1. Develop RoboticDevelop Robotic
Manipulator for BasicManipulator for Basic
Operations in GarmentOperations in Garment
ManufacturingManufacturing
Project SupervisorProject Supervisor
Dr. A. M. Harsha S. AbeykoonDr. A. M. Harsha S. Abeykoon
1212 thth
November 2010November 2010
A. M. P. JayamanneA. M. P. Jayamanne
08/9307 (IA)08/9307 (IA)
2. ContentContent
► Background StudyBackground Study
► Available GripersAvailable Gripers
► ProjectProject
► Design and EvaluationDesign and Evaluation
► Modeling the RobotModeling the Robot
► ControllingControlling
► Error DynamicsError Dynamics
► ConclusionConclusion
3. The Background StudyThe Background Study
Problems in Garment Industry
► High price competition (low buying power , competition in developing countries)
► Increase labour wages ( around 30 % of total cost)
► Increase material costs ( around 60 % of total cost)
► Reduce labour inflow ( stressfulness due to repetitive work)
► Uncertainties in efficiency due to total human involvement in production
The solutions in practice
► Optimization of production by use of 5S, TPS, Innovation, est.
► Introducing automations to the production floors
► Online system monitoring
► Method shearing
Project
► Robot for pick place operation in Garment manufacturing
10 %
4. Process of Garment Manufacturing (operations)Process of Garment Manufacturing (operations)
Fabric stores
Trims stores
Cutting
Pattern
Making
Numbering
Fusing Assembling
Washing Finishing
Product
Development
5. Payback CalculationPayback Calculation
► Monthly wages + overhead per operatorMonthly wages + overhead per operator = 150 US$= 150 US$
► Motors for the robotMotors for the robot = 338 * 4 = 1356 US$= 338 * 4 = 1356 US$
► Electronics and sensorsElectronics and sensors = 1000 US$= 1000 US$
► Mechanical and other accessoriesMechanical and other accessories = 1000 US$= 1000 US$
► Monthly maintenanceMonthly maintenance = 50 US$= 50 US$
Total for robotTotal for robot = 3356 US$= 3356 US$
► PaybackPayback == 30 months30 months
Robot can operate in 2- 10 hour shifts per dayRobot can operate in 2- 10 hour shifts per day
► New paybackNew payback == 15 months15 months
Note – Efficiency changes were not includedNote – Efficiency changes were not included
6. Available Basic Griping DevicesAvailable Basic Griping Devices
► Vacuumed ejectorsVacuumed ejectors
► Static chargersStatic chargers
► Abrasive padsAbrasive pads
► Mechanical gripers/ BellowsMechanical gripers/ Bellows
► Pneumatic/ solenoid actuated gripersPneumatic/ solenoid actuated gripers
► MagneticMagnetic
► Special griping devicesSpecial griping devices
Kaunas university Lithuania Duerkopp- AdlerKaunas university Lithuania Duerkopp- Adler
Apparel
Industry
Motor
Spring
Holder
Stack
Arm
Cam
Needle
Griper
Pickup
Rotor
7. ProjectProject
Gather information of
fabrics and there
construction
Develop a grasping
method of fabrics
Do tests in actual
working environments
Method
performs
Study for the
best manipulator
configuration
Design Manipulator
Do kinematics and
dynamic analysis
Decide motors,
drive system,
transform metrics
and velocity matrices
Do model (mechanical)
Electronics and control
Programming
Performance evaluation
YesNo
9. Performance of the MechanismPerformance of the Mechanism
Fabric
Fabric
Thickness
mm
Griper
Depth
mm
Griper Width
mm
Performance
Multiple
Grasp
Basic poplin 0.015 3.0 7.0 good yes
Heavy poplin 0.025 3.0 12.0 good no
Basic twill 0.035 3.5 8.5 not good no
Heavy twill 0.500 4.0 16.0 not good no
Heavy denim 0.650 5.0 17.0 not good no
Basic nit 0.017 2.0 12.0 good yes
Medium nit 0.500 3.0 12.0 not good no
Heavy nit 0.800 3.0 15.0 good yes
Basic interlining 0.200 5.0 16.0 not good yes
10. Problems and Modifications DoneProblems and Modifications Done
► Force of the cylinder is not enough to close the finger when disturbance
occurs.
