leveraging cnc-controlled robots in manufacturing · coordination of multiple robots w/ machine...

Leveraging CNC-controlled Robots

in Manufacturing Presented by Roger Hart

Manufacturing in America │ March 14-15, 2018

Unrestricted © Siemens 2018 All rights reserved. Community. Collaboration. Innovation.

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Why Robots?

Compared to Traditional Machines

Lower cost

Smaller footprint

Easier installation

Larger reach

Access to more sides of work-piece

Work simultaneously on a single part


Why CNCs?

Compared to traditional Robot Controllers

Manage more complex end effectors requiring motion and

integrated automation.

Maintain common programming with CNC machines

Reduced control complexity

Integration of additional Kinematics

Coordination of multiple robots w/ machine tools


CNC Controlled Robots

Leveraging the Best of Both

Robot kinematics can be part of a larger kinematic chain supported by

the CNC

For example a robot riding on a 3 axis Cartesian system with a

rotating workpiece.

Include end-effector axes

Entire kinematics chain solved

by CNC

Traditional CNC TCP and orientation

programming




A single CNC can coordinate and synchronize multiple machines

For example a Lathe with a loader robot and de-burring robot

controlled by a single CNC.


SINUMERIK Run MyRobot —

Portfolio

SINUMERIK provides a complete range of robot integration possibilities,

from intelligent interfaces to fully integrated robot kinematics.

Functional scope

SINUMERIK

Run MyRobot /EasyConnect

Communication via PLC I/O interface

Operation and programming of the

robot via robot control

828D 840D sl

SINUMERIK

Run MyRobot /Machining

Continuous path control with

SINUMERIK

Connection at the motion control level

All CNC programming methods are employed

Digital twin with NX-CAM and VNCK

828D 840D sl

CNC

CAD

CAM

SINUMERIK

Run MyRobot /Direct Control

SINUMERIK



SINUMERIK (Single Controller)

Full integration of the robot kinematics



828D 840D sl 828D 840D sl

CNC

CAD

CAM

SINUMERIK



SINUMERIK (Single Controller)

Full integration of the robot kinematics



828D 840D sl

CNC

CAD

CAM

SINUMERIK

Run MyRobot /Handling

SINUMERIK


Robot commands via PLC

Complete operation and programming of the

robot via SINUMERIK Operate

828D 840D sl 828D 840D sl

PLC

SINUMERIK


Robot commands via PLC

Complete operation and programming of the

robot via SINUMERIK Operate

828D 840D sl

PLC


Fu

ncti

on

al sco

pe

Depth of integration

Full functional scope of


+ • System-integrated robot mechanical

system

• Robot control using SINAMICS

drives

• Additional robot compensation

• No additional robot controller


Full integration of the robot

into the production process


Continuous-path control with

SINUMERIK

Connection at the motion control

level

Application of all CNC

programming methods

Digital twin with NX-CAM and

VNCK

Diagnostics and remote

maintenance via SINUMERIK

Integrate machining robot

into the production process


Robot commands via a PLC

Complete operation and

programming of a robot via

SINUMERIK Operate

Diagnostics and remote

maintenance via SINUMERIK

Operate handling robot

and MT in a uniform way

Run MyRobot /EasyConnect

Communication via

PLC-I/O interface

Robot operated with robot

controller

Connect handling robot

quickly and easily

SINUMERIK Run MyRobot portfolio

- from simple connection to full integration of the robot


Run MyRobot /Direct Control —

Overview

Simple configuration with direct connection of the robot.

This solution ensures high precision and better dynamics.

Robot Data


SINUMERIK Run MyRobot /Direct Control

- integrated process chain for CNC machining using robots

3. Engineering

Create MyConfig

TIA Portal

Sizer

• NX CAM Robotics

• VNCK

2. Robot

simulation

NX CAD

NX CAE

Teamcenter

Virtual.Lab

1 1. Machine

design

4. Offline programming

and operational integration

Run MyRobot /Easy Connect




Mindsphere

SINUMERIK Integrate

OPC UA

MTConect

5. Data transparency


Feature / function Benefits

• Single point of operation • Efficient operation via the CNC

• CNC programming acc. to

• standard DIN 66025/ ISO 6983

• ProgramGUIDE

• Efficient programming of the

machining robot with G-Code

• No robot-specific knowledge

necessary

• Milling cycles: face milling, drilling,

pockets, engraving, etc.

