diff --git a/notes.html b/notes.html index 7b850d2..3433b73 100644 --- a/notes.html +++ b/notes.html @@ -3,7 +3,7 @@ "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> - + EUSPEN @@ -30,185 +30,158 @@

Table of Contents

+
+

This report is also available as a pdf.

+
-
-

1 Tutorial: Design concepts for sub-micrometer positioning   @huub_janssen

+
+

1 Tutorial: Design concepts for sub-micrometer positioning   @huub_janssen

-
-

1.1 Positioning Terminology

+
+

1.1 Positioning Terminology

  • Accuracy: -Accuracy describes how close the mean result is to the reference value. (Figure 1)
    • +Accuracy describes how close the mean result is to the reference value. (Figure 1)
  • Repeatability: -Repeatability describes the variation between results. (Figure 1)
    • +Repeatability describes the variation between results. (Figure 1)
  • Resolution: -The resolution of a system is equal to the smallest incremental step that can be made (Figure 2)
    • +The resolution of a system is equal to the smallest incremental step that can be made (Figure 2)
  • Stability: The stability of a system is the maximum deviation from a constant reference value over time. -The stability is always related to the time frame taken into account. (Figure 3)
    • +The stability is always related to the time frame taken into account. (Figure 3)
-
-

position_terminology.png +

+

position_terminology.png

Figure 1: Accuracy and Repeatability

-
+

position_resolution.png

Figure 2: Position Resolution

-
+

position_stability.png

Figure 3: Position Stability

@@ -216,11 +189,11 @@ The stability is always related to the time frame taken into account. (Figure
-
-

1.2 Principles of accuracy

+
+

1.2 Principles of accuracy

-Limited stiffness, play and friction will induce an hysteresis for a positioning system as shown in Figure 4. +Limited stiffness, play and friction will induce an hysteresis for a positioning system as shown in Figure 4.

@@ -228,7 +201,7 @@ The hysteresis can actually help estimating the play and friction present in the

-
+

stiffness_friction.png

Figure 4: Stiffness, play and Friction

@@ -244,7 +217,7 @@ Ways to make the hysteresis smaller:

-The position uncertainty of a system can be estimated as follow (Figure 5): +The position uncertainty of a system can be estimated as follow (Figure 5):

\begin{equation} \text{Position Uncertainty} = \text{play} + 2 \times \text{Virtual Play} @@ -257,7 +230,7 @@ where the virtual play can be estimated as follow: \end{equation} -
+

position_uncertainty.png

Figure 5: Hysterestis, play and virtual play

@@ -281,11 +254,11 @@ Note that it is very difficult to make a system with constant friction in practi
-
-

1.3 Case 1 - Estimate the virtual play

+
+

1.3 Case 1 - Estimate the virtual play

-Estimate the virtual play of the system in Figure 6 with following characteristics: +Estimate the virtual play of the system in Figure 6 with following characteristics:

  • Payload: \(m = 20\,kg\)
    • @@ -296,7 +269,7 @@ Estimate the virtual play of the system in Figure 6 wi
-
+

case_1.png

Figure 6: Studied system for “Case 1”

@@ -333,43 +306,43 @@ And finally:
-
-

1.4 Conventional elements for constraining DoFs

+
+

1.4 Conventional elements for constraining DoFs

There exist many conventional elements for constraining DoFs. Some of them are:

    -
  • Struts with ball joint: 1DoF constrained (Figure 7)
    • -
  • Ball bearing: 5DoF constrained (Figure 8)
    • -
  • Guide with roller bearing: 4DoF constrained (Figure 9)
    • -
  • Roller rail guide: 5DoF constrained (Figure 10)
    • +
  • Struts with ball joint: 1DoF constrained (Figure 7)
    • +
  • Ball bearing: 5DoF constrained (Figure 8)
    • +
  • Guide with roller bearing: 4DoF constrained (Figure 9)
    • +
  • Roller rail guide: 5DoF constrained (Figure 10)
-
+

ball_joint.png

Figure 7: Ball Joint

-
+

ball_bearing.png

Figure 8: Ball Bearing

-
+

roller_bearing.png

Figure 9: Roller Bearing

-
+

roller_rail_guide.png

Figure 10: Roller Rail Guide

@@ -377,19 +350,19 @@ Some of them are:
-
-

1.5 Compliant elements for constraining DoFs

+
+

1.5 Compliant elements for constraining DoFs

-
-

1.5.1 Basic leaf springs and folded leaf springs

+
+

1.5.1 Basic leaf springs and folded leaf springs

-An example of a complaint element is shown in Figure 11. +An example of a complaint element is shown in Figure 11.

-
+

compliant_1dof.png

Figure 11: Example of 1dof constrained compliant element

@@ -399,28 +372,28 @@ An example of a complaint element is shown in Figure 11
    -
  • Leaf spring: constrains 3 dof (Figure 12)
    • -
  • Folded leaf spring: constrains only 1dof (Figure 13) +
  • Leaf spring: constrains 3 dof (Figure 12)
    • +
  • Folded leaf spring: constrains only 1dof (Figure 13) These are generally used in combination with other folded leaf springs.
    • -
  • Flexure pivots: constrains 5 dofs (Figure 14)
    • +
  • Flexure pivots: constrains 5 dofs (Figure 14)
-
+

leaf_springs.png

Figure 12: Leaf springs

-
+

folded_leaf_springs.png

Figure 13: Folded Leaf springs

-
+

flexure_pivots.png

Figure 14: Flexure Pivots (5dof constrained)

@@ -428,11 +401,11 @@ These are generally used in combination with other folded leaf springs.
-
-

1.5.2 1dof Parallel Guiding

+
+

1.5.2 1dof Parallel Guiding

-Parallel guiding can be made using two leaf springs (Figure 15): +Parallel guiding can be made using two leaf springs (Figure 15):

  • 2 parallel leaf springs
    • @@ -445,26 +418,26 @@ This sag is predictible and reproducible: \delta z = 0.6 \frac{x^2}{L} \end{equation}
  • Vertical stiffness negatively affected by displacement
    • -
  • Take care of maximum buckling (Figure 16)
    • -
  • Improve buckling load and Z stiffness by reinforced mid-section (Figure 17)
    • +
  • Take care of maximum buckling (Figure 16)
    • +
  • Improve buckling load and Z stiffness by reinforced mid-section (Figure 17)
-
+

parallel_guiding.png

Figure 15: Parallel guiding

-
+

buckling.png

Figure 16: Example of bucklink

-
+

reinforced_leaf_springs.png

Figure 17: Reinforced leaf springs

@@ -472,11 +445,11 @@ This sag is predictible and reproducible:
-
-

1.5.3 Rotation Compliant Mechanism

+
+

1.5.3 Rotation Compliant Mechanism

-Figure 18 shows a rotation compliant mechanism: +Figure 18 shows a rotation compliant mechanism:

  • 3 leaf springs
    • @@ -484,7 +457,7 @@ Figure 18 shows a rotation compliant mechanism:
-
+

rotation_leaf_springs.png

Figure 18: Example of rotation stage using leaf springs

@@ -492,11 +465,11 @@ Figure 18 shows a rotation compliant mechanism:
-
-

1.5.4 Z translation

+
+

1.5.4 Z translation

-Figure 19 shows a Z translation mechanism: +Figure 19 shows a Z translation mechanism:

  • 5 struts (“needles”)
    • @@ -509,18 +482,18 @@ This parasitic rotation is however predictable.

