Stepper motors
41
Relative positioning is very precise Constant speed Motor can be locked at any position. Available in various size and packages Easy to interface Easily available STEPPER MOTOR IN ROBOTICS
Transcript of Stepper motors
Relative positioning is very precise Constant speed Motor can be locked at any position. Available in various size and packages Easy to interface Easily available
STEPPER MOTOR IN ROBOTICS
TYPES OF STEPPER MOTORS
UNIPOLAR STEPPER MOTORUNIPOLAR STEPPER MOTORUnipolar stepper motor with center tap windingFour coils are required for unipolar stepper motor
BIPOLAR STEPPER MOTORBIPOLAR STEPPER MOTOR Bipolar motors are constructed with wired more
simply, with no center taps. Two coils are used in bipolar stepper motors
OPERATION OF STEPPER MOTOR
OPERATION OF STEPPER MOTOROPERATION OF STEPPER MOTOR
Energize a combination of stator coils (phases),through electrical pulses.
This create various magnetic fields within the motor, depending on which coils are energized.
OPERATION OF STEPPER MOTOROPERATION OF STEPPER MOTOR
The rotor then aligns itself with the presently active magnetic field. When the coils are energized in the correct sequence, the rotor will rotate or “step”, creating circular motion. So the name “Stepper” Motor
“STEPS” IN STEPPER MOTOR
STEPS IN STEPPER MOTOR Full step
One coil is energized at a time. Half step
Two coils are energized to get rotor in between step. Micro step
Two coils are energized at different current levels.
FULL STEP FULL STEP
FULL STEP FULL STEP
FULL STEP FULL STEP
FULL STEP FULL STEP
A4
B3
C2
D1
comment
1 0 0 0 take a step clockwise
0 1 0 0 another step clockwise
0 0 1 0 another step clockwise
0 0 0 1 another step clockwise
0 0 0 1 Wait right here!
0 0 1 0 Take a step back.
FULL STEP SEQUENCE
HALF STEPHALF STEP
HALF STEPHALF STEP
HALF STEPHALF STEP
HALF STEPHALF STEP
HALF STEPHALF STEP
HALF STEPHALF STEP
HALF STEPHALF STEP
HALF STEPHALF STEP
A4
B3
C2
D1
comment
1 0 0 0 start here
1 1 0 0 half a step clockwise
0 1 0 0 complete the first full step clockwise
0 1 1 0 another half step
0 0 1 0 complete that step
0 0 1 1 another half step
0 0 0 1 complete that step
1 0 0 1 final half step
1 0 0 0 back to the starting position
HALF STEP SEQUENCE
MICRO STEPPINGMICRO STEPPING
Microstepping allows a stepping motor to stop and hold a position between the full or half-step positions.
It largely eliminates the jerky character of low speed stepping motor operation and the noise at intermediate speeds.
Microstepping controls the current in motor to degree Typically used in application that requires accurate positioning and fine Resolution over wide range of speeds.
MICRO STEPPINGMICRO STEPPING
.5
Micro stepping control circuit
X,Y => determine motor winding is on or off,current through winding
V0, V1 => Reference voltage trough Motor Winding
IC FOR INTERFACING STEPPER MOTORIC FOR INTERFACING STEPPER MOTOR
IC L293d
1,2EN1A1Y
Heat Sink,ground Heat Sink,ground
2Y2AVs
4A
VCC
4Y
3Y3A3,4EN
8051
STM
L293D
VCC
Vs
IC FOR INTERFACING STEPPER MOTORIC FOR INTERFACING STEPPER MOTOR
4,5,12,13
63
16,1,9 8
2
15
P3.0
P3.3
7
10
11
14
12V
P3..1
P3..2
Stepper_logic:
Stepper_logic
start=0?No Yes
Out
Outdelay_unit
=0?
step
YesNo
Out
delay_unit=100delay_unit=delay_unit-1
Step:
step
hs=1?
No Yes
direction=0?
Out
Yes
hs_backward
No
hs_forward
Out
direction=0?
Out
Yes
fs_backward
No
fs_forward
Out
0011 1001
1000
11000100
0110
0010
0001
hs_backward:
hs_backward
0011 1001
1000
11000100
0110
0010
0001
hs_forward:
hs_forward
0001
00101000
0100
fs_forward:
fs_forward
0001
00101000
0100
fs_backward:
fs_backward
Application of Stepper MotorApplication of Stepper Motor
Application Use
Printer Papper drivePlotter X-Y-Z Positioning
Paper Drive Mechanism using Paper Drive Mechanism using stepper machinestepper machine
Thank YouThank You
STEPPER MOTOR
SHAFT
COUPLING
BEARING
BLOCK
LINEAR MOTION
PIVOT
BEARING
NUT OR BLOCK WITH THREADED HOLE
ARM
ARM MOVESAS SHOWNBASE OR OTHER
MOUNTINGSURFACE
SLOTTED HOLE
LEAD SCREW OR THREADEDROD
BEARING CLOCK
INTERFACING A STEPPER MOTOR TO A MECHANICAL LINKAGE AND ARM USING A LEAD SCREW
Stepper Motor In RoboticsStepper Motor In Robotics
Hard Disk Drive (HDD) spindle motors are what cause the disks in HDDs to rotate.
The precision of these motors determine the capacity and speed of HDDs, making these Components critical to HDD performance. Accordingly, these motors must offer superior performance in terms of rotational speed and low Non-Repeatable Run Out (NRRO).
