├── images
    └── crosshair.jpg
├── README.asciidoc
├── package.xml
├── scripts
    ├── wheel_scaler.py
    ├── twist_to_motors.py
    ├── wheel_loopback.py
    ├── virtual_joystick.py
    ├── pid_velocity.py
    └── diff_tf.py
├── CMakeLists.txt
└── LICENSE


/images/crosshair.jpg:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/jfstepha/differential-drive/HEAD/images/crosshair.jpg


--------------------------------------------------------------------------------
/README.asciidoc:
--------------------------------------------------------------------------------
 1 | = differential-drive
 2 | 
 3 | This is the `differential_drive` ROS package written by Jon Stephan.
 4 | The originally published version of the package was released on
 5 | Google Code. When Google Code was archived, a copy was pulled into
 6 | GitHub.
 7 | 
 8 | The original package was written for ROS Groovy. In 2015 Mark Rose
 9 | made minor source changes to update the package for ROS Hydro and above,
10 | moving to catkin, removing code warnings,
11 | and changing the package layout to match current ROS guidelines.
12 | 
13 | ROS package page::
14 | http://wiki.ros.org/differential_drive
15 | 
16 | Jon Stephan’s repository location::
17 | https://github.com/jfstepha/differential-drive
18 | 
19 | Original, archived code repository::
20 | https://code.google.com/p/differential-drive/
21 | 
22 | == API Docs
23 | 
24 | Please refer to the ROS Wiki page for this package for API information:
25 | http://wiki.ros.org/differential_drive.
26 | 
27 | == License
28 | 
29 | The code is licensed under the terms of the Gnu General Public
30 | License, Version 3. See the file `LICENSE` for details.
31 | 
32 | 
33 | 


--------------------------------------------------------------------------------
/package.xml:
--------------------------------------------------------------------------------
 1 | <?xml version="1.0"?>
 2 | <package>
 3 |   <name>differential_drive</name>
 4 |   <version>0.1.0</version>
 5 |   <description>
 6 |     The differential_drive packageProvides some basic tools for interfacing a differential-drive 
 7 |     robot with the ROS navigation stack.  The intent is to make this 
 8 |     independent of specific robot implementation.
 9 |   </description>
10 | 
11 |   <maintainer email="jfstepha@gmail.com">Jon Stephan</maintainer>
12 | 
13 |   <license>GPLv3</license>
14 | 
15 |   <url type="repository">https://github.com/jstepha/differential_drive</url>
16 |   <url type="website">https://code.google.com/p/differential-drive/</url>
17 | 
18 |   <author email="jfstepha@gmail.com">Jon Stephan</author>
19 |   <author email="markrose@acm.org">Mark Rose</author>
20 | 
21 |   <buildtool_depend>catkin</buildtool_depend>
22 |   <build_depend>rospy</build_depend>
23 |   <build_depend>std_msgs</build_depend>
24 |   <build_depend>tf</build_depend>
25 |   <run_depend>rospy</run_depend>
26 |   <run_depend>std_msgs</run_depend>
27 |   <run_depend>tf</run_depend>
28 | 
29 | 
30 |   <!-- The export tag contains other, unspecified, tags -->
31 |   <export>
32 |     <!-- Other tools can request additional information be placed here -->
33 |   </export>
34 | 
35 | </package>
36 | 


--------------------------------------------------------------------------------
/scripts/wheel_scaler.py:
--------------------------------------------------------------------------------
 1 | #!/usr/bin/env python
 2 | 
 3 | """
 4 |    wheel_scaler
 5 |    scales the wheel readings (and inverts the sign)
 6 |    
 7 |      Copyright (C) 2012 Jon Stephan. 
 8 |      
 9 |     This program is free software: you can redistribute it and/or modify
10 |     it under the terms of the GNU General Public License as published by
11 |     the Free Software Foundation, either version 3 of the License, or
12 |     (at your option) any later version.
13 | 
14 |     This program is distributed in the hope that it will be useful,
15 |     but WITHOUT ANY WARRANTY; without even the implied warranty of
16 |     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17 |     GNU General Public License for more details.
18 | 
19 |     You should have received a copy of the GNU General Public License
20 |     along with this program.  If not, see <http://www.gnu.org/licenses/>.
21 |    
22 | """
23 | 
24 | import rospy
25 | import roslib
26 | 
27 | from std_msgs.msg import Int16
28 | 
29 | def scaleWheel():
30 |     rospy.init_node("wheel_scaler")
31 |     rospy.loginfo("wheel_scaler started")
32 |     
33 |     scale = rospy.get_param('distance_scale', 1)
34 |     rospy.loginfo("wheel_scaler scale: %0.2f", scale)
35 |     
36 |     rospy.Subscriber("lwheel", Int16, lwheelCallback)
37 |     rospy.Subscriber("rwheel", Int16, rwheelCallback)
38 |     
39 |     lscaled_pub = rospy.Publisher("lwheel_scaled", Int16, queue_size=10)
40 |     rscaled_pub = rospy.Publisher("rwheel_scaled", Int16, queue_size=10) 
41 |     
42 |     ### testing sleep CPU usage
43 |     r = rospy.Rate(50) 
44 |     while not rospy.is_shutdown:
45 |         r.sleep()
46 |         
47 |     rospy.spin()
48 | 
49 | def lwheelCallback(msg):
50 |     lscaled_pub.publish( msg.data * -1 * scale)
51 | 
52 | def rwheelCallback(msg):
53 |     rscaled_pub.publish( msg.data * -1 * scale)
54 | 
55 | 
56 | if __name__ == '__main__':
57 |     """main"""
58 |     try:
59 |         scaleWheel()
60 |     except rospy.ROSInterruptException:
61 |         pass
62 | 


--------------------------------------------------------------------------------
/scripts/twist_to_motors.py:
--------------------------------------------------------------------------------
  1 | #!/usr/bin/env python
  2 | """
  3 |    twist_to_motors - converts a twist message to motor commands.  Needed for navigation stack
  4 |    
  5 |    
  6 |     Copyright (C) 2012 Jon Stephan. 
  7 |      
  8 |     This program is free software: you can redistribute it and/or modify
  9 |     it under the terms of the GNU General Public License as published by
 10 |     the Free Software Foundation, either version 3 of the License, or
 11 |     (at your option) any later version.
 12 | 
 13 |     This program is distributed in the hope that it will be useful,
 14 |     but WITHOUT ANY WARRANTY; without even the implied warranty of
 15 |     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 16 |     GNU General Public License for more details.
