This package implements active compliant control in task space. It utilizes the ros_control framework. Your robot needs a force(-torque) sensor located at the end-effector for this controller to work.
Clone this repository into your catkin workspace and compile it.
First you need to create a yaml-file that defines the controller. Following parameters are available:
| Parameter | Description |
|---|---|
| type | Name of the controller as defined by the controller plugin.(position_controllers/CompliantController, velocity_controllers/CompliantController or effort_controllers/CompliantController) |
| ft_sensor_name | Name of the ft-sensor handle |
| joints | Joint names that are to be controlled |
| segments | Link names connecting the controlled links |
| moveit_group | Only needed if type of controller is position. Name of the moveit group that is controlled. Joint names have to match joints listed in this file |
| inertia | Inertia of the end-effector. Overridden by dynamic reconfigure. |
| damping | Damping of the end-effector. Overridden by dynamic reconfigure. |
| stiffness | Stiffness of the end-effector. Overridden by dynamic reconfigure. |
| cmd_topic_name | Topic this controller uses to listen for end-effector position commands |
The controller can then be started using:
<node name="compliant_controller_spawner" pkg="controller_manager" type="spawner" respawn="false" output="screen" args="[Controller name]" />Inverse Kinematics is called using moveit IK plugins. Since the controller is working with sensor feedback, IK needs to be faster than one control loop period. So consider using IKFast or trac_ik.
The compliant controller uses dynamic_reconfigure to change control parameters on runtime. Open up rqt and load the dynamic_reconfigure plugin. Open the node that corresponds to the compliant controller.
| Parameter | Description |
|---|---|
| active | Activate compliant behaviour. Default: false |
| inertia | Mode 0: Virtual inertia of the end-effector. Mode 1: Derivative gain on ext force. |
| damping | Mode 0: Virtual damping of the end-effector. Mode 1: Integral gain on ext force. |
| stiffness | Mode 0: Virtual stiffness of the end-effector. Mode 1: Proportional gain on ext force. |
| dead_zone_trans | Dead zone of the ft-sensor force values |
| dead_zone_rot | Dead zone of the ft-sensor torque values |
| speed_limit_trans | Translational speed limit of the end-effector in m/s |
| speed_limit_rot | Rotational speed limit of the end-effector in m/s |
| mode | Changes the controller mode. 0 uses a set-point, 1 tries to reduce to force to zero without a set-point. |