• New Cylinder (12*25 mm, DA, Basic )
o Grasping force (17:92mm)- 2.307 kg – 12.48 kg
• Pervious cylinder (8*10 mm, DA, Basic )
o Grasping force (17:92mm)- 0.071kg – 0.1894 kg
► Griper end configuration needed to change for correct griping
► Fabric damage occurred when change the end
► For replacement of Sharpe teeth used trapezoid teeth with 2mm base.
► Use Silicon rubber pad instead of metal surface.
12. Performance with ModificationPerformance with Modification
Fabric
Fabric
Thickness
mm
Griper
Depth
mm
Griper Width
mm
Performance
Multiple
Grasp
Basic poplin 0.015 5.0 8.0 good yes
Heavy poplin 0.025 5.0 12.0 good no
Basic twill 0.035 6.0 8.5 good no
Heavy twill 0.500 6.0 13.0 good no
Heavy denim 0.650 7.0 15.0 good no
Basic nit 0.017 2.0 10.0 good yes
Medium nit 0.500 4.0 10.0 good no
Heavy nit 0.800 4.0 12.0 good yes
Basic interlining 0.200 7.0 16.0 not good yes
16. Model with DH ParametersModel with DH Parameters
X0
Y0
Z0
X1
Y1
Z1
Y3
Z2
X2
X3
Z3
X4
X5
Y4
Y5
Z4Z5
Module X Module Y
Module Z
Link 1 Link 2
Link 3
Link 4
Joint 1
Joint 2
Joint 4
Joint 5
d1
d2
d4
a4 =0
d3 = 0
a2
a1
a3
α5 - Angle
{I}
Link ai
mm
αi
0
di
mm
θi
0
0 0 0 Ia
0
1 60.46 +90 d1
0
2 100.5 0 d2
0
3 -450.2 -90 0 -90
4 0 0 d4
0
5 0 α5
0 0
Link 0
Y2
17. Manipulator Kinamatic AnalysisManipulator Kinamatic Analysis
Denavit – Hartenberg (DH)
Homogeneous transformation matrix
I
T5 = where, I
T5 = I
T0 . 0
T1 . 1
T2 . 2
T3 . 3
T4 .4
T5
Linear velocity matrix of the griper
where, J =
0 Sα5
Cα5
-289.2 + d4
0 Cα5
- Sα5
- d2
-1 0 0 d1
+ 10
0 0 0 0
V
V
V
Z
Y
X
=
−100
010
001
4
2
1
d
d
d
.
−100
010
001
V
V
V
Z
Y
X
4
2
1
d
d
d
=
−100
010
001
.
-1
Where, di = D-H geometrical parameter (joint i variable)
Vi = linear velocities of end effector
αi = End effectors orientation
C = Cos
S = Sin
18. Dynamic AnalysisDynamic Analysis
Newton - Euler
For end effector,
θ θT = (Ir
+ Kb
) . K1
. (1 + Kp
)
For Z module,
x xT = (m + Kb
. + m . g). (d/2). K1
. (1 + Kp
)
For Y and X modules
x xT = (m + Kb
. ). (d/2). K1
. (1 + Kp
)
Where,
= angular velocity (rpm)
= angular acceleration (rev/sec2
)
= linear velocity of each module (ms-1
)
= linear acceleration of each module (ms-2
)
Ix, Iy, Iz = moment of inertia around axis (kgm2
)
Ir = mass moment of inertia of rotating axis (kgm2
)
T = motor torque (Nm)
K1 = safety factor = 1.7
Kb = bearing damping coefficient = 0.003
Kp = mechanical loss on belt drive= 2%
m = mass of each module (kg)
g = gravity acceleration (ms-2
)
d = Pulley diameter (mm)
θ
θ
x
x
19. Motor RequirementMotor Requirement
Drive Required
Torque
(Nm)
Motor Torque
(Nm)
Rated Speed
(rpm)
Capacity
(W)
Orientation 0.43 0.64 3000 200
Z 2.269 1.27(use 2:1 gear) 3000 400
Y 2.314 3.18 3000 1000
X 2.314 3.18 3000 1000
Servo Driver
Model – EDC – 08
200VAC
Features – Position Control
232 and pulse control
Encoder Feedback
PID inbuilt
20. ControllerController
Item Specification
Program executing format Loop scan format, timing
scan format
Program format Instruction, C language,
ladder chart
Dispose speed 0.3us
Power cut retentive Use Flash ROM and Li
battery
User program’s capacity 8000 steps
I/O points Input 18 points
Output 14 points
Interior coil’s points (M) 8512 points
Timer points 620 Points
100mS, 10mS,1mS
Counter points 635 points
