upd

CMakeLists.txt

+cmake_minimum_required(VERSION 2.8.3)
+project(rover_driver_base)
+
+## Find catkin macros and libraries
+## if COMPONENTS list like find_package(catkin REQUIRED COMPONENTS xyz)
+## is used, also find other catkin packages
+find_package(catkin REQUIRED COMPONENTS
+  geometry_msgs
+  rospy
+  sensor_msgs
+  std_msgs
+  tf
+)
+
+## System dependencies are found with CMake's conventions
+# find_package(Boost REQUIRED COMPONENTS system)
+
+
+## Uncomment this if the package has a setup.py. This macro ensures
+## modules and global scripts declared therein get installed
+## See http://ros.org/doc/api/catkin/html/user_guide/setup_dot_py.html
+
+catkin_python_setup()
+
+################################################
+## Declare ROS messages, services and actions ##
+################################################
+
+## To declare and build messages, services or actions from within this
+## package, follow these steps:
+## * Let MSG_DEP_SET be the set of packages whose message types you use in
+##   your messages/services/actions (e.g. std_msgs, actionlib_msgs, ...).
+## * In the file package.xml:
+##   * add a build_depend and a run_depend tag for each package in MSG_DEP_SET
+##   * If MSG_DEP_SET isn't empty the following dependencies might have been
+##     pulled in transitively but can be declared for certainty nonetheless:
+##     * add a build_depend tag for "message_generation"
+##     * add a run_depend tag for "message_runtime"
+## * In this file (CMakeLists.txt):
+##   * add "message_generation" and every package in MSG_DEP_SET to
+##     find_package(catkin REQUIRED COMPONENTS ...)
+##   * add "message_runtime" and every package in MSG_DEP_SET to
+##     catkin_package(CATKIN_DEPENDS ...)
+##   * uncomment the add_*_files sections below as needed
+##     and list every .msg/.srv/.action file to be processed
+##   * uncomment the generate_messages entry below
+##   * add every package in MSG_DEP_SET to generate_messages(DEPENDENCIES ...)
+
+## Generate messages in the 'msg' folder
+# add_message_files(
+#   FILES
+#   Message1.msg
+#   Message2.msg
+# )
+
+## Generate services in the 'srv' folder
+# add_service_files(
+#   FILES
+#   Service1.srv
+#   Service2.srv
+# )
+
+## Generate actions in the 'action' folder
+# add_action_files(
+#   FILES
+#   Action1.action
+#   Action2.action
+# )
+
+## Generate added messages and services with any dependencies listed here
+# generate_messages(
+#   DEPENDENCIES
+#   geometry_msgs#   sensor_msgs#   std_msgs
+# )
+
+###################################
+## catkin specific configuration ##
+###################################
+## The catkin_package macro generates cmake config files for your package
+## Declare things to be passed to dependent projects
+## INCLUDE_DIRS: uncomment this if you package contains header files
+## LIBRARIES: libraries you create in this project that dependent projects also need
+## CATKIN_DEPENDS: catkin_packages dependent projects also need
+## DEPENDS: system dependencies of this project that dependent projects also need
+catkin_package(
+#  INCLUDE_DIRS include
+#  LIBRARIES rover_driver_base
+#  CATKIN_DEPENDS geometry_msgs rospy sensor_msgs std_msgs tf
+#  DEPENDS system_lib
+)
+
+###########
+## Build ##
+###########
+
+## Specify additional locations of header files
+## Your package locations should be listed before other locations
+# include_directories(include)
+include_directories(
+  ${catkin_INCLUDE_DIRS}
+)
+
+## Declare a cpp library
+# add_library(rover_driver_base
+#   src/${PROJECT_NAME}/rover_driver_base.cpp
+# )
+
+## Declare a cpp executable
+# add_executable(rover_driver_base_node src/rover_driver_base_node.cpp)
+
+## Add cmake target dependencies of the executable/library
+## as an example, message headers may need to be generated before nodes
+# add_dependencies(rover_driver_base_node rover_driver_base_generate_messages_cpp)
+
+## Specify libraries to link a library or executable target against
+# target_link_libraries(rover_driver_base_node
+#   ${catkin_LIBRARIES}
+# )
+
+#############
+## Install ##
+#############
+install(PROGRAMS
+  nodes/rover_command.py
+  nodes/rover_odom.py
+  nodes/rover_teleop.py
+  nodes/rover_keyboard.py
+  DESTINATION ${CATKIN_PACKAGE_BIN_DESTINATION}
+)
+
+install(DIRECTORY src/rover_driver/
+  DESTINATION ${CATKIN_PACKAGE_PYTHON_DESTINATION}
+  USE_SOURCE_PERMISSIONS
+  PATTERN ".svn" EXCLUDE
+)
+
+
+# all install targets should use catkin DESTINATION variables
+# See http://ros.org/doc/api/catkin/html/adv_user_guide/variables.html
+
+## Mark executable scripts (Python etc.) for installation
+## in contrast to setup.py, you can choose the destination
+# install(PROGRAMS
+#   scripts/my_python_script
+#   DESTINATION ${CATKIN_PACKAGE_BIN_DESTINATION}
+# )
+
+## Mark executables and/or libraries for installation
+# install(TARGETS rover_driver_base rover_driver_base_node
+#   ARCHIVE DESTINATION ${CATKIN_PACKAGE_LIB_DESTINATION}
+#   LIBRARY DESTINATION ${CATKIN_PACKAGE_LIB_DESTINATION}
+#   RUNTIME DESTINATION ${CATKIN_PACKAGE_BIN_DESTINATION}
+# )
+
+## Mark cpp header files for installation
+# install(DIRECTORY include/${PROJECT_NAME}/
+#   DESTINATION ${CATKIN_PACKAGE_INCLUDE_DESTINATION}
+#   FILES_MATCHING PATTERN "*.h"
+#   PATTERN ".svn" EXCLUDE
+# )
+
+## Mark other files for installation (e.g. launch and bag files, etc.)
+# install(FILES
+#   # myfile1
+#   # myfile2
+#   DESTINATION ${CATKIN_PACKAGE_SHARE_DESTINATION}
+# )
+
+#############
+## Testing ##
+#############
+
+## Add gtest based cpp test target and link libraries
+# catkin_add_gtest(${PROJECT_NAME}-test test/test_rover_driver_base.cpp)
+# if(TARGET ${PROJECT_NAME}-test)
+#   target_link_libraries(${PROJECT_NAME}-test ${PROJECT_NAME})
+# endif()
+
+## Add folders to be run by python nosetests
+# catkin_add_nosetests(test)

