This ROS package is a simple youbot arm navigation method. It uses a geometric inverse kinematics solver and a simple ROS service interface to control the arm. You can easily move the arm to certain positions.
It provides a simple rviz based simulation of the arm to have visual checks, but it can also be run on the actual robot with no changes at all.
NOTE: This does not do any (self-) collision checks. So be sure to be able to stop the arm at any moment and only use it to go to points that are collision free!
Change to your catkin workspace src directory, usually its:
cd ~/catkin_ws/src
Checkout this repository:
git clone https://github.com/smARTLab-liv/slaw_youbot_arm_navigation.git
Install dependencies:
rosdep install --from-paths src --ignore-src --rosdistro indigo
catkin_make your workspace:
cd ~/catkin_ws/src
catkin_make
Launch
roslaunch slaw_youbot_arm_navigation_utils fake_arm_navigation.launch
This should show a youbot in rviz with a single arm, rotated 45 degrees to the left. You can test if the services work:
rosservice call /untuck_arm
and
rosservice call /tuck_arm
Also some more fancy movements can be performed
rosrun slaw_youbot_arm_navigation_utils follow_sine.py
rosrun slaw_youbot_arm_navigation_utils follow_circle.py
The arm can also be controlled via service calls:
rosservice call /move_arm_ik "position: {x: 0.25, y: 0.0, z: -0.10}
angle: 0.0
velocity_controlled: true
side: 'left'
endlink_angle: 0.0
horizontal: false
blocking: false
endeffector_offset: 0.0
max_speed: 0.0"
Description of the params: position: is the endeffector position from the arm center point in the base.
angle: is the rotation angle of the last joint
velocity_controlled: true: try a smooth motion, i.e. all joints move the whole time, false: go with the maximum speed of all joints.
side: "left", "right", "front", or "back": which side of the arm is considered front.
endlink_angle: the angle of the second-last joint. Needed to increase range in top-down mode
horizontal: horizontal if true, or top-down if false.
blocking: directly return, or block until the movement is completed
endeffector_offset: extra length for the endeffector. (i.e. if a tool is in the gripper)
max_speed: max speed for velocity controlled mode.
The MIT License (MIT) Copyright (c) 2016 smARTLab, University of Liverpool
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.