 17 | 
 18 |     You should have received a copy of the GNU General Public License
 19 |     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 20 | """
 21 | 
 22 | import rospy
 23 | import roslib
 24 | from std_msgs.msg import Float32
 25 | from geometry_msgs.msg import Twist 
 26 | 
 27 | #############################################################
 28 | #############################################################
 29 | class TwistToMotors():
 30 | #############################################################
 31 | #############################################################
 32 | 
 33 |     #############################################################
 34 |     def __init__(self):
 35 |     #############################################################
 36 |         rospy.init_node("twist_to_motors")
 37 |         nodename = rospy.get_name()
 38 |         rospy.loginfo("%s started" % nodename)
 39 |     
 40 |         self.w = rospy.get_param("~base_width", 0.2)
 41 |     
 42 |         self.pub_lmotor = rospy.Publisher('lwheel_vtarget', Float32, queue_size=10)
 43 |         self.pub_rmotor = rospy.Publisher('rwheel_vtarget', Float32, queue_size=10)
 44 |         rospy.Subscriber('twist', Twist, self.twistCallback)
 45 |     
 46 |     
 47 |         self.rate = rospy.get_param("~rate", 50)
 48 |         self.timeout_ticks = rospy.get_param("~timeout_ticks", 2)
 49 |         self.left = 0
 50 |         self.right = 0
 51 |         
 52 |     #############################################################
 53 |     def spin(self):
 54 |     #############################################################
 55 |     
 56 |         r = rospy.Rate(self.rate)
 57 |         idle = rospy.Rate(10)
 58 |         then = rospy.Time.now()
 59 |         self.ticks_since_target = self.timeout_ticks
 60 |     
 61 |         ###### main loop  ######
 62 |         while not rospy.is_shutdown():
 63 |         
 64 |             while not rospy.is_shutdown() and self.ticks_since_target < self.timeout_ticks:
 65 |                 self.spinOnce()
 66 |                 r.sleep()
 67 |             idle.sleep()
 68 |                 
 69 |     #############################################################
 70 |     def spinOnce(self):
 71 |     #############################################################
 72 |     
 73 |         # dx = (l + r) / 2
 74 |         # dr = (r - l) / w
 75 |             
 76 |         self.right = 1.0 * self.dx + self.dr * self.w / 2 
 77 |         self.left = 1.0 * self.dx - self.dr * self.w / 2
 78 |         # rospy.loginfo("publishing: (%d, %d)", left, right) 
 79 |                 
 80 |         self.pub_lmotor.publish(self.left)
 81 |         self.pub_rmotor.publish(self.right)
 82 |             
 83 |         self.ticks_since_target += 1
 84 | 
 85 |     #############################################################
 86 |     def twistCallback(self,msg):
 87 |     #############################################################
 88 |         # rospy.loginfo("-D- twistCallback: %s" % str(msg))
 89 |         self.ticks_since_target = 0
 90 |         self.dx = msg.linear.x
 91 |         self.dr = msg.angular.z
 92 |         self.dy = msg.linear.y
 93 |     
 94 | #############################################################
 95 | #############################################################
 96 | if __name__ == '__main__':
 97 |     """ main """
 98 |     try:
 99 |         twistToMotors = TwistToMotors()
100 |         twistToMotors.spin()
101 |     except rospy.ROSInterruptException:
102 |         pass
103 | 


--------------------------------------------------------------------------------
/scripts/wheel_loopback.py:
--------------------------------------------------------------------------------
  1 | #!/usr/bin/env python
  2 | """ 
  3 |     wheel_loopback - simulates a wheel - just for testing
  4 |     
  5 | """
  6 | 
  7 | #!/usr/bin/env python
  8 | #   Copyright 2012 Jon Stephan
  9 | #   jfstepha@gmail.com
 10 | #
 11 | #   This program is free software: you can redistribute it and/or modify
 12 | #   it under the terms of the GNU General Public License as published by
 13 | #   the Free Software Foundation, either version 3 of the License, or
 14 | #   (at your option) any later version.
 15 | #
 16 | #   This program is distributed in the hope that it will be useful,
 17 | #   but WITHOUT ANY WARRANTY; without even the implied warranty of
 18 | #   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 19 | #   GNU General Public License for more details.
 20 | #
 21 | #   You should have received a copy of the GNU General Public License
 22 | #   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 23 | 
 24 | import rospy
 25 | import roslib
 26 | from std_msgs.msg import Float32
 27 | from std_msgs.msg import Int16
 28 | 
 29 | ################################################
 30 | ################################################
 31 | class WheelLoopback():
 32 | ################################################
 33 | ################################################
 34 | 
 35 |     ###############################################
 36 |     def __init__(self):
 37 |     ###############################################
 38 |         rospy.init_node("wheel_loopback");
 39 |         self.nodename = rospy.get_name()
 40 |         rospy.loginfo("%s started" % self.nodename)
 41 |         
 42 |         self.rate = rospy.get_param("~rate", 200)
 43 |         self.timeout_secs = rospy.get_param("~timeout_secs", 0.5)
 44 |         self.ticks_meter = float(rospy.get_param('~ticks_meter', 50))
 45 |         self.velocity_scale = float(rospy.get_param('~velocity_scale', 255))
 46 |         self.latest_motor = 0
 47 |         
 48 |         self.wheel = 0
 49 |         
 50 |         rospy.Subscriber('motor', Int16, self.motor_callback)
 51 |         
 52 |         self.pub_wheel = rospy.Publisher('wheel', Int16, queue_size=10)
 53 |         
 54 |     ###############################################
 55 |     def spin(self):
 56 |     ###############################################
 57 |         r = rospy.Rate
 58 |         self.secs_since_target = self.timeout_secs
 59 |         self.then = rospy.Time.now()
 60 |         self.latest_msg_time = rospy.Time.now()
 61 |         rospy.loginfo("-D- spinning")
 62 |         
 63 |         ###### main loop #########
 64 |         while not rospy.is_shutdown():
 65 |             while not rospy.is_shutdown() and self.secs_since_target < self.timeout_secs:
 66 |                 self.spinOnce()
 67 |                 r.sleep
 68 |                 self.secs_since_target = rospy.Time.now() - self.latest_msg_time
 69 |                 self.secs_since_target = self.secs_since_target.to_sec()
 70 |                 #rospy.loginfo("  inside: secs_since_target: %0.3f" % self.secs_since_target)
 71 |                 
 72 |             # it's been more than timeout_ticks since we recieved a message
 73 |             self.secs_since_target = rospy.Time.now() - self.latest_msg_time
 74 |             self.secs_since_target = self.secs_since_target.to_sec()
 75 |             # rospy.loginfo("  outside: secs_since_target: %0.3f" % self.secs_since_target)
 76 |             self.velocity = 0
 77 |             r.sleep
 78 |         
 79 |     ###############################################
 80 |     def spinOnce(self):
 81 |     ###############################################
 82 |         self.velocity = self.latest_motor / self.velocity_scale
 83 |         if abs(self.velocity) > 0:
 84 |             self.seconds_per_tick = abs( 1 / (self.velocity * self.ticks_meter))
 85 |             elapsed = rospy.Time.now() - self.then 
 86 |             elapsed = elapsed.to_sec()
 87 |             rospy.loginfo("spinOnce: vel=%0.3f sec/tick=%0.3f elapsed:%0.3f" % (self.velocity, self.seconds_per_tick, elapsed))
 88 |         
 89 |             if (elapsed > self.seconds_per_tick):
 90 |                 rospy.loginfo("incrementing wheel")
 91 |                 if self.velocity > 0:
 92 |                     self.wheel += 1
 93 |                 else:
 94 |                     self.wheel -= 1
 95 |                 self.pub_wheel.publish(self.wheel)
 96 |                 self.then = rospy.Time.now()
 97 |             
 98 |         
 99 |     
100 |     ###############################################
101 |     def motor_callback(self, msg):
102 |     ###############################################
103 |         # rospy.loginfo("%s recieved %d" % (self.nodename, msg.data))
104 |         self.latest_motor = msg.data
105 |         self.latest_msg_time = rospy.Time.now()
106 |         
107 |         
108 |         
109 | ################################################
110 | ################################################
111 | if __name__ == '__main__':
112 |     """ main """
113 |     try:
114 |         wheelLoopback = WheelLoopback()
115 |         wheelLoopback.spin()
116 |     except rospy.ROSInterruptException:
117 |         pass
118 | 


--------------------------------------------------------------------------------
/scripts/virtual_joystick.py:
--------------------------------------------------------------------------------
  1 | #!/usr/bin/env python
  2 | 
  3 | """
  4 | 
  5 |     Copyright (C) 2012 Jon Stephan. 
  6 |      
  7 |     This program is free software: you can redistribute it and/or modify
  8 |     it under the terms of the GNU General Public License as published by
  9 |     the Free Software Foundation, either version 3 of the License, or
 10 |     (at your option) any later version.
 11 | 
 12 |     This program is distributed in the hope that it will be useful,
 13 |     but WITHOUT ANY WARRANTY; without even the implied warranty of
 14 |     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 15 |     GNU General Public License for more details.
