diogoalmeida / sarafun_folding_assembly

ROS package implementing folding assembly functionality for the SARAFun project.

Folding assembly controller

This package provides the folding assembly functionality to the SARAFun project. It controls the relative pose between two rigid objects in contact, along two motion directions: a translational direction and a rotational axis, which are non-collinear. It also provides adaptive estimators that will estimate kinematic uncertainties on the task, such as the available motion directions and contact point location. Besides a dual-armed robot integrated with ROS, the package assumes the existance of at least one force and torque sensor.

Dependencies

• sarafun_msgs (link to dummy package)
• generic_control_toolbox
• abb_irb14000_support
• ROS Indigo

Running the controller

The file 'config_action_node.yaml' must be edited in order to set the reference frames used for the controller this incudes the name of the KDL end-effector frame and the gripping frame name in which the controller quantities are expressed. The controller is launched with

$ roslaunch folding_assembly_controller controller.launch

After launch, and actionlib server will be running which can be called as

$ rosrun actionlib axclient.py /folding_controller/<action_name>

where <action_name> is set in the configuration file. You should see the following GUI:

The init_t_error and init_k_error variables are useful for controller experiments. goal_force sets the desired contact force along the estimated surface normal.

The controller operates on two different modes: pose control or velocity reference. In pose control (use_pose_goal set to true), the robot will regulate the two rigid parts to a relative pose along the two motion directions. Alternatively (use_pose_goal set to false), the system will command velocities along the estimated motion directions.

Dynamic Reconfigure

A dynamic reconfigure server is provided for facilitating testing the system. Notably, it allows setting the degree to which the arms share the manipulation task, through the alpha parameter under the ects group.

sarafun_folding_assembly's Issues

Add lateral force control

This should help in correcting misalignments in the initial contact.

Infer rotational direction from eef pose in the world frame

Right now if we rotate the gripper 180 degrees, the controller will rotate in the opposite direction.

Separate folding actionlib server from the retreat action

They should exist as separate actionlib servers.

Handling actionlib

When the retreat code was added, it introduced a bug in the folding actionlib server. If the action is preempted, a new goal isn't processed appropriately.

Add arbitrary gripping points' support to the ECTS controller

Currently only accepting the end-effector pose, which forces me to transform back from gripping point to eef before sending commands (see c3f0d1e).