    -
    +

    vertical_stage_compliant.png

    Figure 19: Z translation using 5 struts

    -An alternative is to use folder leaf springs (Figure 20), and this avoid the parasitic rotation. +An alternative is to use folder leaf springs (Figure 20), and this avoid the parasitic rotation.

    -
    +

    vertical_stage_leafs.png

    Figure 20: Z translation using 5 folded leaf springs

    @@ -528,22 +501,22 @@ An alternative is to use folder leaf springs (Figure 20
    -
    -

    1.5.5 X-Y-Rz Stage

    +
    +

    1.5.5 X-Y-Rz Stage

    -An X-Y-Rz stage can be done either using 3 struts (Figure 21) or using 3 folded leaf springs (Figure 22). +An X-Y-Rz stage can be done either using 3 struts (Figure 21) or using 3 folded leaf springs (Figure 22).

    -
    +

    x_y_rz_stage.png

    Figure 21: X,Y,Rz using 3 struts

    -
    +

    x_y_rz_leafs.png

    Figure 22: X,Y,Rz using 3 folded leaf springs

    @@ -551,15 +524,15 @@ An X-Y-Rz stage can be done either using 3 struts (Figure
    -
    -

    1.5.6 Compliant mechanism with only one fixed dof

    +
    +

    1.5.6 Compliant mechanism with only one fixed dof

    -The compliant mechanism shown in Figure 23 only constrain the rotation about the y-axis. +The compliant mechanism shown in Figure 23 only constrain the rotation about the y-axis.

    -
    +

    case_1_leaf_springs.png

    Figure 23: 5dof motion, only the Ry is constrained

    @@ -567,8 +540,8 @@ The compliant mechanism shown in Figure 23 only constr
    -
    -

    1.5.7 Summary

    +
    +

    1.5.7 Summary

    • compliant elements enable defined movements
      • @@ -579,26 +552,26 @@ The compliant mechanism shown in Figure 23 only constr
    -
    -

    1.5.8 Examples

    +
    +

    1.5.8 Examples

    -An example of a complex compliant mechanism is shown in Figure 24. +An example of a complex compliant mechanism is shown in Figure 24.

    -
    +

    compliant_example_1.png

    Figure 24: Design concept

    -Figure 25 shown a reinforced part to avoid buckling and improve vertical stiffness. +Figure 25 shown a reinforced part to avoid buckling and improve vertical stiffness.

    -
    +

    linear_bearing_leafs.png

    Figure 25: Use leaf springs instead of linear roller bearings

    @@ -606,11 +579,11 @@ Figure 25 shown a reinforced part to avoid buckling an
    -
    -

    1.5.9 Mechatronics positioning challenge

    +
    +

    1.5.9 Mechatronics positioning challenge

    -A X-Y-Rz stage is shown in Figure 26. +A X-Y-Rz stage is shown in Figure 26. To make this stage usable for nano-metric positioning, the following ideas where used:

      @@ -641,7 +614,7 @@ To make this stage usable for nano-metric positioning, the following ideas where
    -
    +

    xyRz_positioning_challenge.png

    Figure 26: Example of X-Y-Rz positioning stage

    @@ -653,11 +626,11 @@ To make this stage usable for nano-metric positioning, the following ideas where
    -
    -

    1.5.10 Case - Play Free parallel Stage

    +
    +

    1.5.10 Case - Play Free parallel Stage

    -Figure 27 shows a parallel mechanism that should be converted to a compliant mechanism. +Figure 27 shows a parallel mechanism that should be converted to a compliant mechanism. Its characteristics are:

      @@ -670,7 +643,7 @@ Its characteristics are:
    -
    +

    play_free_parallel_stage.png

    Figure 27: Example of a parallel stage that should be converting to a compliant mechanism

    @@ -686,11 +659,11 @@ The goals are to:

-The solution is shown in Figure 28. +The solution is shown in Figure 28.

-
+

play_free_parallel_stage_solution.png

Figure 28: Case Solution

@@ -699,12 +672,12 @@ The solution is shown in Figure 28.
-
-

1.6 Thin plate design

+
+

1.6 Thin plate design

-
-

1.6.1 Thin plate in torsion

+
+

1.6.1 Thin plate in torsion

Thin plates are very important for compliant mechanisms. @@ -737,7 +710,7 @@ where \(A\) is the area of the cross section.

-
+

thin_plate_torsion.png

Figure 29: A plate under torsion

@@ -745,8 +718,8 @@ where \(A\) is the area of the cross section.
-
-

1.6.2 Difference between open and close profile

+
+

1.6.2 Difference between open and close profile

The close profile has much more torsional stiffness than the open profile. @@ -757,7 +730,7 @@ Just by opening the tube, we have a much smaller torsional stiffness (but almost

-
+

open_close_profil_torsion_stiffness.png

Figure 30: Stiffness comparison open and closed tube (torsion)

@@ -766,22 +739,22 @@ Just by opening the tube, we have a much smaller torsional stiffness (but almost

We have similar behavior with an open/closed box. -If we remove one side of the cube shown in Figure 31, we would have much smaller torsional stiffness along the axis perpendicular to the removed side. +If we remove one side of the cube shown in Figure 31, we would have much smaller torsional stiffness along the axis perpendicular to the removed side.

-
+

closed_box.png

Figure 31: Closed box.

-If we use triangles, we obtain high torsional stiffness as shown in Figure 32. +If we use triangles, we obtain high torsional stiffness as shown in Figure 32.

-
+

torsion_stiffness_box_double_triangle.png

Figure 32: Open box (double triangle)

@@ -793,11 +766,11 @@ On way to reinforce it is using triangles.

-A nice way to have a 1dof flexure guiding with stiff frame is shown in Figure 33. +A nice way to have a 1dof flexure guiding with stiff frame is shown in Figure 33.

-
+

z_stage_triangles.png

Figure 33: Box with integrated flexure guiding

@@ -807,12 +780,12 @@ A nice way to have a 1dof flexure guiding with stiff frame is shown in Figure
-
-

2 Keynote: Mechatronic challenges in optical lithography   @hans_butler

+
+

2 Keynote: Mechatronic challenges in optical lithography   @hans_butler

-
-

2.1 Introduction

+
+

2.1 Introduction

Question: in chip manufacturing, how do developments in optical lithography impact the mechatronic design? @@ -830,15 +803,15 @@ Main developments:

-
-

2.2 Chip manufacturing loop

+
+

2.2 Chip manufacturing loop

In this presentation, only the exposure step is discussed (lithography).

-
+

asml_chip_manufacturing_loop.png

Figure 34: Chip manufacturing loop

@@ -846,19 +819,19 @@ In this presentation, only the exposure step is discussed (lithography).
-
-

2.3 Imaging process - Basics

+
+

2.3 Imaging process - Basics

-
+

asml_imaging_process.png

Figure 35: Imaging process - basics

@@ -866,8 +839,8 @@ This will induce a sinusoidal wave on the wafer as shown in Figure -

2.4 From stepper to scanner

+
+

2.4 From stepper to scanner

Before, one chip was illumating at a time, but people wanted to make bigger chips. @@ -880,7 +853,7 @@ This implied many requirements in dynamics and accuracy!