 16 | 
 17 |     You should have received a copy of the GNU General Public License
 18 |     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 19 | 
 20 | """
 21 | import sys
 22 | 
 23 | import roslib; roslib.load_manifest('differential_drive')
 24 | import rospy
 25 | from geometry_msgs.msg import Twist
 26 | import inspect, os
 27 | 
 28 | 
 29 | from PySide import QtGui, QtCore
 30 | 
 31 | ##########################################################################
 32 | ##########################################################################
 33 | class MainWindow(QtGui.QMainWindow):
 34 | ##########################################################################
 35 | ##########################################################################
 36 | 
 37 |     #####################################################################    
 38 |     def __init__(self):
 39 |     #####################################################################    
 40 |         super(MainWindow, self).__init__()
 41 |         self.timer_rate = rospy.get_param('~publish_rate', 50)
 42 |         self.pub_twist = rospy.Publisher('twist', Twist, queue_size=10)
 43 |         
 44 |         self.initUI()
 45 |         
 46 |     #####################################################################    
 47 |     def initUI(self):      
 48 |     #####################################################################    
 49 |         
 50 |         img_path = os.path.dirname(os.path.abspath(inspect.getfile(inspect.currentframe()))) + "/../images/crosshair.jpg"
 51 |         rospy.loginfo("initUI img_path: %s" % img_path)
 52 | 
 53 |         self.statusBar()
 54 |         
 55 |         self.setStyleSheet("QMainWindow { border-image: url(%s); }" % img_path)
 56 |         
 57 |                 
 58 |         self.setGeometry(0, 600, 200, 200)
 59 |         self.setWindowTitle('Virtual Joystick')
 60 |         self.show()
 61 |         self.timer = QtCore.QBasicTimer()
 62 |         
 63 |         self.statusBar().showMessage('started')
 64 |         
 65 |     #####################################################################    
 66 |     def mousePressEvent(self, event):
 67 |     #####################################################################    
 68 |         self.statusBar().showMessage('mouse clicked')
 69 |         self.timer.start(self.timer_rate, self)
 70 |         self.get_position(event)
 71 |         
 72 |     #####################################################################    
 73 |     def mouseReleaseEvent(self, event):
 74 |     #####################################################################    
 75 |         self.statusBar().showMessage('mouse released')
 76 |         self.timer.stop()
 77 |         
 78 |     #####################################################################    
 79 |     def mouseMoveEvent(self, event):
 80 |     #####################################################################    
 81 |         self.get_position(event)
 82 |         
 83 |     #####################################################################    
 84 |     def get_position(self, event):
 85 |     #####################################################################    
 86 |         s = self.size()
 87 |         s_w = s.width()
 88 |         s_h = s.height()
 89 |         pos = event.pos()
 90 |         self.x = 1.0 * pos.x() / s_w
 91 |         self.y = 1.0 * pos.y() / s_h
 92 |         
 93 |         self.statusBar().showMessage('point (%0.2f, %0.2f)' % (self.x,self.y))
 94 |         
 95 |     #####################################################################    
 96 |     def timerEvent(self, event):
 97 |     #####################################################################    
 98 |         # self.statusBar().showMessage("timer tick")
 99 |         self.pubTwist()
100 |         
101 |     #######################################################
102 |     def pubTwist(self):
103 |     #######################################################
104 |         # rospy.loginfo("publishing twist from (%0.3f,%0.3f)" %(self.x,self.y))
105 |         self.twist = Twist()
106 |         self.twist.linear.x = (1-self.y) * (x_max - x_min) + x_min
107 |         self.twist.linear.y = 0
108 |         self.twist.linear.z = 0
109 |         self.twist.angular.x = 0
110 |         self.twist.angular.y = 0
111 |         self.twist.angular.z = (1-self.x) * (r_max - r_min) + r_min
112 |         
113 |         if self.twist.linear.x > x_max:
114 |             self.twist.linear.x = x_max
115 |         if self.twist.linear.x < x_min:
116 |             self.twist.linear.x = x_min
117 |         if self.twist.angular.z > r_max:
118 |             self.twist.angular.z = r_max
119 |         if self.twist.angular.z < r_min:
120 |             self.twist.angular.z = r_min
121 |         
122 |         self.pub_twist.publish( self.twist )
123 |         
124 | ##########################################################################
125 | ##########################################################################
126 | def main():
127 | ##########################################################################
128 | ##########################################################################
129 |     rospy.init_node('virtual_joystick')
130 |     rospy.loginfo('virtual_joystick started')
131 |     global x_min
132 |     global x_max
133 |     global r_min
134 |     global r_max
135 |     
136 |     x_min = rospy.get_param("~x_min", -0.20)
137 |     x_max = rospy.get_param("~x_max", 0.20)
138 |     r_min = rospy.get_param("~r_min", -1.0)
139 |     r_max = rospy.get_param("~r_max", 1.0)
140 |     
141 |     app = QtGui.QApplication(sys.argv)
142 |     ex = MainWindow()
143 |     sys.exit(app.exec_())
144 | 
145 | if __name__ == '__main__':
146 |     try:
147 |         main()
148 |     except rospy.ROSInterruptException: pass
149 | 


--------------------------------------------------------------------------------
/CMakeLists.txt:
--------------------------------------------------------------------------------
  1 | cmake_minimum_required(VERSION 2.8.3)
  2 | project(differential_drive)
  3 | 
  4 | ## Find catkin macros and libraries
  5 | ## if COMPONENTS list like find_package(catkin REQUIRED COMPONENTS xyz)
  6 | ## is used, also find other catkin packages
  7 | find_package(catkin REQUIRED)
  8 | 
  9 | ## System dependencies are found with CMake's conventions
 10 | # find_package(Boost REQUIRED COMPONENTS system)
 11 | 
 12 | 
 13 | ## Uncomment this if the package has a setup.py. This macro ensures
 14 | ## modules and global scripts declared therein get installed
 15 | ## See http://ros.org/doc/api/catkin/html/user_guide/setup_dot_py.html
 16 | # catkin_python_setup()
 17 | 
 18 | ################################################
 19 | ## Declare ROS messages, services and actions ##
 20 | ################################################
 21 | 
 22 | ## To declare and build messages, services or actions from within this
 23 | ## package, follow these steps:
 24 | ## * Let MSG_DEP_SET be the set of packages whose message types you use in
 25 | ##   your messages/services/actions (e.g. std_msgs, actionlib_msgs, ...).
 26 | ## * In the file package.xml:
 27 | ##   * add a build_depend tag for "message_generation"
 28 | ##   * add a build_depend and a run_depend tag for each package in MSG_DEP_SET
 29 | ##   * If MSG_DEP_SET isn't empty the following dependency has been pulled in
 30 | ##     but can be declared for certainty nonetheless:
 31 | ##     * add a run_depend tag for "message_runtime"
 32 | ## * In this file (CMakeLists.txt):
 33 | ##   * add "message_generation" and every package in MSG_DEP_SET to
 34 | ##     find_package(catkin REQUIRED COMPONENTS ...)
 35 | ##   * add "message_runtime" and every package in MSG_DEP_SET to
 36 | ##     catkin_package(CATKIN_DEPENDS ...)
 37 | ##   * uncomment the add_*_files sections below as needed
 38 | ##     and list every .msg/.srv/.action file to be processed
 39 | ##   * uncomment the generate_messages entry below
 40 | ##   * add every package in MSG_DEP_SET to generate_messages(DEPENDENCIES ...)
 41 | 
 42 | ## Generate messages in the 'msg' folder
 43 | # add_message_files(
 44 | #   FILES
 45 | #   Message1.msg
 46 | #   Message2.msg
 47 | # )
 48 | 
 49 | ## Generate services in the 'srv' folder
 50 | # add_service_files(
 51 | #   FILES
 52 | #   Service1.srv
 53 | #   Service2.srv
 54 | # )
 55 | 
 56 | ## Generate actions in the 'action' folder
 57 | # add_action_files(
 58 | #   FILES
 59 | #   Action1.action
 60 | #   Action2.action
 61 | # )
 62 | 
 63 | ## Generate added messages and services with any dependencies listed here
 64 | # generate_messages(
 65 | #   DEPENDENCIES
 66 | #   std_msgs  # Or other packages containing msgs
 67 | # )
 68 | 
 69 | ################################################
 70 | ## Declare ROS dynamic reconfigure parameters ##
 71 | ################################################
 72 | 
 73 | ## To declare and build dynamic reconfigure parameters within this
 74 | ## package, follow these steps:
 75 | ## * In the file package.xml:
 76 | ##   * add a build_depend and a run_depend tag for "dynamic_reconfigure"
 77 | ## * In this file (CMakeLists.txt):
 78 | ##   * add "dynamic_reconfigure" to
 79 | ##     find_package(catkin REQUIRED COMPONENTS ...)
