gz-sim: joint_trajectory_controller.sdf

[azeey-test]

Configuration

• os: Any

Links

• Source

Process

Step 1 - Instructions work

Step 2 - Images (if there are any) match the result

[Combuster54]

Interested

[Combuster54]

Running, I'm facing some warnings

gz  sim joint_trajectory_controller.sdf

Warnings

Warning [Utils.cc:132] [/sdf/world[@name="default"]/model[@name="RR_velocity_control"]/joint[@name="RR_velocity_control_joint1"]/dynamics:/usr/share/gz/gz-sim9/worlds/joint_trajectory_controller.sdf:L483]: XML Element[dynamics], child of element[joint], not defined in SDF. Copying[dynamics] as children of [joint].
Warning [Utils.cc:132] [/sdf/world[@name="default"]/model[@name="RR_velocity_control"]/joint[@name="RR_velocity_control_joint2"]/dynamics:/usr/share/gz/gz-sim9/worlds/joint_trajectory_controller.sdf:L494]: XML Element[dynamics], child of element[joint], not defined in SDF. Copying[dynamics] as children of [joint].

<dynamics> tags should be inside <axis>

URL: http://sdformat.org/spec?ver=1.6&elem=joint

    line 475 
      <!-- Joints -->
      <joint name="RR_velocity_control_joint1" type="revolute">
        <pose relative_to="RR_velocity_control_link0">0 0 0 0 0 0</pose>
        <parent>RR_velocity_control_link0</parent>
        <child>RR_velocity_control_link1</child>
        <axis>
          <xyz>1 0 0</xyz>
        </axis>
        <dynamics>
          <damping>0.02</damping>
        </dynamics>
      </joint>
      <joint name="RR_velocity_control_joint2" type="revolute">
        <pose relative_to="RR_velocity_control_link1">0 0 0.1 0 0 0</pose>
        <parent>RR_velocity_control_link1</parent>
        <child>RR_velocity_control_link2</child>
        <axis>
          <xyz>1 0 0</xyz>
        </axis>
        <dynamics>
          <damping>0.01</damping>
        </dynamics>
      </joint>

Solution

Reposition the dynamics tags of the joints RR_velocity_control_joint1 and RR_velocity_control_joint2 inside the axis tag.

    line 475 
      <!-- Joints -->
      <joint name="RR_velocity_control_joint1" type="revolute">
        <pose relative_to="RR_velocity_control_link0">0 0 0 0 0 0</pose>
        <parent>RR_velocity_control_link0</parent>
        <child>RR_velocity_control_link1</child>
        <axis>
          <xyz>1 0 0</xyz>
          <dynamics>
            <damping>0.01</damping>
          </dynamics>
        </axis>
      </joint>
      <joint name="RR_velocity_control_joint2" type="revolute">
        <pose relative_to="RR_velocity_control_link1">0 0 0.1 0 0 0</pose>
        <parent>RR_velocity_control_link1</parent>
        <child>RR_velocity_control_link2</child>
        <axis>
          <xyz>1 0 0</xyz>
          <dynamics>
            <damping>0.01</damping>
          </dynamics>
        </axis>
      </joint>

Testing joint trajectory commands

Position control (Red RR robot)

Velocity control (Green RR robot)

Effort control (Blue RR robot)

[ahcorde]

PR gazebosim/gz-sim#2580

[ahcorde]

thank you for testing! PR is merged