-
+

asml_stepper_to_scanner.png

Figure 36: From stepper to scanner

@@ -888,8 +861,8 @@ This implied many requirements in dynamics and accuracy!
-
-

2.5 Dual stage scanners

+
+

2.5 Dual stage scanners

Both the reticle stage and wafer stage are moving. @@ -914,7 +887,7 @@ Which are solved by: -

+

asml_dual_stage_scanners.png

Figure 37: Machine based on the dual stage scanners

@@ -922,20 +895,20 @@ Which are solved by:
-
-

2.6 Immersion technology

+
+

2.6 Immersion technology

Water is used between the lens and the wafer to increase the “NA” and thus decreasing the “critical dimension”.

-The “hood” is there to prevent any bubble to enter the illumination area (Figure 38). +The “hood” is there to prevent any bubble to enter the illumination area (Figure 38). The position of the “hood” is actively control to follow the wafer stage (that can move in z direction and tilt).

-Three solutions are used for the positioning control of the “hood” system (Figure 39): +Three solutions are used for the positioning control of the “hood” system (Figure 39):

  • Disturbance decoupling
    • @@ -944,14 +917,14 @@ Three solutions are used for the positioning control of the “hood” s
-
+

asml_hood_system.png

Figure 38: Hood System

-
+

asml_immersion.png

Figure 39: Control system for the “hood”

@@ -959,8 +932,8 @@ Three solutions are used for the positioning control of the “hood” s
-
-

2.7 Multiple Patterning

+
+

2.7 Multiple Patterning

The multiple patterning approach adds few mechatronics challenges: @@ -980,16 +953,16 @@ This was solved by:

-
-

2.8 Machine layout

+
+

2.8 Machine layout

-Each stage is controlled with 6dof lorentz short stroke actuators (Figure 40). +Each stage is controlled with 6dof lorentz short stroke actuators (Figure 40). The magnet stage can move horizontally (due to reaction forces of the wafer stages): it asks as a balance mass.

-
+

asml_machine_layout_bis.png

Figure 40: Machine layout

@@ -997,8 +970,8 @@ The magnet stage can move horizontally (due to reaction forces of the wafer stag
-
-

2.9 EUV Lithography

+
+

2.9 EUV Lithography

Vacuum is required which implies: @@ -1026,7 +999,7 @@ Wafer stage: -

+

asml_euv.png

Figure 41: Schematic of the ASML EUV machine

@@ -1034,22 +1007,22 @@ Wafer stage:
-
-

2.10 The future: high-NA EUV

+
+

2.10 The future: high-NA EUV

-
+

asml_na_euv.png

Figure 42: The CD will be 8nm

-In order to do so, high “opening” of the optics is required which is very challenges because the reflectiveness of mirror is decreasing as high angle of incidence (Figure 43). +In order to do so, high “opening” of the optics is required which is very challenges because the reflectiveness of mirror is decreasing as high angle of incidence (Figure 43).

-
+

asml_reflection_angle.png

Figure 43: Change of reflection of a mirror as a function of the angle of indicence

@@ -1057,8 +1030,8 @@ In order to do so, high “opening” of the optics is required which is
-
-

2.11 Challenges for future Optical Lithography machines

+
+

2.11 Challenges for future Optical Lithography machines

Challenges: @@ -1080,8 +1053,8 @@ In order to do so, high “opening” of the optics is required which is

-
-

2.12 Conclusion

+
+

2.12 Conclusion

The conclusions are: @@ -1102,12 +1075,12 @@ The conclusions are:

-
-

3 Designing anti-aliasing-filters for control loops of mechatronic systems regarding the rejection of aliased resonances   @ulrich_schonhoff

+
+

3 Designing anti-aliasing-filters for control loops of mechatronic systems regarding the rejection of aliased resonances   @ulrich_schonhoff

-
-

3.1 The phenomenon of aliasing of resonances

+
+

3.1 The phenomenon of aliasing of resonances

Weakly damped flexible modes of the mechanism can limit the performance of motion control systems. @@ -1118,36 +1091,36 @@ For discrete time controlled systems, there can be an additional limitation: ali

-
+

aliasing_resonances.png

Figure 44: Example of high frequency lighlty damped resonances

-The aliasing of signals is well known (Figure 45). +The aliasing of signals is well known (Figure 45).

-However, aliasing in systems can also happens and is schematically shown in Figure 46. +However, aliasing in systems can also happens and is schematically shown in Figure 46.

-
+

aliasing_signals.png

Figure 45: Aliasing of Signals

-
+

aliasing_system.png

Figure 46: Aliasing of Systems

-The poles of the system will be aliased and their location will change in the complex plane as shown in Figure 47. +The poles of the system will be aliased and their location will change in the complex plane as shown in Figure 47.

@@ -1163,7 +1136,7 @@ Therefore, the damping of the aliased resonances are foreseen to have larger dam

-
+

aliasing_poles.png

Figure 47: Aliasing of poles in the complex plane

@@ -1178,7 +1151,7 @@ Let’s consider two systems with a resonance:

-Then looking at the same systems in the digital domain, one can see thathen the resonance is above the Nyquist frequency (Figure 48): +Then looking at the same systems in the digital domain, one can see thathen the resonance is above the Nyquist frequency (Figure 48):

  • the resonance mirrors
    • @@ -1190,14 +1163,14 @@ Therefore, when identifying a low damped resonance, it could be that it comes fo

    -
    +

    aliasing_above_nyquist.png

    Figure 48: Aliazed resonance shown on the Bode Diagram

    -
    +

    alising_much_above_nyquist.png

    Figure 49: Higher resonance frequency

    @@ -1205,26 +1178,26 @@ Therefore, when identifying a low damped resonance, it could be that it comes fo
    -
    -

    3.2 Nature, Modelling and Mitigation of potentially aliasing resonances

    +
    +

    3.2 Nature, Modelling and Mitigation of potentially aliasing resonances

    -The aliased modes can for instance comes from local modes in the actuators that are lightly damped and at high frequency (Figure 50) +The aliased modes can for instance comes from local modes in the actuators that are lightly damped and at high frequency (Figure 50)

    -
    +

    alising_nature.png

    Figure 50: Local vibration mode that will be alized

    -The proposed idea to better model aliasing resonances is to include more modes in the FEM software as shown in Figure 51 and then perform an order reduction in matlab. +The proposed idea to better model aliasing resonances is to include more modes in the FEM software as shown in Figure 51 and then perform an order reduction in matlab.

