tolerances.hpp

// Copyright 2013 PAL Robotics S.L.
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//
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#ifndef JOINT_TRAJECTORY_CONTROLLER__TOLERANCES_HPP_
#define JOINT_TRAJECTORY_CONTROLLER__TOLERANCES_HPP_
 
#include <limits>
#include <stdexcept>
#include <string>
#include <vector>
 
#include "control_msgs/action/follow_joint_trajectory.hpp"
#include "joint_trajectory_controller_parameters.hpp"
 
namespace joint_trajectory_controller
{
struct StateTolerances
{
  double position = 0.0;
  double velocity = 0.0;
  double acceleration = 0.0;
};
 
struct SegmentTolerances
{
  explicit SegmentTolerances(size_t size = 0) : state_tolerance(size), goal_state_tolerance(size) {}
 
  std::vector<StateTolerances> state_tolerance;
 
  std::vector<StateTolerances> goal_state_tolerance;
 
  double goal_time_tolerance = 0.0;
};
 
SegmentTolerances get_segment_tolerances(rclcpp::Logger & jtc_logger, const Params & params)
{
  auto const & constraints = params.constraints;
  auto const n_joints = params.joints.size();
 
  SegmentTolerances tolerances;
  tolerances.goal_time_tolerance = constraints.goal_time;
  static auto logger = jtc_logger.get_child("tolerance");
  RCLCPP_DEBUG(logger, "goal_time %f", constraints.goal_time);
 
  // State and goal state tolerances
  tolerances.state_tolerance.resize(n_joints);
  tolerances.goal_state_tolerance.resize(n_joints);
  for (size_t i = 0; i < n_joints; ++i)
  {
    auto const joint = params.joints[i];
    tolerances.state_tolerance[i].position = constraints.joints_map.at(joint).trajectory;
    tolerances.goal_state_tolerance[i].position = constraints.joints_map.at(joint).goal;
    tolerances.goal_state_tolerance[i].velocity = constraints.stopped_velocity_tolerance;
 
    RCLCPP_DEBUG(
      logger, "%s %f", (joint + ".trajectory.position").c_str(),
      tolerances.state_tolerance[i].position);
    RCLCPP_DEBUG(
      logger, "%s %f", (joint + ".goal.position").c_str(),
      tolerances.goal_state_tolerance[i].position);
    RCLCPP_DEBUG(
      logger, "%s %f", (joint + ".goal.velocity").c_str(),
      tolerances.goal_state_tolerance[i].velocity);
  }
 
  return tolerances;
}
 
double resolve_tolerance_source(const double default_value, const double goal_value)
{
  // from
  // https://github.com/ros-controls/control_msgs/blob/master/control_msgs/msg/JointTolerance.msg
  // There are two special values for tolerances:
  // * 0 - The tolerance is unspecified and will remain at whatever the default is
  // * -1 - The tolerance is "erased".
  //        If there was a default, the joint will be allowed to move without restriction.
  constexpr double ERASE_VALUE = -1.0;
  auto is_erase_value = [=](double value)
  { return fabs(value - ERASE_VALUE) < std::numeric_limits<float>::epsilon(); };
 
  if (goal_value > 0.0)
  {
    return goal_value;
  }
  else if (is_erase_value(goal_value))
  {
    return 0.0;
  }
  else if (goal_value < 0.0)
  {
    throw std::runtime_error("Illegal tolerance value.");
  }
  return default_value;
}
 
SegmentTolerances get_segment_tolerances(
  rclcpp::Logger & jtc_logger, const SegmentTolerances & default_tolerances,
  const control_msgs::action::FollowJointTrajectory::Goal & goal,
  const std::vector<std::string> & joints)
{
  SegmentTolerances active_tolerances(default_tolerances);
  static auto logger = jtc_logger.get_child("tolerance");
 
  try
  {
    active_tolerances.goal_time_tolerance = resolve_tolerance_source(
      default_tolerances.goal_time_tolerance, rclcpp::Duration(goal.goal_time_tolerance).seconds());
  }
  catch (const std::runtime_error & e)
  {
    RCLCPP_ERROR_STREAM(
      logger, "Specified illegal goal_time_tolerance: "
                << rclcpp::Duration(goal.goal_time_tolerance).seconds()
                << ". Using default tolerances");
    return default_tolerances;
  }
  RCLCPP_DEBUG(logger, "%s %f", "goal_time", active_tolerances.goal_time_tolerance);
 
  // State and goal state tolerances
  for (auto joint_tol : goal.path_tolerance)
  {
    auto const joint = joint_tol.name;
    // map joint names from goal to active_tolerances
    auto it = std::find(joints.begin(), joints.end(), joint);
    if (it == joints.end())
    {
      RCLCPP_ERROR(
        logger, "%s",
        ("joint '" + joint +
         "' specified in goal.path_tolerance does not exist. "
         "Using default tolerances.")
          .c_str());
      return default_tolerances;
    }
    auto i = static_cast<size_t>(std::distance(joints.cbegin(), it));
    std::string interface = "";
    try
    {
      interface = "position";
      active_tolerances.state_tolerance[i].position = resolve_tolerance_source(
        default_tolerances.state_tolerance[i].position, joint_tol.position);
      interface = "velocity";
      active_tolerances.state_tolerance[i].velocity = resolve_tolerance_source(
        default_tolerances.state_tolerance[i].velocity, joint_tol.velocity);
      interface = "acceleration";
      active_tolerances.state_tolerance[i].acceleration = resolve_tolerance_source(
        default_tolerances.state_tolerance[i].acceleration, joint_tol.acceleration);
    }
    catch (const std::runtime_error & e)
    {
      RCLCPP_ERROR_STREAM(
        logger, "joint '" << joint << "' specified in goal.path_tolerance has a invalid "
                          << interface << " tolerance. Using default tolerances.");
      return default_tolerances;
    }
 
