phd-simscape-nass/simscape-nass.org

#+TITLE: Simscape Model - Nano Active Stabilization System
:DRAWER:
#+LANGUAGE: en
#+EMAIL: dehaeze.thomas@gmail.com
#+AUTHOR: Dehaeze Thomas

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* Notes                                                             :noexport:
** Notes
Prefix is =nass=

The goals of this report are:
- [X] ([[file:~/Cloud/work-projects/ID31-NASS/matlab/nass-simscape/org/positioning_error.org][positioning_error]]): Explain how the NASS control is made (computation of the wanted position, measurement of the sample position, computation of the errors)
- [X] ([[file:~/Cloud/work-projects/ID31-NASS/matlab/nass-simscape/org/uncertainty_experiment.org][uncertainty_experiment]]): Effect of experimental conditions on the plant (payload mass, Ry position, Rz position, Rz velocity, etc...)
- [ ] Determination of the *optimal stiffness* for the hexapod actuators:
  - [ ] [[file:~/Cloud/work-projects/ID31-NASS/matlab/nass-simscape/org/uncertainty_optimal_stiffness.org][uncertainty_optimal_stiffness]]
  - [ ] [[file:~/Cloud/work-projects/ID31-NASS/matlab/nass-simscape/org/optimal_stiffness_disturbances.org][optimal_stiffness_disturbances]]
  - [ ] [[file:~/Cloud/work-projects/ID31-NASS/documents/state-of-thesis-2020/index.org][state-of-thesis-2020]]
  - [ ] [[file:/home/thomas/Cloud/meetings/group-meetings-me/2020-04-06-NASS-Design/2020-04-06-NASS-Design.org][group-meeting-optimal-stiffness]]
  Should this be in this report? *This should be in chapter 2*
- [X] Explain why HAC-LAC strategy is nice (*It was already explained in uniaxial model*)
  - [X] [[file:~/Cloud/work-projects/ID31-NASS/matlab/nass-simscape/org/control.org][different control architectures]]
  - [X] [[file:~/Cloud/work-projects/ID31-NASS/matlab/stewart-simscape/org/control-vibration-isolation.org][hexapod - vibration isolation]]
- [X] How to apply/optimize IFF on an hexapod? ([[file:~/Cloud/work-projects/ID31-NASS/matlab/nass-simscape/org/control_active_damping.org][control_active_damping]], [[file:~/Cloud/work-projects/ID31-NASS/matlab/stewart-simscape/org/control-active-damping.org][active damping for stewart platforms]])
- [X] ([[file:~/Cloud/research/matlab/decoupling-strategies/svd-control.org][decoupling-strategies]]): Decoupling strategies for HAC? (maybe also in previous report)
  *Will be in chapter 2*
- [X] Validation of the concept using simulations:
  - [X] Find where this simulation in OL/CL is made (maybe for the conference?)
    It was re-made for micro-station validation. Will just have to do the same simulation but with nano-hexapod in closed-loop
  - Tomography experiment (maybe also Ty scans)
  - Open VS Closed loop results
  - *Conclusion*: concept validation
    nano hexapod architecture with APA
    decentralized IFF + centralized HAC

- In this section simple control (in the frame of the struts)
- Justify future used control architecture (control in the frame of the struts? Need to check what was done in ID31 tests)
- Table that compares different approaches (specify performances in different DoF, same plans on the diagonal, etc...)
- Literature review about Stewart platform control?
*In chapter 2: Special section about MIMO control, complementary filters, etc...*

** Outline
*** Control Kinematics

- Explain how the position error can be expressed in the frame of the nano-hexapod
- ([[file:~/Cloud/work-projects/ID31-NASS/matlab/nass-simscape/org/positioning_error.org][positioning_error]]): Explain how the NASS control is made (computation of the wanted position, measurement of the sample position, computation of the errors)
- Control architecture, block diagram

*** LAC

- How to apply/optimize IFF on an hexapod? ([[file:~/Cloud/work-projects/ID31-NASS/matlab/nass-simscape/org/control_active_damping.org][control_active_damping]], [[file:~/Cloud/work-projects/ID31-NASS/matlab/stewart-simscape/org/control-active-damping.org][active damping for stewart platforms]])
- Robustness to payload mass
- Root Locus
- Damping optimization

*** HAC

- ([[file:~/Cloud/work-projects/ID31-NASS/matlab/nass-simscape/org/uncertainty_experiment.org][uncertainty_experiment]]): Effect of experimental conditions on the plant (payload mass, Ry position, Rz position, Rz velocity, etc...)
- Determination of the *optimal stiffness* for the hexapod actuators:
  - [ ] [[file:~/Cloud/work-projects/ID31-NASS/matlab/nass-simscape/org/uncertainty_optimal_stiffness.org][uncertainty_optimal_stiffness]]
  - [ ] [[file:~/Cloud/work-projects/ID31-NASS/matlab/nass-simscape/org/optimal_stiffness_disturbances.org][optimal_stiffness_disturbances]]
  - [ ] [[file:~/Cloud/work-projects/ID31-NASS/documents/state-of-thesis-2020/index.org][state-of-thesis-2020]]
  - [ ] [[file:/home/thomas/Cloud/meetings/group-meetings-me/2020-04-06-NASS-Design/2020-04-06-NASS-Design.org][group-meeting-optimal-stiffness]]
- Effect of micro-station compliance
- Effect of IFF
- Effect of payload mass
- Decoupled plant
- Controller design

