pr2_gripper_controller.cpp
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00034 
00035 #include "pr2_mechanism_controllers/pr2_gripper_controller.h"
00036 #include "angles/angles.h"
00037 #include "pluginlib/class_list_macros.h"
00038 
00039 PLUGINLIB_EXPORT_CLASS( controller::Pr2GripperController, pr2_controller_interface::Controller)
00040 
00041 using namespace std;
00042 
00043 namespace controller {
00044 
00045 Pr2GripperController::Pr2GripperController()
00046 : joint_state_(NULL),
00047   loop_count_(0), robot_(NULL), last_time_(0)
00048 {
00049 }
00050 
00051 Pr2GripperController::~Pr2GripperController()
00052 {
00053   sub_command_.shutdown();
00054 }
00055 
00056 bool Pr2GripperController::init(pr2_mechanism_model::RobotState *robot, ros::NodeHandle &n)
00057 {
00058   assert(robot);
00059   node_ = n;
00060   robot_ = robot;
00061 
00062   std::string joint_name;
00063   if (!node_.getParam("joint", joint_name)) {
00064     ROS_ERROR("No joint given (namespace: %s)", node_.getNamespace().c_str());
00065     return false;
00066   }
00067   if (!(joint_state_ = robot_->getJointState(joint_name)))
00068   {
00069     ROS_ERROR("Could not find joint named \"%s\" (namespace: %s)",
00070               joint_name.c_str(), node_.getNamespace().c_str());
00071     return false;
00072   }
00073   if (joint_state_->joint_->type != urdf::Joint::PRISMATIC)
00074   {
00075     ROS_ERROR("The joint \"%s\" was not prismatic (namespace: %s)",
00076               joint_name.c_str(), node_.getNamespace().c_str());
00077     return false;
00078   }
00079 
00080   if (!joint_state_->calibrated_)
00081   {
00082     ROS_ERROR("Joint %s is not calibrated (namespace: %s)",
00083               joint_state_->joint_->name.c_str(), node_.getNamespace().c_str());
00084     return false;
00085   }
00086 
00087   if (!pid_.init(ros::NodeHandle(node_, "pid")))
00088     return false;
00089 
00090   controller_state_publisher_.reset(
00091     new realtime_tools::RealtimePublisher<pr2_controllers_msgs::JointControllerState>
00092     (node_, "state", 1));
00093 
00094   sub_command_ = node_.subscribe<pr2_controllers_msgs::Pr2GripperCommand>(
00095     "command", 1, &Pr2GripperController::commandCB, this);
00096 
00097   return true;
00098 }
00099 
00100 void Pr2GripperController::update()
00101 {
00102   if (!joint_state_->calibrated_)
00103     return;
00104 
00105   assert(robot_ != NULL);
00106   double error(0);
00107   ros::Time time = robot_->getTime();
00108   assert(joint_state_->joint_);
00109   ros::Duration dt = time - last_time_;
00110 
00111   pr2_controllers_msgs::Pr2GripperCommandConstPtr command;
00112   command_box_.get(command);
00113   assert(command);
00114 
00115   // Computes the position error
00116   error = joint_state_->position_ - command->position;
00117 
00118   // Sets the effort (limited)
00119   double effort = pid_.updatePid(error, joint_state_->velocity_, dt);
00120   if (command->max_effort >= 0.0)
00121   {
00122     effort = std::max(-command->max_effort, std::min(effort, command->max_effort));
00123   }
00124   joint_state_->commanded_effort_ = effort;
00125 
00126   if(loop_count_ % 10 == 0)
00127   {
00128     if(controller_state_publisher_ && controller_state_publisher_->trylock())
00129     {
00130       controller_state_publisher_->msg_.header.stamp = time;
00131       controller_state_publisher_->msg_.set_point = command->position;
00132       controller_state_publisher_->msg_.process_value = joint_state_->position_;
00133       controller_state_publisher_->msg_.process_value_dot = joint_state_->velocity_;
00134       controller_state_publisher_->msg_.error = error;
00135       controller_state_publisher_->msg_.time_step = dt.toSec();
00136       controller_state_publisher_->msg_.command = effort;
00137 
00138       double dummy;
00139       pid_.getGains(controller_state_publisher_->msg_.p,
00140                     controller_state_publisher_->msg_.i,
00141                     controller_state_publisher_->msg_.d,
00142                     controller_state_publisher_->msg_.i_clamp,
00143                     dummy);
00144       controller_state_publisher_->unlockAndPublish();
00145     }
00146   }
00147   loop_count_++;
00148 
00149   last_time_ = time;
00150 }
00151 
00152 void Pr2GripperController::commandCB(const pr2_controllers_msgs::Pr2GripperCommandConstPtr& msg)
00153 {
00154   command_box_.set(msg);
00155 }
00156 
00157 }


pr2_mechanism_controllers
Author(s): Sachin Chita, John Hsu, Melonee Wise
autogenerated on Thu Apr 24 2014 15:44:51