    RCLCPP_DEBUG(
      logger, "%s %f", (joint + ".state_tolerance.position").c_str(),
      active_tolerances.state_tolerance[i].position);
    RCLCPP_DEBUG(
      logger, "%s %f", (joint + ".state_tolerance.velocity").c_str(),
      active_tolerances.state_tolerance[i].velocity);
    RCLCPP_DEBUG(
      logger, "%s %f", (joint + ".state_tolerance.acceleration").c_str(),
      active_tolerances.state_tolerance[i].acceleration);
  }
  for (auto goal_tol : goal.goal_tolerance)
  {
    auto const joint = goal_tol.name;
    // map joint names from goal to active_tolerances
    auto it = std::find(joints.begin(), joints.end(), joint);
    if (it == joints.end())
    {
      RCLCPP_ERROR(
        logger, "%s",
        ("joint '" + joint +
         "' specified in goal.goal_tolerance does not exist. "
         "Using default tolerances.")
          .c_str());
      return default_tolerances;
    }
    auto i = static_cast<size_t>(std::distance(joints.cbegin(), it));
    std::string interface = "";
    try
    {
      interface = "position";
      active_tolerances.goal_state_tolerance[i].position = resolve_tolerance_source(
        default_tolerances.goal_state_tolerance[i].position, goal_tol.position);
      interface = "velocity";
      active_tolerances.goal_state_tolerance[i].velocity = resolve_tolerance_source(
        default_tolerances.goal_state_tolerance[i].velocity, goal_tol.velocity);
      interface = "acceleration";
      active_tolerances.goal_state_tolerance[i].acceleration = resolve_tolerance_source(
        default_tolerances.goal_state_tolerance[i].acceleration, goal_tol.acceleration);
    }
    catch (const std::runtime_error & e)
    {
      RCLCPP_ERROR_STREAM(
        logger, "joint '" << joint << "' specified in goal.goal_tolerance has a invalid "
                          << interface << " tolerance. Using default tolerances.");
      return default_tolerances;
    }
 
    RCLCPP_DEBUG(
      logger, "%s %f", (joint + ".goal_state_tolerance.position").c_str(),
      active_tolerances.goal_state_tolerance[i].position);
    RCLCPP_DEBUG(
      logger, "%s %f", (joint + ".goal_state_tolerance.velocity").c_str(),
      active_tolerances.goal_state_tolerance[i].velocity);
    RCLCPP_DEBUG(
      logger, "%s %f", (joint + ".goal_state_tolerance.acceleration").c_str(),
      active_tolerances.goal_state_tolerance[i].acceleration);
  }
 
  return active_tolerances;
}
 
inline bool check_state_tolerance_per_joint(
  const trajectory_msgs::msg::JointTrajectoryPoint & state_error, size_t joint_idx,
  const StateTolerances & state_tolerance, bool show_errors = false)
{
  using std::abs;
  const double error_position = state_error.positions[joint_idx];
  const double error_velocity =
    state_error.velocities.empty() ? 0.0 : state_error.velocities[joint_idx];
  const double error_acceleration =
    state_error.accelerations.empty() ? 0.0 : state_error.accelerations[joint_idx];
 
  const bool is_valid =
    !(state_tolerance.position > 0.0 && abs(error_position) > state_tolerance.position) &&
    !(state_tolerance.velocity > 0.0 && abs(error_velocity) > state_tolerance.velocity) &&
    !(state_tolerance.acceleration > 0.0 && abs(error_acceleration) > state_tolerance.acceleration);
 
  if (is_valid)
  {
    return true;
  }
 
  if (show_errors)
  {
    const auto logger = rclcpp::get_logger("tolerances");
    RCLCPP_ERROR(logger, "State tolerances failed for joint %lu:", joint_idx);
 
    if (state_tolerance.position > 0.0 && abs(error_position) > state_tolerance.position)
    {
      RCLCPP_ERROR(
        logger, "Position Error: %f, Position Tolerance: %f", error_position,
        state_tolerance.position);
    }
    if (state_tolerance.velocity > 0.0 && abs(error_velocity) > state_tolerance.velocity)
    {
      RCLCPP_ERROR(
        logger, "Velocity Error: %f, Velocity Tolerance: %f", error_velocity,
        state_tolerance.velocity);
    }
    if (
      state_tolerance.acceleration > 0.0 && abs(error_acceleration) > state_tolerance.acceleration)
    {
      RCLCPP_ERROR(
        logger, "Acceleration Error: %f, Acceleration Tolerance: %f", error_acceleration,
        state_tolerance.acceleration);
    }
  }
  return false;
}
 
}  // namespace joint_trajectory_controller
 
#endif  // JOINT_TRAJECTORY_CONTROLLER__TOLERANCES_HPP_