Develop Robotic Develop Robotic Manipulator for Basic Manipulator for Basic

Operations in Garment Operations in Garment ManufacturingManufacturing

Project SupervisorProject SupervisorDr. A. M. Harsha S. AbeykoonDr. A. M. Harsha S. Abeykoon

12 12 thth November 2010 November 2010

A. M. P. JayamanneA. M. P. Jayamanne08/9307 (IA)08/9307 (IA)

ContentContent

► Background StudyBackground Study► Available GripersAvailable Gripers► ProjectProject► Design and EvaluationDesign and Evaluation► Modeling the RobotModeling the Robot► ControllingControlling► Error DynamicsError Dynamics► ConclusionConclusion

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 %

Process of Garment Manufacturing (operations)Process of Garment Manufacturing (operations)

Fabric stores

Trims stores

Cutting

PatternMaking

Numbering

Fusing Assembling

Washing Finishing

Product Development

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 = 338 * 4 = 1356

US$US$► 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$= 3356 US$► Payback Payback = = 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

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

ApparelIndustry

Motor

Spring

Holder

Stack

Arm

Cam

Needle

Griper

Pickup

Rotor

ProjectProjectGather 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 evaluationYesNo

Grasping MethodGrasping Method

38

32

27.5

95

4523

23

Measurements used 3-D Model

Physical Model

Enlarged view of Griper

Performance of the MechanismPerformance of the Mechanism

Fabric Fabric

Thicknessmm

Griper Depthmm

Griper Widthmm

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

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.

New DesignNew Design

Modified griper end

Performance with ModificationPerformance with Modification

Fabric Fabric

Thicknessmm

Griper Depthmm

Griper Widthmm

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

SeparatorSeparator

1 2

3 4

Changers in Separation UnitChangers in Separation Unit

Previous Design New Design

Canter of orientation

Canter of Grip

ManipulatorManipulatorY

Z

End Effecter

X

Base Height Adjuster

Model with DH ParametersModel with DH Parameters

X0

Y0 Z0

X1

Y1

Z1

Y3

Z2X2

X3

Z3

X4

X5

Y4

Y5

Z4Z5

Module X Module Y

Module Z

Link 1 Link 2

Link 3Link 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

αi0 di

mm

θi0

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

Manipulator Kinamatic AnalysisManipulator Kinamatic Analysis

Denavit – Hartenberg (DH)

Homogeneous transformation matrix

IT5 = where, IT5 = IT0 . 0T1 . 1T2 . 2T3 . 3T4 .4T5

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

Dynamic AnalysisDynamic Analysis

Newton - Euler

For end effector,

T = (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 = 1.7Kb = bearing damping coefficient = 0.003Kp = mechanical loss on belt drive= 2%m = mass of each module (kg)g = gravity acceleration (ms-2) d = Pulley diameter (mm)

xx

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 200VACFeatures – Position Control 232 and pulse control Encoder Feedback PID inbuilt

ControllerControllerItem 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 pointsOutput 14 points

Interior coil’s points (M) 8512 points

Timer points 620 Points100mS, 10mS,1mS

Counter points 635 points16 bits counter set value K0~3276732 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 interrupt

Thinget XCM 32 RT-E - 4 Axis motion controller

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

OP PanelOP Panel

OP 320 A OP panel OP Series edit tool

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

NoStart segregation

Move X +Move Y +Orientate

Encoder x ok + Encoder Y ok

YesDischarge Griper + Return home position

No

Sensor 3

YesNo

Stop

500

700

100

100

2000

100

2000

2000

100

200

100

Time Slots in milliseconds

100

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

Controlproceedings

Main controller

CurrentPositionVelocity

Requested Data

RequestedData, updated

data

D8000-

FD 0- D 0 -

Error compensation Data

Z - Module and Gripper Control DiagramZ - Module and Gripper Control Diagram

Griper Controller

Z - module controller

Griper Actuators5/2 valves

Expander actuators5/3 valves

Separator actuators5/2 valves + motor

Z – Servo Drive (PID)

