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ROS_CANopen can't start velocity_controller and trajectory_controller

asked 2016-10-29 01:13:57 -0500

Craig gravatar image

updated 2016-10-29 04:10:02 -0500

gvdhoorn gravatar image

Hi, I am working with ros_canopen to control a robot arm. The arm uses Copley drives. Please check out the github repo that I'm working on here.

  1. The position controller (point to point move) works fine now. A littile problem here is I don't know how to specify the speed during the point-to-point move.

  2. When I tried to start the velocity_controller:

    rosrun controller_manager controller_manager start I_Joint_velocity_controller

    errors would show up:

    [ERROR]: I_Jointcould not enter mode 2
    [ERROR]: Could not switch one joint for I_Joint_velocity_controller, will stop all related joints and the controller.
    [ERROR]: I_Joint is not ready to switch mode
    [ERROR]: Could not switch controllers. The hardware interface combination for the requested controllers is unfeasible.

    and if I start the trajectory_controller:

    rosrun controller_manager controller_manager start joint_trajectory_controller

    errors would be:

    abort60c1#1, reason: Invalid value for parameter (download only).
    Could not process message
    [ERROR]: RPDO timeout; RPDO timeout;ros_canopen/canopen_master/src/sdo.cpp(429): Throw in function void canopen::SDOClient::transmitAndWait(const canopen::ObjectDict::Entry&, const canopen::String&, canopen::String*)
    Dynamic exception type: boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<canopen::TimeoutException> >
    std::exception::what: SDO
    [canopen::tag_objectdict_key*] = 60c1sub1

Are these problems caused by wrong configuration of my dcf file? I mapped the PDOs according to the Copley programming manual p. 25

Many thanks.

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Just a tip (I always get confused as well): Askbot does not support github flavoured markdown. Use four spaces to start a code block, not three backticks.

gvdhoorn gravatar image gvdhoorn  ( 2016-10-29 04:11:00 -0500 )edit

Thanks. : )

Craig gravatar image Craig  ( 2016-10-29 07:16:56 -0500 )edit

1 Answer

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answered 2016-10-29 05:23:24 -0500

Mathias Lüdtke gravatar image

A littile problem here is I don't know how to specify the speed during the point-to-point move.

canopen_motor_node does not support setting the velocity dynamically (for this mode). You can set it at start-up to a fixed value (Object 0x6081, the drive even supports more options). I have opened a new issue for dynamic setting:

I_Joint could not enter mode 2

According to the manual the drive just supports mode 3 (profiled velocity). You should not have copied the Schunk DCF, the Copley drive seems to be more like the Elmo..

and if I start the trajectory_controller:

The error message suggests that you should check the sent command. Perhaps the drive have to be configured in a different way. Please map 60c1sub1 to a PDO, otherwise IP mode will not work as expected. ( )

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Hi Mathias. Thank you for your help.

I set the 6081 in dcf_overlay, as you've suggested, and used cansend can0 601# to change the velocity of the motor after initialization.

It would nicer that the position_controller support speed adjustment after strart-up.

Craig gravatar image Craig  ( 2016-10-29 09:36:19 -0500 )edit

I mapped 60c1sub1 to RPDO2 with

     "1601sub2": "0x60c10120"

It produced the same error when I called the canopen_motor init service. And candump stopped at :

can0  TX - -  601    40 C1 60 01 00 00 00 00
can0  RX - -  581    80 C1 60 01 01 00 01 06 # obj write only
Craig gravatar image Craig  ( 2016-10-30 21:11:21 -0500 )edit

(This is not the same error!) Not sure what's going on here. It should be RW. You can get rid o the read if you set a default value for 60c1sub1 in your DCF.

Mathias Lüdtke gravatar image Mathias Lüdtke  ( 2016-10-31 05:03:23 -0500 )edit

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Asked: 2016-10-29 01:13:57 -0500

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Last updated: Oct 29 '16