Simple UR Move

A minimal example of how to move a UR robot with the new Universal Robot ROS Driver. This package also includes some useful utilities to take care of common tasks such as running joint or cartesian waypoint trajectories.

Installation

1. Clone this package to the src folder of your catkin workspace
2. In the root folder of your workspace, install dependencies:
   • rosdep install --from-paths src --ignore-src -r -y
3. Build your workspace (catkin_make)

Usage

This package has some useful python objects you can import into your own nodes to send trajectories to the robot.

• JointTrajectoryHandler: Sends joint trajectories to the robot.
  • Choose between several UR ROS controllers: scaled_pos_joint_traj_controller, scaled_vel_joint_traj_controller, pos_joint_traj_controller, vel_joint_traj_controller, and forward_joint_traj_controller
  • You can also go to specific joint configurations via the go_to_point() function.
• CartesianTrajectoryHandler: Sends end effector pose trajectories to the robot.
  • Choose between several UR ROS controllers: pose_based_cartesian_traj_controller, joint_based_cartesian_traj_controller, and forward_cartesian_traj_controller
  • You can also go to specific cartesian poses via the go_to_point() function.
• TwistHandler: Sends cartesian end effector velocities to the robot.
  • This uses the twist_controller from the UR ROS controllers.

Bringup the robot

1. (Teach Pendant) Turn on the robot, get into manual mode, then load the "EXTERNAL_CONTROL.urp" program.
2. (Host Computer) roslaunch ur_user_calibration bringup_armando.launch
3. (Teach Pendant) Run the "EXTERNAL_CONTROL.urp" program.

Using the joint command interface

Run a joint trajectory

1. Set up a trajectory config (see config folder for examples)
2. roslaunch simple_ur_move run_joint_trajectory.launch traj:=test_traj_joint.yaml

Check out these launch files for information on different joint controllers you can use.

Use the joint trajectory handler

1. Import necessary packages

import os
import rospkg
from simple_ur_move.joint_trajectory_handler import JointTrajectoryHandler

2. Create a trajectory handler

traj_handler = JointTrajectoryHandler(
    name="",
    controller="scaled_pos_joint_traj_controller",
    debug=False)

3a. Load the trajectory/config from a file

filepath_config = os.path.join(rospkg.RosPack().get_path('simple_ur_move'), 'config')
traj_file="test_traj_joint.yaml"
traj_handler.load_config(filename=traj_file, directory=filepath_config)

3b. OR Set trajectory config directly

config={TRAJECTORY CONFIG DICT}
traj_handler.set_config(config)

4. Run the trajectory

traj_handler.set_initialize_time(3.0)
traj_handler.run_trajectory(blocking=True)
traj_handler.shutdown()

5. Move directly to a point

point={'position',[0,0,0,0,0,0]}    # Define the home configuration
traj_handler.set_initialize_time(3.0) # Set the transition time
traj_handler.go_to_point(point)      # Go to the point

All together:

import os
import rospkg
from simple_ur_move.joint_trajectory_handler import JointTrajectoryHandler

# Create a trajectory handler
traj_handler = JointTrajectoryHandler(
    name="",
    controller="scaled_pos_joint_traj_controller",
    debug=False)

# Load trajectory config from a file
filepath_config = os.path.join(rospkg.RosPack().get_path('simple_ur_move'), 'config')
traj_file="test_traj_joint.yaml"
traj_handler.load_config(filename=traj_file, directory=filepath_config)

# OR Set trajectory config directly
#config={TRAJECTORY CONFIG DICT}
#traj_handler.set_config(config)

# Run the trajectory
traj_handler.set_initialize_time(3.0)
traj_handler.run_trajectory(blocking=True)
traj_handler.shutdown()

# OR: Go directly to a single point
point={'position',[0,0,0,0,0,0]}    # Define the home configuration
traj_handler.set_initialize_time(3.0) # Set the transition time here
traj_handler.go_to_point(point)      # Go to the point

Using the cartesian command interface

Run a cartesian trajectory

1. Set up a trajectory config (see config folder for examples)
2. roslaunch simple_ur_move run_cartesian_trajectory.launch traj:=test_traj.yaml
3. roslaunch simple_ur_move run_cartesian_trajectory.launch traj:=pick_place.yaml

Check out these launch files for information on different cartesian controllers you can use.

