Robotics initiation class materials by Passault Grégoire, Olivier Ly and Remi Fabre is licensed under a Creative Commons Attribution 4.0 International License.

A simple simulation based on PyBullet.

Tested on Python 3.6 but should work on any recent version of Python:

pip install numpy pybullet onshape-to-robot transforms3d scipy

python sim_hexa.py --help gives some info on how to use this.

python3 sim_hexa.py --mode frozen-direct

python3 sim_hexa.py --mode direct

python3 sim_hexa.py --mode inverse

python3 sim_hexa.py --mode robot-ik

python3 sim_hexa.py --mode walk

https://youtu.be/w3psAbh3AoM

python3 sim_hexa.py --mode frozen-direct

Controlling a Bioloid hexapod

Tested on Python 3.6 but should work on any recent version of Python:

pip install pypot

Before trying to run this on the real robot. Check that:

• You set ROBOT_TYPE = BIOLOID in constants.py
• Check that your IK and DK functions give correct answers. Some results to check:

computeDK(0, -90, -90) -->  [81.70844556523558, 0.0, -33.04585438182947]
computeDK(0, 0, 0) -->  [118.79421209003992, 0.0, -115.14351525756761]
computeDK(90, 0, 0) -->  [7.274047579664959e-15, 118.79421209003992, -115.14351525756761]
computeDK(180, -30.501, -67.819) -->  [-64.13126891250484, 7.853815319895721e-15, -67.79136156948073]
computeDK(0, -30.645, 38.501) -->  [203.22984674011096, 0.0, -14.30057614144421]
computeIK(200, 30, -60) -->  [8.530765609948132, 0.9495664162204136, 64.25]
computeIK(150, -50, -90) -->  [-18.434948822922014, -13.452636970582287, 9.669311402298497]

-> If your results don't match check the following:

• Units (mm vs m, rads vs degrees)
• The actual robot pieces are not straight. The angles need to be "compensated" to account for that. The file constants.py should give you a hint.
• Some (Some? A few? All? None?) points have several IK solutions. How do you chose which one to use?
• Check the direction of Z (I might have inverted it)

python3 main.py

chmod 777 /dev/ttyUSB0 

ou alors mettre l'utilisateur courant dans le groupe dialout

ipython

scanner le robot et les pattes détéctées

dxl_io.scan()

envoyer la position 0 à prendre en degré à la patte 3

dxl_io.set_goal_position({3:0})

relacher la patte 2

dxl_io.disable_torque([2])

avoir la position de la patte 2

dxl_io.get_present_position([2])

changer l'identifiant de la patte n°2 en n°3

dxl_io._to_change_id(2,3)

mettre en place une limite d'angle

set_to_angle_limit(1:(90,0))