tolerances.h

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// Copyright (C) 2013, PAL Robotics S.L.
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#ifndef JOINT_TRAJECTORY_CONTROLLER_TOLERANCES_H
#define JOINT_TRAJECTORY_CONTROLLER_TOLERANCES_H

// C++ standard
#include <cassert>
#include <cmath>
#include <string>
#include <vector>

// ROS
#include <ros/node_handle.h>

// ROS messages
#include <control_msgs/FollowJointTrajectoryAction.h>

namespace joint_trajectory_controller
{

template<class Scalar>
struct StateTolerances
{
  StateTolerances(Scalar position_tolerance     = static_cast<Scalar>(0.0),
                  Scalar velocity_tolerance     = static_cast<Scalar>(0.0),
                  Scalar acceleration_tolerance = static_cast<Scalar>(0.0))
    : position(position_tolerance),
      velocity(velocity_tolerance),
      acceleration(acceleration_tolerance)
  {}

  Scalar position;
  Scalar velocity;
  Scalar acceleration;
};

template<class Scalar>
struct SegmentTolerances
{
  SegmentTolerances(const typename std::vector<StateTolerances<Scalar> >::size_type& size = 0)
    : state_tolerance(size, static_cast<Scalar>(0.0)),
      goal_state_tolerance(size, static_cast<Scalar>(0.0)),
      goal_time_tolerance(static_cast<Scalar>(0.0))
  {}

  std::vector<StateTolerances<Scalar> > state_tolerance;

  std::vector<StateTolerances<Scalar> > goal_state_tolerance;

  Scalar goal_time_tolerance;
};

template <class State>
inline bool checkStateTolerance(const State&                                                 state_error,
                                const std::vector<StateTolerances<typename State::Scalar> >& state_tolerance,
                                bool show_errors = false)
{
  const unsigned int n_joints = state_tolerance.size();

  // Preconditions
  assert(n_joints == state_error.position.size());
  assert(n_joints == state_error.velocity.size());
  assert(n_joints == state_error.acceleration.size());

  for (unsigned int i = 0; i < n_joints; ++i)
  {
    using std::abs;
    const StateTolerances<typename State::Scalar>& tol = state_tolerance[i]; // Alias for brevity
    const bool is_valid = !(tol.position     > 0.0 && abs(state_error.position[i])     > tol.position) &&
                          !(tol.velocity     > 0.0 && abs(state_error.velocity[i])     > tol.velocity) &&
                          !(tol.acceleration > 0.0 && abs(state_error.acceleration[i]) > tol.acceleration);

    if (!is_valid)
    {
      if( show_errors )
      {
        ROS_ERROR_STREAM_NAMED("tolerances","Path state tolerances failed on joint " << i);

        if (tol.position     > 0.0 && abs(state_error.position[i])     > tol.position)
          ROS_ERROR_STREAM_NAMED("tolerances","Position Error: " << state_error.position[i] <<
            " Position Tolerance: " << tol.position);
        if (tol.velocity     > 0.0 && abs(state_error.velocity[i])     > tol.velocity)
          ROS_ERROR_STREAM_NAMED("tolerances","Velocity Error: " << state_error.velocity[i] <<
            " Velocity Tolerance: " << tol.velocity);
        if (tol.acceleration > 0.0 && abs(state_error.acceleration[i]) > tol.acceleration)
          ROS_ERROR_STREAM_NAMED("tolerances","Acceleration Error: " << state_error.acceleration[i] <<
            " Acceleration Tolerance: " << tol.acceleration);
      }
      return false;
    }
  }
  return true;
}

template<class Scalar>
void updateStateTolerances(const control_msgs::JointTolerance& tol_msg, StateTolerances<Scalar>& tols)
{
  if      (tol_msg.position     > 0.0) {tols.position     = static_cast<Scalar>(tol_msg.position);}
  else if (tol_msg.position     < 0.0) {tols.position     = static_cast<Scalar>(0.0);}

  if      (tol_msg.velocity     > 0.0) {tols.velocity     = static_cast<Scalar>(tol_msg.velocity);}
  else if (tol_msg.velocity     < 0.0) {tols.velocity     = static_cast<Scalar>(0.0);}

  if      (tol_msg.acceleration > 0.0) {tols.acceleration = static_cast<Scalar>(tol_msg.acceleration);}
  else if (tol_msg.acceleration < 0.0) {tols.acceleration = static_cast<Scalar>(0.0);}
}

template<class Scalar>
void updateSegmentTolerances(const control_msgs::FollowJointTrajectoryGoal& goal,
                             const std::vector<std::string>&                joint_names,
                             SegmentTolerances<Scalar>&                     tols
)
{
  // Preconditions
  assert(joint_names.size() == tols.state_tolerance.size());
  assert(joint_names.size() == tols.goal_state_tolerance.size());

  typedef typename std::vector<std::string>::const_iterator                  StringConstIterator;
  typedef typename std::vector<control_msgs::JointTolerance>::const_iterator TolMsgConstIterator;

  for (StringConstIterator names_it = joint_names.begin(); names_it != joint_names.end(); ++names_it)
  {
    const typename std::vector<std::string>::size_type id = std::distance(joint_names.begin(), names_it);

    // Update path tolerances
    const std::vector<control_msgs::JointTolerance>& state_tol = goal.path_tolerance;
    for(TolMsgConstIterator state_tol_it = state_tol.begin(); state_tol_it != state_tol.end(); ++state_tol_it)
    {
      if (*names_it == state_tol_it->name) {updateStateTolerances(*state_tol_it, tols.state_tolerance[id]);}
    }

    // Update goal state tolerances
    const std::vector<control_msgs::JointTolerance>& g_state_tol = goal.goal_tolerance;
    for(TolMsgConstIterator g_state_tol_it = g_state_tol.begin(); g_state_tol_it != g_state_tol.end(); ++g_state_tol_it)
    {
      if (*names_it == g_state_tol_it->name) {updateStateTolerances(*g_state_tol_it, tols.goal_state_tolerance[id]);}
    }
  }

  // Update goal time tolerance
  const ros::Duration& goal_time_tolerance = goal.goal_time_tolerance;
  if      (goal_time_tolerance < ros::Duration(0.0)) {tols.goal_time_tolerance = 0.0;}
  else if (goal_time_tolerance > ros::Duration(0.0)) {tols.goal_time_tolerance = goal_time_tolerance.toSec();}
}

template<class Scalar>
SegmentTolerances<Scalar> getSegmentTolerances(const ros::NodeHandle& nh,
                                               const std::vector<std::string>& joint_names)
{
  const unsigned int n_joints = joint_names.size();
  joint_trajectory_controller::SegmentTolerances<Scalar> tolerances;

  // State and goal state tolerances
  double stopped_velocity_tolerance;
  nh.param("stopped_velocity_tolerance", stopped_velocity_tolerance, 0.01);

  tolerances.state_tolerance.resize(n_joints);
  tolerances.goal_state_tolerance.resize(n_joints);
  for (unsigned int i = 0; i < n_joints; ++i)
  {
    nh.param(joint_names[i] + "/trajectory", tolerances.state_tolerance[i].position,      0.0);
    nh.param(joint_names[i] + "/goal",       tolerances.goal_state_tolerance[i].position, 0.0);
    tolerances.goal_state_tolerance[i].velocity = stopped_velocity_tolerance;
  }

  // Goal time tolerance
  nh.param("goal_time", tolerances.goal_time_tolerance, 0.0);

  return tolerances;
}

} // namespace

#endif // header guard