launch/rover.launch

+<launch>
+
+ <!-- joy node -->
+  <node respawn="true" pkg="joy" type="joy_node" name="joy" >
+    <!-- <param name="dev" type="string" value="/dev/input/js0" /> -->
+    <!-- <param name="deadzone" value="0.12" /> -->
+    <param name="autorepeat_rate" value="10.0" />
+  </node>
+
+ <!-- Axes -->
+
+  <node pkg="rover_driver_base" type="rover_teleop.py" name="teleop">
+      <param name="axis_linear_x" value="1" type="int"/>
+      <param name="axis_linear_y" value="0" type="int"/>
+      <param name="axis_angular" value="3" type="int"/>
+      <param name="scale_linear" value="1.0" type="double"/>
+      <param name="scale_angular" value="0.7" type="double"/>
+      <remap from="/teleop/joy" to="/joy"/>
+      <remap from="/teleop/twistCommand" to="/rover/twistCommand"/>
+  </node>
+
+  <node pkg="rover_driver_base" type="rover_command.py" name="rover" output="screen">
+      <param name="rover_name" value="rover"/>
+      <param name="skidsteer" value="false"/>
+  </node>
+
+</launch>

launch/rover_odom.launch

+<launch>
+
+ <!-- joy node -->
+  <node respawn="true" pkg="joy" type="joy_node" name="joy" >
+    <!-- <param name="dev" type="string" value="/dev/input/js0" /> -->
+    <!-- <param name="deadzone" value="0.12" /> -->
+    <param name="autorepeat_rate" value="10.0" />
+  </node>
+
+ <!-- Axes -->
+
+  <node pkg="rover_driver_base" type="rover_teleop.py" name="teleop">
+      <param name="axis_linear_x" value="1" type="int"/>
+      <param name="axis_linear_y" value="0" type="int"/>
+      <param name="axis_angular" value="3" type="int"/>
+      <param name="scale_linear" value="1.0" type="double"/>
+      <param name="scale_angular" value="0.7" type="double"/>
+      <remap from="/teleop/joy" to="/joy"/>
+      <remap from="/teleop/twistCommand" to="/rover/twistCommand"/>
+  </node>
+
+  <node pkg="rover_driver_base" type="rover_command.py" name="rover" output="screen">
+      <param name="rover_name" value="rover"/>
+      <param name="skidsteer" value="false"/>
+  </node>
+
+  <node pkg="rover_driver_base" type="rover_odom.py" name="odom" output="screen">
+      <param name="rover_name" value="rover"/>
+  </node>
+
+</launch>

nodes/rover_command.py

+#!/usr/bin/env python
+import roslib; roslib.load_manifest('rover_driver_base')
+import rospy
+from std_msgs.msg import Float64
+from sensor_msgs.msg import JointState
+from geometry_msgs.msg import Twist,Pose
+from math import atan2, hypot, pi, cos, sin
+import tf
+import message_filters
+import numpy
+from numpy.linalg import pinv
+
+from rover_driver_base.rover_kinematics import *
+
+
+class RoverDriver:
+    def __init__(self,name):
+        self.name = name
+        rospy.init_node('rover_driver')
+        self.name = rospy.get_param("~rover_name",self.name)
+        self.skidsteer = rospy.get_param("~skidsteer",False)
+        self.check_timeout = rospy.get_param("~check_timeout",True)
+        rospy.loginfo("Starting rover driver for rover '%s'" % self.name)
+        self.last_cmd = rospy.Time.now()
+        self.listener = tf.TransformListener()
+        self.steering_pub={}
+        self.drive_pub={}
