spring_transmission.cpp

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/*
 * Author: Stuart Glaser
 */
#include <math.h>
#include <pluginlib/class_list_macros.h>
#include "pr2_mechanism_model/robot.h"
#include "pr2_examples_gazebo/spring_transmission.h"
#include <angles/angles.h>

using namespace pr2_examples_gazebo;
using namespace pr2_hardware_interface;

PLUGINLIB_DECLARE_CLASS(pr2_examples_gazebo, SpringTransmission, 
                        pr2_examples_gazebo::SpringTransmission, 
                        pr2_mechanism_model::Transmission)


bool SpringTransmission::initXml(TiXmlElement *elt, pr2_mechanism_model::Robot *robot)
{
  const char *name = elt->Attribute("name");
  name_ = name ? name : "";

  TiXmlElement *jel = elt->FirstChildElement("joint");
  const char *joint_name = jel ? jel->Attribute("name") : NULL;
  if (!joint_name)
  {
    ROS_ERROR("SpringTransmission did not specify joint name");
    return false;
  }

  const boost::shared_ptr<const urdf::Joint> joint = robot->robot_model_.getJoint(joint_name);
  if (!joint)
  {
    ROS_ERROR("SpringTransmission could not find joint named \"%s\"", joint_name);
    return false;
  }
  joint_names_.push_back(joint_name);



  TiXmlElement *ael = elt->FirstChildElement("actuator");
  const char *actuator_name = ael ? ael->Attribute("name") : NULL;
  Actuator *a;
  if (!actuator_name || (a = robot->getActuator(actuator_name)) == NULL )
  {
    ROS_ERROR("SpringTransmission could not find actuator named \"%s\"", actuator_name);
    return false;
  }
  a->command_.enable_ = true;
  actuator_names_.push_back(actuator_name);




  spring_stiffness_ = atof(elt->FirstChildElement("springStiffness")->GetText());

  return true;
}

void SpringTransmission::propagatePosition(
   std::vector<Actuator*>& as, std::vector<pr2_mechanism_model::JointState*>& js)
{
  // propagate position to joint
  assert(as.size() == 1);
  assert(js.size() == 1);
  js[0]->position_ = as[0]->state_.position_;
  js[0]->velocity_ = as[0]->state_.velocity_;
  js[0]->measured_effort_ = as[0]->state_.last_measured_effort_;
}

void SpringTransmission::propagatePositionBackwards(
  std::vector<pr2_mechanism_model::JointState*>& js, std::vector<Actuator*>& as)
{
  assert(as.size() == 1);
  assert(js.size() == 1);
  as[0]->state_.position_ = js[0]->position_;
  as[0]->state_.velocity_ = js[0]->velocity_;
  as[0]->state_.last_measured_effort_ = js[0]->measured_effort_;
}

void SpringTransmission::propagateEffort(
   std::vector<pr2_mechanism_model::JointState*>& js, std::vector<Actuator*>& as)
{
  assert(as.size() == 1);
  assert(js.size() == 1);
  as[0]->command_.effort_ = -spring_stiffness_ * js[0]->position_;
}

void SpringTransmission::propagateEffortBackwards(
  std::vector<Actuator*>& as, std::vector<pr2_mechanism_model::JointState*>& js)
{
  assert(as.size() == 1);
  assert(js.size() == 1);
  js[0]->commanded_effort_ = as[0]->command_.effort_;
}