yaskawa electric america understanding & applying camming techniques with

Understanding and Applying Camming Techniques with the MP2000iec and MotionWorks IEC 1

Yaskawa Electric America

Understanding & Applying Camming Techniques

with

MP2000iec / MotionWorks IEC

iec


Camming Overview• Core Concept

Six Essential Camming features• Data Management• Function Blocks• Parameters• Engage Modes• Adjust Modes• Block Diagram

Application Discussions• Rotary Knife• Linear Flying Shear• Feed to Length

Webinar Highlights


Mechanical Origin• Shaft rotation

• Represents the master• Typically a 360 cycle

• Linear motion• Position is dictated by the

angular position of the shaft

• Lots of limitations with mechanical cams

Camming Overview


Sla

ve

Po

sit

ion

3.00

0Time

Ma

ste

r P

os

itio

n

360

0

Core Concept• Electronic Camming controls the

positional relationship of two axes

Camming Overview

3603.00

0

Repeat


That’s It!• Everything else relates back to the

core concept.• Positional relationship of two axes.• Master can be a servo, external encoder,

or time (virtual master.)

Camming OverviewS

lav

e P

os

itio

n

3.00

0Time

Ma

ste

r P

os

itio

n

360

0

3603.00

0

Repeat


Camming Overview

(OK we lied) There’s more• Master / Slave lookup table is the core with

these surrounding topics• We will focus on these six supporting features


10 Function blocks • Firmware Library PLCopen-v_2_2

All functions customized by Yaskawa• Based on:

• PLCopen specification• Previous controllers cam technology• Decades of synchronized motion experience

The cam engine operates at the Mechatrolink update rate.• Camming performance not dependant on

application scan rate.

Camming Overview

On the Surface….


Camming Block Diagram

Camming Overview

Below the Surface….


Function Block Breakdown• 4 functional topics

Camming Overview


Cam Data Management

Common Theme: CamTableID


Cam Data Management

Two basic methods for loading cam data

• Externally generated• Internally generated

• These functions are only required once per power up.• If the same cam is disengaged and re engaged, the

CamTableID remains valid until Y_ReleaseCamTable or power is cycled.


Cam Data Management

Mechatrolink Update Rate

Application Task Rate


Computer Disk

Cam Memory

Controller File System

Cam Data Management

External Source: Cam Tool or Excel

Other methods for sending files will be addressed


Data Structure

Cam Data Management

Watch window is a great place to verify the correct data has

been applied


Code Example

Cam Data Management

All Cam DataTypes included in New Project Template


Cam Engagement


Cam Masters• Virtual • External Encoder

• LIO-01, LIO-02, LIO-06– Quadrature pulses only

• Another Mechatrolink Axis• Programming is identical regardless of

master type. AXIS_REF function block input is a logical reference.

Cam Engagement


Capabilities & Performance• Multiple methods for engaging based on

application scenarios.• Function block input parameter lets the

programmer decide how the slave should engage to the master.

Cam Engagement


Cam Engagement

Engage Modes

• AtPosition is better if the master is already moving.• Immediate is situations when the master is stationary, and

the slaves cannot wait idle for the master to move a portion of the cycle, such as during E-Stop recovery.


Starting the process

Cam Engagement

0 0 0 0 0

0

360

720

1080

1440

360 360 360 360


On-The-Fly Adjustments

Identical function blocks, except for

one input


Master

Slave


Shifting• Master Side Adjustment• Useful when a registration

mark detects products on the master axis

• Slave pattern is unchanged

Shifting is a controlled slippage of the red cam lobe on the black shaft



90 degree shift

180

deg

ree

du

rati

on



Scaling• Slave Side Adjustment• Simple Multiplier on all data points• Slave pattern can be magnified or reduced.

No way to do this on a mechanical cam!



Slave Offset• Slave Side Adjustment• Simple Addition to all data points• Slave pattern can will be the same, but

repositioned over a different range.

Master

Slave



AdjustMode• We’ve described the three types of

adjustments, now lets discuss the “When” and “What.”

• When should the adjustment start?• When must the adjustment finish?• What is the profile from A to B?

Detailed help is available by right clicking on any function block!


AdjustModes• Three types

• Master Distance– The adjustment starts immediately and completes when

the master has traveled the specified Master Distance. • Within Range

– The adjustment starts when the master first crosses the StartPosition and completes when the master reaches the EndPosition.

• Time– The adjustment starts immediately and completes within

the specified Time (in seconds).

