[ros-users] Running a realtime joint controller: Tutorial Error

koen buys koen.buys at mech.kuleuven.be
Tue Aug 3 18:02:15 UTC 2010


$ cat controller_plugins.xml
<library path="lib/libmy_controller_lib">
  <class name="MyControllerPlugin"
         type="my_controller_ns::MyControllerClass"
         base_class_type="pr2_controller_interface::Controller" />
</library>


On 3 August 2010 18:44, Rob Wheeler <wheeler at willowgarage.com> wrote:
> What does your controller_plugins.xml file look like?
>
> -R
>
> On Tue, Aug 3, 2010 at 7:23 AM, koen buys <koen.buys at mech.kuleuven.be>
> wrote:
>>
>> Hi all,
>>
>> I'm trying to run the following tutorial:
>>
>> http://www.ros.org/wiki/pr2_mechanism/Tutorials/Running%20a%20realtime%20joint%20controller
>> Rxconsole is giving me the following error:
>>
>> "Could not load class MyControllerPlugin: Failed to load library
>>
>> /home/kbuys/ros/private-kul-ros-pkg/ros_controller_tutorials/my_controller_pkg/lib/libmy_controller_lib.so.
>> Make sure that you are calling the PLUGINLIB_REGISTER_CLASS macro in
>> the library code, and that names are consistent between this macro and
>> your XML. Error string: Cannot load library: No manifest in
>>
>> /home/kbuys/ros/private-kul-ros-pkg/ros_controller_tutorials/my_controller_pkg/lib/libmy_controller_lib.so:
>> MyControllerPlugin"
>>
>> Together with the following error after:
>>
>> "Could not load controller 'my_controller_name' because controller
>> type 'MyControllerPlugin' does not exist"
>>
>> We couldn't find the cause of it. When I did a :
>>
>> $ rosrun pr2_controller_manager pr2_controller_manager list-types
>> CartesianTrajectoryController
>> ContactObserverPlugin
>> JTTeleopController
>> JointGravityController
>> JointPendulumController
>> MyControllerPlugin
>> SlipGripControllerPlugin
>> SrhFakeJointCalibrationController
>> StanfordWBCPump
>> VelController
>> ethercat_trigger_controllers/MultiTriggerController
>> ethercat_trigger_controllers/ProjectorController
>> ethercat_trigger_controllers/TriggerController
>> ft_eval/PoseForceController
>> ft_eval/TwistForceController
>> joint_qualification_controllers/CheckoutController
>> joint_qualification_controllers/CounterbalanceTestController
>> joint_qualification_controllers/HeadPositionController
>> joint_qualification_controllers/HysteresisController
>> joint_qualification_controllers/JointLimitCalibrationController
>> joint_qualification_controllers/MotorJointCalibrationController
>> joint_qualification_controllers/WristDifferenceController
>> pr2_calibration_controllers/CasterCalibrationController
>> pr2_calibration_controllers/GripperCalibrationController
>> pr2_calibration_controllers/JointCalibrationController
>> pr2_calibration_controllers/WristCalibrationController
>> pr2_controller_manager/TestController
>> pr2_mechanism_controllers/CasterController
>> pr2_mechanism_controllers/CasterControllerNode
>> pr2_mechanism_controllers/LaserScannerTrajController
>> pr2_mechanism_controllers/Pr2BaseController
>> pr2_mechanism_controllers/Pr2BaseController2
>> pr2_mechanism_controllers/Pr2GripperController
>> pr2_mechanism_controllers/Pr2Odometry
>> robot_mechanism_controllers/CartesianPoseController
>> robot_mechanism_controllers/CartesianTwistController
>> robot_mechanism_controllers/CartesianWrenchController
>> robot_mechanism_controllers/JointEffortController
>> robot_mechanism_controllers/JointPositionController
>> robot_mechanism_controllers/JointSplineTrajectoryController
>> robot_mechanism_controllers/JointTrajectoryActionController
>> robot_mechanism_controllers/JointVelocityController
>> rttuning_controllers/JointTuningController
>> teleop_controllers/JinvTeleopController7
>> tff_controller/TFFController
>> tirt/TirtController