+        self.ready = False
+
+        self.kinematics = RoverKinematics()
+
+        self.twist_sub = rospy.Subscriber('~twistCommand', Twist, self.twist_cb)
+        # print "Initialising wheel data structure"
+        for k in prefix:
+            self.steering_pub[k] = rospy.Publisher("/vrep/%s/%sSteerCommand" % (self.name,k), Float64, queue_size=1)
+            self.drive_pub[k] = rospy.Publisher("/vrep/%s/%sDriveCommand" % (self.name,k), Float64, queue_size=1)
+
+
+    def twist_cb(self,twist):
+        if not self.ready:
+            return
+        # print "Got twist: " + str(twist)
+        self.last_cmd = rospy.Time.now()
+        # Get the pose of all drives
+        drive_cfg={}
+        for k in prefix:
+            # try:
+                # self.listener.waitForTransform('/%s/ground'%(self.name),
+                #         '/%s/%sDrive'%(self.name,k), self.last_cmd, rospy.Duration(1.0))
+                ((x,y,z),rot) = self.listener.lookupTransform('/%s/ground'%(self.name),
+                        '/%s/%sDrive'%(self.name,k), rospy.Time(0))
+                drive_cfg[k] = DriveConfiguration(self.radius[k],x,y,z)
+            # except (tf.LookupException, tf.ConnectivityException, tf.ExtrapolationException):
+            #    return
+        # Now compute for each drive, its rotation speed and steering angle
+        motors = self.kinematics.twist_to_motors(twist,drive_cfg,self.skidsteer)
+        self.publish(motors)
+
+    def publish(self, motor):
+        for k in prefix:
+            self.drive_pub[k].publish(Float64(motor.drive[k]))
+            self.steering_pub[k].publish(Float64(motor.steering[k]))
+            
+
+    def run(self):
+        timeout = True
+        rate = rospy.Rate(10)
+        rospy.loginfo("Waiting for initial transforms")
+        rospy.sleep(1.0)
+        self.radius={}
+        for k in prefix:
+            try:
+                self.listener.waitForTransform('/%s/ground'%(self.name),
+                        '/%s/%sDrive'%(self.name,k), rospy.Time(0), rospy.Duration(5.0))
+                ((x,y,z),rot) = self.listener.lookupTransform('/%s/ground'%(self.name),
+                        '/%s/%sDrive'%(self.name,k), rospy.Time(0))
+                self.radius[k] = z
+                rospy.loginfo("Got transform for " + k)
+            except tf.Exception,e:
+                rospy.logerr("TF exception: " + repr(e))
+        self.ready = True
+        while not rospy.is_shutdown():
+            if self.check_timeout:
+                if (rospy.rostime.get_time() - self.last_cmd.to_sec()) < 0.5: 
+                    if timeout:
+                        timeout = False
+                        rospy.loginfo("Accepting joystick commands")
+                else:
+                    if not timeout:
+                        timeout = True
+                        rospy.loginfo("Timeout: ignoring joystick commands")
+                    motors = RoverMotors()
+                    self.publish(motors)
+            rate.sleep()
+
+
+if __name__ == '__main__':
+    try:
+        rd = RoverDriver("rover") 
+        rd.run()
+    except rospy.ROSInterruptException:
+        pass