 80 | ##   * uncomment the "generate_dynamic_reconfigure_options" section below
 81 | ##     and list every .cfg file to be processed
 82 | 
 83 | ## Generate dynamic reconfigure parameters in the 'cfg' folder
 84 | # generate_dynamic_reconfigure_options(
 85 | #   cfg/DynReconf1.cfg
 86 | #   cfg/DynReconf2.cfg
 87 | # )
 88 | 
 89 | ###################################
 90 | ## catkin specific configuration ##
 91 | ###################################
 92 | ## The catkin_package macro generates cmake config files for your package
 93 | ## Declare things to be passed to dependent projects
 94 | ## INCLUDE_DIRS: uncomment this if you package contains header files
 95 | ## LIBRARIES: libraries you create in this project that dependent projects also need
 96 | ## CATKIN_DEPENDS: catkin_packages dependent projects also need
 97 | ## DEPENDS: system dependencies of this project that dependent projects also need
 98 | catkin_package(
 99 | #  INCLUDE_DIRS include
100 | #  LIBRARIES differential_drive
101 | #  CATKIN_DEPENDS other_catkin_pkg
102 | #  DEPENDS system_lib
103 | )
104 | 
105 | ###########
106 | ## Build ##
107 | ###########
108 | 
109 | ## Specify additional locations of header files
110 | ## Your package locations should be listed before other locations
111 | # include_directories(include)
112 | 
113 | ## Declare a C++ library
114 | # add_library(differential_drive
115 | #   src/${PROJECT_NAME}/differential_drive.cpp
116 | # )
117 | 
118 | ## Add cmake target dependencies of the library
119 | ## as an example, code may need to be generated before libraries
120 | ## either from message generation or dynamic reconfigure
121 | # add_dependencies(differential_drive ${${PROJECT_NAME}_EXPORTED_TARGETS} ${catkin_EXPORTED_TARGETS})
122 | 
123 | ## Declare a C++ executable
124 | # add_executable(differential_drive_node src/differential_drive_node.cpp)
125 | 
126 | ## Add cmake target dependencies of the executable
127 | ## same as for the library above
128 | # add_dependencies(differential_drive_node ${${PROJECT_NAME}_EXPORTED_TARGETS} ${catkin_EXPORTED_TARGETS})
129 | 
130 | ## Specify libraries to link a library or executable target against
131 | # target_link_libraries(differential_drive_node
132 | #   ${catkin_LIBRARIES}
133 | # )
134 | 
135 | #############
136 | ## Install ##
137 | #############
138 | 
139 | # all install targets should use catkin DESTINATION variables
140 | # See http://ros.org/doc/api/catkin/html/adv_user_guide/variables.html
141 | 
142 | ## Mark executable scripts (Python etc.) for installation
143 | ## in contrast to setup.py, you can choose the destination
144 | # install(PROGRAMS
145 | #   scripts/my_python_script
146 | #   DESTINATION ${CATKIN_PACKAGE_BIN_DESTINATION}
147 | # )
148 | 
149 | ## Mark executables and/or libraries for installation
150 | # install(TARGETS differential_drive differential_drive_node
151 | #   ARCHIVE DESTINATION ${CATKIN_PACKAGE_LIB_DESTINATION}
152 | #   LIBRARY DESTINATION ${CATKIN_PACKAGE_LIB_DESTINATION}
153 | #   RUNTIME DESTINATION ${CATKIN_PACKAGE_BIN_DESTINATION}
154 | # )
155 | 
156 | ## Mark cpp header files for installation
157 | # install(DIRECTORY include/${PROJECT_NAME}/
158 | #   DESTINATION ${CATKIN_PACKAGE_INCLUDE_DESTINATION}
159 | #   FILES_MATCHING PATTERN "*.h"
160 | #   PATTERN ".svn" EXCLUDE
161 | # )
162 | 
163 | ## Mark other files for installation (e.g. launch and bag files, etc.)
164 | # install(FILES
165 | #   # myfile1
166 | #   # myfile2
167 | #   DESTINATION ${CATKIN_PACKAGE_SHARE_DESTINATION}
168 | # )
169 | 
170 | #############
171 | ## Testing ##
172 | #############
173 | 
174 | ## Add gtest based cpp test target and link libraries
175 | # catkin_add_gtest(${PROJECT_NAME}-test test/test_differential_drive.cpp)
176 | # if(TARGET ${PROJECT_NAME}-test)
177 | #   target_link_libraries(${PROJECT_NAME}-test ${PROJECT_NAME})
178 | # endif()
179 | 
180 | ## Add folders to be run by python nosetests
181 | # catkin_add_nosetests(test)
182 | 


--------------------------------------------------------------------------------
/scripts/pid_velocity.py:
--------------------------------------------------------------------------------
  1 | #!/usr/bin/env python
  2 | """
  3 |    pid_velocity - takes messages on wheel_vtarget 
  4 |       target velocities for the wheels and monitors wheel for feedback
  5 |       
  6 |     Copyright (C) 2012 Jon Stephan. 
  7 |      
  8 |     This program is free software: you can redistribute it and/or modify
  9 |     it under the terms of the GNU General Public License as published by
 10 |     the Free Software Foundation, either version 3 of the License, or
 11 |     (at your option) any later version.
 12 | 
 13 |     This program is distributed in the hope that it will be useful,
 14 |     but WITHOUT ANY WARRANTY; without even the implied warranty of
 15 |     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 16 |     GNU General Public License for more details.