16 bits counter set value
K0~32767
32 bits counter set value
K0~2147483647
Data Register （ D ） 4512 words
Flash ROM Register
（ FD ）
576 words
High speed dispose High speed count, pulse (0
– 20kHz) output, external
Thinget XCM 32 RT-E - 4 Axis motion controller
21. Programming the PathProgramming the Path
► Use teaching method to feed the points of movement
► Set the pattern number and move points
► In desired point use ‘set’ key to enter
► The motion controller have inbuilt function for linear, clockwise, anticlockwise
interpolation facility which can decide in position programming
X
Y
current
X2,Y2 current
X4,Y4
X target Y target Centre X Centre Y Centre Z Speed
23. Start
Orientate Gripper Move Z axis in speed 2
Read sensor 1
Yes
No
Move Z axis in speed 1
Encoder 0 +
penetrate height ok
Yes
No
Stop Z axis + grip
Encoder 1 reading
ok
Yes
No
Start segregation
Move X +
Move Y +
Orientate
Encoder x ok +
Encoder Y ok
YesDischarge Griper + Return home
position
No
Sensor 3
Yes
No
Stop
500
700
100
100
2000
100
2000
2000
100
200
100
Time Slots in milliseconds
100
24. Memory Allocation and ControlMemory Allocation and Control
Data Memory
Program Memory
Runtime volatile
memory
Instruction register
Execute
instruction
Memory
controller
Operation Pattern Grip Data
OP 320 A
Control
proceedings
Main
controller
Current
Position
Velocity
Requested Data
Requested
Data, updated
data
D8000-
FD 0-
D 0 -
Error compensation Data
25. Z - Module and Gripper Control DiagramZ - Module and Gripper Control Diagram
Griper Controller
Z - module controller
Griper Actuators
5/2 valves
Expander actuators
5/3 valves
Separator actuators
5/2 valves + motor
Z – Servo
Drive (PID)
Z – Motor
Encoder mz
Encoder 0
Z
Encoder 1
Grip
Start
Grip
Fabric
Data
Fabric sense
Distance sense
Constrains
Position Sense 1,2
26. X,Y module controlX,Y module control
X,Y Controller
Coordinate
generator
Transformation
matrix
Velocity
matrix
Pulse
generator
Clock
Servo Driver – X
+PID control
Servo motor - X
Encoder 1X
Servo Driver – Y
+ PID control
Servo motor - Y
Encoder 1Y
Encoder 2X Encoder 2Y
X position Y position
Encoder 2X Encoder 2Y
X,Y
position
Constrains
27. Errors/ Accuracy NeededErrors/ Accuracy Needed
► Deflection error (structural)
► Belt driver errors
► Errors due to resolution of motor driver
and encoders
► Controller and programming errors
► Added errors in dynamic motion
Needed Accuracy in Positioning
X, Y - 1.5mm ( Stitching accuracy in garment Production 1/16” – 1.59mm)
±0.75mm
But using guiding mechanism can extend this to 3mm,Then required tolerance is
±1.5mm
Z - 1mm (Griper penetration accuracy – 1mm)
±0.5mm
Coordinate tracking mode
Teaching mode
29. Deflection ErrorDeflection Error
1.61 1.44 1.26 1.09 0.91 0.74 0.56 0.43 0.21
210
270
330
390
450
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.60-0.70
0.50-0.60
0.40-0.50
0.30-0.40
0.20-0.30
0.10-0.20
0.00-0.10
ez(mm)
e (mm)
z (mm)
Note – Maximum Y axis error is 0.0012mm , there fore this is not taken in the process
θ
ez
e
D dw
z
ez = z.e /D
Assuming θ<<< 1
Deflexion Error in X axis
30. Belt Driver ErrorsBelt Driver Errors
► Belt use in system MXL, 3 mm Pitch
► Belt positioning error given by Stock- Drive Products Canada – 0.002mm
► Pulley slack 0.1mm
