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00001 /********************************************************************* 00002 * Software License Agreement (BSD License) 00003 * 00004 * Copyright (c) 2008, Willow Garage, Inc. 00005 * All rights reserved. 00006 * 00007 * Redistribution and use in source and binary forms, with or without 00008 * modification, are permitted provided that the following conditions 00009 * are met: 00010 * 00011 * * Redistributions of source code must retain the above copyright 00012 * notice, this list of conditions and the following disclaimer. 00013 * * Redistributions in binary form must reproduce the above 00014 * copyright notice, this list of conditions and the following 00015 * disclaimer in the documentation and/or other materials provided 00016 * with the distribution. 00017 * * Neither the name of the Willow Garage nor the names of its 00018 * contributors may be used to endorse or promote products derived 00019 * from this software without specific prior written permission. 00020 * 00021 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 00022 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 00023 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 00024 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 00025 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 00026 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 00027 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 00028 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 00029 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 00030 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 00031 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 00032 * POSSIBILITY OF SUCH DAMAGE. 00033 *********************************************************************/ 00034 00035 #include "robot_mechanism_controllers/joint_velocity_controller.h" 00036 #include "pluginlib/class_list_macros.h" 00037 00038 PLUGINLIB_DECLARE_CLASS(robot_mechanism_controllers, JointVelocityController, controller::JointVelocityController, pr2_controller_interface::Controller) 00039 00040 using namespace std; 00041 00042 namespace controller { 00043 00044 JointVelocityController::JointVelocityController() 00045 : joint_state_(NULL), command_(0), robot_(NULL), last_time_(0), loop_count_(0) 00046 { 00047 } 00048 00049 JointVelocityController::~JointVelocityController() 00050 { 00051 sub_command_.shutdown(); 00052 } 00053 00054 bool JointVelocityController::init(pr2_mechanism_model::RobotState *robot, const std::string &joint_name, 00055 const control_toolbox::Pid &pid) 00056 { 00057 assert(robot); 00058 robot_ = robot; 00059 last_time_ = robot->getTime(); 00060 00061 joint_state_ = robot_->getJointState(joint_name); 00062 if (!joint_state_) 00063 { 00064 ROS_ERROR("JointVelocityController could not find joint named \"%s\"\n", 00065 joint_name.c_str()); 00066 return false; 00067 } 00068 00069 pid_controller_ = pid; 00070 00071 return true; 00072 } 00073 00074 bool JointVelocityController::init(pr2_mechanism_model::RobotState *robot, ros::NodeHandle &n) 00075 { 00076 assert(robot); 00077 node_ = n; 00078 robot_ = robot; 00079 00080 std::string joint_name; 00081 if (!node_.getParam("joint", joint_name)) { 00082 ROS_ERROR("No joint given (namespace: %s)", node_.getNamespace().c_str()); 00083 return false; 00084 } 00085 if (!(joint_state_ = robot->getJointState(joint_name))) 00086 { 00087 ROS_ERROR("Could not find joint \"%s\" (namespace: %s)", 00088 joint_name.c_str(), node_.getNamespace().c_str()); 00089 return false; 00090 } 00091 00092 if (!pid_controller_.init(ros::NodeHandle(node_, "pid"))) 00093 return false; 00094 00095 controller_state_publisher_.reset( 00096 new realtime_tools::RealtimePublisher<pr2_controllers_msgs::JointControllerState> 00097 (node_, "state", 1)); 00098 00099 sub_command_ = node_.subscribe<std_msgs::Float64>("command", 1, &JointVelocityController::setCommandCB, this); 00100 00101 return true; 00102 } 00103 00104 00105 void JointVelocityController::setGains(const double &p, const double &i, const double &d, const double &i_max, const double &i_min) 00106 { 00107 pid_controller_.setGains(p,i,d,i_max,i_min); 00108 00109 } 00110 00111 void JointVelocityController::getGains(double &p, double &i, double &d, double &i_max, double &i_min) 00112 { 00113 pid_controller_.getGains(p,i,d,i_max,i_min); 00114 } 00115 00116 std::string JointVelocityController::getJointName() 00117 { 00118 return joint_state_->joint_->name; 00119 } 00120 00121 // Set the joint velocity command 00122 void JointVelocityController::setCommand(double cmd) 00123 { 00124 command_ = cmd; 00125 } 00126 00127 // Return the current velocity command 00128 void JointVelocityController::getCommand(double & cmd) 00129 { 00130 cmd = command_; 00131 } 00132 00133 void JointVelocityController::update() 00134 { 00135 assert(robot_ != NULL); 00136 ros::Time time = robot_->getTime(); 00137 00138 double error = joint_state_->velocity_ - command_; 00139 dt_ = time - last_time_; 00140 double command = pid_controller_.updatePid(error, dt_); 00141 joint_state_->commanded_effort_ += command; 00142 00143 if(loop_count_ % 10 == 0) 00144 { 00145 if(controller_state_publisher_ && controller_state_publisher_->trylock()) 00146 { 00147 controller_state_publisher_->msg_.header.stamp = time; 00148 controller_state_publisher_->msg_.set_point = command_; 00149 controller_state_publisher_->msg_.process_value = joint_state_->velocity_; 00150 controller_state_publisher_->msg_.error = error; 00151 controller_state_publisher_->msg_.time_step = dt_.toSec(); 00152 controller_state_publisher_->msg_.command = command; 00153 00154 double dummy; 00155 getGains(controller_state_publisher_->msg_.p, 00156 controller_state_publisher_->msg_.i, 00157 controller_state_publisher_->msg_.d, 00158 controller_state_publisher_->msg_.i_clamp, 00159 dummy); 00160 controller_state_publisher_->unlockAndPublish(); 00161 } 00162 } 00163 loop_count_++; 00164 00165 last_time_ = time; 00166 } 00167 00168 void JointVelocityController::setCommandCB(const std_msgs::Float64ConstPtr& msg) 00169 { 00170 command_ = msg->data; 00171 } 00172 00173 } // namespace