diff --git a/dcm-simscape.org b/dcm-simscape.org
index 38ec2fd..88720e2 100644
--- a/dcm-simscape.org
+++ b/dcm-simscape.org
@@ -22,6 +22,7 @@
 #+PROPERTY: header-args:matlab+ :comments org
 #+PROPERTY: header-args:matlab+ :exports both
 #+PROPERTY: header-args:matlab+ :results none
+#+PROPERTY: header-args:matlab+ :tangle no
 #+PROPERTY: header-args:matlab+ :eval no-export
 #+PROPERTY: header-args:matlab+ :noweb yes
 #+PROPERTY: header-args:matlab+ :mkdirp yes
@@ -47,12 +48,23 @@
   <hr>
 #+end_export
 
-\clearpage
+#+latex: \clearpage
+
+* Introduction                                                        :ignore:
+In this document, a Simscape (.e.g. multi-body) model of the ESRF Double Crystal Monochromator (DCM) is presented and used to develop and optimize the control strategy.
+
+It is structured as follow:
+- Section [[sec:dcm_kinematics]]: the kinematics of the DCM is presented, and Jacobian matrices which are used to solve the inverse and forward kinematics are computed.
+- Section [[sec:open_loop_identification]]: the system dynamics is identified in the absence of control.
+- Section [[sec:active_damping_strain_gauges]]: it is studied whether if the strain gauges fixed to the piezoelectric actuators can be used to actively damp the plant.
+- Section [[sec:active_damping_iff]]: piezoelectric force sensors are added in series with the piezoelectric actuators and are used to actively damp the plant using the Integral Force Feedback (IFF) control strategy.
+- Section [[sec:hac_iff]]: the High Authority Control - Low Authority Control (HAC-LAC) strategy is tested on the Simscape model.
 
 * System Kinematics
 :PROPERTIES:
 :header-args:matlab+: :tangle matlab/dcm_kinematics.m
 :END:
+<<sec:dcm_kinematics>>
 ** Introduction                                                      :ignore:
 
 ** Matlab Init                                              :noexport:ignore:
@@ -375,10 +387,11 @@ save('matlab/mat/dcm_kinematics.mat', 'J_a_111', 'J_s_111')
 save('mat/dcm_kinematics.mat', 'J_a_111', 'J_s_111')
 #+end_src
 
-* System Identification
+* Open Loop System Identification
 :PROPERTIES:
 :header-args:matlab+: :tangle matlab/dcm_identification.m
 :END:
+<<sec:open_loop_identification>>
 ** Introduction                                                      :ignore:
 ** Matlab Init                                              :noexport:ignore:
 #+begin_src matlab
@@ -680,10 +693,11 @@ Here, we map the piezo forces at the center of stiffness.
 
 Let's first compute the Jacobian:
 
-* Active Damping Plant (Strain gauge)
+* Active Damping Plant (Strain gauges)
 :PROPERTIES:
 :header-args:matlab+: :tangle matlab/dcm_active_damping_strain_gauges.m
 :END:
+<<sec:active_damping_strain_gauges>>
 ** Introduction                                                      :ignore:
 In this section, we wish to see whether if strain gauges fixed to the piezoelectric actuator can be used for active damping.
 
@@ -796,6 +810,7 @@ xlim([freqs(1), freqs(end)]);
 :PROPERTIES:
 :header-args:matlab+: :tangle matlab/dcm_active_damping_iff.m
 :END:
+<<sec:active_damping_iff>>
 ** Introduction                                                      :ignore:
 Force sensors are added above the piezoelectric actuators.
 They can consists of a simple piezoelectric ceramic stack.
@@ -1078,6 +1093,7 @@ save('mat/Kiff.mat', 'Kiff');
 :PROPERTIES:
 :header-args:matlab+: :tangle matlab/dcm_hac_iff.m
 :END:
+<<sec:hac_iff>>
 ** Introduction                                                      :ignore:
 ** Matlab Init                                              :noexport:ignore:
 #+begin_src matlab
diff --git a/dcm-simscape.pdf b/dcm-simscape.pdf
index 724180e..6732f54 100644
Binary files a/dcm-simscape.pdf and b/dcm-simscape.pdf differ