► The maximum error 0.1002 mm - and this is not considered in the controller
programming
Errors - Resolution of Motor, DriverErrors - Resolution of Motor, Driver
and Encodersand Encoders
► Pulses per revolution - 1 ~ 10000, setting in motion – 5000, (0 – 3000 rpm)
► Pulley diameter - d - 50mm,
► positioning accuracy - - 0.03mm,
► Encoder out - 2500 ppr
► Electronic gear ratio - 1 ~ 65535/ 1 ~ 65535, setting - 1:2, - 5000 ppr
5000/dπ
31. Precision Control of Depth –Z -MotionPrecision Control of Depth –Z -Motion
TURCK
Part No – Ni15-M30-LIU
Sense – 2 – 12mm
60 Hz
OMRON
Part No – E2K-X15ME1 2M
OMRON
Part No – E3X-DA21F-S
250 μs
OMRON
Part No – E2K-X15ME1 2M
Pulse dispose speed at 500 rpm - 41500 pps
Pulse generate speed - 24 μs
Sensor reading speed - 250 μs
Pulse overshoot when sensor reads - 10
Error - 0.03 * 10 – 0.3mm
250 μs
New DesignPrevious design
Note – Controller and programming errors will be corrected while real model in implementation
32. Added errors in dynamic motionAdded errors in dynamic motion
► Tested actual Z module for position errors
Stepper Motor
A10k- S545W
1Nm
Step -0.36
With 2:1 Pulley
Resolution - 1000
Driver
MD2U-Md20
Micro step
1,2,4,5,8,10,16
,20
Used ratio - 5
Encoder
E30S4
Res. – 1024
Use 1:5 pulley
Resolution
5120
Z module
Weight- 3.38 kg
Controller
Thinget XC3 - 34
Speed – 28000 pps, (required 25000pps)
Ramp up/Down – 0.1s
33. ConstrainsConstrains
Speed
TimeTime slot for operation
Motion signals feeds to steppers must be in above pattern
Max. Increase of speed from 0 – 300 rpm by 0.1 S
Same output given to motion control cannot assigned twice in any manner
Material data have to use in grip configuration and Z - motion
Height have to maintain not to roll the fabric piece
Data identified in deflection analysis have to combine with position data
Final positions in power failure or any other disturbance have to store
Z - movement would independently handle with sensor data and X-Y point
Bearing clearance errors has to be added to coordinate system with direction
Use of interpolation method to assign path configuration and speed
Z - axis
35. ConclusionConclusion
► It is needed to employ robots in garment industryIt is needed to employ robots in garment industry
► The cost is a barrierThe cost is a barrier
► The problem of segregating fabric can sorted by new griper and separatorThe problem of segregating fabric can sorted by new griper and separator
► Required accuracy levels can match with available hardwareRequired accuracy levels can match with available hardware
► Separation process have to be fine tuned after model implementationSeparation process have to be fine tuned after model implementation
► Much involvement needed in actual implementation in production linesMuch involvement needed in actual implementation in production lines
► More Researches needed to implement and fine tune griper to Some fabricsMore Researches needed to implement and fine tune griper to Some fabrics
(Nit)(Nit)
► Still robot speed is same time of manual labour, need attentionStill robot speed is same time of manual labour, need attention
Hope the robot will run in actual production process in nearHope the robot will run in actual production process in near
future..future..
