ros 指令

1. FollowJointTrajectoryGoal()

from control_msgs.msg import *
g = FollowJointTrajectoryGoal()
print(g)

输出

runfile('/home/wgb/.config/spyder/temp.py', wdir='/home/wgb/.config/spyder')
trajectory: 
  header: 
    seq: 0
    stamp: 
      secs: 0
      nsecs:         0
    frame_id: ''
  joint_names: []
  points: []
path_tolerance: []
goal_tolerance: []
goal_time_tolerance: 
  secs: 0
  nsecs:         0

原文

control_msgs/FollowJointTrajectoryGoal Message
File: control_msgs/FollowJointTrajectoryGoal.msg
# ====== DO NOT MODIFY! AUTOGENERATED FROM AN ACTION DEFINITION ======
# The joint trajectory to follow
trajectory_msgs/JointTrajectory trajectory

# Tolerances for the trajectory（轨迹偏差）.  If the measured joint values fall
# outside the tolerances the trajectory goal is aborted.  Any
# tolerances that are not specified (by being omitted or set to 0) are
# set to the defaults for the action server (often taken from the
# parameter server).

# Tolerances applied to the joints as the trajectory is executed.  If
# violated, the goal aborts with error_code set to
# PATH_TOLERANCE_VIOLATED.
JointTolerance[] path_tolerance

# To report success, the joints must be within goal_tolerance of the
# final trajectory value.  The goal must be achieved by time the
# trajectory ends plus goal_time_tolerance.  (goal_time_tolerance
# allows some leeway in time, so that the trajectory goal can still
# succeed even if the joints reach the goal some time after the
# precise end time of the trajectory).
#
# If the joints are not within goal_tolerance after "trajectory finish
# time" + goal_time_tolerance, the goal aborts with error_code set to
# GOAL_TOLERANCE_VIOLATED
JointTolerance[] goal_tolerance
duration goal_time_tolerance


Expanded Definition
trajectory_msgs/JointTrajectory trajectory
    Header header
        uint32 seq
        time stamp
        string frame_id
    string[] joint_names
    trajectory_msgs/JointTrajectoryPoint[] points
        float64[] positions
        float64[] velocities
        float64[] accelerations
        duration time_from_start
JointTolerance[] path_tolerance
    string name
    float64 position
    float64 velocity
    float64 acceleration
JointTolerance[] goal_tolerance
    string name
    float64 position
    float64 velocity
    float64 acceleration
duration goal_time_tolerance

trajectory 	英 [trəˈdʒektəri]
	美 [trəˈdʒɛktəri]
n. 	[物] 弹道，轨道; [几] 轨线;
[例句]In this paper, the engineering design approach of manned spacecraft ascent trajectory is described.

2.JointTrajectory()

原文：

trajectory_msgs/JointTrajectory Message
File: trajectory_msgs/JointTrajectory.msg
Raw Message Definition
Header header
string[] joint_names
JointTrajectoryPoint[] points
Compact Message Definition
std_msgs/Header header
string[] joint_names
trajectory_msgs/JointTrajectoryPoint[] points

3.