This package implements the LPV-DS motion generator from [1] together with the passive-DS controller for the KUKA LWR 4+ robot in both simulation (gazebo) and with the real robot for the following tasks learned from demonstration:

• Task 1: Inspection Line

• Task 2: Branding Line

• Task 3: Shelf-Arranging (top only)

Videos of the execution of these tasks on the real robot can be found here: robot-experiments

• Task 4: Letter Writing (from LASA-Dataset)

To run this package you must install the following dependencies:

• kuka-lwr-ros checkout 'nadia' branch | Control Interface for Kuka LWR 4+
• ds-motion-generator checkout 'nadia' branch | DS motion generation nodes
• lpvDS-lib | lpv-DS class used by ds-motion-generator
• grasp-interface | To control the Robotiq S gripper from code

1. Bring up the kuka-lwr-ros controller and simulator:

$ roslaunch kuka_lpvds_tasks sim.launch force-interface:=true

2. Run the planning-interface to send joint commands:

$ roslaunch kuka_lpvds_tasks planning_client.launch
$ roslaunch kuka_lpvds_tasks planning_console.launch

Default commands (go_home, go_left, go_right, go_candle) These commands are use to send the robot to a "good" initial joint configuration, generally you should go_home or go_right to test a learned ds-motion generator.

3. Load DS motion generators and Task Planning Node

• For Inspection Line Task

  $ roslaunch kuka_lpvds_tasks run_inspection_task.launch sim:=true
  

• For Branding Line Task

  $ roslaunch kuka_lpvds_tasks run_branding_task.launch sim:=true
  

• For Shelf Arranging Task

  $ roslaunch kuka_lpvds_tasks run_shelf_task.launch sim:=true
  

To apply external forces during the execution (to test the reactivity of the DS and impedance controller) you can define the force in the following topic:

/lwr/joint_controllers/passive_ds_external_force

the force will be applied by manipulating the boolean command:

/lwr/joint_controllers/passive_ds_apply_force

To run the tasks on the real robot you should follow the same instructions above, except for

1. Bring up the kuka-lwr-ros controller and console in different terminals:

$ roslaunch lwr_simple_example real.launch
$ roslaunch lwr_fri lwr_fri_console.launch

and for the 3. Load DS motion generators and Task Planning Node you should either set sim:=false or not set at all, as it is the default.

Additionally you should bring up the gripper grasp-interface:

$ roslaunch grasp_interface rs_gripper.launch

To modify the gripper state during execution you can launch the gripper voice controller from the demo-voice-control package:

roslaunch demo_voice_control gripper_voice_control.launch

References

[1] Figueroa, N. and Billard, A. (2018) "A Physically-Consistent Bayesian Non-Parametric Mixture Model for Dynamical System Learning". Conference on Robot Learning (CoRL) - 2018 Edition. To Appear.

Contact: Nadia Figueroa (nadia.figueroafernandez AT epfl dot ch)

Acknowledgments This work was supported by the EU project Cogimon H2020-ICT-23-2014.