diff_drive_controller.h

Go to the documentation of this file.

/*********************************************************************
 * Software License Agreement (BSD License)
 *
 *  Copyright (c) 2013, PAL Robotics, S.L.
 *  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above
 *     copyright notice, this list of conditions and the following
 *     disclaimer in the documentation and/or other materials provided
 *     with the distribution.
 *   * Neither the name of the PAL Robotics nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 *  FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 *  COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 *  BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 *  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 *  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 *  LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 *  ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 *  POSSIBILITY OF SUCH DAMAGE.
 *********************************************************************/

/*
 * Author: Enrique Fernández
 */

#include <controller_interface/controller.h>
#include <hardware_interface/joint_command_interface.h>
#include <pluginlib/class_list_macros.hpp>
#include <dynamic_reconfigure/server.h>

#include <geometry_msgs/TwistStamped.h>
#include <nav_msgs/Odometry.h>
#include <tf/tfMessage.h>

#include <realtime_tools/realtime_buffer.h>
#include <realtime_tools/realtime_publisher.h>

#include <diff_drive_controller/odometry.h>
#include <diff_drive_controller/speed_limiter.h>
#include <diff_drive_controller/DiffDriveControllerConfig.h>

namespace diff_drive_controller{

  class DiffDriveController
      : public controller_interface::Controller<hardware_interface::VelocityJointInterface>
  {
  public:
    DiffDriveController();

    bool init(hardware_interface::VelocityJointInterface* hw,
              ros::NodeHandle& root_nh,
              ros::NodeHandle &controller_nh);

    void update(const ros::Time& time, const ros::Duration& period);

    void starting(const ros::Time& time);

    void stopping(const ros::Time& /*time*/);

  private:
    std::string name_;

    ros::Duration publish_period_;
    ros::Time last_state_publish_time_;
    bool open_loop_;

    std::vector<hardware_interface::JointHandle> left_wheel_joints_;
    std::vector<hardware_interface::JointHandle> right_wheel_joints_;

    struct Commands
    {
      double lin;
      double ang;
      ros::Time stamp;

      Commands() : lin(0.0), ang(0.0), stamp(0.0) {}
    };
    realtime_tools::RealtimeBuffer<Commands> command_;
    Commands command_struct_;
    ros::Subscriber sub_command_;

    boost::shared_ptr<realtime_tools::RealtimePublisher<geometry_msgs::TwistStamped> > cmd_vel_pub_;

    boost::shared_ptr<realtime_tools::RealtimePublisher<nav_msgs::Odometry> > odom_pub_;
    boost::shared_ptr<realtime_tools::RealtimePublisher<tf::tfMessage> > tf_odom_pub_;
    Odometry odometry_;

    double wheel_separation_;

    double wheel_radius_;

    double wheel_separation_multiplier_;
    double left_wheel_radius_multiplier_;
    double right_wheel_radius_multiplier_;

    double cmd_vel_timeout_;

    bool allow_multiple_cmd_vel_publishers_;

    std::string base_frame_id_;

    std::string odom_frame_id_;

    bool enable_odom_tf_;

    size_t wheel_joints_size_;

    Commands last1_cmd_;
    Commands last0_cmd_;
    SpeedLimiter limiter_lin_;
    SpeedLimiter limiter_ang_;

    bool publish_cmd_;

    // A struct to hold dynamic parameters
    // set from dynamic_reconfigure server
    struct DynamicParams
    {
      bool update;

      double left_wheel_radius_multiplier;
      double right_wheel_radius_multiplier;
      double wheel_separation_multiplier;

      bool publish_cmd;

      double publish_rate;
      bool enable_odom_tf;

      DynamicParams()
        : left_wheel_radius_multiplier(1.0)
        , right_wheel_radius_multiplier(1.0)
        , wheel_separation_multiplier(1.0)
        , publish_cmd(false)
        , publish_rate(50)
        , enable_odom_tf(true)
      {}

      friend std::ostream& operator<<(std::ostream& os, const DynamicParams& params)
      {
        os << "DynamicParams:\n"
           //
           << "\tOdometry parameters:\n"
           << "\t\tleft wheel radius: "   << params.left_wheel_radius_multiplier  << "\n"
           << "\t\tright wheel radius: "  << params.right_wheel_radius_multiplier << "\n"
           << "\t\twheel separation: "    << params.wheel_separation_multiplier   << "\n"
           //
           << "\tPublication parameters:\n"
           << "\t\tPublish executed velocity command: " << params.publish_cmd << "\n"
           << "\t\tPublication rate: " << params.publish_rate                 << "\n"
           << "\t\tPublish frame odom on tf: " << params.enable_odom_tf;

        return os;
      }
    };

    realtime_tools::RealtimeBuffer<DynamicParams> dynamic_params_;

    typedef dynamic_reconfigure::Server<DiffDriveControllerConfig> ReconfigureServer;
        boost::shared_ptr<ReconfigureServer> dyn_reconf_server_;

  private:
    void brake();

    void cmdVelCallback(const geometry_msgs::Twist& command);

    bool getWheelNames(ros::NodeHandle& controller_nh,
                       const std::string& wheel_param,
                       std::vector<std::string>& wheel_names);

    bool setOdomParamsFromUrdf(ros::NodeHandle& root_nh,
                               const std::string& left_wheel_name,
                               const std::string& right_wheel_name,
                               bool lookup_wheel_separation,
                               bool lookup_wheel_radius);

    void setOdomPubFields(ros::NodeHandle& root_nh, ros::NodeHandle& controller_nh);

    void reconfCallback(DiffDriveControllerConfig& config, uint32_t /*level*/);

    void updateDynamicParams();
  };

  PLUGINLIB_EXPORT_CLASS(diff_drive_controller::DiffDriveController, controller_interface::ControllerBase);
} // namespace diff_drive_controller