EffortJointInterface not found when loading joint_effort_controller

[ivan140]

Hi,

I'm trying to get running the joint_effort_controller with the ros_canopen package. My motor supports the target_torque obj6071 and it moves when I set some values in this object directly. However, when I try to load the effort_controller I get the following error:

[INFO] [1630575428.170701]: Loading controller: wheel_left_joint_effort_controller [ERROR] [1630575428.177604104]: Exception thrown while initializing controller 'wheel_left_joint_effort_controller'. Could not find resource 'wheel_left_joint' in 'hardware_interface::EffortJointInterface'. [ERROR] [1630575428.177679782]: Initializing controller 'wheel_left_joint_effort_controller' failed It seems, that the EffortJointInterface is not available. Here are my configs:

controller.yaml:

joint_names: [wheel_left_joint, wheel_right_joint, body_joint]

## control_mode_adapter
max_command_silence: 0.5

## joint_state_controller
joint_state_controller:
    type: joint_state_controller/JointStateController
    publish_rate: 50

wheel_left_joint_effort_controller:
  type: effort_controllers/JointEffortController
  joint: wheel_left_joint
  required_drive_mode: 4

driver.yaml:

defaults:
  eds_pkg: robot_model
  eds_file: "diff_drive/config/KINCO-JD_FD.eds"
  motor_allocator: canopen::Motor402::Allocator # select allocator for motor layer
  motor_layer: # settings passed to motor layer (plugin-specific)
    switching_state: 5 # (Operation_Enable), state for mode switching
  pos_to_device: "rint(pos*140000/2/pi)" # rad -> encoder ticks
  pos_from_device: "obj6063*2*pi/140000" # actual position [encoder ticks] -> rad
  vel_to_device: "rint(vel*30/pi/1875*512*140000)" # rad/s -> mdeg/s
  vel_from_device: "(obj606C*1875/512/140000)*pi/30" # actual velocity [mdeg/s] -> rad/s
  eff_to_device: "rint(obj6071)" # just round to integer
  eff_from_device: "0" # unset

  dcf_overlay:
    "6007": "0x0001"
    "6081": "250000"
    "6083": "15000"
    "6084": "15000"
    "1016sub1" : "0x7F0064" # heartbeat timeout of 100 ms for master at 127

nodes:
  wheel_left_joint:
    id: 1538
  wheel_right_joint:
    id: 1537

Any help would be appreciated!

[mathias-luedtke]

This issue tracker is not a support forum, so please use ROS answers instead.

My motor supports the target_torque obj6071

canopen_motor_node does not check the objects, it just checks the supported drive modes from EDS/DCF or directly from the drive.

eff_to_device: "rint(obj6071)" # just round to integer

Where did you copy this from?

This would just command the last torque (as read from the device / 6071).

The effort command (from ros_control) can be read from the eff variable and should be passed to the device.

[ivan140]

Hi,

The error message sounded to me like the effort interface is not implemented thus not loading. That's why I assumed it's an issue. Also this table states, that torque control is not supported and I found no statements, whether in issues nor in ROS answers, about a working setup with ros_canopen and the effort controller.

However, your hint about the drive modes check from the EDS file was very helpful! Thanks a lot.

[mathias-luedtke]

The error message sounded to me like the effort interface is not implemented thus not loading

It is implemented, but not available, if the drive not support it.

Also this table states, that torque control is not supported and I found no statements

The Schnunk robots do (did?) not support the (standard) torque control modes. Elmo does, but I haven't tested them yet. That's why the support is "Unknown/?".