lorepieri8
commented
3 years ago This is the config file for the servoing:
###############################################
# Modify all parameters related to servoing here
###############################################
use_gazebo: false # Whether the robot is started in a Gazebo simulation environment
## Properties of incoming commands
command_in_type: "unitless" # "unitless"> in the range [-1:1], as if from joystick. "speed_units"> cmds are in m/s and rad/s
scale:
# Scale parameters are only used if command_in_type=="unitless"
linear: 0.2 # Max linear velocity. Meters per publish_period. Unit is [m/s]. Only used for Cartesian commands.
rotational: 0.4 # Max angular velocity. Rads per publish_period. Unit is [rad/s]. Only used for Cartesian commands.
# Max joint angular/linear velocity. Rads or Meters per publish period. Only used for joint commands on joint_command_in_topic.
joint: 0.25
## Properties of outgoing commands
publish_period: 0.034 # 1/Nominal publish rate [seconds]
low_latency_mode: false # Set this to true to publish as soon as an incoming Twist command is received (publish_period is ignored)
# What type of topic does your robot driver expect?
# Currently supported are std_msgs/Float64MultiArray or trajectory_msgs/JointTrajectory
command_out_type: trajectory_msgs/JointTrajectory
# What to publish? Can save some bandwidth as most robots only require positions or velocities
publish_joint_positions: true
publish_joint_velocities: true
publish_joint_accelerations: false
## Incoming Joint State properties
low_pass_filter_coeff: 2.0 # Larger --> trust the filtered data more, trust the measurements less.
## MoveIt properties
move_group_name: xarm6 # Often 'manipulator' or 'arm'
planning_frame: link_base # The MoveIt planning frame. Often 'base_link' or 'world'
## Other frames
ee_frame_name: link6 # The name of the end effector link, used to return the EE pose
robot_link_command_frame: link_base # commands must be given in the frame of a robot link. Usually either the base or end effector
## Stopping behaviour
incoming_command_timeout: 0.2 # Stop servoing if X seconds elapse without a new command
# If 0, republish commands forever even if the robot is stationary. Otherwise, specify num. to publish.
# Important because ROS may drop some messages and we need the robot to halt reliably.
num_outgoing_halt_msgs_to_publish: 4
## Configure handling of singularities and joint limits
lower_singularity_threshold: 17.0 # Start decelerating when the condition number hits this (close to singularity)
hard_stop_singularity_threshold: 30.0 # Stop when the condition number hits this
joint_limit_margin: 0.1 # added as a buffer to joint limits [radians]. If moving quickly, make this larger.
## Topic names
cartesian_command_in_topic: ~/delta_twist_cmds # Topic for incoming Cartesian twist commands
joint_command_in_topic: ~/delta_joint_cmds # Topic for incoming joint angle commands
joint_topic: /joint_states
status_topic: ~/status # Publish status to this topic
command_out_topic: /xarm6_traj_controller/joint_trajectory # Publish outgoing commands here
## Collision checking for the entire robot body
check_collisions: false # Check collisions?
collision_check_rate: 5.0 # [Hz] Collision-checking can easily bog down a CPU if done too often.
# Two collision check algorithms are available:
# "threshold_distance" begins slowing down when nearer than a specified distance. Good if you want to tune collision thresholds manually.
# "stop_distance" stops if a collision is nearer than the worst-case stopping distance and the distance is decreasing. Requires joint acceleration limits
collision_check_type: threshold_distance
# Parameters for "threshold_distance"-type collision checking
self_collision_proximity_threshold: 0.0025 # Start decelerating when a self-collision is this far [m]
scene_collision_proximity_threshold: 0.0005 # Start decelerating when a scene collision is this far [m]
# Parameters for "stop_distance"-type collision checking
collision_distance_safety_factor: 10.0 # Must be >= 1. A large safety factor is recommended to account for latency
min_allowable_collision_distance: 0.0025 # Stop if a collision is closer than this [m]
penglongxiang
MeticulousFishFrier
Akumar201
peterdavidfagan
I've adapted the real time servoing tutorial to work with Xarm6. All good in simulation, both using the ros2_control_plugin fake_components/GenericSystem (as done in the Panda tutorial) and the gazebo_ros2_control/GazeboSystem. I'm using a PS3 joystick to control joints and cartesian movements. If I use xarm_control/XArmHW with Gazebo it's also fine, but when working with the real arm, the arm starts shaking and it hardly moves.
To control the real arm I'm using:
ros2 launch xarm_moveit_config xarm6_moveit_realmove.launch.py robot_ip:=myipand
ros2 launch moveit2_tutorials servo_teleop.launch.pyWhat is causing the shaking? Do I have to tune any PID values? Or perhaps should I set a lower frequency for the controllers?