command_to_pwm.cpp

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/*
* Copyright (c) 2013, Shadow Robot Company, All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 3.0 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library.
*/

#include "sr_ronex_transmissions/mapping/general_io/command_to_pwm.hpp"
#include <ros_ethercat_model/robot_state.hpp>
#include <boost/lexical_cast.hpp>
#include <math.h>

namespace ronex
{
namespace mapping
{
namespace general_io
{
CommandToPWM::CommandToPWM(TiXmlElement* mapping_el, ros_ethercat_model::RobotState* robot)
  : RonexMapping(), pin_out_of_bound_(true)
{
  const char *ronex_name = mapping_el ? mapping_el->Attribute("ronex") : NULL;
  if (!ronex_name)
  {
    ROS_ERROR("RonexTransmission transmission did not specify the ronex name");
    return;
  }

  init_timer_ = nh_.createTimer(ros::Duration(0.01),
                                boost::bind(&CommandToPWM::try_init_cb_, this, _1, mapping_el, robot, ronex_name));
}

bool CommandToPWM::try_init_cb_(const ros::TimerEvent&, TiXmlElement* mapping_el, ros_ethercat_model::RobotState* robot,
                                const char* ronex_name)
{
  if ( !init_(mapping_el, robot, ronex_name) )
  {
    return false;
  }

  ROS_DEBUG_STREAM("RoNeX" << ronex_name << " is initialised now.");
  // stopping timer
  init_timer_.stop();

  is_initialized_ = true;
  return true;
}

bool CommandToPWM::init_(TiXmlElement* mapping_el, ros_ethercat_model::RobotState* robot, const char* ronex_name)
{
  // has the ronex been added by the driver?
  if ( robot->getCustomHW(ronex_name) == NULL )
    return false;

  general_io_ = static_cast<ronex::GeneralIO*>(robot->getCustomHW(ronex_name));
  if (!general_io_)
  {
    ROS_ERROR_STREAM("The RoNeX: " << ronex_name << " was not found on the system.");
    return false;
  }

  // read PWM module index from urdf
  const char *pwm_module = mapping_el ? mapping_el->Attribute("pwm_module") : NULL;
  if (!pwm_module)
  {
    ROS_ERROR("RonexTransmission transmission did not specify the pwm module.");
    return false;
  }
  // convert to size_t
  try
  {
    pwm_module_ = boost::lexical_cast<size_t>(pwm_module);
  }
  catch( boost::bad_lexical_cast const& )
  {
    ROS_ERROR("RonexTransmission: Couldn't parse pwm_module to a size_t.");
    return false;
  }

  // read PWM pin index from urdf
  const char *pin = mapping_el ? mapping_el->Attribute("pwm_pin") : NULL;
  if (!pin)
  {
    ROS_ERROR("RonexTransmission transmission did not specify the pwm pin.");
    return false;
  }
  // convert to size_t
  try
  {
    pwm_pin_index_ = boost::lexical_cast<size_t>(pin);
  }
  catch( boost::bad_lexical_cast const& )
  {
    ROS_ERROR("RonexTransmission: Couldn't parse pwm_pin to a size_t.");
    return false;
  }

  // read motor direction pin index from urdf
  const char *d_pin = mapping_el ? mapping_el->Attribute("direction_pin") : NULL;
  if (!d_pin)
  {
    ROS_ERROR("RonexTransmission transmission did not specify the direction pin.");
    return false;
  }
  // convert to size_t
  try
  {
    digital_pin_index_ = boost::lexical_cast<size_t>(d_pin);
  }
  catch( boost::bad_lexical_cast const& )
  {
    ROS_ERROR("RonexTransmission: Couldn't parse direction_pin to a size_t.");
    return false;
  }

  return true;
}

bool CommandToPWM::check_pins_in_bound_()
{
  // we ignore the first iteration as the array is not yet initialised.
  if ( first_iteration_ )
  {
    pin_out_of_bound_ = true;
    first_iteration_ = false;
    return false;
  }

  // we have to check here for the size otherwise the general io hasn't been updated.
  if ( pin_out_of_bound_ )
  {
    if ( pwm_module_ >= general_io_->command_.pwm_.size() )
    {
      // size_t is always >= 0 so no need to check lower bound
      ROS_ERROR_STREAM("Specified PWM module index is out of bound: " << pwm_module_ << " / max = " <<
                               general_io_->command_.pwm_.size() << ", not propagating the command to the RoNeX.");
      pin_out_of_bound_ = true;
      return false;
    }
    if ( pwm_pin_index_ > 1 )
    {
      // size_t is always >= 0 so no need to check lower bound
      ROS_ERROR_STREAM("Specified PWM pin is out of bound: " << pwm_pin_index_ <<
                               " / max = 1, not propagating the command to the RoNeX.");
      pin_out_of_bound_ = true;
      return false;
    }
    if ( digital_pin_index_ > general_io_->command_.digital_.size() )
    {
      // size_t is always >= 0 so no need to check lower bound
      ROS_ERROR_STREAM("Specified direction pin is out of bound: " << digital_pin_index_ << " / max = " <<
                               general_io_->command_.digital_.size() << " , not propagating the command to the RoNeX.");
      pin_out_of_bound_ = true;
      return false;
    }
  }

  pin_out_of_bound_ = false;
  return true;
}

void CommandToPWM::propagateToRonex(ros_ethercat_model::JointState *js)
{
  if ( !is_initialized_ )
    return;

  if ( check_pins_in_bound_() )
  {
    if ( pwm_pin_index_ == 0 )
      general_io_->command_.pwm_[pwm_module_].on_time_0 =
              static_cast<uint16_t>((static_cast<double>(general_io_->command_.pwm_[pwm_module_].period) *
                      abs(js->commanded_effort_) ) / 100);
    else
      general_io_->command_.pwm_[pwm_module_].on_time_1 =
              static_cast<uint16_t>((static_cast<double>(general_io_->command_.pwm_[pwm_module_].period) *
                      abs(js->commanded_effort_) ) / 100);

    // This is assigned by convention: negative effort sets the direction pin to 1.
    general_io_->command_.digital_[digital_pin_index_] = (js->commanded_effort_ < 0.0);
  }
}
}  // namespace general_io
}  // namespace mapping
}  // namespace ronex
/* For the emacs weenies in the crowd.
Local Variables:
c-basic-offset: 2
End:
*/