    -
    +

    aliasing_modeling.png

    Figure 51: Common procedure and proposed procedure to include aliazed resonances

    @@ -1232,32 +1205,32 @@ The proposed idea to better model aliasing resonances is to include more modes i
    -
    -

    3.3 Anti aliasing filter design

    +
    +

    3.3 Anti aliasing filter design

    -
    -

    3.3.1 Introduction

    +
    +

    3.3.1 Introduction

    • Anti-aliasing filtering can be used to reject aliasing of resonances and to maintain the stability of the control loop
    • However, its phase lag deteriorates the control loop performances:
        -
      • phase margin decreases (Figure 52)
        • -
      • sensitivity peak increases (Figure 53)
        • +
      • phase margin decreases (Figure 52)
        • +
      • sensitivity peak increases (Figure 53)
    • Thus, the anti-aliasing filter should be targeted at sufficient rejection at least possible phase lag
    -
    +

    alising_filter_introduction.png

    Figure 52: Example of the effect of aliased resonance on the open-loop

    -
    +

    aliasing_sensitivity_effect.png

    Figure 53: Example of the effect of aliased resonance on sensitivity function

    @@ -1265,8 +1238,8 @@ The proposed idea to better model aliasing resonances is to include more modes i
    -
    -

    3.3.2 Concept of equivalent delay

    +
    +

    3.3.2 Concept of equivalent delay

    Concept: @@ -1290,7 +1263,7 @@ Similarly, \(\omega_{0zi}\) is the natural frequency \(\xi_{zi}\) is the damping

-Examples (Figure 54): +Examples (Figure 54):

  • First order low pass filter: @@ -1302,7 +1275,7 @@ Similarly, \(\omega_{0zi}\) is the natural frequency \(\xi_{zi}\) is the damping
-
+

aliasing_equivalent_delay.png

Figure 54: Magnitude, Phase and Phase delay of 3 filters

@@ -1310,26 +1283,26 @@ Similarly, \(\omega_{0zi}\) is the natural frequency \(\xi_{zi}\) is the damping
-
-

3.3.3 Budgeting of phase lag

+
+

3.3.3 Budgeting of phase lag

-The budgeting of the phase lag is done by expressing the phase lag of each element by a time delay (Figure 55) +The budgeting of the phase lag is done by expressing the phase lag of each element by a time delay (Figure 55)

-
+

aliasing_budget_phase.png

Figure 55: Typical control loop with several phase lag / time delays

-The equivalent delay of each element are listed in Figure 56. +The equivalent delay of each element are listed in Figure 56.

-
+

aliasing_budget_table.png

Figure 56: Equivalent delay for all the elements of the control loop

@@ -1337,23 +1310,23 @@ The equivalent delay of each element are listed in Figure
-
-

3.3.4 Selecting the filter order

+
+

3.3.4 Selecting the filter order

The filter order can be chosen depending on the frequency of the resonance. -Some example of Butterworth filters are shown in Figure 57 and summarized in Figure 58. +Some example of Butterworth filters are shown in Figure 57 and summarized in Figure 58.

-
+

aliasing_filter_order_bode.png

Figure 57: Example of few Butterworth filters

-
+

aliasing_filter_order_table.png

Figure 58: Butterworth filters

@@ -1361,8 +1334,8 @@ Some example of Butterworth filters are shown in Figure 57
-
-

3.3.5 Reducing the phase lag

+
+

3.3.5 Reducing the phase lag

The equivalent delay of a low pass (here second order) depends on its damping, since: @@ -1370,7 +1343,7 @@ The equivalent delay of a low pass (here second order) depends on its damping, s

-
+

aliasing_reduce_phase_lag.png

Figure 59: Change of the phase delay with the damping of the filter

@@ -1379,8 +1352,8 @@ The equivalent delay of a low pass (here second order) depends on its damping, s
-
-

3.4 Conclusion

+
+

3.4 Conclusion

The phenomenon of aliasing of resonances: @@ -1415,12 +1388,12 @@ Anti-aliasing filter design:

-
-

4 Flexure positioning stage based on delta technology for high precision and dynamic industrial machining applications   @mikael_bianchi

+
+

4 Flexure positioning stage based on delta technology for high precision and dynamic industrial machining applications   @mikael_bianchi

-
-

4.1 Introduction

+
+

4.1 Introduction

  • Goal: flexure positioning stage to do high precision and high dynamic/acceleration positioning. @@ -1433,30 +1406,30 @@ The control architecture should be as simple as possible.
-
-

4.2 Design

+
+

4.2 Design

-
-

4.2.1 Description of the Delta robot

+
+

4.2.1 Description of the Delta robot

-Technical choice: flexure based delta robot (Figure 60). +Technical choice: flexure based delta robot (Figure 60).

  • Advantages: high mechanical precision without backlash
    • -
  • Disadvantage: the motion is coupled, some transformations are required from motor coordinates to machine coordinates (Figure 61)
    • +
  • Disadvantage: the motion is coupled, some transformations are required from motor coordinates to machine coordinates (Figure 61)
-
+

flexure_delta_robot.png

Figure 60: Picture of the Delta Robot

-
+

flexure_delta_robot_schematic.png

Figure 61: x1, x2 x3 are the motor positions. f1,f2 f3 are the force motors. x,y,z are the position of the final point in cartesian coordinates

@@ -1464,8 +1437,8 @@ The control architecture should be as simple as possible.
-
-

4.2.2 Modelling and validation of the delta robot

+
+

4.2.2 Modelling and validation of the delta robot

Lagrange equations are used to model the dynamics of the delta robot. @@ -1473,33 +1446,33 @@ The motor positions are used as the general coordinate system.

-The system is then linearized around the working point (Figure 62). +The system is then linearized around the working point (Figure 62).

-
+

flexure_equations.png

Figure 62: Linearized equations of the Delta Robot

-Then the parameters are identified from experiment (Figure 63). +Then the parameters are identified from experiment (Figure 63).

-
+

flexure_identification.png

Figure 63: Identification fo the transfer function from \(F_1\) to \(x_1\)

-The measurement of the coupling is move complicated as shown in Figure 64. +The measurement of the coupling is move complicated as shown in Figure 64.

-
+

flexure_identification_coupling.png

Figure 64: Problem of identifying the coupling between F1 and x2 at low frequency

@@ -1507,8 +1480,8 @@ The measurement of the coupling is move complicated as shown in Figure -

4.2.3 Control design for high trajectory tracking

+
+

4.2.3 Control design for high trajectory tracking

Control requirements: @@ -1521,7 +1494,7 @@ Control requirements: -

+

flexure_control_concept.png

Figure 65: Control concept used for the Delta robot

@@ -1529,11 +1502,11 @@ Control requirements:
-
-

4.2.4 Electronic board

+
+

4.2.4 Electronic board

-A 3 axis servo control board as been developed (Figure 66) which includes: +A 3 axis servo control board as been developed (Figure 66) which includes:

  • identification algorithm of the coupled system integrated in the board
    • @@ -1547,19 +1520,19 @@ A 3 axis servo control board as been developed (Figure 66<
-
-

4.3 Results

+
+

4.3 Results

-
-

4.3.1 Current control

+
+

4.3.1 Current control

-Step response of the current control loop is shown in Figure 66. +Step response of the current control loop is shown in Figure 66.

-
+

flexure_current_control_results.png

Figure 66: Step response for the current control loop

@@ -1567,40 +1540,40 @@ Step response of the current control loop is shown in Figure -

4.3.2 Trajectory tracking: results with laser interferometer and encoder

+
+

4.3.2 Trajectory tracking: results with laser interferometer and encoder

-XY renishaw interferometers used to verify the performance of the system (Figure 67). +XY renishaw interferometers used to verify the performance of the system (Figure 67).

-
+

flexure_sensors.png

Figure 67: Experimental setup to verify the performances of the system

-Some results are shown in Figures 68, 69 and 70. +Some results are shown in Figures 68, 69 and 70.

-
+

flexure_results.png

Figure 68: Circuit motion results and point to point motion results

-
+

flexure_steps.png

Figure 69: Step response of the system

-
+

flexure_dynamics_errors.png

Figure 70: Measured dynamical errors

@@ -1609,8 +1582,8 @@ Some results are shown in Figures 68, -

4.4 Conclusion

+
+

4.4 Conclusion

As a conclusion, here are the identified conditions for precise and high dynamic positioning: @@ -1629,19 +1602,19 @@ Resonances at mid frequencies are an issue for further improvements.

