joint_states topic name field sorted alphabetically
I'm using joint_state_controller
to publish the joint_states
topics. My robot is composed by a crane and an arm. The origin of the chain is the crane_bridge_joint
and joint_states
topic is:
name: [ 'arm_1_joint', 'arm_2_joint', 'arm_3_joint', 'arm_4_joint', 'arm_5_joint', 'arm_6_joint', 'crane_bridge_joint', 'crane_arm_joint']
position: [0.03484964823276627, 3.1446214877979326, 0.11884834747659312, 0.056190650599306835, -0.9346745113914041, 3.128057174527214, 3.290371433787131, -0.0005012796984654981]
However if I change the names of the joints the topic look like this:
name: ['crane_bridge_joint', 'crane_hercules_joint', 'hercules_1_joint', 'hercules_2_joint', 'hercules_3_joint', 'hercules_4_joint', 'hercules_5_joint', 'hercules_6_joint']
position: [3.290371433787131, -0.0005012796984654981, 0.03484964823276627, 3.1446214877979326, 0.11884834747659312, 0.056190650599306835, -0.9346745113914041, 3.128057174527214]
I thought that the the publication of the joint_state
was based on the robot joints chain (the first joint the base_link
and the last one, the tip_link
) but I have realized that the joints are sorted alphabetically. Is there any way to avoid this order?
Thanks in advance,
Ane
Afaict there is no code in the
joint_state_controller
that sorts joint names that way (or in any way, really). It should just use whatever order it receives. Can you verify and possibly post some exampleJointState
messages?Also, the order should be irrelevant as long as
name[0]
corresponds toposition[0]
and so forth. May I ask what you are trying to achieve and why this matters?To add on previous comments, what do you mean by 'if I change the names of the joints in the topic'?.