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

X & XY Positioning table

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).