-
-

5 Multivariable performance analysis of position-controlled payloads with flexible eigenmodes   @luca_mettenleiter

+
+

5 Multivariable performance analysis of position-controlled payloads with flexible eigenmodes   @luca_mettenleiter

-
-

5.1 Motivation

+
+

5.1 Motivation

Flexible eigenmodes are present in every system component and leads to::

@@ -1649,25 +1622,25 @@ Flexible eigenmodes are present in every system component and leads to::

-
+

mimo_flexible_modes.png

Figure 71: Limitation of the control bandwidth due to flexible eigenmodes

-
+

mimo_flexible_modes_coupling.png

Figure 72: Coupling due to flexible eigenmodes

-In order to estimate the performances of a system, the sensitivity function can be used (Figure 73). +In order to estimate the performances of a system, the sensitivity function can be used (Figure 73).

-
+

mimo_sensitivity_performance.png

Figure 73: Bode plot of a typical Sensitivity function

@@ -1675,11 +1648,11 @@ In order to estimate the performances of a system, the sensitivity function can
-
-

5.2 Performance analysis with different sensitivity functions

+
+

5.2 Performance analysis with different sensitivity functions

-There are different way to analyse the sensitivity function base on different plants (Figure 74): +There are different way to analyse the sensitivity function base on different plants (Figure 74):

  1. the full system (complicated): @@ -1696,7 +1669,7 @@ One loop is closed at a time, and the coupling effects are taken into account.

    -
    +

    mimo_sensitivity_functions.png

    Figure 74: Visual representation of the three systems

    @@ -1704,11 +1677,11 @@ One loop is closed at a time, and the coupling effects are taken into account.
    -
    -

    5.3 Example system

    +
    +

    5.3 Example system

    -In order to compare the use of the three systems to estimate the performances of a MIMO system, the system shown in Figure 75 is used. +In order to compare the use of the three systems to estimate the performances of a MIMO system, the system shown in Figure 75 is used. The 4 top masses are used to represent a payload that will add coupling in the system due to its resonances.

    @@ -1717,7 +1690,7 @@ A diagonal PID controller is used.

    -
    +

    mimo_example_system.png

    Figure 75: Schematic representation of the example system

    @@ -1725,24 +1698,24 @@ A diagonal PID controller is used.

    -The bode plot of the MIMO system is shown in Figure 76 where we can see the resonances in the off-diagonal elements. +The bode plot of the MIMO system is shown in Figure 76 where we can see the resonances in the off-diagonal elements.

    -
    +

    mimo_example_bode.png

    Figure 76: Bode plot of the full MIMO system

    -In Figure 77 is shown that the sensitivity function computed from the SISO system is not correct. +In Figure 77 is shown that the sensitivity function computed from the SISO system is not correct. Whereas for the “interaction method” system, it is correct and almost match the full system sensibility. However, as expected, the off-diagonal sensibilities are not modelled.

    -
    +

    mimo_example_sensitivity.png

    Figure 77: Bode plots of sensitivity functions

    @@ -1750,11 +1723,11 @@ However, as expected, the off-diagonal sensibilities are not modelled.
    -
    -

    5.4 Conclusion

    +
    +

    5.4 Conclusion

    -The conclusion are the following and summarized in Figure 78: +The conclusion are the following and summarized in Figure 78:

    • Choice of suitable analysis method is key concept in mechatronics engineering
      • @@ -1768,7 +1741,7 @@ The conclusion are the following and summarized in Figure - -
      -

      6 High-precision motion system design by topology optimization considering additive manufacturing   @arnoud_delissen

      +
      +

      6 High-precision motion system design by topology optimization considering additive manufacturing   @arnoud_delissen

      -
      -

      6.1 Introduction

      +
      +

      6.1 Introduction

      The goal of this project is to perform a topology optimization of a 6dof magnetic levitated stage suitable for vacuum.

      -For the current system (Figure 79), the bandwidth is limited by the short-stroke dynamics (eigenfrequencies). +For the current system (Figure 79), the bandwidth is limited by the short-stroke dynamics (eigenfrequencies).

      @@ -1797,7 +1770,7 @@ The goal here is to make the eigen-frequency higher as this will allow more band

      -
      +

      mimoopt_6dof_stage.png

      Figure 79: Schematic of the 6dof levitating stage

      @@ -1805,15 +1778,15 @@ The goal here is to make the eigen-frequency higher as this will allow more band
      -
      -

      6.2 Case

      +
      +

      6.2 Case

      -More precisely, the goal is to automatically maximize the three eigen-frequencies of the system shown in Figure 80. +More precisely, the goal is to automatically maximize the three eigen-frequencies of the system shown in Figure 80.

      -
      +

      mimoopt_case.png

      Figure 80: System to be optimized

      @@ -1821,16 +1794,16 @@ More precisely, the goal is to automatically maximize the three eigen-frequencie
      -
      -

      6.3 Manufacturing process

      +
      +

      6.3 Manufacturing process

      The manufacturing process must be embedded in the optimization such that the obtained design is producible. -The process is shown in Figure 81. +The process is shown in Figure 81.

      -
      +

      mimoopt_process.png

      Figure 81: Manufacturing process

      @@ -1838,26 +1811,26 @@ The process is shown in Figure 81.
      -
      -

      6.4 Topology optimization

      +
      +

      6.4 Topology optimization

      Problem: for a given volume, maximize the eigen-frequencies of the system.

      -To do so, the system is discretized into small elements (Figure 82). +To do so, the system is discretized into small elements (Figure 82). Then, a Finite Element Analysis is performed to compute the eigen-frequencies of the system. Finally, for each element, the “gradient is computed” and we determine if material should be added or removed.

      -This is done in 3D. The individual 1mm x 1mm x 1mm elements are shown in Figure 82. +This is done in 3D. The individual 1mm x 1mm x 1mm elements are shown in Figure 82. The number of elements is 1 million (=> 15 minutes per iteration to compute the 3 eigen-frequencies).

      -
      +

      mimoopt_3d_opti.png

      Figure 82: Results of the topology optimization and zoom to see individual elements

      @@ -1865,26 +1838,26 @@ The number of elements is 1 million (=> 15 minutes per iteration to compute t
      -
      -

      6.5 Performance Comparison

      +
      +

      6.5 Performance Comparison

      -The obtained mass and eigen-frequencies of the optimized system and the solid equivalents are compared in Figure 83. +The obtained mass and eigen-frequencies of the optimized system and the solid equivalents are compared in Figure 83.

      -
      +

      mimoopt_performance.png

      Figure 83: Comparison of the obtained performances

      -Identification on the realized system shown that the obtained eigen-frequencies are very closed to the estimated ones (Figure 84). +Identification on the realized system shown that the obtained eigen-frequencies are very closed to the estimated ones (Figure 84).

      -
      +

      mimoopt_frf_identification.png

      Figure 84: Results very close to simulation (~1% for the eigen frequencies)

      @@ -1892,8 +1865,8 @@ Identification on the realized system shown that the obtained eigen-frequencies
      -
      -

      6.6 Conclusion

      +
      +

      6.6 Conclusion

      • Increase in performance (~2x) compared to solid designs
        • @@ -1905,12 +1878,12 @@ Identification on the realized system shown that the obtained eigen-frequencies
      -
      -

      7 A multivariable experiment design framework for accurate FRF identification of complex systems   @nic_dirkx

      +
      +

      7 A multivariable experiment design framework for accurate FRF identification of complex systems   @nic_dirkx

      -
      -

      7.1 Introduction

      +
      +

      7.1 Introduction

      Goal: Need for higher quality FRF models that are used to: @@ -1927,7 +1900,7 @@ High quality FRFs requires careful design of excitation \(w\).