Z – Motor

Encoder mz

Encoder 0

Z

Encoder 1

GripStart Grip

FabricData

Fabric sense

Distance sense

Constrains

Position Sense 1,2

X,Y module controlX,Y module control

X,Y ControllerCoordinategenerator

Transformation matrix

Velocity matrix

Pulsegenerator

Clock

Servo Driver – X+PID control

Servo motor - X

Encoder 1X

Servo Driver – Y+ PID control

Servo motor - Y

Encoder 1YEncoder 2X Encoder 2Y

X position Y position

Encoder 2X Encoder 2Y

X,Yposition

Constrains

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) ±0.75mmBut using guiding mechanism can extend this to 3mm,Then required tolerance is

±1.5mmZ - 1mm (Griper penetration accuracy – 1mm)

±0.5mm

Coordinate tracking mode

Teaching mode

Deflection ErrorsDeflection Errors

-0.05

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

100173.4

246.8320.2

393.6 467540.4

613.8687.2

760.6 834

D istance (mm)

Defl

ectio

n (m

m)

4.347kg 6.697kg 9.047kg

Y - Module Y -Module

0

0.5

1

1.5

2

2.5

3

302 442.3 582.6 722.9 863.2 1003.5 1143.8 1284.1 1424.4 1564.7

D istance (mm)

Defl

ectio

n (m

m)

6.93kg 9.193kg 11.693kg

X - Module

Deflection ErrorDeflection Error

1.61 1.44 1.26 1.09 0.91 0.74 0.56 0.43 0.21210

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

0.00-0.10ez (m

m)

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

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, Driver Errors - Resolution of Motor, Driver and Encoders and 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/d

Precision Control of Depth –Z -MotionPrecision Control of Depth –Z -MotionTURCK

Part No – Ni15-M30-LIUSense – 2 – 12mm

60 Hz

OMRON

Part No – E2K-X15ME1 2M OMRONPart No – E3X-DA21F-S

250 μs

OMRON

Part No – E2K-X15ME1 2M

Pulse dispose speed at 500 rpm - 41500 ppsPulse generate speed - 24 μsSensor reading speed - 250 μsPulse overshoot when sensor reads - 10Error - 0.03 * 10 – 0.3mm

250 μs

New DesignPrevious design

Note – Controller and programming errors will be corrected while real model in implementation

Added errors in dynamic motionAdded errors in dynamic motion

► Tested actual Z module for position errors

Stepper MotorA10k- S545W

1NmStep -0.36

With 2:1 PulleyResolution - 1000

DriverMD2U-Md20Micro step

1,2,4,5,8,10,16,20

Used ratio - 5

EncoderE30S4

Res. – 1024Use 1:5 pulley

Resolution5120

Z moduleWeight- 3.38 kg

ControllerThinget XC3 - 34

Speed – 28000 pps, (required 25000pps)Ramp up/Down – 0.1s

ConstrainsConstrainsSpeed

TimeTime slot for operation

Motion signals feeds to steppers must be in above patternMax. Increase of speed from 0 – 300 rpm by 0.1 SSame output given to motion control cannot assigned twice in any mannerMaterial data have to use in grip configuration and Z - motionHeight have to maintain not to roll the fabric piece Data identified in deflection analysis have to combine with position dataFinal positions in power failure or any other disturbance have to storeZ - movement would independently handle with sensor data and X-Y pointBearing clearance errors has to be added to coordinate system with directionUse of interpolation method to assign path configuration and speed

Z - axis

Z - Motion Accuracy ChartZ - Motion Accuracy Chart

10 50 100 150 200 250 30050

2000

50

100

150

200

250

300

350

300-350

250-300

200-250

150-200

100-150

50-100

0-50

Speed (rpm)

Fin

ished p

osi

tion (

mm

)Actual position (mm)Position

(mm)

Speed (rpm) 50 100 150 200 250 300

10 57 107 157.1 207 257 307

50 57 107 157 207 257.1 307

100 57 107 157 207.3 257 307.2

150 57 107 157.1 207.3 257.3 307.2

200 57.2 107.5 157.3 207.5 257.3 307.2

250 57.7 107.8 158 207.7 257.4 307.5

300 58 108.1 158.1 208 257.4 307.6

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 The problem of segregating fabric can sorted by new griper and

separatorseparator► 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 Much involvement needed in actual implementation in production

lineslines► More Researches needed to implement and fine tune griper to Some More Researches needed to implement and fine tune griper to Some

fabrics (Nit) fabrics (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 Hope the robot will run in actual production process in near future.. near future..

Thank YouThank You

Q&A Session..Q&A Session..