nodes/rover_keyboard.py

+#!/usr/bin/env python
+# source for this file:
+# http://ftp.isr.ist.utl.pt/pub/roswiki/stage%282f%29Tutorials%282f%29SimulatingOneRobot.html
+import roslib; roslib.load_manifest('rover_driver_base')
+import rospy
+from geometry_msgs.msg import Twist
+import sys, select, termios, tty
+
+msg = """
+Reading from the keyboard  and Publishing to Twist!
+---------------------------
+Moving around:
+   u    i    o
+   j    k    l
+   m    ,    .
+
+q/z : increase/decrease max speeds by 10%
+w/x : increase/decrease only linear speed by 10%
+e/c : increase/decrease only angular speed by 10%
+anything else : stop
+
+CTRL-C to quit
+"""
+
+moveBindings = {
+        'i':(1,0),
+        'o':(1,-1),
+        'j':(0,1),
+        'l':(0,-1),
+        'k':(0,0),
+        'u':(1,1),
+        ',':(-1,0),
+        '.':(-1,1),
+        'm':(-1,-1),
+}
+angularBindings = {
+        'a':+1,
+        's':0,
+        'd':-1,
+}
+
+speedBindings={
+        'q':(1.1,1.1),
+        'z':(.9,.9),
+        'w':(1.1,1),
+        'x':(.9,1),
+        'e':(1,1.1),
+        'c':(1,.9),
+          }
+
+def getKey():
+    tty.setraw(sys.stdin.fileno())
+    select.select([sys.stdin], [], [], 0)
+    key = sys.stdin.read(1)
+    termios.tcsetattr(sys.stdin, termios.TCSADRAIN, settings)
+    return key
+
+speed = .5
+turn = 1
+
+def vels(speed,turn):
+    return "currently:\tspeed %s\tturn %s " % (speed,turn)
+
+if __name__=="__main__":
+    settings = termios.tcgetattr(sys.stdin)
+    
+    rospy.init_node('teleop_twist_keyboard')
+    twist_topic = rospy.resolve_name("output")
+    pub = rospy.Publisher(twist_topic, Twist)
+
+    x = 0
+    y = 0
+    th = 0
+    status = 0
+
+    try:
+        print msg
+        print vels(speed,turn)
+        while(1):
+            key = getKey()
+            if key in moveBindings.keys():
+                x,y = moveBindings[key]
+                print "Direction: %.1f %.1f" % (x*speed,y*speed)
+            elif key in angularBindings.keys():
+                th = angularBindings[key]
+                print "Angular: %.1f " % th
+            elif key in speedBindings.keys():
+                speed = speed * speedBindings[key][0]
+                turn = turn * speedBindings[key][1]
+
+                print vels(speed,turn)
+                if (status == 14):
+                    print msg
+                status = (status + 1) % 15
+            else:
+                x = 0
+                th = 0
+                if (key == '\x03'):
+                    break
+
+            twist = Twist()
+            twist.linear.x = x*speed; 
+            twist.linear.y = y*speed; 
+            twist.linear.z = 0
+            twist.angular.x = 0; 
+            twist.angular.y = 0; 
+            twist.angular.z = th*turn
+            pub.publish(twist)
+
+    except e:
+        print e
+
+    finally:
+        twist = Twist()
+        twist.linear.x = 0; twist.linear.y = 0; twist.linear.z = 0
+        twist.angular.x = 0; twist.angular.y = 0; twist.angular.z = 0
+        pub.publish(twist)
+        termios.tcsetattr(sys.stdin, termios.TCSADRAIN, settings)

