trajectory_generator.cpp

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#include <pilz_industrial_motion_planner/trajectory_generator.h>
 
#include <cassert>
 
#include <tf2_eigen/tf2_eigen.hpp>
#include <tf2_kdl/tf2_kdl.hpp>
#include <boost/range/combine.hpp>
 
#include <kdl/velocityprofile_trap.hpp>
#include <moveit/robot_state/conversions.h>
 
#include <pilz_industrial_motion_planner/limits_container.h>
 
namespace pilz_industrial_motion_planner
{
static const rclcpp::Logger LOGGER = rclcpp::get_logger("moveit.pilz_industrial_motion_planner.trajectory_generator");
 
sensor_msgs::msg::JointState TrajectoryGenerator::filterGroupValues(const sensor_msgs::msg::JointState& robot_state,
                                                                    const std::string& group) const
{
  const std::vector<std::string>& group_joints{ robot_model_->getJointModelGroup(group)->getActiveJointModelNames() };
  sensor_msgs::msg::JointState group_state;
  group_state.name.reserve(group_joints.size());
  group_state.position.reserve(group_joints.size());
  group_state.velocity.reserve(group_joints.size());
 
  for (size_t i = 0; i < robot_state.name.size(); ++i)
  {
    if (std::find(group_joints.begin(), group_joints.end(), robot_state.name.at(i)) != group_joints.end())
    {
      group_state.name.push_back(robot_state.name.at(i));
      group_state.position.push_back(robot_state.position.at(i));
      if (i < robot_state.velocity.size())
      {
        group_state.velocity.push_back(robot_state.velocity.at(i));
      }
    }
  }
  return group_state;
}
 
void TrajectoryGenerator::cmdSpecificRequestValidation(const planning_interface::MotionPlanRequest& /*req*/) const
{
  // Empty implementation, in case the derived class does not want
  // to provide a command specific request validation.
}
 
void TrajectoryGenerator::checkVelocityScaling(const double& scaling_factor)
{
  if (!isScalingFactorValid(scaling_factor))
  {
    std::ostringstream os;
    os << "Velocity scaling not in range [" << MIN_SCALING_FACTOR << ", " << MAX_SCALING_FACTOR << "], "
       << "actual value is: " << scaling_factor;
    throw VelocityScalingIncorrect(os.str());
  }
}
 
void TrajectoryGenerator::checkAccelerationScaling(const double& scaling_factor)
{
  if (!isScalingFactorValid(scaling_factor))
  {
    std::ostringstream os;
    os << "Acceleration scaling not in range [" << MIN_SCALING_FACTOR << ", " << MAX_SCALING_FACTOR << "], "
       << "actual value is: " << scaling_factor;
    throw AccelerationScalingIncorrect(os.str());
  }
}
 
void TrajectoryGenerator::checkForValidGroupName(const std::string& group_name) const
{
  if (!robot_model_->hasJointModelGroup(group_name))
  {
    std::ostringstream os;
    os << "Unknown planning group: " << group_name;
    throw UnknownPlanningGroup(os.str());
  }
}
 
void TrajectoryGenerator::checkStartState(const moveit_msgs::msg::RobotState& start_state,
                                          const std::string& group) const
{
  if (start_state.joint_state.name.size() != start_state.joint_state.position.size())
  {
    throw SizeMismatchInStartState("Joint state name and position do not match in start state");
  }
 
  sensor_msgs::msg::JointState group_start_state{ filterGroupValues(start_state.joint_state, group) };
 
  // verify joint position limits
  const JointLimitsContainer& limits{ planner_limits_.getJointLimitContainer() };
  std::string error_msg;
  for (auto joint : boost::combine(group_start_state.name, group_start_state.position))
  {
    if (!limits.verifyPositionLimit(joint.get<0>(), joint.get<1>()))
    {
      error_msg.append(error_msg.empty() ? "start state joints outside their position limits: " : ", ");
      error_msg.append(joint.get<0>());
    }
  }
  if (!error_msg.empty())
  {
    throw JointsOfStartStateOutOfRange(error_msg);
  }
 
