Develop Robotic Develop Robotic Manipulator for Manipulator for Basic Operations in Basic Operations in Garment Garment Manufacturing Manufacturing Project Supervisor Project Supervisor Dr. A. M. Harsha S. Abeykoon Dr. A. M. Harsha S. Abeykoon 12 12 th th November 2010 November 2010 A. M. P. Jayamanne A. M. P. Jayamanne 08/9307 (IA) 08/9307 (IA)
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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
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
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
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..