 17 | 
 18 |     You should have received a copy of the GNU General Public License
 19 |     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 20 | """
 21 | 
 22 | import rospy
 23 | import roslib
 24 | 
 25 | from std_msgs.msg import Int16
 26 | from std_msgs.msg import Float32
 27 | from numpy import array
 28 | 
 29 |     
 30 | ######################################################
 31 | ######################################################
 32 | class PidVelocity():
 33 | ######################################################
 34 | ######################################################
 35 | 
 36 | 
 37 |     #####################################################
 38 |     def __init__(self):
 39 |     #####################################################
 40 |         rospy.init_node("pid_velocity")
 41 |         self.nodename = rospy.get_name()
 42 |         rospy.loginfo("%s started" % self.nodename)
 43 |         
 44 |         ### initialize variables
 45 |         self.target = 0
 46 |         self.motor = 0
 47 |         self.vel = 0
 48 |         self.integral = 0
 49 |         self.error = 0
 50 |         self.derivative = 0
 51 |         self.previous_error = 0
 52 |         self.wheel_prev = 0
 53 |         self.wheel_latest = 0
 54 |         self.then = rospy.Time.now()
 55 |         self.wheel_mult = 0
 56 |         self.prev_encoder = 0
 57 |         
 58 |         ### get parameters #### 
 59 |         self.Kp = rospy.get_param('~Kp',10)
 60 |         self.Ki = rospy.get_param('~Ki',10)
 61 |         self.Kd = rospy.get_param('~Kd',0.001)
 62 |         self.out_min = rospy.get_param('~out_min',-255)
 63 |         self.out_max = rospy.get_param('~out_max',255)
 64 |         self.rate = rospy.get_param('~rate',30)
 65 |         self.rolling_pts = rospy.get_param('~rolling_pts',2)
 66 |         self.timeout_ticks = rospy.get_param('~timeout_ticks',4)
 67 |         self.ticks_per_meter = rospy.get_param('ticks_meter', 20)
 68 |         self.vel_threshold = rospy.get_param('~vel_threshold', 0.001)
 69 |         self.encoder_min = rospy.get_param('encoder_min', -32768)
 70 |         self.encoder_max = rospy.get_param('encoder_max', 32768)
 71 |         self.encoder_low_wrap = rospy.get_param('wheel_low_wrap', (self.encoder_max - self.encoder_min) * 0.3 + self.encoder_min )
 72 |         self.encoder_high_wrap = rospy.get_param('wheel_high_wrap', (self.encoder_max - self.encoder_min) * 0.7 + self.encoder_min )
 73 |         self.prev_vel = [0.0] * self.rolling_pts
 74 |         self.wheel_latest = 0.0
 75 |         self.prev_pid_time = rospy.Time.now()
 76 |         rospy.logdebug("%s got Kp:%0.3f Ki:%0.3f Kd:%0.3f tpm:%0.3f" % (self.nodename, self.Kp, self.Ki, self.Kd, self.ticks_per_meter))
 77 |         
 78 |         #### subscribers/publishers 
 79 |         rospy.Subscriber("wheel", Int16, self.wheelCallback) 
 80 |         rospy.Subscriber("wheel_vtarget", Float32, self.targetCallback) 
 81 |         self.pub_motor = rospy.Publisher('motor_cmd',Float32, queue_size=10) 
 82 |         self.pub_vel = rospy.Publisher('wheel_vel', Float32, queue_size=10)
 83 |    
 84 |         
 85 |     #####################################################
 86 |     def spin(self):
 87 |     #####################################################
 88 |         self.r = rospy.Rate(self.rate) 
 89 |         self.then = rospy.Time.now()
 90 |         self.ticks_since_target = self.timeout_ticks
 91 |         self.wheel_prev = self.wheel_latest
 92 |         self.then = rospy.Time.now()
 93 |         while not rospy.is_shutdown():
 94 |             self.spinOnce()
 95 |             self.r.sleep()
 96 |             
 97 |     #####################################################
 98 |     def spinOnce(self):
 99 |     #####################################################
100 |         self.previous_error = 0.0
101 |         self.prev_vel = [0.0] * self.rolling_pts
102 |         self.integral = 0.0
103 |         self.error = 0.0
104 |         self.derivative = 0.0 
105 |         self.vel = 0.0
106 |         
107 |         # only do the loop if we've recently recieved a target velocity message
108 |         while not rospy.is_shutdown() and self.ticks_since_target < self.timeout_ticks:
109 |             self.calcVelocity()
110 |             self.doPid()
111 |             self.pub_motor.publish(self.motor)
112 |             self.r.sleep()
113 |             self.ticks_since_target += 1
114 |             if self.ticks_since_target == self.timeout_ticks:
115 |                 self.pub_motor.publish(0)
116 |             
117 |     #####################################################
118 |     def calcVelocity(self):
119 |     #####################################################
120 |         self.dt_duration = rospy.Time.now() - self.then
121 |         self.dt = self.dt_duration.to_sec()
122 |         rospy.logdebug("-D- %s caclVelocity dt=%0.3f wheel_latest=%0.3f wheel_prev=%0.3f" % (self.nodename, self.dt, self.wheel_latest, self.wheel_prev))
123 |         
124 |         if (self.wheel_latest == self.wheel_prev):
125 |             # we haven't received an updated wheel lately
126 |             cur_vel = (1 / self.ticks_per_meter) / self.dt    # if we got a tick right now, this would be the velocity
127 |             if abs(cur_vel) < self.vel_threshold: 
128 |                 # if the velocity is < threshold, consider our velocity 0
129 |                 rospy.logdebug("-D- %s below threshold cur_vel=%0.3f vel=0" % (self.nodename, cur_vel))
130 |                 self.appendVel(0)
131 |                 self.calcRollingVel()
132 |             else:
133 |                 rospy.logdebug("-D- %s above threshold cur_vel=%0.3f" % (self.nodename, cur_vel))
134 |                 if abs(cur_vel) < self.vel:
135 |                     rospy.logdebug("-D- %s cur_vel < self.vel" % self.nodename)
136 |                     # we know we're slower than what we're currently publishing as a velocity
137 |                     self.appendVel(cur_vel)
138 |                     self.calcRollingVel()
139 |             
140 |         else:
141 |             # we received a new wheel value
142 |             cur_vel = (self.wheel_latest - self.wheel_prev) / self.dt
143 |             self.appendVel(cur_vel)
144 |             self.calcRollingVel()
145 |             rospy.logdebug("-D- %s **** wheel updated vel=%0.3f **** " % (self.nodename, self.vel))
146 |             self.wheel_prev = self.wheel_latest
147 |             self.then = rospy.Time.now()
148 |             
149 |         self.pub_vel.publish(self.vel)
150 |         
151 |     #####################################################
152 |     def appendVel(self, val):
153 |     #####################################################
154 |         self.prev_vel.append(val)
155 |         del self.prev_vel[0]
156 |         
157 |     #####################################################
158 |     def calcRollingVel(self):
159 |     #####################################################
160 |         p = array(self.prev_vel)
161 |         self.vel = p.mean()
162 |         
163 |     #####################################################
164 |     def doPid(self):
165 |     #####################################################
166 |         pid_dt_duration = rospy.Time.now() - self.prev_pid_time
167 |         pid_dt = pid_dt_duration.to_sec()
168 |         self.prev_pid_time = rospy.Time.now()
169 |         
170 |         self.error = self.target - self.vel
171 |         self.integral = self.integral + (self.error * pid_dt)
172 |         # rospy.loginfo("i = i + (e * dt):  %0.3f = %0.3f + (%0.3f * %0.3f)" % (self.integral, self.integral, self.error, pid_dt))
173 |         self.derivative = (self.error - self.previous_error) / pid_dt
174 |         self.previous_error = self.error
175 |     
176 |         self.motor = (self.Kp * self.error) + (self.Ki * self.integral) + (self.Kd * self.derivative)
177 |     
178 |         if self.motor > self.out_max:
179 |             self.motor = self.out_max
180 |             self.integral = self.integral - (self.error * pid_dt)
181 |         if self.motor < self.out_min:
182 |             self.motor = self.out_min
183 |             self.integral = self.integral - (self.error * pid_dt)
184 |       
185 |         if (self.target == 0):
186 |             self.motor = 0
187 |     
188 |         rospy.logdebug("vel:%0.2f tar:%0.2f err:%0.2f int:%0.2f der:%0.2f ## motor:%d " % 
189 |                       (self.vel, self.target, self.error, self.integral, self.derivative, self.motor))
190 |     
191 |     
192 | 
193 | 
194 |     #####################################################
195 |     def wheelCallback(self, msg):
196 |     ######################################################
197 |         enc = msg.data
198 |         if (enc < self.encoder_low_wrap and self.prev_encoder > self.encoder_high_wrap) :
199 |             self.wheel_mult = self.wheel_mult + 1
200 |             
201 |         if (enc > self.encoder_high_wrap and self.prev_encoder < self.encoder_low_wrap) :
202 |             self.wheel_mult = self.wheel_mult - 1
203 |            
204 |          
205 |         self.wheel_latest = 1.0 * (enc + self.wheel_mult * (self.encoder_max - self.encoder_min)) / self.ticks_per_meter 
206 |         self.prev_encoder = enc
207 |         
208 |         
209 | #        rospy.logdebug("-D- %s wheelCallback msg.data= %0.3f wheel_latest = %0.3f mult=%0.3f" % (self.nodename, enc, self.wheel_latest, self.wheel_mult))
210 |     
211 |     ######################################################
212 |     def targetCallback(self, msg):
213 |     ######################################################
214 |         self.target = msg.data
215 |         self.ticks_since_target = 0
216 |         # rospy.logdebug("-D- %s targetCallback " % (self.nodename))
217 |     
218 |     
219 | if __name__ == '__main__':
220 |     """ main """
221 |     try:
222 |         pidVelocity = PidVelocity()
223 |         pidVelocity.spin()
224 |     except rospy.ROSInterruptException:
225 |         pass
226 | 


--------------------------------------------------------------------------------
/scripts/diff_tf.py:
--------------------------------------------------------------------------------
  1 | #!/usr/bin/env python
  2 | 
  3 | """
  4 |    diff_tf.py - follows the output of a wheel encoder and
  5 |    creates tf and odometry messages.