Use the cartesian trajectory handler

1. Import nessecary packages

import os
import rospkg
from simple_ur_move.cartesian_trajectory_handler import CartesianTrajectoryHandler

2. Create a trajectory handler

traj_handler = CartesianTrajectoryHandler(
    name="",
    controller="pose_based_cartesian_traj_controller",
    debug=False)

3a. Load the trajectory/config from a file

filepath_config = os.path.join(rospkg.RosPack().get_path('simple_ur_move'), 'config')
traj_file="pick_place.yaml"
traj_handler.load_config(filename=traj_file, directory=filepath_config)

3b. OR Set trajectory config directly

config={TRAJECTORY CONFIG DICT}
traj_handler.set_config(config)

4. Run the trajectory

traj_handler.set_initialize_time(3.0)
traj_handler.run_trajectory(blocking=True)
traj_handler.shutdown()

5. Move directly to a point

point={'position',[0.5, 0.5, 0.2]}    # Define the point
traj_handler.set_initialize_time(3.0) # Set the transition time
traj_handler.go_to_point(point)      # Go to the point

All together:

import os
import rospkg
from simple_ur_move.cartesian_trajectory_handler import CartesianTrajectoryHandler

# Create a trajectory handler
traj_handler = CartesianTrajectoryHandler(
    name="",
    controller="pose_based_cartesian_traj_controller",
    debug=False)

# Load trajectory config from a file
filepath_config = os.path.join(rospkg.RosPack().get_path('simple_ur_move'), 'config')
traj_file="pick_place.yaml"
traj_handler.load_config(filename=traj_file, directory=filepath_config)

# OR Set trajectory config directly
#config={TRAJECTORY CONFIG DICT}
#traj_handler.set_config(config)

# Run the trajectory
traj_handler.set_initialize_time(3.0)
traj_handler.run_trajectory(blocking=True)
traj_handler.shutdown()

# OR: Go directly to a single point
point={'position',[0.5, 0.5, 0.2]}    # Define the point
traj_handler.set_initialize_time(3.0) # Set the transition time here
traj_handler.go_to_point(point)      # Go to the point

Using the twist command interface

Use the twist handler

1. Import nessecary packages

import os
import time
import rospkg
from simple_ur_move.twist_handler import TwistHandler

2. Create a twist handler

traj_handler = TwistHandler(
    name="",
    debug=False)

3a. Load the config from a file

filepath_config = os.path.join(rospkg.RosPack().get_path('simple_ur_move'), 'config')
traj_file="twist_config.yaml"
traj_handler.load_config(filename=traj_file, directory=filepath_config)

3b. OR Set config directly

config={TRAJECTORY CONFIG DICT}
traj_handler.set_config(config)

4. Set a twist of 5 mm/sec in the z-direction

traj_handler.set_speed_factor(1.0)
twist={'linear':[0,0,0.005], 'angular':[0,0,0]}
traj_handler.set_twist(twist)
time.sleep(4)
traj_handler.shutdown() # Sets speeds back to zero

All together:

import os
import time
import rospkg
from simple_ur_move.twist_handler import TwistHandler

# Create a twist handler
traj_handler = TwistHandler(
    name="",
    debug=False)

# Load config from a file
filepath_config = os.path.join(rospkg.RosPack().get_path('simple_ur_move'), 'config')
traj_file="twist_config.yaml"
traj_handler.load_config(filename=traj_file, directory=filepath_config)

# OR Set config directly
#config={TWIST CONFIG DICT}
#traj_handler.set_config(config)

# Set a twist of 5 mm/sec in the z-direction
traj_handler.set_speed_factor(1.0)
twist={'linear':[0,0,0.005], 'angular':[0,0,0]}
traj_handler.set_twist(twist)
time.sleep(4)
traj_handler.shutdown() # Sets speeds back to zero