This commit fixes the bug #76

[juanjqo]

@dqrobotics/developers

Hi @bvadorno,

This PR proposes the following modifications to fix #76 :

• Removed the public property type from subclasses DQ_SerialManipulatorDH and DQ_SerialManipulatorMDH. Added the protected property joint_types in DQ_SerialManipulator. Motivations:
  • The joint types do not depend on any specific parametrization. Therefore, obj.joint_types is a property common to all subclasses, like obj.n_joints.
  • Since we now have the method set_joint_types (and get_joint_types, both added in this PR) there is no need to keep obj.joint_types as a public property. (Currently, the user can freely get and set the property obj.type.
• The following methods were added in DQ_SerialManipulator:
  • get_supported_joint_types() (protected, abstract)
  • check_joint_types() (public)
  • get_joint_types() (public) (returns the joint types as a vector)
  • get_joint_type(ith) (public) (returns only the ith joint type as a double)
  • set_joint_types() (public) (sets all joints)
  • set_joint_type(ith) (public) (sets only the ith joint)

UML:

Example of use:
Minimal example used in #76

clear all;
clc;
close all;

ax18_DH_theta   = [0       0      -pi/2   -pi/2      -pi/2];  % theta
ax18_DH_d       = [0.167   0       0     0.1225          0];  % d
ax18_DH_a       = [0      0.159    0.02225    0      0.170];  % a
ax18_DH_alpha   = [-pi/2   0      -pi/2   -pi/2          0];  % alpha

R = double(DQ_JointType.REVOLUTE);
P = double(DQ_JointType.PRISMATIC);
H = double(DQ_JointType.HELICAL);
S = double(DQ_JointType.SPHERICAL);
C = double(DQ_JointType.CYLINDRICAL);
Pl = double(DQ_JointType.PLANAR);
SD = double(DQ_JointType.SIX_DOF);

ax18_DH_type    = [SD P H S C];


ax18_DH_matrix = [  ax18_DH_theta;
    ax18_DH_d;
    ax18_DH_a;
    ax18_DH_alpha;
    ax18_DH_type;
    ]; % D&H parameters matrix for the arm model

ax = DQ_SerialManipulatorDH(ax18_DH_matrix)

Output:

Error using DQ_SerialManipulator/check_joint_types
Unsupported joint types. Use valid joint types:  DQ_JointType.REVOLUTE,
DQ_JointType.PRISMATIC.

Error in DQ_SerialManipulator/set_joint_types (line 146)
            obj.check_joint_types();

Error in DQ_SerialManipulatorDH (line 196)
            obj.set_joint_types(A(5,:));

Error in untitled2 (line 30)
ax = DQ_SerialManipulatorDH(ax18_DH_matrix)

Best regards,

Juancho

[bvadorno]

Hi @juanjqo,

The modification is overall fine, although there are some minor issues to solve before I approve it.

Best wishes,
Bruno

[bvadorno]

'joint_types' is a vector containing the joint types.

[bvadorno]

Change it according to my comment for the set_joint_type method.

[bvadorno]

Is there any reason for ignoring the arguments? (That is, for using ~)

[juanjqo]

Hi @bvadorno, as discussed internally, I removed the '~'.

Current:

methods (Static, Access = protected) 
     function ret = get_supported_joint_types()
     % This method returns the supported joint types.
        ret = [DQ_JointType.REVOLUTE, DQ_JointType.PRISMATIC];
     end
end

[bvadorno]

@juanjqo, is get_joint_type returning a vector? I thought we were sticking with your initial implementation, in which get_joint_type would return just a double.

[juanjqo]

@bvadorno I was a typo. You're right, get_joint_type returns a double.

[bvadorno]

Hi @juanjqo, there is just one outstanding clarification before merging this pull request.