  6 |    some code borrowed from the arbotix diff_controller script
  7 |    A good reference: http://rossum.sourceforge.net/papers/DiffSteer/
  8 |    
  9 |     Copyright (C) 2012 Jon Stephan. 
 10 |      
 11 |     This program is free software: you can redistribute it and/or modify
 12 |     it under the terms of the GNU General Public License as published by
 13 |     the Free Software Foundation, either version 3 of the License, or
 14 |     (at your option) any later version.
 15 | 
 16 |     This program is distributed in the hope that it will be useful,
 17 |     but WITHOUT ANY WARRANTY; without even the implied warranty of
 18 |     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 19 |     GNU General Public License for more details.
 20 | 
 21 |     You should have received a copy of the GNU General Public License
 22 |     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 23 |    
 24 |    ----------------------------------
 25 |    Portions of this code borrowed from the arbotix_python diff_controller.
 26 |    
 27 | diff_controller.py - controller for a differential drive
 28 |   Copyright (c) 2010-2011 Vanadium Labs LLC.  All right reserved.
 29 | 
 30 |   Redistribution and use in source and binary forms, with or without
 31 |   modification, are permitted provided that the following conditions are met:
 32 |       * Redistributions of source code must retain the above copyright
 33 |         notice, this list of conditions and the following disclaimer.
 34 |       * Redistributions in binary form must reproduce the above copyright
 35 |         notice, this list of conditions and the following disclaimer in the
 36 |         documentation and/or other materials provided with the distribution.
 37 |       * Neither the name of Vanadium Labs LLC nor the names of its 
 38 |         contributors may be used to endorse or promote products derived 
 39 |         from this software without specific prior written permission.
 40 |   
 41 |   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 42 |   ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 43 |   WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 44 |   DISCLAIMED. IN NO EVENT SHALL VANADIUM LABS BE LIABLE FOR ANY DIRECT, INDIRECT,
 45 |   INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 46 |   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
 47 |   OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 48 |   LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
 49 |   OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 50 |   ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 51 | 
 52 | """
 53 | 
 54 | import rospy
 55 | import roslib
 56 | roslib.load_manifest('differential_drive')
 57 | from math import sin, cos, pi
 58 | 
 59 | from geometry_msgs.msg import Quaternion
 60 | from geometry_msgs.msg import Twist
 61 | from nav_msgs.msg import Odometry
 62 | from tf.broadcaster import TransformBroadcaster
 63 | from std_msgs.msg import Int16
 64 | 
 65 | #############################################################################
 66 | class DiffTf:
 67 | #############################################################################
 68 | 
 69 |     #############################################################################
 70 |     def __init__(self):
 71 |     #############################################################################
 72 |         rospy.init_node("diff_tf")
 73 |         self.nodename = rospy.get_name()
 74 |         rospy.loginfo("-I- %s started" % self.nodename)
 75 |         
 76 |         #### parameters #######
 77 |         self.rate = rospy.get_param('~rate',10.0)  # the rate at which to publish the transform
 78 |         self.ticks_meter = float(rospy.get_param('ticks_meter', 50))  # The number of wheel encoder ticks per meter of travel
 79 |         self.base_width = float(rospy.get_param('~base_width', 0.245)) # The wheel base width in meters
 80 |         
 81 |         self.base_frame_id = rospy.get_param('~base_frame_id','base_link') # the name of the base frame of the robot
 82 |         self.odom_frame_id = rospy.get_param('~odom_frame_id', 'odom') # the name of the odometry reference frame
 83 |         
 84 |         self.encoder_min = rospy.get_param('encoder_min', -32768)
 85 |         self.encoder_max = rospy.get_param('encoder_max', 32768)
 86 |         self.encoder_low_wrap = rospy.get_param('wheel_low_wrap', (self.encoder_max - self.encoder_min) * 0.3 + self.encoder_min )
 87 |         self.encoder_high_wrap = rospy.get_param('wheel_high_wrap', (self.encoder_max - self.encoder_min) * 0.7 + self.encoder_min )
 88 |  
 89 |         self.t_delta = rospy.Duration(1.0/self.rate)
 90 |         self.t_next = rospy.Time.now() + self.t_delta
 91 |         
 92 |         # internal data
 93 |         self.enc_left = None        # wheel encoder readings
 94 |         self.enc_right = None
 95 |         self.left = 0               # actual values coming back from robot
 96 |         self.right = 0
 97 |         self.lmult = 0
 98 |         self.rmult = 0
 99 |         self.prev_lencoder = 0
100 |         self.prev_rencoder = 0
101 |         self.x = 0                  # position in xy plane 
102 |         self.y = 0
103 |         self.th = 0
104 |         self.dx = 0                 # speeds in x/rotation
105 |         self.dr = 0
106 |         self.then = rospy.Time.now()
107 |         
108 |         # subscriptions
109 |         rospy.Subscriber("lwheel", Int16, self.lwheelCallback)
110 |         rospy.Subscriber("rwheel", Int16, self.rwheelCallback)
111 |         self.odomPub = rospy.Publisher("odom", Odometry, queue_size=10)
112 |         self.odomBroadcaster = TransformBroadcaster()
113 |         
114 |     #############################################################################
115 |     def spin(self):
116 |     #############################################################################
117 |         r = rospy.Rate(self.rate)
118 |         while not rospy.is_shutdown():
119 |             self.update()
120 |             r.sleep()
121 |        
122 |      
123 |     #############################################################################
124 |     def update(self):
125 |     #############################################################################
126 |         now = rospy.Time.now()
127 |         if now > self.t_next:
128 |             elapsed = now - self.then
129 |             self.then = now
130 |             elapsed = elapsed.to_sec()
131 |             
132 |             # calculate odometry
133 |             if self.enc_left == None:
134 |                 d_left = 0
135 |                 d_right = 0
136 |             else:
137 |                 d_left = (self.left - self.enc_left) / self.ticks_meter
138 |                 d_right = (self.right - self.enc_right) / self.ticks_meter
139 |             self.enc_left = self.left
140 |             self.enc_right = self.right
141 |            
142 |             # distance traveled is the average of the two wheels 
143 |             d = ( d_left + d_right ) / 2
144 |             # this approximation works (in radians) for small angles
145 |             th = ( d_right - d_left ) / self.base_width
146 |             # calculate velocities
147 |             self.dx = d / elapsed
148 |             self.dr = th / elapsed
149 |            
150 |              
151 |             if (d != 0):
152 |                 # calculate distance traveled in x and y
153 |                 x = cos( th ) * d
154 |                 y = -sin( th ) * d
155 |                 # calculate the final position of the robot
156 |                 self.x = self.x + ( cos( self.th ) * x - sin( self.th ) * y )
157 |                 self.y = self.y + ( sin( self.th ) * x + cos( self.th ) * y )
158 |             if( th != 0):
159 |                 self.th = self.th + th
160 |                 
161 |             # publish the odom information
162 |             quaternion = Quaternion()
163 |             quaternion.x = 0.0
164 |             quaternion.y = 0.0
165 |             quaternion.z = sin( self.th / 2 )
166 |             quaternion.w = cos( self.th / 2 )
167 |             self.odomBroadcaster.sendTransform(
168 |                 (self.x, self.y, 0),
169 |                 (quaternion.x, quaternion.y, quaternion.z, quaternion.w),
170 |                 rospy.Time.now(),
171 |                 self.base_frame_id,
172 |                 self.odom_frame_id
173 |                 )
174 |             
175 |             odom = Odometry()
176 |             odom.header.stamp = now
177 |             odom.header.frame_id = self.odom_frame_id
178 |             odom.pose.pose.position.x = self.x
179 |             odom.pose.pose.position.y = self.y
180 |             odom.pose.pose.position.z = 0
181 |             odom.pose.pose.orientation = quaternion
182 |             odom.child_frame_id = self.base_frame_id
183 |             odom.twist.twist.linear.x = self.dx
184 |             odom.twist.twist.linear.y = 0
185 |             odom.twist.twist.angular.z = self.dr
186 |             self.odomPub.publish(odom)
187 |             
188 |             
189 | 
190 | 
191 |     #############################################################################
192 |     def lwheelCallback(self, msg):
193 |     #############################################################################
194 |         enc = msg.data
195 |         if (enc < self.encoder_low_wrap and self.prev_lencoder > self.encoder_high_wrap):
196 |             self.lmult = self.lmult + 1
