Compliant Control and Application

It contains the compliant control algorithms in robotic arm, and the chosen robot is universal robot which is popular collaborate robot in the world.

Compile

mkdir catkin_ws/src && cd catkin_ws/src
git clone https://github.com/MingshanHe/Compliant-Control-and-Application.git
catkin build (or cd .. && catkin_make)

Check

using the following command to check the self-defined controller. Like:cartesian_velocity_controller

rospack plugins --attrib=plugin controller_interface

Run

Notice: In this repository, I have used ur5e robot and its urdf file need to be changed in different situation, like need or not a force/torque sensor in the end effector. Please check the urdf file seriously and run the algorithm, Thanks.

1. Admittance

roslaunch ur_gazebo ur5e_bringup.launch transmission_hw_interface:=hardware_interface/PositionJointInterface specified_controller:=cartesian_velocity_controller

roslaunch admittance Admittance_test.launch

2. Impedance

roslaunch ur_gazebo ur5e_bringup.launch transmission_hw_interface:=hardware_interface/EffortJointInterface specified_controller:=joint_torque_controller

roslaunch impedance Impedance.launch

3. Application (Hybrid Admittance Control)

roslaunch mir_gazebo mir_single_test.launch tf_prefix:=robot1

roslaunch admittance HybridAdmittance.launch tf_prefix:=robot1

4. Hybrid Position Force Control

Rebuilding soon.......------......-----.... ^ . ^

​ In industrial polishing, coating painting, and so forth, the robotic arm needs to be controlled to move along the surface with pressure. The constant pressure provides a vertical force along the surface and won't be changed during moving. Because of it, the end effector and contact surface exist friction which causes the polishing and painting.

In this control algorithms, I have used a car wheel to imitate a curve surface that needs to be processed. This control algorithm contains position servo and forces closed-loop control as its name.

First of all, running the gazebo environment which contains a universal robot and a car wheel beside it.

$ roslaunch ur_e_gazebo ur5e.launch controller:=cartesian_velocity_controller_sim environment:=polish

Then, running the hybrid position force control

$ roslaunch hybrid_position_force_control hybrid_position_force_control.launch

And then it needs to use the topic publish command in the terminal. It is recommended to move to $[0.1,0.4,0.45]$ which along the x Axis at first, and then move to $[0.1,0.4,0.3]$ in z Axis. This makes the end contact with the curve surface and has a little slope angle. According to the force close-loop algorithm, the end effector will change its orientation to adapt it. At last, you command it to move to $[-0,1,0.4,0.3]$ along the x Axis which is simulated in the polish experiment. And the performance is shown in the following Gif file.

Performance

1. Admittance

2. Hybrid Admittance Control

3. Hybrid Position Force Control