      -Typical experimental identification of the FRFs is shown in Figure 85. +Typical experimental identification of the FRFs is shown in Figure 85.

      @@ -1939,7 +1912,7 @@ The design trade-off is:

    -
    +

    frf_introduction.png

    Figure 85: schematic of the identification of the FRF

    @@ -1968,14 +1941,14 @@ For MIMO systems:
    -
    -

    7.2 Role of directions and constrains in multivariable excitation design

    +
    +

    7.2 Role of directions and constrains in multivariable excitation design

    The classical way to estimate MIMO FRFs is the following:

      -
    • First start with one direction and increase the gain until constrains is attained (Figure 86)
      • +
    • First start with one direction and increase the gain until constrains is attained (Figure 86)
    • Do the same with the second input
    @@ -1984,18 +1957,18 @@ This lead to non-optimal FRFs estimation.

    -
    +

    frf_direction_excitation.png

    Figure 86: Example of a SISO approach to identify MIMO FRFs

    -When having a MIMO approach and choosing both the direction and gain of the excitation inputs, we can obtained much better FRFs uncertainty while still fulfilling the constraints (Figure 87). +When having a MIMO approach and choosing both the direction and gain of the excitation inputs, we can obtained much better FRFs uncertainty while still fulfilling the constraints (Figure 87).

    -
    +

    frf_mimo.png

    Figure 87: Example of the MIMO approach that gives much better FRFs

    @@ -2003,15 +1976,15 @@ When having a MIMO approach and choosing both the direction and gain of the exci
    -
    -

    7.3 Solving the optimization problem

    +
    +

    7.3 Solving the optimization problem

    The optimization problem is to minimize the model uncertainty by choosing the design variables which are the magnitude and direction of the inputs \(w\).

    -The optimization is a two step process as shown in Figure 88: +The optimization is a two step process as shown in Figure 88:

    1. first identification without optimization that allows to have data to run the optimization process
      2. @@ -2028,7 +2001,7 @@ In this work, two algorithms are proposed and not further detailed here.

      -
      +

      frf_optimization_steps.png

      Figure 88: Two step optimization process

      @@ -2036,8 +2009,8 @@ In this work, two algorithms are proposed and not further detailed here.
      -
      -

      7.4 Experimental validation

      +
      +

      7.4 Experimental validation

      Experimental identification of a 7x8 MIMO plant was performed in for different cases: @@ -2050,24 +2023,24 @@ Experimental identification of a 7x8 MIMO plant was performed in for different c

    -The obtained FRFs are shown in Figure 89. +The obtained FRFs are shown in Figure 89.

    -
    +

    frf_experiment.png

    Figure 89: Obtained MIMO FRFs

    -A comparison of one of the obtained FRFs is shown in Figure 90. +A comparison of one of the obtained FRFs is shown in Figure 90. It is quite clear that the MIMO approach can give much lower FRF uncertainty. The RR proposed algorithm is giving the best results

    -
    +

    frf_experiment_optimized.png

    Figure 90: Example of one of the obtained FRF

    @@ -2075,8 +2048,8 @@ The RR proposed algorithm is giving the best results
    -
    -

    7.5 Conclusion

    +
    +

    7.5 Conclusion

    • The uncertainty of the obtained FRF are obtained by doing several experimental identification with a deterministic input signal. @@ -2090,19 +2063,19 @@ The FRF are computed multiple times, and the spread of the results at each frequ
    -
    -

    8 Keynote: High precision mechatronic approaches for advanced nanopositioning and nanomeasuring technologies   @eberhard_manske

    +
    +

    8 Keynote: High precision mechatronic approaches for advanced nanopositioning and nanomeasuring technologies   @eberhard_manske

    -
    -

    8.1 Coordinate Measurement Machines (CMM)

    +
    +

    8.1 Coordinate Measurement Machines (CMM)

    -Examples of Nano Coordinate Measuring Machines are shown in Figure 91. +Examples of Nano Coordinate Measuring Machines are shown in Figure 91.

    -
    +

    prec_cmm.png

    Figure 91: Example of Coordinate Measuring Machines

    @@ -2110,11 +2083,11 @@ Examples of Nano Coordinate Measuring Machines are shown in Figure -

    8.2 Difference between CMM and nano-CMM

    +
    +

    8.2 Difference between CMM and nano-CMM

    -With classical CMM, the Abbe-principle is not fulfilled in the x and y directions (Figure 92). +With classical CMM, the Abbe-principle is not fulfilled in the x and y directions (Figure 92).

    @@ -2139,15 +2112,16 @@ Then, the classical CMM will not work for nano precision

    -
    +

    prec_cmm_nano_cmm.png

    +

    Figure 92: Schematic of a CMM

    -
    -

    8.3 How to do nano-CMM

    +
    +

    8.3 How to do nano-CMM

    High precision mechatronic approaches are required for advanced nano-positionign and nano-measuring technologies: @@ -2167,11 +2141,11 @@ Combined with:

    -
    -

    8.4 Concept - Minimization of the Abbe Error

    +
    +

    8.4 Concept - Minimization of the Abbe Error

    -In order to minimize the Abbe error, the measuring “lines” should have a common point of intersection (Figure 93). +In order to minimize the Abbe error, the measuring “lines” should have a common point of intersection (Figure 93).

    @@ -2183,7 +2157,7 @@ The 3D-realization of Abbe-principle is as follows: -

    +

    prec_nano_cmm_concept.png

    Figure 93: Error minimal measuring principle

    @@ -2191,15 +2165,15 @@ The 3D-realization of Abbe-principle is as follows:
    -
    -

    8.5 Minimization of residual Abbe error

    +
    +

    8.5 Minimization of residual Abbe error

    -Still some residual Abbe error can happen as shown in Figure 94 due to both a change of angle and change of position. +Still some residual Abbe error can happen as shown in Figure 94 due to both a change of angle and change of position.

    -
    +

    prec_abbe_min.png

    Figure 94: Residual Abbe error

    @@ -2207,15 +2181,15 @@ Still some residual Abbe error can happen as shown in Figure -

    8.6 Compare of long travel guiding systems

    +
    +

    8.6 Compare of long travel guiding systems

    -In order to have the Abbe error compatible with nano-meter precision, the precision of the spindle should be less and one arcsec which is not easily feasible with air bearing of precision roller bearing technologies as shown in Figure 95. +In order to have the Abbe error compatible with nano-meter precision, the precision of the spindle should be less and one arcsec which is not easily feasible with air bearing of precision roller bearing technologies as shown in Figure 95.

    -
    +

    prec_comp_guid.png

    Figure 95: Characteristics of guidings

    @@ -2223,11 +2197,11 @@ In order to have the Abbe error compatible with nano-meter precision, the precis
    -
    -

    8.7 Extended 6 DoF Abbe comparator principle

    +
    +

    8.7 Extended 6 DoF Abbe comparator principle

    -The solution used was to measure in real time the angles of the frame using autocollimators as shown in Figure 96 and then to minimize this tilt by close loop operation with additional actuators. +The solution used was to measure in real time the angles of the frame using autocollimators as shown in Figure 96 and then to minimize this tilt by close loop operation with additional actuators.

