Subject : Stepper Motor Lecturer: Bo Prak Member in group : Sun Chanras,Lim Hoklay National Polytechnic Institute of Cambodia Department of Electronics Engineering Assignment Submit :29 th February 2012 Present :29 th February 201
Sep 07, 2014
Subject : Stepper Motor
Lecturer: Bo Prak
Member in group : Sun Chanras,Lim Hoklay
National Polytechnic Institute of Cambodia
Department of
Electronics Engineering
Assignment
Submit :29th February 2012Present :29th February 2012
Content
• I-Introduction
• II-Stepper motor type
• III-Using
• IV-Basic operation
• V-Calculation and parameter
• VI-Interface with PIC microcontroller
Content
• VII-Reference
I-Introduction
Fig 1.1: Stepper motor
I-Introduction
• Stepper motor is an electromechanical device which
convert electrical pulse into discrete mechanical
movement.
• The shaft of a stepper motor rotates in discrete step
when electrical command pulses are applied to it in the
proper sequence.
II-Stepper motor types
• There are three basic stepper motor type . They are:
• Variable-reluctance(VR)
• Permanent-magnet(PM)
• -Hybrid(HB)
II-Stepper motor types
• Variable Reluctance(VR):
• This type of stepper motor has been around for along
time. It’s probably the easiest to understand from a
structural point of view.
• Figure 2.1 shows a cross-section of a typical variable-
reluctance stepper motor.
II-Stepper motor types
• Figure 2.2 shows The variable-reluctance stepper motors.
Fig 2.2 :Variable-reluctance stepper motor
Fig 2.1 : Cross-section ofvariable reluctance stepper motor
II-Stepper motor types
• Permanent Magnet(PM):
• The permanent-magnet stepper motor is a low cost and
low resolution type motor with typical step angles of 7.5 to
15 degree.
• Figure 2.3 show the cross-section of permanent-magnet
stepper motor.
II-Stepper motor types
• Figure 2.4 show the permanent-magnet stepper motor.
Fig 2.4 :Permanent-magnet stepper motor
Fig 2.3 : Cross-section ofPermanent-magnet stepper motor
II-Stepper motor types
• Hybrid(HB):
• The hybrid stepper motor is more expensive than the PM
motor but provides better performance with respect to
step resolution , torque and speed.
• Typical step angle for the HB stepper motor rang from 3.6
degree to 0.9 degree
II-Stepper motor types
• The hybrid stepper motor combines the best features of
both the PM and VR type stepper motors.
• Figure 2.5 show the cross-section of hybrid stepper motor.
• Figure 2.6 show the hybrid stepper motor.
II-Stepper motor types
Fig 2.6 :Hybrid stepper motorFig 2.5 : Cross-section ofHybrid stepper motor
III-Using
• There are a lot of stepper motor application such as:
• Robot arm control.
• Car mirror controls
• Automated door windows
IV-Basic operation
• Stepper motors consist of a permanent magnet rotating
shaft, called the rotor.
• Electromagnets on the stationary portion that surrounds
the motor, called the stator.
• At position 1, we can see that the rotor is beginning at the
upper electromagnet, which is currently active.
IV-Basic operation
Fig 4.1 : Show position 1
IV-Basic operation
• To move the rotor clockwise (CW), the upper
electromagnet is deactivated and the right electromagnet
is activated.
• causing the rotor to move 90 degrees CW, aligning itself
with the active magnet.
IV-Basic operation
• Figure 5.2 show this operation.
Fig 4.2 : Show position 2
IV-Basic operation
• This process is repeated in the same manner until we
once again reach the starting position..
• Figure 4.3 and 4.4 show the position 3 and position 4
IV-Basic operation
Fig 4.3 : Show position 3 Fig 4.4 : Show position 4
V-Calculation and parameter
• Step sequence:
• Stepper motors can be driven in two different patterns or
sequences . namely:
• Full Step Sequence
• Half Step Sequence
V-Calculation and parameter
• Full step sequence:
• In the full step sequence, two coils are energized at the
same time and motor shaft rotates. The order in which
coils has to be energized is given in the table below.
V-Calculation and parameter
.• Table 5.1 show the step sequence in full mode:
Table 5.1 : Full step sequence
V-Calculation and parameter
• Half step sequence:
• In Half mode step sequence, motor step angle reduces to
half the angle in full mode. So the angular resolution is
also increased i.e. it becomes double the angular
resolution in full mode. Also in half mode sequence the
number of steps gets doubled as that of full mode.
V-Calculation and parameter
• Table 5.2 show the half step sequence:
Table 5.2 : Half step sequence
V-Calculation and parameter
• To calculate step angle , simply divide 360 by number of
steps a motor takes to complete one revolution.
• Step Angle ø = 360° / 4 = 90°
• and in case of half mode step angle gets half so 45°.
• Step angle:
VI-Interface with PIC microcontroller
• Connecting Stepper Motor with Microcontroller
(PIC16F887) using ULN2003
• Simulate in proteus
• Figure 6.1 show the simulation in proteus.
VI-Interface with PIC microcontroller
• Figure 6.1 : Simulation in proteus
VI-Interface with PIC microcontrollerFull step programming:
void main()
{
ANSEL = 0; // Configure AN pins as digital I/O
ANSELH = 0;
PORTD = 0;
TRISD = 0; // Configure PORTD as output
while(1)
{
PORTD=0x09;
Delay_ms(500);
PORTD=0x0C;
Delay_ms(500);
PORTD=0x06;
Delay_ms(500);
PORTD=0x03;
Delay_ms(500);
}
}
VI-Interface with PIC microcontrollerHalf step programming:
void main()
{
ANSEL = 0; // Configure AN pins as digital I/O
ANSELH = 0;
PORTD = 0;
TRISD = 0; // Configure PORTD as output
while(1)
{
PORTD=0×08;
Delay_ms(500);
PORTD=0x0C;
Delay_ms(500);
PORTD=0×04;
VI-Interface with PIC microcontrollerDelay_ms(500);
PORTD=0×06;
Delay_ms(500);
PORTD=0×02;
Delay_ms(500);
PORTD=0×03;
Delay_ms(500);
PORTD=0×01;
Delay_ms(500);
PORTD=0×09;
Delay_ms(500);
Delay_ms(500);
}
}
VI-Reference
• http://
ssecganesh.blogspot.com/2008/05/driving-stepper-motor-using-uln2003.html
• http://www.engineersgarage.com/articles/stepper-motors
• http://www.circuitspecialists.com/stepper-motor
End of presentation
Thanks for yourattention