>>
>> It shows up. However now:
>>
>> $ rosrun pr2_controller_manager pr2_controller_manager load
>> MyControllerPlugin
>> Error when loading MyControllerPlugin
>>
>> This is my manifest:
>>
>> <package>
>>  <description brief="my_controller_pkg">
>>
>>     my_controller_pkg
>>
>>  </description>
>>  <author>Koen</author>
>>  <license>BSD</license>
>>  <review status="unreviewed" notes=""/>
>>  <url>http://ros.org/wiki/my_controller_pkg</url>
>>  <depend package="pr2_controller_interface"/>
>>  <depend package="pr2_mechanism_model"/>
>>  <depend package="pluginlib"/>
>>  <export>
>>    <pr2_controller_interface plugin="${prefix}/controller_plugins.xml" />
>>  </export>
>> </package>
>>
>> This is my CMakeLists:
>>
>> cmake_minimum_required(VERSION 2.4.6)
>> include($ENV{ROS_ROOT}/core/rosbuild/rosbuild.cmake)
>>
>> # Set the build type.  Options are:
>> #  Coverage       : w/ debug symbols, w/o optimization, w/ code-coverage
>> #  Debug          : w/ debug symbols, w/o optimization
>> #  Release        : w/o debug symbols, w/ optimization
>> #  RelWithDebInfo : w/ debug symbols, w/ optimization
>> #  MinSizeRel     : w/o debug symbols, w/ optimization, stripped binaries
>> #set(ROS_BUILD_TYPE RelWithDebInfo)
>>
>> rosbuild_init()
>>
>> #set the default path for built executables to the "bin" directory
>> set(EXECUTABLE_OUTPUT_PATH ${PROJECT_SOURCE_DIR}/bin)
>> #set the default path for built libraries to the "lib" directory
>> set(LIBRARY_OUTPUT_PATH ${PROJECT_SOURCE_DIR}/lib)
>>
>> #uncomment if you have defined messages
>> #rosbuild_genmsg()
>> #uncomment if you have defined services
>> #rosbuild_gensrv()
>>
>> #common commands for building c++ executables and libraries
>> #rosbuild_add_library(${PROJECT_NAME} src/example.cpp)
>> #target_link_libraries(${PROJECT_NAME} another_library)
>> #rosbuild_add_boost_directories()
>> #rosbuild_link_boost(${PROJECT_NAME} thread)
>> #rosbuild_add_executable(example examples/example.cpp)
>> #target_link_libraries(example ${PROJECT_NAME})
>> rosbuild_add_library(my_controller_lib src/my_controller_file.cpp)
>>
>> And this is the content of my source file:
>>
>> #include "my_controller_pkg/my_controller_file.h"
>> #include <pluginlib/class_list_macros.h>
>>
>> using namespace my_controller_ns;
>>
>> /// Register controller to pluginlib
>> PLUGINLIB_REGISTER_CLASS(MyControllerPlugin,
>>                         my_controller_ns::MyControllerClass,
>>                         pr2_controller_interface::Controller)
>>
>> /// Controller initialization in non-realtime
>> bool MyControllerClass::init(pr2_mechanism_model::RobotState *robot,
>>                            ros::NodeHandle &n)
>> {
>>  std::string joint_name;
>>  if (!n.getParam("joint_name", joint_name))
>>  {
>>    ROS_ERROR("No joint given in namespace: '%s')",
>>              n.getNamespace().c_str());
>>    return false;
>>  }
>>
>>  joint_state_ = robot->getJointState(joint_name);
>>  if (!joint_state_)
>>  {
>>    ROS_ERROR("MyController could not find joint named '%s'",
>>              joint_name.c_str());
>>    return false;
>>  }
>>  return true;
>> }
>>
>>
>> /// Controller startup in realtime
>> void MyControllerClass::starting()
>> {
>>  init_pos_ = joint_state_->position_;
>> }
>>
>>
>> /// Controller update loop in realtime
>> void MyControllerClass::update()
>> {
>>  double desired_pos = init_pos_ + 0.5 * sin(ros::Time::now().toSec());
>>  double current_pos = joint_state_->position_;
>>  joint_state_->commanded_effort_ = -10 * (current_pos - desired_pos);
>> }
>>
>>
>> /// Controller stopping in realtime
>> void MyControllerClass::stopping()
>> {}
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>
>



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