    @@ -2242,7 +2216,7 @@ Without an error-minimal approach, nano-meter precision cannot be achieved in la

    -
    +

    prec_6dof_abbe.png

    Figure 96: Use of additional autocollimator and actuators for Abbe minimization

    @@ -2250,15 +2224,15 @@ Without an error-minimal approach, nano-meter precision cannot be achieved in la
    -
    -

    8.8 Practical Realisation

    +
    +

    8.8 Practical Realisation

    -A practical realization of the Extended 6 DoF Abbe comparator principle is shown in Figure 97. +A practical realization of the Extended 6 DoF Abbe comparator principle is shown in Figure 97.

    -
    +

    prec_practical_6dof.png

    Figure 97: Practical Realization of the

    @@ -2266,19 +2240,19 @@ A practical realization of the Extended 6 DoF Abbe comparator principle is shown
    -
    -

    8.9 Tilt Compensation

    +
    +

    8.9 Tilt Compensation

    To measure compensate for any tilt, two solutions are proposed:

      -
    1. Use a zero point angular auto-collimator (Figure 98) +
    2. Use a zero point angular auto-collimator (Figure 98)
      • Resolution: 0.005 arcsec
      • Stability (1h): < 0.05 arcsec
      3. -
    3. 6 DoF laser interferoemter (Figure 99) +
    4. 6 DoF laser interferoemter (Figure 99)
      • Resolution: 0.00002 arcsec
      • Stability (1h): < 0.00005 arcsec
        • @@ -2286,14 +2260,14 @@ To measure compensate for any tilt, two solutions are proposed:
    -
    +

    prec_tilt_corection.png

    Figure 98: Auto-Collimator

    -
    +

    prec_tilt_corection_bis.png

    Figure 99: 6 Interferometers to measure tilts

    @@ -2301,11 +2275,11 @@ To measure compensate for any tilt, two solutions are proposed:
    -
    -

    8.10 Comparison of long travail guiding systems - Bis

    +
    +

    8.10 Comparison of long travail guiding systems - Bis

    -Now, if we actively compensate the tilts are shown previously, we can fulfill the requirements as shown in Figure 100. +Now, if we actively compensate the tilts are shown previously, we can fulfill the requirements as shown in Figure 100.

    @@ -2318,7 +2292,7 @@ Now, if we actively compensate the tilts are shown previously, we can fulfill th -

    +

    prec_comp_guid_bis.png

    Figure 100: Characteristics of the tilt compensation system

    @@ -2326,8 +2300,8 @@ Now, if we actively compensate the tilts are shown previously, we can fulfill th
    -
    -

    8.11 Drive concept

    +
    +

    8.11 Drive concept

    Usually, in order to achieve a large range over small resolution, each axis of motion is a combination of a coarse motion and a fine motion stage. @@ -2335,7 +2309,7 @@ The coarse motion stage generally consist of a stepper motor while the fine moti

    -The approach here is to use an homogenous drive concept for increase dynamics (Figure 101). +The approach here is to use an homogenous drive concept for increase dynamics (Figure 101).

    @@ -2343,7 +2317,7 @@ Only one linear voice coil actuator is used which with large moving range and su

    -
    +

    prec_drive_concept.png

    Figure 101: Voice Coil Actuator

    @@ -2352,11 +2326,11 @@ Only one linear voice coil actuator is used which with large moving range and su
    -
    -

    8.12 NPMM-200 with extended measuring volume

    +
    +

    8.12 NPMM-200 with extended measuring volume

    -The NPMM-200 machine can be seen in Figure 102. +The NPMM-200 machine can be seen in Figure 102.

    @@ -2373,18 +2347,18 @@ Characteristics: -

    +

    prec_mechanics.png

    Figure 102: Picture of the NPMM-200

    -The NPMM-200 actually operates inside a Vacuum chamber as shown in Figure 103. +The NPMM-200 actually operates inside a Vacuum chamber as shown in Figure 103.

    -
    +

    prec_vacuum_cham.png

    Figure 103: Vacuum chamber used

    @@ -2392,26 +2366,26 @@ The NPMM-200 actually operates inside a Vacuum chamber as shown in Figure
    -
    -

    8.13 measurement capability

    +
    +

    8.13 measurement capability

    -Some step responses are shown in Figure 104 and show the nano-metric precision of the machine. +Some step responses are shown in Figure 104 and show the nano-metric precision of the machine.

    -
    +

    prec_results_meas.png

    Figure 104: Sub nano-meter position accuracy

    -Picometer steps can even be achieved as shown in Figure 105. +Picometer steps can even be achieved as shown in Figure 105.

    -
    +

    prec_results_pico.png

    Figure 105: Picometer level control

    @@ -2419,8 +2393,8 @@ Picometer steps can even be achieved as shown in Figure 10
    -
    -

    8.14 Extension of the measuring range (700mm)

    +
    +

    8.14 Extension of the measuring range (700mm)

    If the measuring range is to be increase, there are some limits of the moving stage principle: @@ -2439,11 +2413,11 @@ The proposed solution is to use inverse dynamic concept for minimization of m

    -
    -

    8.15 Inverse kinematic concept - Tetrahedrical concept

    +
    +

    8.15 Inverse kinematic concept - Tetrahedrical concept

    -The proposed concept is shown in Figure 106: +The proposed concept is shown in Figure 106:

    • mirrors and object to be measured are fixed
      • @@ -2461,7 +2435,7 @@ This fulfills the Abbe principe but:
    -
    +

    prec_inverse_kin.png

    Figure 106: Tetrahedrical concept

    @@ -2469,11 +2443,11 @@ This fulfills the Abbe principe but:
    -
    -

    8.16 Inverse kinematic concept - Scanning probe principle

    +
    +

    8.16 Inverse kinematic concept - Scanning probe principle

    -An other concept, the scanning probe principle is shown in Figure 107: +An other concept, the scanning probe principle is shown in Figure 107:

    • cuboidal measuring volume
      • @@ -2483,7 +2457,7 @@ An other concept, the scanning probe principle is shown in Figure +

      prec_inverse_kin_scan.png

      Figure 107: Scanning probe principle

      @@ -2491,8 +2465,8 @@ An other concept, the scanning probe principle is shown in Figure       -

      8.17 Inverse kinematic concept - Compact measuring head

      +
      +

      8.17 Inverse kinematic concept - Compact measuring head

      In order to minimize the moving mass, compact measuring heads have been developed. @@ -2500,18 +2474,18 @@ The goal was to make a lightweight measuring head (<1kg)

      -The interferometer used are fiber coupled laser interferometers with a mass of 37g (Figure 108). +The interferometer used are fiber coupled laser interferometers with a mass of 37g (Figure 108).

      -
      +

      prec_interferometers.png

      Figure 108: Micro Interferometers

      -The concept is shown in Figure 109: +The concept is shown in Figure 109:

      • 6dof interferometers are used
        • @@ -2524,24 +2498,24 @@ There is some abbe offset between measurement axis of probe and of interferomete

        -
        +

        prec_inverse_meas_head.png

      -
      -

      8.18 Inverse kinematic concept - Scanning probe principle

      +
      +

      8.18 Inverse kinematic concept - Scanning probe principle

      -As shown in Figure 110, the abbe error can be compensated from the two top interferometers as: +As shown in Figure 110, the abbe error can be compensated from the two top interferometers as: \[ \text{for } l_x = a: \quad \Delta l_{\text{Abbe}} = \Delta l_{\text{int}} \] Thus the tilt and Abbe errors can be compensated for with sub-nm resolution.