197 |             
198 |         if (enc > self.encoder_high_wrap and self.prev_lencoder < self.encoder_low_wrap):
199 |             self.lmult = self.lmult - 1
200 |             
201 |         self.left = 1.0 * (enc + self.lmult * (self.encoder_max - self.encoder_min)) 
202 |         self.prev_lencoder = enc
203 |         
204 |     #############################################################################
205 |     def rwheelCallback(self, msg):
206 |     #############################################################################
207 |         enc = msg.data
208 |         if(enc < self.encoder_low_wrap and self.prev_rencoder > self.encoder_high_wrap):
209 |             self.rmult = self.rmult + 1
210 |         
211 |         if(enc > self.encoder_high_wrap and self.prev_rencoder < self.encoder_low_wrap):
212 |             self.rmult = self.rmult - 1
213 |             
214 |         self.right = 1.0 * (enc + self.rmult * (self.encoder_max - self.encoder_min))
215 |         self.prev_rencoder = enc
216 | 
217 | #############################################################################
218 | #############################################################################
219 | if __name__ == '__main__':
220 |     """ main """
221 |     try:
222 |         diffTf = DiffTf()
223 |         diffTf.spin()
224 |     except rospy.ROSInterruptException:
225 |         pass
226 | 


--------------------------------------------------------------------------------
/LICENSE:
--------------------------------------------------------------------------------
  1 |                     GNU GENERAL PUBLIC LICENSE
  2 |                        Version 3, 29 June 2007
  3 | 
  4 |  Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
  5 |  Everyone is permitted to copy and distribute verbatim copies
  6 |  of this license document, but changing it is not allowed.
  7 | 
  8 |                             Preamble
  9 | 
 10 |   The GNU General Public License is a free, copyleft license for
 11 | software and other kinds of works.
 12 | 
 13 |   The licenses for most software and other practical works are designed
 14 | to take away your freedom to share and change the works.  By contrast,
 15 | the GNU General Public License is intended to guarantee your freedom to
 16 | share and change all versions of a program--to make sure it remains free
 17 | software for all its users.  We, the Free Software Foundation, use the
 18 | GNU General Public License for most of our software; it applies also to
 19 | any other work released this way by its authors.  You can apply it to
 20 | your programs, too.
 21 | 
 22 |   When we speak of free software, we are referring to freedom, not
 23 | price.  Our General Public Licenses are designed to make sure that you
 24 | have the freedom to distribute copies of free software (and charge for
 25 | them if you wish), that you receive source code or can get it if you
 26 | want it, that you can change the software or use pieces of it in new
 27 | free programs, and that you know you can do these things.
 28 | 
 29 |   To protect your rights, we need to prevent others from denying you
 30 | these rights or asking you to surrender the rights.  Therefore, you have
 31 | certain responsibilities if you distribute copies of the software, or if
 32 | you modify it: responsibilities to respect the freedom of others.
 33 | 
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235 |   A compilation of a covered work with other separate and independent
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245 |   6. Conveying Non-Source Forms.
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247 |   You may convey a covered work in object code form under the terms
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275 |     d) Convey the object code by offering access from a designated
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288 |     e) Convey the object code using peer-to-peer transmission, provided
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318 |   If you convey an object code work under this section in, or with, or
319 | specifically for use in, a User Product, and the conveying occurs as
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338 | in accord with this section must be in a format that is publicly
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342 | 
343 |   7. Additional Terms.
344 | 
345 |   "Additional permissions" are terms that supplement the terms of this
346 | License by making exceptions from one or more of its conditions.
347 | Additional permissions that are applicable to the entire Program shall
348 | be treated as though they were included in this License, to the extent
349 | that they are valid under applicable law.  If additional permissions
350 | apply only to part of the Program, that part may be used separately
351 | under those permissions, but the entire Program remains governed by
352 | this License without regard to the additional permissions.
353 | 
354 |   When you convey a copy of a covered work, you may at your option
355 | remove any additional permissions from that copy, or from any part of
356 | it.  (Additional permissions may be written to require their own
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361 |   Notwithstanding any other provision of this License, for material you
362 | add to a covered work, you may (if authorized by the copyright holders of
363 | that material) supplement the terms of this License with terms:
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365 |     a) Disclaiming warranty or limiting liability differently from the
366 |     terms of sections 15 and 16 of this License; or
367 | 
368 |     b) Requiring preservation of specified reasonable legal notices or
369 |     author attributions in that material or in the Appropriate Legal
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388 |   All other non-permissive additional terms are considered "further
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390 | received it, or any part of it, contains a notice stating that it is
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393 | a further restriction but permits relicensing or conveying under this
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403 |   Additional terms, permissive or non-permissive, may be stated in the
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406 | 
407 |   8. Termination.
408 | 
409 |   You may not propagate or modify a covered work except as expressly
410 | provided under this License.  Any attempt otherwise to propagate or
411 | modify it is void, and will automatically terminate your rights under
412 | this License (including any patent licenses granted under the third
413 | paragraph of section 11).
414 | 
415 |   However, if you cease all violation of this License, then your
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421 | 
422 |   Moreover, your license from a particular copyright holder is
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425 | received notice of violation of this License (for any work) from that
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427 | your receipt of the notice.
428 | 
429 |   Termination of your rights under this section does not terminate the
430 | licenses of parties who have received copies or rights from you under
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432 | reinstated, you do not qualify to receive new licenses for the same
433 | material under section 10.
434 | 
435 |   9. Acceptance Not Required for Having Copies.
436 | 
437 |   You are not required to accept this License in order to receive or
438 | run a copy of the Program.  Ancillary propagation of a covered work
439 | occurring solely as a consequence of using peer-to-peer transmission
440 | to receive a copy likewise does not require acceptance.  However,
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443 | not accept this License.  Therefore, by modifying or propagating a
444 | covered work, you indicate your acceptance of this License to do so.
445 | 
446 |   10. Automatic Licensing of Downstream Recipients.
447 | 
448 |   Each time you convey a covered work, the recipient automatically
449 | receives a license from the original licensors, to run, modify and
450 | propagate that work, subject to this License.  You are not responsible
451 | for enforcing compliance by third parties with this License.
452 | 
453 |   An "entity transaction" is a transaction transferring control of an
454 | organization, or substantially all assets of one, or subdividing an
455 | organization, or merging organizations.  If propagation of a covered
456 | work results from an entity transaction, each party to that
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462 | 
463 |   You may not impose any further restrictions on the exercise of the
464 | rights granted or affirmed under this License.  For example, you may
465 | not impose a license fee, royalty, or other charge for exercise of
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467 | (including a cross-claim or counterclaim in a lawsuit) alleging that
468 | any patent claim is infringed by making, using, selling, offering for
469 | sale, or importing the Program or any portion of it.
470 | 
471 |   11. Patents.
472 | 
473 |   A "contributor" is a copyright holder who authorizes use under this
474 | License of the Program or a work on which the Program is based.  The
475 | work thus licensed is called the contributor's "contributor version".
