driver.cpp

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/*
 * flir_ptu_driver ROS package
 * Copyright (C) 2014 Mike Purvis (mpurvis@clearpathrobotics.com)
 *
 * PTU ROS Package
 * Copyright (C) 2009 Erik Karulf (erik@cse.wustl.edu)
 *
 * Author: Toby Collett (University of Auckland)
 * Date: 2003-02-10
 *
 * Player - One Hell of a Robot Server
 * Copyright (C) 2000  Brian Gerkey   &  Kasper Stoy
 *                     gerkey@usc.edu    kaspers@robotics.usc.edu
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#include <boost/lexical_cast.hpp>
#include <boost/algorithm/string/trim.hpp>
#include <flir_ptu_driver/driver.h>
#include <serial/serial.h>
#include <ros/console.h>

#include <math.h>
#include <string>

using boost::lexical_cast;


namespace flir_ptu_driver
{

template<typename T>
T parseResponse(std::string responseBuffer)
{
  std::string trimmed = responseBuffer.substr(1);
  boost::trim(trimmed);
  T parsed = lexical_cast<T>(trimmed);
  ROS_DEBUG_STREAM("Parsed response value: " << parsed);
  return parsed;
}

bool PTU::initialized()
{
  return !!ser_ && ser_->isOpen() && initialized_;
}

bool PTU::initialize()
{
  ser_->write("ft ");  // terse feedback
  ser_->write("ed ");  // disable echo
  ser_->write("ci ");  // position mode
  ser_->read(20);

  // get pan tilt encoder res
  tr = getRes(PTU_TILT);
  pr = getRes(PTU_PAN);

  PMin = getLimit(PTU_PAN, PTU_MIN);
  PMax = getLimit(PTU_PAN, PTU_MAX);
  TMin = getLimit(PTU_TILT, PTU_MIN);
  TMax = getLimit(PTU_TILT, PTU_MAX);
  PSMin = getLimit(PTU_PAN, PTU_MIN_SPEED);
  PSMax = getLimit(PTU_PAN, PTU_MAX_SPEED);
  TSMin = getLimit(PTU_TILT, PTU_MIN_SPEED);
  TSMax = getLimit(PTU_TILT, PTU_MAX_SPEED);

  if (tr <= 0 || pr <= 0 || PMin == -1 || PMax == -1 || TMin == -1 || TMax == -1)
  {
    initialized_ = false;
  }
  else
  {
    initialized_ = true;
  }

  return initialized();
}

std::string PTU::sendCommand(std::string command)
{
  ser_->write(command);
  ROS_DEBUG_STREAM("TX: " << command);
  std::string buffer = ser_->readline(PTU_BUFFER_LEN);
  ROS_DEBUG_STREAM("RX: " << buffer);
  return buffer;
}

bool PTU::home()
{
  ROS_INFO("Sending command to reset PTU.");

  // Issue reset command
  ser_->flush();
  ser_->write(" r ");

  std::string actual_response, expected_response("!T!T!P!P*");

  // 30 seconds to receive full confirmation of reset action completed.
  for (int i = 0; i < 300; i++)
  {
    usleep(100000);

    if (ser_->available() >= expected_response.length())
    {
      ROS_INFO("PTU reset command response received.");
      ser_->read(actual_response, expected_response.length());
      return (actual_response == expected_response);
    }
  }

  ROS_WARN("PTU reset command response not received before timeout.");
  return false;
}

// get radians/count resolution
float PTU::getRes(char type)
{
  if (!ser_ || !ser_->isOpen()) return -1;

  std::string buffer = sendCommand(std::string() + type + "r ");

  if (buffer.length() < 3 || buffer[0] != '*')
  {
    ROS_ERROR("Error getting pan-tilt res");
    return -1;
  }

  double z = parseResponse<double>(buffer);
  z = z / 3600;  // degrees/count
  return z * M_PI / 180;  // radians/count
}