nodes/rover_odom.py

+#!/usr/bin/env python
+import roslib; roslib.load_manifest('rover_driver_base')
+import rospy
+from std_msgs.msg import Float64
+from sensor_msgs.msg import JointState
+from geometry_msgs.msg import Twist,Pose
+from math import atan2, hypot, pi, cos, sin
+import tf
+import message_filters
+import numpy
+from numpy.linalg import pinv
+
+from rover_driver_base.rover_kinematics import *
+
+
+class RoverDriver:
+    def __init__(self,name):
+        self.name = name
+        rospy.init_node('rover_odom')
+        self.name = rospy.get_param("~rover_name",self.name)
+        rospy.loginfo("Starting rover odometry for rover '%s'" % self.name)
+        self.last_cmd = rospy.Time.now()
+        self.listener = tf.TransformListener()
+        self.broadcaster = tf.TransformBroadcaster()
+        self.steering_sub={}
+        self.drive_sub={}
+        self.ready = False
+        self.connected = False
+
+        self.kinematics = RoverKinematics()
+
+        # print "Initialising wheel data structure"
+        for k in prefix:
+            self.steering_sub[k] = message_filters.Subscriber("/vrep/%s/%sSteerEncoder" % (self.name,k), JointState)
+            self.drive_sub[k] = message_filters.Subscriber("/vrep/%s/%sDriveEncoder" % (self.name,k), JointState)
+            # print "Initialised wheel " + k
+        self.ts = message_filters.TimeSynchronizer(self.steering_sub.values()+self.drive_sub.values(), 10)
+        self.ts.registerCallback(self.sync_odo_cb)
+
+
+    def sync_odo_cb(self,*args):
+        self.connected = True
+        if not self.ready:
+            return
+        if len(args)!=12:
+            rospy.logerr("Invalid number of argument in OdoCallback")
+            return
+        steering_val = [s.position[0] for s in args[0:6]]
+        drive_val = [s.position[0] for s in args[6:12]]
+        motors = RoverMotors()
+        motors.steering = dict(zip(self.steering_sub.keys(),steering_val))
+        motors.drive = dict(zip(self.drive_sub.keys(),drive_val))
+        self.odo_cb(args[0].header.stamp,motors)
+
+    def odo_cb(self,timestamp,motors):
+        # Get the pose of all drives
+        drive_cfg={}
+        for k in prefix:
+            # try:
+                # self.listener.waitForTransform('/%s/ground'%(self.name),
+                #         '/%s/%sDrive'%(self.name,k), self.last_cmd, rospy.Duration(1.0))
+                ((x,y,z),rot) = self.listener.lookupTransform('/%s/ground'%(self.name),
+                        '/%s/%sDrive'%(self.name,k), rospy.Time(0))
+                drive_cfg[k] = DriveConfiguration(self.radius[k],x,y,z)
+            # except (tf.LookupException, tf.ConnectivityException, tf.ExtrapolationException):
+            #    return
+        X = self.kinematics.integrate_odometry(motors, drive_cfg)
+        self.broadcaster.sendTransform((X[0,0], X[1,0], 0),
+                     tf.transformations.quaternion_from_euler(0, 0, X[2,0]),
+                     timestamp, "/%s/ground"%self.name, "/odom")
+        # finally store the value of the motor state
+
+
+    def run(self):
+        timeout = True
+        rate = rospy.Rate(2)
+        rospy.loginfo("Waiting for VREP")
+        while (not rospy.is_shutdown()) and (not self.connected):
+            rate.sleep()
+        if rospy.is_shutdown():
+            return
+        rospy.loginfo("Waiting for initial transforms")
+        rospy.sleep(1.0)
+        self.radius={}
+        for k in prefix:
+            try:
+                self.listener.waitForTransform('/%s/ground'%(self.name),
+                        '/%s/%sDrive'%(self.name,k), rospy.Time(0), rospy.Duration(5.0))
+                ((x,y,z),rot) = self.listener.lookupTransform('/%s/ground'%(self.name),
+                        '/%s/%sDrive'%(self.name,k), rospy.Time(0))
+                self.radius[k] = z
+                rospy.loginfo("Got transform for " + k)
+            except tf.Exception,e:
+                rospy.logerr("TF exception: " + repr(e))
+        self.ready = True
+        while not rospy.is_shutdown():
+            rate.sleep()
+
+if __name__ == '__main__':
+    try:
+        rd = RoverDriver("rover") 
+        rd.run()
+    except rospy.ROSInterruptException:
+        pass

