trajectory_generator_lin.cpp

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#include <pilz_industrial_motion_planner/trajectory_generator_lin.h>
 
#include <pilz_industrial_motion_planner/tip_frame_getter.h>
 
#include <cassert>
#include <sstream>
#include <time.h>
#include <moveit/robot_state/conversions.h>
#include <kdl/path_line.hpp>
#include <kdl/trajectory_segment.hpp>
#include <kdl/utilities/error.h>
#include <tf2/convert.h>
#include <tf2_eigen_kdl/tf2_eigen_kdl.hpp>
#include <rclcpp/logger.hpp>
#include <rclcpp/logging.hpp>
#include <tf2_eigen/tf2_eigen.hpp>
#include <tf2_geometry_msgs/tf2_geometry_msgs.hpp>
 
namespace pilz_industrial_motion_planner
{
static const rclcpp::Logger LOGGER =
    rclcpp::get_logger("moveit.pilz_industrial_motion_planner.trajectory_generator_lin");
TrajectoryGeneratorLIN::TrajectoryGeneratorLIN(const moveit::core::RobotModelConstPtr& robot_model,
                                               const LimitsContainer& planner_limits, const std::string& /*group_name*/)
  : TrajectoryGenerator::TrajectoryGenerator(robot_model, planner_limits)
{
  if (!planner_limits_.hasFullCartesianLimits())
  {
    RCLCPP_ERROR(LOGGER, "Cartesian limits not set for LIN trajectory generator.");
    throw TrajectoryGeneratorInvalidLimitsException("Cartesian limits are not fully set for LIN trajectory generator.");
  }
}
 
void TrajectoryGeneratorLIN::extractMotionPlanInfo(const planning_scene::PlanningSceneConstPtr& scene,
                                                   const planning_interface::MotionPlanRequest& req,
                                                   TrajectoryGenerator::MotionPlanInfo& info) const
{
  RCLCPP_DEBUG(LOGGER, "Extract necessary information from motion plan request.");
 
  info.group_name = req.group_name;
  moveit::core::RobotState robot_state = scene->getCurrentState();
 
  // goal given in joint space
  if (!req.goal_constraints.front().joint_constraints.empty())
  {
    info.link_name = getSolverTipFrame(robot_model_->getJointModelGroup(req.group_name));
 
    if (req.goal_constraints.front().joint_constraints.size() !=
        robot_model_->getJointModelGroup(req.group_name)->getActiveJointModelNames().size())
    {
      std::ostringstream os;
      os << "Number of joints in goal does not match number of joints of group "
            "(Number joints goal: "
         << req.goal_constraints.front().joint_constraints.size() << " | Number of joints of group: "
         << robot_model_->getJointModelGroup(req.group_name)->getActiveJointModelNames().size() << ")";
      throw JointNumberMismatch(os.str());
    }
 
    for (const auto& joint_item : req.goal_constraints.front().joint_constraints)
    {
      info.goal_joint_position[joint_item.joint_name] = joint_item.position;
    }
 
    computeLinkFK(robot_state, info.link_name, info.goal_joint_position, info.goal_pose);
  }
  // goal given in Cartesian space
  else
  {
    std::string frame_id;
 
    info.link_name = req.goal_constraints.front().position_constraints.front().link_name;
    if (req.goal_constraints.front().position_constraints.front().header.frame_id.empty() ||
        req.goal_constraints.front().orientation_constraints.front().header.frame_id.empty())
    {
      RCLCPP_WARN(LOGGER, "Frame id is not set in position/orientation constraints of "
                          "goal. Use model frame as default");
      frame_id = robot_model_->getModelFrame();
    }
    else
    {
      frame_id = req.goal_constraints.front().position_constraints.front().header.frame_id;
    }
 
    // goal pose with optional offset wrt. the planning frame
    info.goal_pose = scene->getFrameTransform(frame_id) * getConstraintPose(req.goal_constraints.front());
    frame_id = robot_model_->getModelFrame();
 
    // check goal pose ik before Cartesian motion plan starts
    std::map<std::string, double> ik_solution;
    if (!computePoseIK(scene, info.group_name, info.link_name, info.goal_pose, frame_id, info.start_joint_position,
                       ik_solution))
    {
      std::ostringstream os;
      os << "Failed to compute inverse kinematics for link: " << info.link_name << " of goal pose";
      throw LinInverseForGoalIncalculable(os.str());
    }
  }
 
  // Ignored return value because at this point the function should always
  // return 'true'.
  computeLinkFK(robot_state, info.link_name, info.start_joint_position, info.start_pose);
}
 
void TrajectoryGeneratorLIN::plan(const planning_scene::PlanningSceneConstPtr& scene,
                                  const planning_interface::MotionPlanRequest& req, const MotionPlanInfo& plan_info,
                                  const double& sampling_time, trajectory_msgs::msg::JointTrajectory& joint_trajectory)
{
  // create Cartesian path for lin
  std::unique_ptr<KDL::Path> path(setPathLIN(plan_info.start_pose, plan_info.goal_pose));
 
  // create velocity profile
  std::unique_ptr<KDL::VelocityProfile> vp(
      cartesianTrapVelocityProfile(req.max_velocity_scaling_factor, req.max_acceleration_scaling_factor, path));
 
  // combine path and velocity profile into Cartesian trajectory
  // with the third parameter set to false, KDL::Trajectory_Segment does not
  // take
  // the ownship of Path and Velocity Profile
  KDL::Trajectory_Segment cart_trajectory(path.get(), vp.get(), false);
 
  moveit_msgs::msg::MoveItErrorCodes error_code;
  // sample the Cartesian trajectory and compute joint trajectory using inverse
  // kinematics
  if (!generateJointTrajectory(scene, planner_limits_.getJointLimitContainer(), cart_trajectory, plan_info.group_name,
                               plan_info.link_name, plan_info.start_joint_position, sampling_time, joint_trajectory,
                               error_code))
  {
    std::ostringstream os;
    os << "Failed to generate valid joint trajectory from the Cartesian path";
    throw LinTrajectoryConversionFailure(os.str(), error_code.val);
  }
}
 
std::unique_ptr<KDL::Path> TrajectoryGeneratorLIN::setPathLIN(const Eigen::Affine3d& start_pose,
                                                              const Eigen::Affine3d& goal_pose) const
{
  RCLCPP_DEBUG(LOGGER, "Set Cartesian path for LIN command.");
 
  KDL::Frame kdl_start_pose, kdl_goal_pose;
  tf2::transformEigenToKDL(start_pose, kdl_start_pose);
  tf2::transformEigenToKDL(goal_pose, kdl_goal_pose);
  double eqradius = planner_limits_.getCartesianLimits().getMaxTranslationalVelocity() /
                    planner_limits_.getCartesianLimits().getMaxRotationalVelocity();
  KDL::RotationalInterpolation* rot_interpo = new KDL::RotationalInterpolation_SingleAxis();
 
  return std::unique_ptr<KDL::Path>(
      std::make_unique<KDL::Path_Line>(kdl_start_pose, kdl_goal_pose, rot_interpo, eqradius, true));
}
 
}  // namespace pilz_industrial_motion_planner