• Same Profile• Modified Sine profile sweeps the correction profile from

the current to requested adjustment.


Start

Finish

Built into the firmware



Smooth Motion

Adjustments



Y_AdjustMode#MasterDistance

n/a

n/a

n/a

360

0

90

180

270

Master Position

Y_CamShift.Execute

180 Degrees

LREAL#180.0

LREAL#72.0

AdjustMode – Type 1• Y_AdjustMode#MasterDistance

• The adjustment starts immediately and completes when the master has traveled the specified relative Master Distance.

• Master speed dictates the amount of time required to complete the correction



Y_AdjustMode#Duration

n/a

LREAL#72.0

n/a

n/a

Y_CamShift.Execute

360

0

90

180

270

Master Position

LREAL#2.5

?

2.5 Seconds

AdjustMode – Type 2• Y_AdjustMode#Duration

• The adjustment starts immediately and takes place over a time period.

• This is a non-synchronized correction method.• Correction is the same regardless of machine speed.

Good method if adjustment value known

before engaging the slave. Set Duration to zero for

instantaneous correction.



Y_AdjustMode#WithinRange

LREAL#72.0

n/a

n/a

Y_CamShift.Execute

360

0

90

180

270

Master Position

AdjustMode – Type 3• Y_AdjustMode#WithinRange

• The adjustment starts when the master is within the StartPosition and is scaled to complete when the master reaches the EndPosition.

• This mode is for applications that must move at synchronized speeds during certain portions of the cycle

LREAL#180.0

LREAL#270.0180 to 270 degreesWaiting…


Axis Parameters

Crucial to establishing the proper operation by coding interlocks and other logical functions.


Block Diagram


Capabilities & Performance• Change cam data on the fly

• CamTableID can be changed and Y-CamIn can be re-executed during motion.

– Allows for use of multiple profiles with similar, yet different characteristics.

– Pick a location where the slave data is the same for a seamless switchover.

Capabilities & Performance

Use parameter 1541, CamTableIDEngaged in cases like this to verify the currently operating profile


Capabilities & Performance• OPC Cam data transfer

• Set the cam data (Y_MS_Cam_Struct) as an OPC variable, and a PC or HMI can send updated cam data to the controller.

• Execute Y_CamStructSelect or Y_WriteCamTable to load the new cam data.



Capabilities & Performance• Hundreds of small cam tables or dozens

of large cam tables can be loaded into the controller flash memory.

• Exact size dependant on other application data stored in flash, such as IEC 61131 source code.

• HTTP file transfer is another method for cam file download.

• Useful for PC HMI applications



Application Discussions


Rotary Placer – The Placer Cycle

Application Discussion

Pick PositionPick On

Pick DecisionWindow

Place Angle

Adjust Region

0 deg

90 deg

Product Flow

Pick Threshold

0 deg

Product Sensor

DistToLatch

ProductPitch(MasterCycle)

ProductPitch(MasterCycle)

MaxShift

MaxShiftThreshold

[A]

[A] 1:1 Match Point

(PickPosition -PickOn) [%]

mCamShiftRemaining


Rotary Placer – The Product Buffer



Rotary Placer – The Cam Shift• Uses #WithinRange adjust mode



Linear Flying Shear• Out & Back slave• Synchronized to product by

registration mark




Linear Flying ShearFlat part of the speed graph is the area where the master & slave are synchronized.

Out

Back



Assembly Machine• Rotary Table• Assembly Stations

ST 2

Indexer Table

ST 1

ST 3

ST 8

6 feet Camming Benefits• Station synchronization at any

machine speed• Use Virtual Master if Rotary table

must stop during station operation• Variable number of operable stations

Table

Station 1

Station 2

Station 3

Station 4

Station 5



Y_CamIn Y_ReleaseCamTableCamFile download

to RAMY_CamFileSelect

PC Cam Selector

Cam SwitchLogic

Y_Cam

In.E

xecu

te

CamSta

te=3

PC Activity MP2300Siec Activity

Set Next Use Cam Info

OPC or Modbus

Check forNext Use Cam Flag

CamFlag

ID C

hang

ed

Circular usage of cam tables controlled by Array of CamSequenceStruct

For Needle location

(Stitch #)

CamSequenceStruct

To know current cam being used

Next Cam Selector Logic

MC_ReadActualPosition


Conclusion• Camming with the MP2000iec series

requires an understanding of these pieces:

Other Resources:

EM.MCD.09.043 = Manual for Simple Cam from CSV file

MC.MCD.09.044 = Example Code for Simple Cam from CSV file

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