nodes/rover_teleop.py

+#!/usr/bin/env python
+import roslib; roslib.load_manifest('rover_driver_base')
+import rospy
+from sensor_msgs.msg import Joy
+from geometry_msgs.msg import Twist
+
+last_joy = -1e10
+joy_value = None
+
+def joy_cb(value):
+    global joy_value
+    global last_joy
+    last_joy = rospy.rostime.get_time()
+    joy_value = value
+
+def talker():
+    global joy_value
+    global last_joy
+    rospy.init_node('vrep_ros_teleop')
+    sub = rospy.Subscriber('~joy', Joy, joy_cb)
+    pub = rospy.Publisher('~twistCommand', Twist, queue_size=1)
+    axis_linear_x = rospy.get_param("~axis_linear_x",1)
+    axis_linear_y = rospy.get_param("~axis_linear_y",0)
+    axis_angular = rospy.get_param("~axis_angular",3)
+    scale_linear = rospy.get_param("~scale_linear",5.)
+    scale_angular = rospy.get_param("~scale_angular",10.)
+    timeout = True
+    while not rospy.is_shutdown():
+        twist = Twist()
+        if (rospy.rostime.get_time() - last_joy) < 0.5: 
+            if timeout:
+                timeout = False
+                rospy.loginfo("Accepting joystick commands")
+            twist.linear.x = joy_value.axes[axis_linear_x] * scale_linear
+            twist.linear.y = joy_value.axes[axis_linear_y] * scale_linear
+            twist.angular.z = joy_value.axes[axis_angular] * scale_angular
+            # if twist.linear.x < 0:
+            #     twist.angular.z = - twist.angular.z
+        else:
+            if not timeout:
+                timeout = True
+                rospy.loginfo("Timeout: ignoring joystick commands")
+        pub.publish(twist)
+        rospy.sleep(0.1)
+
+
+if __name__ == '__main__':
+    try:
+        talker()
+    except rospy.ROSInterruptException:
+        pass

