Missing attributes in DQ_SerialManipulator

[juanjqo]

Hi @mmmarinho

I had working a kinematic control in Python two weeks ago. The last version breaks my current implementation. I understand that DQ robotics is experimental in Python and I'm updating my code. However, some attributes are missing in DQ_SerialManipulator, specifically:

• reference_frame

• base_frame

• n_links

Of course, the legacy attribute 'set_base' is not working either. Temporally, I'm performing some DQ operations manually avoiding 'set_bases' definitions and it is working. =)

Version: dqrobotics 0.1.1.10 Ubuntu 18.04 LTS

Best regards,

Juancho.

Minimal example:

from dqrobotics import *
from dqrobotics.robots         import KukaLw4Robot
from dqrobotics.robot_modeling import DQ_Kinematics
import numpy as np

theta = np.random.rand(7,1)

robot = KukaLw4Robot.kinematics()
x = robot.fkm(theta)   #Working
print(x)

#robot.n_links    # AttributeError: 'dqrobotics.robot_modeling.DQ_SerialManipulator' object has no attribute 'n_links'
robot.theta       # Works
robot.d           # Works
robot.a           # Works
robot.alpha       # Works
robot.dummy       # Works
robot.n_dummy     # Works
robot.convention  # Works
robot.effector    # Works
#robot.reference_frame  #AttributeError: 'dqrobotics.robot_modeling.DQ_SerialManipulator' object has no attribute 'reference_frame'
#robot.base_frame     #AttributeError: 'dqrobotics.robot_modeling.DQ_SerialManipulator' object has no attribute 'base_frame'

[mmmarinho]

Hello, @juanjqo,

It should work now. Note that n_links was replaced by get_dim_configuration_space Also, we are going to remove dummy joints soon so dummy, set_dummy, and n_dummy are no longer available.

I formatted your comment to change it from

quote

to code to make it easier to read. :)

[juanjqo]

@mmmarinho Thanks. However, now, I have another problem with those attributes. Using the same minimal example, print(robot.reference_frame)

returns: <bound method PyCapsule.reference_frame of <dqrobotics.robot_modeling.DQ_SerialManipulator object at 0x7fb074b97f10>>

Is this expected? I was expecting a default dq as DQ([1,0,0,0,0,0,0,0]) (as in Matlab).

Cheers,

Juancho

[mmmarinho]

Hello!

It is a method, not an attribute. print(robot.reference_frame())

Should work.

[juanjqo]

You're right! Thank you!