• Low programming effort

• easy to parameterize

• Alignment and measurement of

workpieces using measuring cycles

• Reduced setup times

• Familiar CNC Look&Feel

• Robot diagnostics via SINUMERIK

Operate

• Fault remedying by the machine

operator

• Operator does not have to be

retrained

• Minimum downtimes Time

Higher productivity of the machine tool

- by involving the robot in the machining process

Time Nu

mb

er

of

fin

ish

ed

part

s

Higher machine productivity of the overall plant:

with hybrid machining with MyRobot /Direct Control

Robot

MT

Handlin

g

Handlin

g

Machin

ing

Machin

ing

Machin

ing

Workpiece measurement with measuring cycles


Precise continuous-path control in the machining process

- full CNC functionality directly on the robot


• Dynamic compression of G0/G1/G2/G3

blocks in polynomial

• Shortest block change times

• High machining precision

• Significantly better look ahead than robot

control

• Optimum calculation of velocity

profiles

• Path planning, interpolation, and

transformation with CNC

• Machining programs are run more

precisely and faster

• Tool management

• Length/radius compensation

• Magazine management

• Unit quantity/tool life monitoring

• Replacement tools

• Highly product machining

processes with simple and intuitive

operation

• Tool wear is taken into account

Polynomial format

Reference

contour

Tolerance

band

CNC Look Ahead

N1 N12

Feedrate


Optimized process chain

- for CNC machining using robots


• CAD / CAM process chain*:

• Programming, simulation

• Collision detection

• Working area

• Digital twin

• G-code based simulation

• Optimized process chain- for CNC

machining using robot kinematics

• Reduced development times with

parallelization

• Parallelized commissioning with virtual

commissioning ("hardware in the loop") • Reduce commissioning times

• Connection to higher-level IT

• Mindsphere *

• OPC UA *

• MTConnect *

• Data transparency of integrated

robot cells

• Support for the I4.0

communication standard

* optional expansion


One control for all tasks

- by fully integrating the robot into the CNC


Three different connection options:

• Standalone

• Hybrid

• Handling

• Flexibility

• Reduction in the machining time

• No robot know-how needed

• SINUMERIK single controller concept • Even greater precision of the path

control

• No robot controller needed

MT and robot implemented on one and

the same controller

• Costs for hardware reduced

• Save space

• Preconfigured SIZER project • Simple to configure

• Automatic conversion of robot data into

SINUMERIK data

(Create MyConfig)

• Robot data are implemented directly in

the SINUMERIK

• Simple commissioning

• Improved performance


From virtual to real production

• 840D sl Post processor incl. Cycles

• Adaptable to individual application with Post Configurator

CAD CAM Programming

CAM Simulation

CAM Post processor Production

NX SINUMERIK

• Integrated Solution for product development • Complex drilling and multi-axis operations • Simulation of the operation on the basis of the real kinematics

NX CAM and SINUMERIK — the perfect process chain for machining with robots

Path Accuracy ? Absolut Accuracy?

Highest path Accuracy


Error classification for 6-axis robots

Static Error

Dynamic Error

Geometric Error (e.g. link length, tools, objects in workspace) Elasticities (base, run-out, gears) Temperature (quasi static)

Following error Gear Cyclic Errors Axis Dynamic Limits


Accurate system through robot calibration (UCI + Isios)

1) Statement on the absolute accuracy

of a robot

2) Statement stating under which

conditions this applies

3) Consideration of the specific

system features

4) Ensuring accuracy along the entire

life cycle of the system

Absolute accuracy: At the TCP, for arbitrary manual orientations, for approaching positions

from arbitrary directions, in the whole machining area

Customer requirements Calibration Compensation

Automated creation of

the customer-specific

calibration travel on the

basis of the CAD data

Fast measurement of

several hundreds of

points using an in-line

measuring system

Calculation of the model

parameters and creation

of the offset data record

Compensation

Compensation

data set

Compensation

data set


References

Siemens AG Technology Center, Chemnitz

Robot type: KUKA KR300 R2500 Quantec with milling spindle

Max. arm length: 2.75 m, distance TCP – flange: 283 mm

Application: Robot-based milling

Independent tracker check measurement :