// get position limit
int PTU::getLimit(char type, char limType)
{
  if (!ser_ || !ser_->isOpen()) return -1;

  std::string buffer = sendCommand(std::string() + type + limType + " ");

  if (buffer.length() < 3 || buffer[0] != '*')
  {
    ROS_ERROR("Error getting pan-tilt limit");
    return -1;
  }

  return parseResponse<int>(buffer);
}


// get position in radians
float PTU::getPosition(char type)
{
  if (!initialized()) return -1;

  std::string buffer = sendCommand(std::string() + type + "p ");

  if (buffer.length() < 3 || buffer[0] != '*')
  {
    ROS_ERROR("Error getting pan-tilt pos");
    return -1;
  }

  return parseResponse<double>(buffer) * getResolution(type);
}


// set position in radians
bool PTU::setPosition(char type, float pos, bool block)
{
  if (!initialized()) return false;

  // get raw encoder count to move
  int count = static_cast<int>(pos / getResolution(type));

  // Check limits
  if (count < (type == PTU_TILT ? TMin : PMin) || count > (type == PTU_TILT ? TMax : PMax))
  {
    ROS_ERROR("Pan Tilt Value out of Range: %c %f(%d) (%d-%d)\n",
              type, pos, count, (type == PTU_TILT ? TMin : PMin), (type == PTU_TILT ? TMax : PMax));
    return false;
  }

  std::string buffer = sendCommand(std::string() + type + "p" +
                                   lexical_cast<std::string>(count) + " ");

  if (buffer.empty() || buffer[0] != '*')
  {
    ROS_ERROR("Error setting pan-tilt pos");
    return false;
  }

  if (block)
    while (getPosition(type) != pos) {};

  return true;
}

// get speed in radians/sec
float PTU::getSpeed(char type)
{
  if (!initialized()) return -1;

  std::string buffer = sendCommand(std::string() + type + "s ");

  if (buffer.length() < 3 || buffer[0] != '*')
  {
    ROS_ERROR("Error getting pan-tilt speed");
    return -1;
  }

  return parseResponse<double>(buffer) * getResolution(type);
}



// set speed in radians/sec
bool PTU::setSpeed(char type, float pos)
{
  if (!initialized()) return false;

  // get raw encoder speed to move
  int count = static_cast<int>(pos / getResolution(type));

  // Check limits
  if (abs(count) < (type == PTU_TILT ? TSMin : PSMin) || abs(count) > (type == PTU_TILT ? TSMax : PSMax))
  {
    ROS_ERROR("Pan Tilt Speed Value out of Range: %c %f(%d) (%d-%d)\n",
              type, pos, count, (type == PTU_TILT ? TSMin : PSMin), (type == PTU_TILT ? TSMax : PSMax));
    return false;
  }

  std::string buffer = sendCommand(std::string() + type + "s" +
                                   lexical_cast<std::string>(count) + " ");

  if (buffer.empty() || buffer[0] != '*')
  {
    ROS_ERROR("Error setting pan-tilt speed\n");
    return false;
  }

  return true;
}


// set movement mode (position/velocity)
bool PTU::setMode(char type)
{
  if (!initialized()) return false;

  std::string buffer = sendCommand(std::string("c") + type + " ");

  if (buffer.empty() || buffer[0] != '*')
  {
    ROS_ERROR("Error setting pan-tilt move mode");
    return false;
  }

  return true;
}

// get ptu mode
char PTU::getMode()
{
  if (!initialized()) return -1;

  // get pan tilt mode
  std::string buffer = sendCommand("c ");

  if (buffer.length() < 3 || buffer[0] != '*')
  {
    ROS_ERROR("Error getting pan-tilt pos");
    return -1;
  }

  if (buffer[2] == 'p')
    return PTU_VELOCITY;
  else if (buffer[2] == 'i')
    return PTU_POSITION;
  else
    return -1;
}

}  // namespace flir_ptu_driver