  // does not allow start velocity
  if (!std::all_of(group_start_state.velocity.begin(), group_start_state.velocity.end(),
                   [this](double v) { return std::fabs(v) < this->VELOCITY_TOLERANCE; }))
  {
    throw NonZeroVelocityInStartState("Trajectory Generator does not allow non-zero start velocity");
  }
}
 
void TrajectoryGenerator::checkJointGoalConstraint(const moveit_msgs::msg::Constraints& constraint,
                                                   const std::string& group_name) const
{
  for (auto const& joint_constraint : constraint.joint_constraints)
  {
    const std::string& curr_joint_name{ joint_constraint.joint_name };
 
    if (!robot_model_->getJointModelGroup(group_name)->hasJointModel(curr_joint_name))
    {
      std::ostringstream os;
      os << "Joint \"" << curr_joint_name << "\" does not belong to group \"" << group_name << "\"";
      throw JointConstraintDoesNotBelongToGroup(os.str());
    }
 
    if (!planner_limits_.getJointLimitContainer().verifyPositionLimit(curr_joint_name, joint_constraint.position))
    {
      std::ostringstream os;
      os << "Joint \"" << curr_joint_name << "\" violates joint limits in goal constraints";
      throw JointsOfGoalOutOfRange(os.str());
    }
  }
}
 
void TrajectoryGenerator::checkCartesianGoalConstraint(const moveit_msgs::msg::Constraints& constraint,
                                                       const moveit::core::RobotState& robot_state,
                                                       const moveit::core::JointModelGroup* const jmg) const
{
  assert(constraint.position_constraints.size() == 1);
  assert(constraint.orientation_constraints.size() == 1);
  const moveit_msgs::msg::PositionConstraint& pos_constraint{ constraint.position_constraints.front() };
  const moveit_msgs::msg::OrientationConstraint& ori_constraint{ constraint.orientation_constraints.front() };
 
  if (pos_constraint.link_name.empty())
  {
    throw PositionConstraintNameMissing("Link name of position constraint missing");
  }
 
  if (ori_constraint.link_name.empty())
  {
    throw OrientationConstraintNameMissing("Link name of orientation constraint missing");
  }
 
  if (pos_constraint.link_name != ori_constraint.link_name)
  {
    std::ostringstream os;
    os << "Position and orientation constraint name do not match"
       << "(Position constraint name: \"" << pos_constraint.link_name << "\" | Orientation constraint name: \""
       << ori_constraint.link_name << "\")";
    throw PositionOrientationConstraintNameMismatch(os.str());
  }
 
  const auto& lm = robot_state.getRigidlyConnectedParentLinkModel(pos_constraint.link_name);
  if (!lm || !jmg->canSetStateFromIK(lm->getName()))
  {
    std::ostringstream os;
    os << "No IK solver available for link: \"" << pos_constraint.link_name << "\"";
    throw NoIKSolverAvailable(os.str());
  }
 
  if (pos_constraint.constraint_region.primitive_poses.empty())
  {
    throw NoPrimitivePoseGiven("Primitive pose in position constraints of goal missing");
  }
}
 
void TrajectoryGenerator::checkGoalConstraints(
    const moveit_msgs::msg::MotionPlanRequest::_goal_constraints_type& goal_constraints, const std::string& group_name,
    const moveit::core::RobotState& rstate) const
{
  if (goal_constraints.size() != 1)
  {
    std::ostringstream os;
    os << "Exactly one goal constraint required, but " << goal_constraints.size() << " goal constraints given";
    throw NotExactlyOneGoalConstraintGiven(os.str());
  }
 
  const moveit_msgs::msg::Constraints& goal_con{ goal_constraints.front() };
  if (!isOnlyOneGoalTypeGiven(goal_con))
  {
    throw OnlyOneGoalTypeAllowed("Only cartesian XOR joint goal allowed");
  }
 
  if (isJointGoalGiven(goal_con))
  {
    checkJointGoalConstraint(goal_con, group_name);
  }
  else
  {
    checkCartesianGoalConstraint(goal_con, rstate, robot_model_->getJointModelGroup(group_name));
  }
}
 
void TrajectoryGenerator::validateRequest(const planning_interface::MotionPlanRequest& req,
                                          const moveit::core::RobotState& rstate) const
{
  checkVelocityScaling(req.max_velocity_scaling_factor);
  checkAccelerationScaling(req.max_acceleration_scaling_factor);
  checkForValidGroupName(req.group_name);
  checkStartState(req.start_state, req.group_name);
  checkGoalConstraints(req.goal_constraints, req.group_name, rstate);
}
 
void TrajectoryGenerator::setSuccessResponse(const moveit::core::RobotState& start_state, const std::string& group_name,
                                             const trajectory_msgs::msg::JointTrajectory& joint_trajectory,
                                             const rclcpp::Time& planning_start,
                                             planning_interface::MotionPlanResponse& res) const
{
  auto rt = std::make_shared<robot_trajectory::RobotTrajectory>(robot_model_, group_name);
  rt->setRobotTrajectoryMsg(start_state, joint_trajectory);
 