*** Simulations

- Take into account disturbances, metrology sensor noise. Maybe say here that we don't take in account other noise sources as they will be optimized latter (detail design phase)
- Tomography + lateral scans (same as what was done in open loop [[file:~/Cloud/work-projects/ID31-NASS/phd-thesis-chapters/A4-simscape-micro-station/simscape-micro-station.org::*Simulation of Scientific Experiments][here]])
- Validation of concept

** DONE Old Outline
CLOSED: [2024-11-07 Thu 16:19]
*** Introduction                                                    :ignore:

Discussion of:
- Transformation matrices / control architecture (computation of the position error in the frame of the nano-hexapod)
- Control of parallel architectures
- Control in the frame of struts or cartesian?
- Effect of rotation on IFF? => APA
- HAC-LAC
- New noise budgeting?

*** Control Kinematics

- Explain how the position error can be expressed in the frame of the nano-hexapod
- block diagram
- Explain how to go from external metrology to the frame of the nano-hexapod

*** High Authority Control - Low Authority Control (HAC-LAC)

- general idea
- case for parallel manipulator: decentralized LAC + centralized HAC

*** Decoupling Strategies for parallel manipulators
[[file:~/Cloud/research/matlab/decoupling-strategies/svd-control.org::+TITLE: Diagonal control using the SVD and the Jacobian Matrix][study]]

- Jacobian matrices, CoK, CoM, ...
- Discussion of cubic architecture
- SVD, Modal, ...

*** Decentralized Integral Force Feedback (LAC)

- Root Locus
- Damping optimization

*** Decoupled Dynamics

- Centralized HAC
- Control in the frame of the struts
- Effect of IFF

*** Centralized Position Controller (HAC)

- Decoupled plant
- Controller design

*** Time domain simulations

Goal: validation of the concept
- Take into account disturbances, sensor noise, etc...
- Tomography + lateral scans (same as what was done in open loop [[file:~/Cloud/work-projects/ID31-NASS/phd-thesis-chapters/A4-simscape-micro-station/simscape-micro-station.org::*Simulation of Scientific Experiments][here]])

** TODO [#A] Merge the micro-station model with the nano-hexapod model
** TODO [#B] Rework the Simulink file

- [ ] Change the variable names to make things consistent
- [ ] Rework the org files to match the new variable names

** DONE [#A] Where to discuss the necessity of estimated Rz?
CLOSED: [2025-02-06 Thu 16:35]

One big advantage of doing the control in the cartesian plane, is that we don't need the estimation of nano-hexapod Rz, therefore we don't need the encoders anymore!

Maybe this should be done *here*.
Here it can be reminded when doing the control in the cartesian frame.

** CANC [#C] What performance metric can we use?                   :@christophe:
CLOSED: [2024-11-12 Tue 09:22]
- State "CANC"       from "QUES"       [2024-11-12 Tue 09:22]
This can be nice to have a (scalar) performance metric that can be used for optimization.

In cite:hauge04_sensor_contr_space_based_six, a (scalar) performance metric representing the 6dof transmissibility is used.

** DONE [#C] Identify the sensibility to disturbances without the nano-hexapod and save the results
CLOSED: [2024-11-07 Thu 09:20]
This can then be used to compare with obtained performance with the nano-hexapod.

This should be done in the ustation report (A4).

* Introduction                                                        :ignore:

From last sections:
- Uniaxial: No stiff nano-hexapod (should also demonstrate that here)
- Rotating: No soft nano-hexapod, Decentralized IFF can be used robustly by adding parallel stiffness

In this section:
- Take the model of the nano-hexapod with stiffness 1um/N
- Apply decentralized IFF
- Apply HAC-LAC
- Check robustness to payload change
- Simulation of experiments

#+name: tab:nass_section_matlab_code
#+caption: Report sections and corresponding Matlab files
#+attr_latex: :environment tabularx :width 0.6\linewidth :align lX
#+attr_latex: :center t :booktabs t
| *Sections*               | *Matlab File* |
|--------------------------+---------------|
| Section ref:sec:nass_1_a | =nass_1_.m=   |

* Control Kinematics
:PROPERTIES:
:HEADER-ARGS:matlab+: :tangle matlab/nass_1_kinematics.m
:END:
<<sec:nass_kinematics>>
** Introduction                                                      :ignore:

- Explain how the position error can be expressed in the frame of the nano-hexapod
- [ ] [[file:~/Cloud/work-projects/ID31-NASS/matlab/nass-simscape/org/positioning_error.org][positioning_error]]: Explain how the NASS control is made (computation of the wanted position, measurement of the sample position, computation of the errors)
- Control architecture, block diagram

- Schematic with micro-station + nass + metrology + control system
- Zoom in the control system with blocs
- Then explain all the blocs
- Say that there are many control strategies.
  It will be the topic of chapter 2.3.
  Here, we start with something simple: control in the frame of the struts

** Matlab Init                                              :noexport:ignore:
#+begin_src matlab :tangle no :exports none :results silent :noweb yes :var current_dir=(file-name-directory buffer-file-name)
<<matlab-dir>>
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#+begin_src matlab :noweb yes
<<m-init-other>>
#+end_src

#+begin_src matlab
%% Uniaxial Simscape model name
mdl = 'nass_uniaxial_model';
#+end_src

#+begin_src matlab
%% Frequency Vector [Hz]
freqs = logspace(0, 3, 1000);
#+end_src

#+begin_src matlab
%% Load the micro-station parameters
load('uniaxial_micro_station_parameters.mat')
#+end_src


** Micro Station Kinematics

- from ref:ssec:ustation_kinematics, computation of the wanted sample pose from the setpoint of each stage.

** Computation of the sample's pose error

From metrology (here supposed to be perfect 6-DoF), compute the sample's pose error.
Has to invert the homogeneous transformation.

** Position error in the frame of the nano-hexapod

Explain how to compute the errors in the frame of the struts (rotating)

* Decentralized Active Damping
:PROPERTIES:
:HEADER-ARGS:matlab+: :tangle matlab/nass_2_active_damping.m
:END:
<<sec:nass_active_damping>>
** Introduction                                                      :ignore:

- How to apply/optimize IFF on an hexapod? ()
- Robustness to payload mass
- Root Locus
- Damping optimization

- [ ][[file:~/Cloud/work-projects/ID31-NASS/matlab/nass-simscape/org/control_active_damping.org][control_active_damping]]
- [ ][[file:~/Cloud/work-projects/ID31-NASS/matlab/stewart-simscape/org/control-active-damping.org][active damping for stewart platforms]]
- [ ][[file:~/Cloud/work-projects/ID31-NASS/matlab/stewart-simscape/org/bibliography.org::*Vibration Control and Active Damping][Vibration Control and Active Damping]]

** IFF Plant

- Show how it changes with the payload mass (1, 25, 50)
- Effect of rotation (1rpm, 60rpm)

** Controller Design

- Apply IFF
- Show Root Locus
- Choose optimal gain.
  Here in MIMO, cannot have optimal damping for all modes. (there is a paper that tries to optimize that)
- Show robustness to change of payload (loci?)
- Reference to paper showing stability in MIMO for decentralized IFF

** Sensitivity to disturbances

- Compute transfer functions from spindle vertical error to sample vertical error with IFF (and compare without the NASS)
- Same for horizontal
- Maybe noise budgeting, but may be complex in MIMO...

* Centralized Active Vibration Control
:PROPERTIES:
:HEADER-ARGS:matlab+: :tangle matlab/nass_3_hac.m
:END:
<<sec:nass_hac>>
** Introduction                                                      :ignore:

- [ ] [[file:~/Cloud/work-projects/ID31-NASS/matlab/nass-simscape/org/uncertainty_experiment.org][uncertainty_experiment]]: Effect of experimental conditions on the plant (payload mass, Ry position, Rz position, Rz velocity, etc...)
- Effect of micro-station compliance
- Effect of IFF
- Effect of payload mass
- Decoupled plant
- Controller design

From control kinematics:
- Talk about issue of not estimating Rz from external metrology? (maybe could be nice to discuss that during the experiments!)
- Show what happens is Rz is not estimated (for instance supposed equaled to zero => increased coupling)

** HAC Plant

- Compute transfer function from u to dL (with IFF applied)

** Effect of Payload mass

- Show effect of payload mass + rotation

** Controller design

- Show robustness with Loci

** Sensitivity to disturbances

- Compute transfer functions from spindle vertical error to sample vertical error with HAC-IFF
  Compare without the NASS, and with just IFF
- Same for horizontal
- Maybe noise budgeting, but may be complex in MIMO...

** Tomography experiment

- With HAC-IFF, perform tomography experiment, and compare with open-loop

- Take into account disturbances, metrology sensor noise. Maybe say here that we don't take in account other noise sources as they will be optimized latter (detail design phase)
- Tomography + lateral scans (same as what was done in open loop [[file:~/Cloud/work-projects/ID31-NASS/phd-thesis-chapters/A4-simscape-micro-station/simscape-micro-station.org::*Simulation of Scientific Experiments][here]])
- Validation of concept

* Conclusion
<<sec:nass_conclusion>>


* Bibliography                                                        :ignore:
#+latex: \printbibliography[heading=bibintoc,title={Bibliography}]

* Helping Functions                                                 :noexport:
** Initialize Path
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