xy_theta_iterator.cpp

/*
 * Software License Agreement (BSD License)
 *
 *  Copyright (c) 2017, Locus Robotics
 *  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 copyright holder 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 HOLDER 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.
 */
 
#include "dwb_plugins/xy_theta_iterator.hpp"
 
#include <cmath>
#include <memory>
#include <string>
 
#include "nav2_ros_common/node_utils.hpp"
 
namespace dwb_plugins
{
void XYThetaIterator::initialize(
  const nav2::LifecycleNode::SharedPtr & nh,
  KinematicsHandler::Ptr kinematics,
  const std::string & plugin_name)
{
  kinematics_handler_ = kinematics;
 
  nav2::declare_parameter_if_not_declared(
    nh,
    plugin_name + ".vx_samples", rclcpp::ParameterValue(20));
  nav2::declare_parameter_if_not_declared(
    nh,
    plugin_name + ".vy_samples", rclcpp::ParameterValue(5));
  nav2::declare_parameter_if_not_declared(
    nh,
    plugin_name + ".vtheta_samples", rclcpp::ParameterValue(20));
 
  nh->get_parameter(plugin_name + ".vx_samples", vx_samples_);
  nh->get_parameter(plugin_name + ".vy_samples", vy_samples_);
  nh->get_parameter(plugin_name + ".vtheta_samples", vtheta_samples_);
}
 
void XYThetaIterator::startNewIteration(
  const nav_2d_msgs::msg::Twist2D & current_velocity,
  double dt)
{
  KinematicParameters kinematics = kinematics_handler_->getKinematics();
  x_it_ = std::make_shared<OneDVelocityIterator>(
    current_velocity.x,
    kinematics.getMinX(), kinematics.getMaxX(),
    kinematics.getAccX(), kinematics.getDecelX(),
    dt, vx_samples_);
  y_it_ = std::make_shared<OneDVelocityIterator>(
    current_velocity.y,
    kinematics.getMinY(), kinematics.getMaxY(),
    kinematics.getAccY(), kinematics.getDecelY(),
    dt, vy_samples_);
  th_it_ = std::make_shared<OneDVelocityIterator>(
    current_velocity.theta,
    kinematics.getMinTheta(), kinematics.getMaxTheta(),
    kinematics.getAccTheta(), kinematics.getDecelTheta(),
    dt, vtheta_samples_);
  if (!isValidVelocity()) {
    iterateToValidVelocity();
  }
}
 
bool XYThetaIterator::isValidVelocity()
{
  return kinematics_handler_->getKinematics().isValidSpeed(
    x_it_->getVelocity(), y_it_->getVelocity(), th_it_->getVelocity());
}
 
bool XYThetaIterator::hasMoreTwists()
{
  return x_it_ && !x_it_->isFinished();
}
 
nav_2d_msgs::msg::Twist2D XYThetaIterator::nextTwist()
{
  nav_2d_msgs::msg::Twist2D velocity;
  velocity.x = x_it_->getVelocity();
  velocity.y = y_it_->getVelocity();
  velocity.theta = th_it_->getVelocity();
 
  iterateToValidVelocity();
 
  return velocity;
}
 
void XYThetaIterator::iterateToValidVelocity()
{
  bool valid = false;
  while (!valid && hasMoreTwists()) {
    ++(*th_it_);
    if (th_it_->isFinished()) {
      th_it_->reset();
      ++(*y_it_);
      if (y_it_->isFinished()) {
        y_it_->reset();
        ++(*x_it_);
      }
    }
    valid = isValidVelocity();
  }
}
 
}  // namespace dwb_plugins