package.xml

+<?xml version="1.0"?>
+<package>
+  <name>rover_driver_base</name>
+  <version>0.0.0</version>
+  <description>The rover_driver_base package</description>
+
+  <!-- One maintainer tag required, multiple allowed, one person per tag --> 
+  <!-- Example:  -->
+  <!-- <maintainer email="jane.doe@example.com">Jane Doe</maintainer> -->
+  <maintainer email="cedricp@todo.todo">cedricp</maintainer>
+
+
+  <!-- One license tag required, multiple allowed, one license per tag -->
+  <!-- Commonly used license strings: -->
+  <!--   BSD, MIT, Boost Software License, GPLv2, GPLv3, LGPLv2.1, LGPLv3 -->
+  <license>TODO</license>
+
+
+  <!-- Url tags are optional, but mutiple are allowed, one per tag -->
+  <!-- Optional attribute type can be: website, bugtracker, or repository -->
+  <!-- Example: -->
+  <!-- <url type="website">http://wiki.ros.org/rover_driver_base</url> -->
+
+
+  <!-- Author tags are optional, mutiple are allowed, one per tag -->
+  <!-- Authors do not have to be maintianers, but could be -->
+  <!-- Example: -->
+  <!-- <author email="jane.doe@example.com">Jane Doe</author> -->
+
+
+  <!-- The *_depend tags are used to specify dependencies -->
+  <!-- Dependencies can be catkin packages or system dependencies -->
+  <!-- Examples: -->
+  <!-- Use build_depend for packages you need at compile time: -->
+  <!--   <build_depend>message_generation</build_depend> -->
+  <!-- Use buildtool_depend for build tool packages: -->
+  <!--   <buildtool_depend>catkin</buildtool_depend> -->
+  <!-- Use run_depend for packages you need at runtime: -->
+  <!--   <run_depend>message_runtime</run_depend> -->
+  <!-- Use test_depend for packages you need only for testing: -->
+  <!--   <test_depend>gtest</test_depend> -->
+  <buildtool_depend>catkin</buildtool_depend>
+  <build_depend>geometry_msgs</build_depend>
+  <build_depend>rospy</build_depend>
+  <build_depend>sensor_msgs</build_depend>
+  <build_depend>std_msgs</build_depend>
+  <build_depend>tf</build_depend>
+  <run_depend>geometry_msgs</run_depend>
+  <run_depend>rospy</run_depend>
+  <run_depend>sensor_msgs</run_depend>
+  <run_depend>std_msgs</run_depend>
+  <run_depend>tf</run_depend>
+
+
+  <!-- The export tag contains other, unspecified, tags -->
+  <export>
+    <!-- You can specify that this package is a metapackage here: -->
+    <!-- <metapackage/> -->
+
+    <!-- Other tools can request additional information be placed here -->
+
+  </export>
+</package>
\ No newline at end of file

setup.py

+#!/usr/bin/env python
+
+from distutils.core import setup
+from catkin_pkg.python_setup import generate_distutils_setup
+
+d = generate_distutils_setup(
+    install_requires=['rospy'],
+   packages=['rover_driver_base'],
+   package_dir={'': 'src'}
+    )
+
+setup(**d)

src/rover_driver_base/rover_kinematics.py

+#!/usr/bin/env python
+import roslib; roslib.load_manifest('rover_driver_base')
+import rospy
+from geometry_msgs.msg import Twist
+import numpy
+from numpy.linalg import pinv
+from math import atan2, hypot, pi, cos, sin
+
+prefix=["FL","FR","CL","CR","RL","RR"]
+
+class RoverMotors:
+    def __init__(self):
+        self.steering={}
+        self.drive={}
+        for k in prefix:
+            self.steering[k]=0.0
+            self.drive[k]=0.0
+    def copy(self,value):
+        for k in prefix:
+            self.steering[k]=value.steering[k]
+            self.drive[k]=value.drive[k]
+
+class DriveConfiguration:
+    def __init__(self,radius,x,y,z):
+        self.x = x
+        self.y = y
+        self.z = z
+        self.radius = radius
+
+
+class RoverKinematics:
+    def __init__(self):
+        self.X = numpy.asmatrix(numpy.zeros((3,1)))
+        self.motor_state = RoverMotors()
+        self.first_run = True
+
+    def twist_to_motors(self, twist, drive_cfg, skidsteer=False):
+        motors = RoverMotors()
+        if skidsteer:
+            for k in drive_cfg.keys():