      -
      +

      prec_abbe_compensation.png

      Figure 110: Use of the interferometers to compensate for the Abbe errors

      @@ -2549,8 +2523,8 @@ Thus the tilt and Abbe errors can be compensated for with sub-nm resolution.
      -
      -

      8.19 Conclusion

      +
      +

      8.19 Conclusion

      Proposed approaches to push the nano-positioning and nano-measuring technology: @@ -2565,15 +2539,19 @@ Proposed approaches to push the nano-positioning and nano-measuring technology:

      -
      -

      9 Reducing control delay times to enhance dynamic stiffness of magnetic bearings   @jan_philipp_schmidtmann

      +
      +

      9 Reducing control delay times to enhance dynamic stiffness of magnetic bearings   @jan_philipp_schmidtmann

      +
      +
      +

      9.1 Introduction

      +

      -This projects focuses on reducing the control delay times of a magnetic bearing shown in Figure 111. +This projects focuses on reducing the control delay times of a magnetic bearing shown in Figure 111.

      -
      +

      magn_bear_intro.png

      Figure 111: 6 DoF Position System - Concept

      @@ -2583,20 +2561,25 @@ This projects focuses on reducing the control delay times of a magnetic bearing Active magnetic bearings are unstable systems and require active control. However, the active control of magnet forces leads to a control delay that limits the performances (stiffness) of the bearing.

      +
      +
      +
      +

      9.2 Time Delay Reduction

      +

      -Typical contributors to the control delay time are shown in Figure 112. +Typical contributors to the control delay time are shown in Figure 112.

      -
      +

      magn_bear_delay.png

      Figure 112: Typical Contributors to control delay time

      -The reduction of the control time delay will increase the dynamic stiffness of the bearing as well as decrease the effects of external disturbances and hence improve the positioning errors (Figure 113). +The reduction of the control time delay will increase the dynamic stiffness of the bearing as well as decrease the effects of external disturbances and hence improve the positioning errors (Figure 113).

      @@ -2609,18 +2592,23 @@ The steps to reduce the control delay time are:

-
+

magn_bear_distur.png

Figure 113: The effect of control delay on stiffness

+
+
+
+

9.3 Practical Realization

+

-Therefore, the position and current control have been merged into one controller (Figure 114). +Therefore, the position and current control have been merged into one controller (Figure 114).

-
+

magn_controller.png

Figure 114: Controller for position and current

@@ -2628,56 +2616,67 @@ Therefore, the position and current control have been merged into one controller

A dSpace rapid prototyping system is used for fast position and current control. -Characteristics of the used elements are shown in Figure 115. +Characteristics of the used elements are shown in Figure 115.

-
+

magn_bear_setup.png

Figure 115: Setup for reduced delay times

+
+
+
+

9.4 Results

+

-Differences between the previous PWM controller and the new SiC controller are shown in Figure 116. +Differences between the previous PWM controller and the new SiC controller are shown in Figure 116. The delay time is almost completely eliminated.

-
+

magn_bear_results.png

Figure 116: Reduction of delay in PWM Driver

+
+
+
+

9.5 Conclusion

+

Due to all the performed modifications, the control delay time could be reduced by 80%. -The next steps for this project are shown in Figure 117. +The next steps for this project are shown in Figure 117.

-
+

magn_bear_conclusion.png

Figure 117: Next Steps

+
-
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10 Digital twins in control: From fault detection to predictive maintenance in precision mechatronics   @koen_classens

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10 Digital twins in control: From fault detection to predictive maintenance in precision mechatronics   @koen_classens

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10.1 Motivation

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10.1 Motivation

Models are usually for the control design part that can be either physical models (FEM, first principle) or data-driven models. -However, these models are usually not used after control system is implemented (Figure 118). +However, these models are usually not used after control system is implemented (Figure 118).

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twins_motivation.png

Figure 118: Typical of of models in a mechatronic system

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Here, the models are exploited to monitor the system and predict future possible failures in the system. -Use models as digital twin for fault detection and Isolation for predictive maintenance in precision mechatronics (Figure 119). +Use models as digital twin for fault detection and Isolation for predictive maintenance in precision mechatronics (Figure 119).

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Figure 119: FDI is using the model of the plant

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10.2 Predictive Maintenance

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10.2 Predictive Maintenance

-Classical maintenance happens when the system is not working anymore as shown in Figure 120. +Classical maintenance happens when the system is not working anymore as shown in Figure 120.

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twins_predictive_maintenance.png

Figure 120: Maintenance done when a failure is appearing

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Figure 121: Preventive Maintenance

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Figure 122: Predictive maintenance

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10.3 Objectives

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10.3 Objectives

The main objective is to develop a system monitoring approach for precision mechatronic systems, exploiting prior information (models) and integrating posterior information (real-time measured data). @@ -2755,39 +2754,39 @@ Even though state of the art system monitoring are already in used in aerospace,

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10.4 Null-space based FDI

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10.4 Null-space based FDI

-The goal is to applied a decentralized Fault Detection on the system shown in Figure 123 to detect actuator faults at \(J_1\). +The goal is to applied a decentralized Fault Detection on the system shown in Figure 123 to detect actuator faults at \(J_1\). This should take into account the control loop, interaction in the system and be FRF based.

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twings_fdi_test.png

Figure 123: Test System

-The architecture to estimate faults in the system is shown in Figure 124. +The architecture to estimate faults in the system is shown in Figure 124. The goal is to design \(Q_u\) and \(Q_y\) such that \(\epsilon\) is a representation of faults in the system.

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twins_null_space_fdi.png

Figure 124: Residual Generator

-When a fault happens (Figure 125), the outputs signals are not changing that much (because of feedback), however the system is able to find that there is a problem using the residual \(\epsilon\). +When a fault happens (Figure 125), the outputs signals are not changing that much (because of feedback), however the system is able to find that there is a problem using the residual \(\epsilon\).

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Figure 125: Simulation Results

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10.5 Roadmap from fault detection to predictive maintenance

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10.5 Roadmap from fault detection to predictive maintenance

-The proposed system can detect faults in the system (Figure 126). +The proposed system can detect faults in the system (Figure 126). This proof of principle should now be applied on industrial systems. -Moreover, from the fault detection, predictive maintenance should be performed (Figure 126). +Moreover, from the fault detection, predictive maintenance should be performed (Figure 126).

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Figure 126: From proof of principle to industrial application

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Figure 127: From fault detection to predictive maintenance

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Author: Dehaeze Thomas

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Created: 2020-11-20 ven. 09:23

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Created: 2020-11-20 ven. 09:48

diff --git a/notes.org b/notes.org index d70cd8e..8dd6215 100644 --- a/notes.org +++ b/notes.org @@ -43,6 +43,12 @@ #+PROPERTY: header-args:latex+ :post pdf2svg(file=*this*, ext="png") :END: +#+begin_export html +
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This report is also available as a pdf.

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+#+end_export + * Build :noexport: #+NAME: startblock #+BEGIN_SRC emacs-lisp :results none