报错如下：

xrh@xrh-Dell-G15-5511:~/ros-project/gazebo_test/src/urplan$ python plan.py 
[ INFO] [1690115646.188716433]: Loading robot model 'ur3_robot'...
[ WARN] [1690115646.193306402]: Link base has visual geometry but no collision geometry. Collision geometry will be left empty. Fix your URDF file by explicitly specifying collision geometry.
[ INFO] [1690115647.712039623]: Ready to take commands for planning group marm.
 mo duan is -------------------------->   tool0
Traceback (most recent call last):
  File "plan.py", line 76, in <module>
    arm.execute(traj)
  File "/opt/ros/noetic/lib/python3/dist-packages/moveit_commander/move_group.py", line 689, in execute
    return self._g.execute(conversions.msg_to_string(trajectory))
  File "/opt/ros/noetic/lib/python3/dist-packages/moveit_commander/conversions.py", line 50, in msg_to_string
    msg.serialize(buf)
  File "/opt/ros/noetic/lib/python3/dist-packages/moveit_msgs/msg/_RobotTrajectory.py", line 156, in serialize
    buff.write(_get_struct_3I().pack(_x.joint_trajectory.header.seq, _x.joint_trajectory.header.stamp.secs, _x.joint_trajectory.header.stamp.nsecs))
AttributeError: 'tuple' object has no attribute 'header'

源代码如下：

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import rospy, sys
import moveit_commander
from control_msgs.msg import GripperCommand
from geometry_msgs.msg import PoseStamped, Pose
from control_msgs.msg import GripperCommand

import tf
from moveit_msgs.msg import RobotTrajectory
from trajectory_msgs.msg import JointTrajectoryPoint

from tf.transformations import euler_from_quaternion, quaternion_from_euler
from time import sleep

# from darknet_ros_msgs.msg import Yoloxy
# from darknet_ros_msgs.msg import BoundingBoxes

# import roslib; roslib.load_manifest('robotiq_2f_gripper_control')
from robotiq_2f_gripper_control.msg import _Robotiq2FGripper_robot_output  as outputMsg
from time import sleep

#
# pub = rospy.Publisher('Robotiq2FGripperRobotOutput', outputMsg.Robotiq2FGripper_robot_output,queue_size=10)
# command = outputMsg.Robotiq2FGripper_robot_output()
#



if __name__ == '__main__':

        moveit_commander.roscpp_initialize(sys.argv)
        rospy.init_node('moveit_demo')
        arm = moveit_commander.MoveGroupCommander('marm')
        end_effector_link = arm.get_end_effector_link()
        print(' mo duan is -------------------------->  ',end_effector_link )
        reference_frame = 'base_link'
        arm.set_pose_reference_frame(reference_frame)
                        
        arm.allow_replanning(True)
                
        arm.set_goal_position_tolerance(0.001)
        arm.set_goal_orientation_tolerance(0.001)
                
        arm.set_max_acceleration_scaling_factor(0.5)
        arm.set_max_velocity_scaling_factor(0.5)

        target_pose = PoseStamped()
        target_pose.header.frame_id = reference_frame
        target_pose.header.stamp = rospy.Time.now() 

        arm.set_named_target('ready_low')
        arm.go()
        rospy.sleep(1)

        target_pose = PoseStamped()
        target_pose.header.frame_id = reference_frame
        target_pose.header.stamp = rospy.Time.now() 

        target_pose.pose.position.x = 0.1
        target_pose.pose.position.y = 0.3
        target_pose.pose.position.z = 0.3
        # target_pose.pose.orientation.x =  0.6859990784771295
        # target_pose.pose.orientation.y = -0.6859990784771295
        # target_pose.pose.orientation.z = -0.17103878018896507
        # target_pose.pose.orientation.w =-0.17103878018896507
        target_pose.pose.orientation.x = 0.911822
        target_pose.pose.orientation.y = -0.0269758
        target_pose.pose.orientation.z = 0.285694
        target_pose.pose.orientation.w = -0.293653
        arm.set_start_state_to_current_state()
        arm.set_pose_target(target_pose, end_effector_link)
        
        traj = arm.plan()
        arm.execute(traj)
        rospy.sleep(2)