  res.trajectory_ = rt;
  res.error_code_.val = moveit_msgs::msg::MoveItErrorCodes::SUCCESS;
  res.planning_time_ = (clock_->now() - planning_start).seconds();
}
 
void TrajectoryGenerator::setFailureResponse(const rclcpp::Time& planning_start,
                                             planning_interface::MotionPlanResponse& res) const
{
  if (res.trajectory_)
  {
    res.trajectory_->clear();
  }
  res.planning_time_ = (clock_->now() - planning_start).seconds();
}
 
std::unique_ptr<KDL::VelocityProfile>
TrajectoryGenerator::cartesianTrapVelocityProfile(const double& max_velocity_scaling_factor,
                                                  const double& max_acceleration_scaling_factor,
                                                  const std::unique_ptr<KDL::Path>& path) const
{
  std::unique_ptr<KDL::VelocityProfile> vp_trans = std::make_unique<KDL::VelocityProfile_Trap>(
      max_velocity_scaling_factor * planner_limits_.getCartesianLimits().getMaxTranslationalVelocity(),
      max_acceleration_scaling_factor * planner_limits_.getCartesianLimits().getMaxTranslationalAcceleration());
 
  if (path->PathLength() > std::numeric_limits<double>::epsilon())  // avoid division by zero
  {
    vp_trans->SetProfile(0, path->PathLength());
  }
  else
  {
    vp_trans->SetProfile(0, std::numeric_limits<double>::epsilon());
  }
  return vp_trans;
}
 
bool TrajectoryGenerator::generate(const planning_scene::PlanningSceneConstPtr& scene,
                                   const planning_interface::MotionPlanRequest& req,
                                   planning_interface::MotionPlanResponse& res, double sampling_time)
{
  RCLCPP_INFO_STREAM(LOGGER, "Generating " << req.planner_id << " trajectory...");
  rclcpp::Time planning_begin = clock_->now();
 
  try
  {
    validateRequest(req, scene->getCurrentState());
  }
  catch (const MoveItErrorCodeException& ex)
  {
    RCLCPP_ERROR_STREAM(LOGGER, ex.what());
    res.error_code_.val = ex.getErrorCode();
    setFailureResponse(planning_begin, res);
    return false;
  }
 
  try
  {
    cmdSpecificRequestValidation(req);
  }
  catch (const MoveItErrorCodeException& ex)
  {
    RCLCPP_ERROR_STREAM(LOGGER, ex.what());
    res.error_code_.val = ex.getErrorCode();
    setFailureResponse(planning_begin, res);
    return false;
  }
 
  MotionPlanInfo plan_info(scene, req);
  try
  {
    extractMotionPlanInfo(scene, req, plan_info);
  }
  catch (const MoveItErrorCodeException& ex)
  {
    RCLCPP_ERROR_STREAM(LOGGER, ex.what());
    res.error_code_.val = ex.getErrorCode();
    setFailureResponse(planning_begin, res);
    return false;
  }
 
  trajectory_msgs::msg::JointTrajectory joint_trajectory;
  try
  {
    plan(plan_info.start_scene, req, plan_info, sampling_time, joint_trajectory);
  }
  catch (const MoveItErrorCodeException& ex)
  {
    RCLCPP_ERROR_STREAM(LOGGER, ex.what());
    res.error_code_.val = ex.getErrorCode();
    setFailureResponse(planning_begin, res);
    return false;
  }
 
  setSuccessResponse(plan_info.start_scene->getCurrentState(), req.group_name, joint_trajectory, planning_begin, res);
  return true;
}
 
TrajectoryGenerator::MotionPlanInfo::MotionPlanInfo(const planning_scene::PlanningSceneConstPtr& scene,
                                                    const planning_interface::MotionPlanRequest& req)
{
  auto ps = scene->diff();
  auto& start_state = ps->getCurrentStateNonConst();
  // update start state from req
  moveit::core::robotStateMsgToRobotState(scene->getTransforms(), req.start_state, start_state);
  start_state.update();
  start_scene = std::move(ps);
 
  // initialize info.start_joint_position with active joint values from start_state
  const double* positions = start_state.getVariablePositions();
  for (const auto* jm : start_state.getRobotModel()->getJointModelGroup(req.group_name)->getActiveJointModels())
  {
    const auto& names = jm->getVariableNames();
    for (std::size_t i = 0, j = jm->getFirstVariableIndex(); i < jm->getVariableCount(); ++i, ++j)
    {
      start_joint_position[names[i]] = positions[j];
    }
  }
}
 
}  // namespace pilz_industrial_motion_planner