add spacenav example

Signed-off-by: Borong Yuan <[email protected]>

Author: borongyuan

doc/examples/realtime_servo/launch/servo_spacenav_input.launch.py

@@ -0,0 +1,12 @@
+from launch import LaunchDescription
+from launch_ros.actions import Node
+
+
+def generate_launch_description():
+    return LaunchDescription([
+        Node(package='spacenav', executable='spacenav_node',
+             name='spacenav', namespace='', output='screen',
+             parameters=[{'zero_when_static': True,
+                          'use_twist_stamped': True}],
+             remappings=[('spacenav/twist', 'servo_node/delta_twist_cmds')]),
+    ])

doc/examples/realtime_servo/realtime_servo_tutorial.rst

@@ -31,6 +31,13 @@ Make a service request to start Servo ::
 
 You should be able to control the arm with your controller now, with MoveIt Servo automatically avoiding singularities and collisions.
 
+Using a SpaceMouse
+^^^^^^^^^^^^^^^^^^^^
+
+If you have a 3Dconnexion SpaceMouse, you can send 6DoF Cartesian commands using a single joystick. With the demo still running, in a new terminal, run ::
+
+    ros2 launch moveit2_tutorials servo_spacenav_input.launch.py
+
 Without a Controller
 ^^^^^^^^^^^^^^^^^^^^