Average fault (AF): 0.91 0.19 mm

(before the milling spindle, milling cutter tip calibrated)

Standard deviation (SD): 0.49 0.10 mm

Maximum error (MaxErr): 2.41 0.63 mm

Robot on the linear axis

Arm length: 3.4 m

Distance meas. point - flange: 190 mm

Independent tracker check measurement




Robot on the linear axis

Max. arm length: 2.6 m

DistanceTCP - flange: 470 mm

Independent tracker check measurement




Customer A Customer B


Error classification for 6-axis robots

Static Error

Dynamic Error

Geometric Error (e.g. link length, tools, objects in workspace) Elasticities (base, run-out, gears) Temperature (quasi static)

Following error Gear Cyclic Errors Axis Dynamic Limits


The basic idea: a universal 3D Multi-body Model

Real Robot 840D sl – SINAMICS/SIMOTICS Compile cycle ROCO

X

Z

Y

3D-multibody-simulation Contains entire drive train of all axes Simulation in Matlab-environment Any kind of machine/ robot can be modelled

Source: MABI Robotics

Input data for each axis: Joint specific data: Inertia Tensor, Mass, Center of gravity, Stiffness

(Trans/Rot) Axis specific drive train: stiffness and inertia of

motor and gears Maximum allowable torque Functionality: Adaptive torque feed forward Compensation of cyclic errors at joints Adaptive Dynamic Limits More .. .


Conformity of model and real robot

External device for measurement

X-direction

Y-direction

Z-direction

3 N/µm

0.3 N/µm

0.6 N/µm

0.04 N/µm

1.1 N/µm

0.08 N/µm

X

Z

Y


Adaptive Torque feed forward

Functionality: Feedforward the adapted torque depending on

the current pose /inertia of the robot axis Effect: Elimination of pose dependent path deviations

by reducing the following error to a minimum Higher path accuracy independently of the

programmed feed rate

Pose 1 Adaptive T.-FFW Fixed T.-FFW: Jax = 0,01 kgm2 Fixed T.-FFW: Jax = 0,018 kgm2 Fixed T.-FFW: Jax = 0,025 kgm2



0 1 2 3 4 5 6 -0.02

-0.01

0

0.01

0.02

Po

sit

ion

RA

11-A

xis

[°

]

Time [s]

5° 3° 1°

RRR11.ST1

RU11.ST1

RM11.ST1

RR11.ST1

0 1 2 3 4 5 6 -0.02

-0.015

-0.01

-0.005

0

0.005

0.01

0.015

0.02

Po

sit

ion

RA

11

-Axis

[°

]

Time [s]

5° 3° 1°

RRR14.ST1

RU14.ST1

RM14.ST1

RR14.ST1

0 1 2 3 4 5 6 -0.02

-0.015

-0.01

-0.005

0

0.005

0.01

0.015

0.02

Po

sit

ion

RA

11-A

xis

[°

]

Time [s]

5° 3° 1°

RRR1A.ST1

RU1A.ST1

RM1A.ST1

RR1A.ST1


Gear and Joint Cyclic Errors —

Measure

- Exemplary for axis 2 Functionality: Measure path deviation

(in multiple directions) for each axis

Determine periodic error function

Compensate for load dependent cogging effects of the gears based on the 3D multi-body model

Effect: Higher path accuracy

-0.1

-0.05

0

0.05

0.1

Devi

atio

n [

mm

]

Perp

en

dic

ula

r to

circula

r pla

ne

-140 -120 -100 -80 -60 -40 -20 -0.1

-0.05

0

0.05

0.1

Devi

atio

n[m

m]

in c

ircula

r pla

ne

Angle [°]

Setpoint path

Measured path


Gear and Joint Cyclic Errors —

Calculate error function and compensate

- Exemplary for axis 2 Functionality: Measure path deviation

(in multiple directions) for each axis

Determine normed periodic error function Compensate for load dependent cogging effects

of the gears based on the 3D multi-body model Effect: Higher path accuracy

i

i

n

i

iAx

2

1

22 2sin

-20 -40 -60 -80 -100 -120 -140 -0.1

-0.08

-0.06

-0.04

-0.02

0

0.02

0.04

0.06

0.08

0.1

Angle [°]