476 | 
477 |   A contributor's "essential patent claims" are all patent claims
478 | owned or controlled by the contributor, whether already acquired or
479 | hereafter acquired, that would be infringed by some manner, permitted
480 | by this License, of making, using, or selling its contributor version,
481 | but do not include claims that would be infringed only as a
482 | consequence of further modification of the contributor version.  For
483 | purposes of this definition, "control" includes the right to grant
484 | patent sublicenses in a manner consistent with the requirements of
485 | this License.
486 | 
487 |   Each contributor grants you a non-exclusive, worldwide, royalty-free
488 | patent license under the contributor's essential patent claims, to
489 | make, use, sell, offer for sale, import and otherwise run, modify and
490 | propagate the contents of its contributor version.
491 | 
492 |   In the following three paragraphs, a "patent license" is any express
493 | agreement or commitment, however denominated, not to enforce a patent
494 | (such as an express permission to practice a patent or covenant not to
495 | sue for patent infringement).  To "grant" such a patent license to a
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497 | patent against the party.
498 | 
499 |   If you convey a covered work, knowingly relying on a patent license,
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503 | then you must either (1) cause the Corresponding Source to be so
504 | available, or (2) arrange to deprive yourself of the benefit of the
505 | patent license for this particular work, or (3) arrange, in a manner
506 | consistent with the requirements of this License, to extend the patent
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508 | actual knowledge that, but for the patent license, your conveying the
509 | covered work in a country, or your recipient's use of the covered work
510 | in a country, would infringe one or more identifiable patents in that
511 | country that you have reason to believe are valid.
512 | 
513 |   If, pursuant to or in connection with a single transaction or
514 | arrangement, you convey, or propagate by procuring conveyance of, a
515 | covered work, and grant a patent license to some of the parties
516 | receiving the covered work authorizing them to use, propagate, modify
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519 | work and works based on it.
520 | 
521 |   A patent license is "discriminatory" if it does not include within
522 | the scope of its coverage, prohibits the exercise of, or is
523 | conditioned on the non-exercise of one or more of the rights that are
524 | specifically granted under this License.  You may not convey a covered
525 | work if you are a party to an arrangement with a third party that is
526 | in the business of distributing software, under which you make payment
527 | to the third party based on the extent of your activity of conveying
528 | the work, and under which the third party grants, to any of the
529 | parties who would receive the covered work from you, a discriminatory
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533 | contain the covered work, unless you entered into that arrangement,
534 | or that patent license was granted, prior to 28 March 2007.
535 | 
536 |   Nothing in this License shall be construed as excluding or limiting
537 | any implied license or other defenses to infringement that may
538 | otherwise be available to you under applicable patent law.
539 | 
540 |   12. No Surrender of Others' Freedom.
541 | 
542 |   If conditions are imposed on you (whether by court order, agreement or
543 | otherwise) that contradict the conditions of this License, they do not
544 | excuse you from the conditions of this License.  If you cannot convey a
545 | covered work so as to satisfy simultaneously your obligations under this
546 | License and any other pertinent obligations, then as a consequence you may
547 | not convey it at all.  For example, if you agree to terms that obligate you
548 | to collect a royalty for further conveying from those to whom you convey
549 | the Program, the only way you could satisfy both those terms and this
550 | License would be to refrain entirely from conveying the Program.
551 | 
552 |   13. Use with the GNU Affero General Public License.
553 | 
554 |   Notwithstanding any other provision of this License, you have
555 | permission to link or combine any covered work with a work licensed
556 | under version 3 of the GNU Affero General Public License into a single
557 | combined work, and to convey the resulting work.  The terms of this
558 | License will continue to apply to the part which is the covered work,
559 | but the special requirements of the GNU Affero General Public License,
560 | section 13, concerning interaction through a network will apply to the
561 | combination as such.
562 | 
563 |   14. Revised Versions of this License.
564 | 
565 |   The Free Software Foundation may publish revised and/or new versions of
566 | the GNU General Public License from time to time.  Such new versions will
567 | be similar in spirit to the present version, but may differ in detail to
568 | address new problems or concerns.
569 | 
570 |   Each version is given a distinguishing version number.  If the
571 | Program specifies that a certain numbered version of the GNU General
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573 | option of following the terms and conditions either of that numbered
574 | version or of any later version published by the Free Software
575 | Foundation.  If the Program does not specify a version number of the
576 | GNU General Public License, you may choose any version ever published
577 | by the Free Software Foundation.
578 | 
579 |   If the Program specifies that a proxy can decide which future
580 | versions of the GNU General Public License can be used, that proxy's
581 | public statement of acceptance of a version permanently authorizes you
582 | to choose that version for the Program.
583 | 
584 |   Later license versions may give you additional or different
585 | permissions.  However, no additional obligations are imposed on any
586 | author or copyright holder as a result of your choosing to follow a
587 | later version.
588 | 
589 |   15. Disclaimer of Warranty.
590 | 
591 |   THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
592 | APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
593 | HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
594 | OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
595 | THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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597 | IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
598 | ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
599 | 
600 |   16. Limitation of Liability.
601 | 
602 |   IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
603 | WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
604 | THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
605 | GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
606 | USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
607 | DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
608 | PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
609 | EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
610 | SUCH DAMAGES.
611 | 
612 |   17. Interpretation of Sections 15 and 16.
613 | 
614 |   If the disclaimer of warranty and limitation of liability provided
615 | above cannot be given local legal effect according to their terms,
616 | reviewing courts shall apply local law that most closely approximates
617 | an absolute waiver of all civil liability in connection with the
618 | Program, unless a warranty or assumption of liability accompanies a
619 | copy of the Program in return for a fee.
620 | 
621 |                      END OF TERMS AND CONDITIONS
622 | 
623 |             How to Apply These Terms to Your New Programs
624 | 
625 |   If you develop a new program, and you want it to be of the greatest
626 | possible use to the public, the best way to achieve this is to make it
627 | free software which everyone can redistribute and change under these terms.
628 | 
629 |   To do so, attach the following notices to the program.  It is safest
630 | to attach them to the start of each source file to most effectively
631 | state the exclusion of warranty; and each file should have at least
632 | the "copyright" line and a pointer to where the full notice is found.
633 | 
634 |     {one line to give the program's name and a brief idea of what it does.}
635 |     Copyright (C) {year}  {name of author}
636 | 
637 |     This program is free software: you can redistribute it and/or modify
638 |     it under the terms of the GNU General Public License as published by
639 |     the Free Software Foundation, either version 3 of the License, or
640 |     (at your option) any later version.
641 | 
642 |     This program is distributed in the hope that it will be useful,
643 |     but WITHOUT ANY WARRANTY; without even the implied warranty of
644 |     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
645 |     GNU General Public License for more details.
646 | 
647 |     You should have received a copy of the GNU General Public License
648 |     along with this program.  If not, see <http://www.gnu.org/licenses/>.
649 | 
650 | Also add information on how to contact you by electronic and paper mail.
651 | 
652 |   If the program does terminal interaction, make it output a short
653 | notice like this when it starts in an interactive mode:
654 | 
655 |     {project}  Copyright (C) {year}  {fullname}
656 |     This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
657 |     This is free software, and you are welcome to redistribute it
658 |     under certain conditions; type `show c' for details.
659 | 
660 | The hypothetical commands `show w' and `show c' should show the appropriate
661 | parts of the General Public License.  Of course, your program's commands
662 | might be different; for a GUI interface, you would use an "about box".
663 | 
664 |   You should also get your employer (if you work as a programmer) or school,
665 | if any, to sign a "copyright disclaimer" for the program, if necessary.
666 | For more information on this, and how to apply and follow the GNU GPL, see
667 | <http://www.gnu.org/licenses/>.
668 | 
669 |   The GNU General Public License does not permit incorporating your program
670 | into proprietary programs.  If your program is a subroutine library, you
671 | may consider it more useful to permit linking proprietary applications with
672 | the library.  If this is what you want to do, use the GNU Lesser General
673 | Public License instead of this License.  But first, please read
674 | <http://www.gnu.org/philosophy/why-not-lgpl.html>.
675 | 
676 | 


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