tdehaeze/nass-simscape
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- Modify the joints for Ty, Ry, Rz to have only one bushing joint.
- Compensation of gravity
This commit is contained in:
Thomas Dehaeze
2020-02-25 17:49:08 +01:00
parent dfdfcff4db
commit 12c2e4a508
36 changed files with 798 additions and 545 deletions
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kinematics/index.org
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@@ -97,7 +97,7 @@ The three rotations that we define thus corresponds to the Euler U-V-W angles.
We should have the *same behavior* for the Micro-Hexapod on Simscape (same inputs at least).
However, the Bushing Joint makes rotations around mobiles axes (X, Y' and then Z'') and not fixed axes (X, Y and Z).
*** TODO Using Inverse Kinematics and Leg Actuators
*** Using Inverse Kinematics and Leg Actuators
Here, we can use the Inverse Kinematic of the Hexapod to determine the length of each leg in order to obtain some defined translation and rotation of the mobile platform.
The advantages are:
@@ -147,20 +147,20 @@ Otherwise, when the limbs' lengths derived yield complex numbers, then the posit
**** Matlab Implementation
We open the Simulink file.
#+begin_src matlab
open('nass_model.slx')
#+end_src
We load the configuration and set a small =StopTime=.
#+begin_src matlab
load('mat/conf_simulink.mat');
set_param(conf_simulink, 'StopTime', '0.5');
set_param(conf_simulink, 'StopTime', '0.1');
#+end_src
We define the wanted position/orientation of the Hexapod under study.
#+begin_src matlab
tx = 0.1; % [rad]
ty = 0.2; % [rad]
tz = 0.05; % [rad]
tx = 0.05; % [rad]
ty = 0.1; % [rad]
tz = 0.02; % [rad]
Rx = [1 0 0;
0 cos(tx) -sin(tx);
@@ -175,34 +175,47 @@ We define the wanted position/orientation of the Hexapod under study.
0 0 1];
ARB = Rz*Ry*Rx;
AP = [0.01; 0.02; 0.03]; % [m]
AP = [0.1; 0.005; 0.01]; % [m]
#+end_src
hexapod = initializeMicroHexapod('AP', AP, 'ARB', ARB);
#+begin_src matlab
initializeSimscapeConfiguration('gravity', false);
initializeGround('type', 'none');
initializeGranite('type', 'none');
initializeTy('type', 'none');
initializeRy('type', 'none');
initializeRz('type', 'none');
initializeMicroHexapod('type', 'rigid', 'AP', AP, 'ARB', ARB);
initializeAxisc('type', 'none');
initializeMirror('type', 'none');
initializeNanoHexapod('type', 'none');
initializeSample('type', 'none');
initializeLoggingConfiguration('log', 'all');
#+end_src
We run the simulation.
#+begin_src matlab
sim()
sim('nass_model');
#+end_src
And we verify that we indeed succeed to go to the wanted position.
#+begin_src matlab :results table replace
[simout.x.Data(end) ; simout.y.Data(end) ; simout.z.Data(end)] - AP
[simout.Dhm.x.Data(end) ; simout.Dhm.y.Data(end) ; simout.Dhm.z.Data(end)] - AP
#+end_src
#+RESULTS:
| 1.611e-10 |
| -1.3748e-10 |
| 8.4879e-11 |
| 8.4655e-16 |
| 1.5586e-15 |
| -2.1337e-16 |
#+begin_src matlab :results table replace
simout.R.Data(:, :, end)-ARB
simout.Dhm.R.Data(:, :, end)-ARB
#+end_src
#+RESULTS:
| -1.2659e-10 | 6.5603e-11 | 6.2183e-10 |
| 1.0354e-10 | -5.2439e-11 | -5.2425e-10 |
| -5.9816e-10 | 5.532e-10 | -1.7737e-10 |
| -1.1102e-16 | -1.36e-15 | 4.2744e-15 |
| 1.0651e-15 | 6.6613e-16 | 5.1278e-15 |
| -4.2882e-15 | -4.9336e-15 | 1.1102e-16 |
* TODO Tests on the transformation from reference to wanted position :noexport:
:PROPERTIES: