Add support for 2D SLAM with a depth camera. (#54)

This changes the URDF and timeout for the TurtleBot configuration,
and adds a Dockerfile with everything that is needed to run 2D SLAM
with a depth camera. Verified to work on a TurtleBot 2 with an
ASUS Xtion.

And tiny style fixes.

cartographer_ros/configuration_files/turtlebot.lua

@@ -28,7 +28,7 @@ options = {
   horizontal_laser_max_range = 30.,
   horizontal_laser_missing_echo_ray_length = 5.,
   num_lasers_3d = 0,
-  lookup_transform_timeout_sec = 0.01,
+  lookup_transform_timeout_sec = 0.2,
   submap_publish_period_sec = 0.3,
   pose_publish_period_sec = 5e-3,
 }

cartographer_ros/urdf/turtlebot.urdf

@@ -45,9 +45,24 @@
     </visual>
   </link>
 
+  <link name="camera_link" />
+  <link name="base_footprint" />
+
   <joint name="horizontal_laser_link_joint" type="fixed">
     <parent link="base_link" />
     <child link="horizontal_laser_link" />
     <origin xyz="0. 0. 0.6" />
   </joint>
+
+  <joint name="camera_link_joint" type="fixed">
+    <parent link="base_link" />
+    <child link="camera_link" />
+    <origin xyz="0.15 0. 0.6" />
+  </joint>
+
+  <joint name="base_link_base_footprint_joint" type="fixed">
+    <parent link="base_footprint" />
+    <child link="base_link" />
+    <origin xyz="0. 0. 0." />
+  </joint>
 </robot>

cartographer_turtlebot/Dockerfile

@@ -0,0 +1,23 @@
+# Copyright 2016 The Cartographer Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+FROM cartographer_ros_image
+RUN apt-get update && apt-get install -y \
+    ros-indigo-depthimage-to-laserscan \
+    ros-indigo-kobuki \
+    ros-indigo-kobuki-core \
+    ros-indigo-openni2-launch \
+    ros-indigo-turtlebot-bringup \
+    tmux \
+ && rm -rf /var/lib/apt/lists/*