Po

sit

ion

[m

m]

-140 -120 -100 -80 -60 -40 -20 -3000

-2000

-1000

0

1000

2000

3000

Angle [°]

To

rqu

e [

Nm

]

-0.1

-0.05

0

0.05

0.1

Devi

atio

n [

mm

]

Perp

en

dic

ula

r to

circula

r pla

ne

-140 -120 -100 -80 -60 -40 -20 -0.1

-0.05

0

0.05

0.1

Devi

atio

n [

mm

]

In c

ircula

r pla

ne

Angle [°]

-20 -40 -60 -80 -100 -120 -140 -0.1

-0.05

0

0.05

0.1

Angle [°]

Po

sit

ion

[m

m]

20 10 9 8 7 6 5 4 3 2 1,5 1 0

0.005

0.01

0.015

0.02

0.025

0.03

0.035

0.04

Wave length [°]

|Po

sit

ion

[m

m]|


Axis Dynamics —

Adaption of Acceleration

- Exemplary for Axis 1 - Torque in the drive train is limited - Motor inertia and stiffness of the drive train

are known - The max. acceleration can be computed

depending on the pose and hence depending on the total inertia of the axis

Functionality: Adapt the acceleration of an axis depending on

the pose of the robot (up to factor 5 between worst and best pose)

Adapt the jerk depending on the 1st Eigen frequency (up to factor 4 between worst and best pose)

Effect: Optimized dynamics for

each robot pose Higher productivity while keeping the same high

path accuracy Faster positioning with PTP

0

2

4

6

8

10

12

14

16

18

20

0.00

0.20

0.40

0.60

0.80

1.00

1.20

0.01 0.02 0.03 0.04 0.05 0.06 0.07

Fre

qu

en

cy [

Hz]

Accele

rati

on

[re

v/s

2]

Sum inertia [kgm2]

Max. accel First eigenfrequency


Axis Dynamics —

What is the jerk?

Jerk Limitation with Sinumerik

Path

veloci

ty

SOFT BRISK

Without jerk limitation »BRISK«

With Jerk limitation »SOFT«

Smooth Movements: Acceleration without undesired excitation of the mechanics








Axis Dynamics —

Adaption of Jerk

- Exemplary for Axis 1 - The jerk limitation is proportional to the

first Eigen frequency of the robot axis - It has been verified that the overshoot

remains under 0,005°during positioning







0

1

2

3

4

5

6

7

8

9

10

0.00

0.20

0.40

0.60

0.80

1.00

1.20

0.01 0.02 0.03 0.04 0.05 0.06 0.07

Jerk

lim

it [

m/s

3]

Accele

rati

on

[re

v/s

2]

Inertia [kgm2]

Max. jerk for tol. 0,005° Max. accel Computed max. jerk


Axis Dynamics —

Example

- Exemplary for Axis 1 - Positioning time (45°, F5000) when adapting

acceleration and jerk







0

0.5

1

1.5

2

0.01 0.02 0.03 0.04 0.05 0.06 0.07

Po

s.

Tim

e [

s]

Inertia [kgm2]

Pos. Time with adaption Pos. Time without adaption


Absolute path accuracy

- the controller makes the difference

Reference

contour

Tolerance

band

0,001 – 0,05mm 0,7 – 2mm

CNC-Algorithms

Direct Encoders

Calibration

0,2 – 0,7mm

Machine Tools Standard robot SINUMERIK

RMR /Direct Control


Static + Dynamic Accuracy, what can it do?

Reference

contour

Tolerance

band


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Seminar Slides

After MiA, seminar slides will be available at:

http://www.usa.siemens.com/mia-seminars





Questions?

Roger Hart

Head of R&D, DF MC Machine Tool Systems

Siemens Industry, Inc.

4170 Columbia Road

Lebanon, OH 45036

Phone: +1 513 218-1626

E-mail: [email protected]

mailto:[email protected]

leveraging cnc-controlled robots in manufacturing · coordination of multiple robots w/ machine...

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