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

[koen buys]

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()
{}