for Task 3

S1 S2 d

0 0 0

0

1

1

1 0 1

1 1 0

Note:

ForS1&S2:0=Notpress&1=Press

Ford:0=Retract&1=Extend

You are required to:

1. Formulate the logic equations based on the truth table.2. Design the electro-pneumatic circuit you had designed.3. Validate the design with the experiment observation.4. Identify which logic function that has the same truth table as Table 2.3.

B1

0V

+24V

S1

3

4

S2

3

4

1

B1

0V

+24V

S1

3

4

S2

3

4

1 2

B1

0V

+24V

S1

1

2

1


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3. PROBLEMS

3.1. Electro-Hydraulic

Application of Electro-hydraulic in Vehicle Lift.

Practice Objective

After working through this practice, students are expected to be able to design and implement

an electro-hydraulic circuit which behaves as vehicle lift.

Assignment

A vehicle lift as shown in Figure 3.1has been widely used in the automobile service centres.

Figure 3.1: Vehicle lift

Design and demonstrate an electro-hydraulic circuit that meets the following requirements:

1. Use a 4/3 single-solenoid spring return control valve to actuate the cylinder.2. The cylinder should lift the car to half its maximum position when S1 is pressed. The

lift will stop after being contact with limit switch.3. Then, the cylinder should lift the car to its maximum position when S2 is pressed.4. If the S3 is pressed at any period of time, the cylinder will return to its initial/home

position.

5. Incorporates memory circuit for all the pushbuttons (S1, S2 and S3).6. Include two physical contact switches to detect whether all the car tires are on the

platform for safety purposed. Requirement 2 to 4 can only be execute if and only if

all the car tires are detected by the contact switches.

In your report, please include (but not limited to) the following information:

1. The truth table of the expected result.

2. The logic equations based on the truth table.3. The hydraulic and electrical circuits that you had designed.


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Problem #2: Application of Electro-Pneumatic in Box Sorting

Practice Objective

After working through this practice, students are expected to design and install an electro-

pneumatic circuit using multiple cylinders with sequence motion.

Assignment

Figure 3.2 illustrates the application of electro-pneumatic system in a box sorting system.

The objective of this assignment is to place the boxes either into container A or B

accordingly based on size. You are needed to design an electro-pneumatic circuit for the

following requirements:1. Conveyor belt is used to move the boxes.2. Cylinder c is used to push the box to the continuously moving conveyor belt.3. Stop the conveyor belt if the big box is detected on the conveyor belt and use

cylinder d to push the big box into container A.

4. The small box will be delivered into container B which located at the end of theconveyor.

Figure 3.2: Box sorting in industry

Your electro-pneumatic design must fulfill (but not limited to) the following criteria:1. Use pushbutton S1 and S2 to respectively start and stop the operation of the system.2. Use the proximity sensors / limit switches to detect the positions of cylinders and to

determine the size of boxes.3. Use two 5/2 ways DCV with spring return.4. Incorporates memory circuit for the pushbutton.

Once you have completed the design, please demonstrate your result to the facilitator. In

your report, please include (but not limited to) the electro-pneumatic circuit you had

designed.

20142015 sem2 mechatronics labsheet

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