Walker Bot

Simple ROS-based obstacle avoidance robot.

Overview

Walker bot is a turtlebot3-based robot capable of moving in an environment while avoiding obstacles. If the bot encounters an obstacle within a pre-defined distance range it stops moving forward and turns until there is no obstacle in its path.

The ros_walker_bot_node in this package gets the distances of the obstacles by subscribing to the \scan topic that contains the laser scan data of the Turtlebot and publishes linear and angular velocity commands to \cmd_vel topic of the Turtlebot.

Note: The implementation of this package does support Level 1 (with gtest) and Level 2 (with gtest + rostest) unit testing.

obstacle_avoidance.cpp - level 1 testing
walkerbot_pubsub.cpp - level 2 testing

Dependencies

Ubuntu 18.04 (LTS)
ROS Melodic
Turtlebot3 ROS Package

Instructions to build and run the code

Make sure you have ROS Melodic installed in your computer. If not, refer to site.

Create a workspace:

mkdir -p ~/walkerbot_ws/src
cd ~/walkerbot_ws/src

Clone the repository into the workspace:

git clone https://github.com/anubhavparas/ros-walker-bot.git

Build the workspace:

cd ~/walkerbot_ws
catkin_make or catkin build (preferred)
source devel/setup.bash

Turtlebot3 installation:

This ros_walker_bot package also needs Turtlebot3 ROS package to be there. Follow the instructions to install turtlebot3:

cd ~/walkerbot_ws/src
git clone https://github.com/ROBOTIS-GIT/turtlebot3_msgs.git
git clone https://github.com/ROBOTIS-GIT/turtlebot3.git
cd ~/walkerbot_ws/
catkin_make or catkin build (preferred)
source devel/setup.bash

Set the environment variable for the turtlebot's model:
```
echo "export TURTLEBOT3_MODEL=burger" >> ~/.bashrc
```

Running with the launch file

Run using launch file: This will spawn:

a ros_walker_bot node: ros_walker_bot_node
gazebo world with turtlebot3

roslaunch ros_walker_bot ros_walker_bot.launch 

# arguments are:
# is_record_bag - default=false
# launch_gazebo - default=true
# bagfile - default=recorded_topics.bag

To enable rosbag recording (by default it is disabled):
- This will store the rosbag recording in a file home/<username>/.ros/recorded_topics.bag
```
roslaunch ros_walker_bot ros_walker_bot.launch is_record_bag:=true
```
- Note: rosbag record will not be recording any messages in any of the */camera* topics.

Running without the launch file

To launch gazebo and turtlebot3 run the following in a new terminal. This will start rosmaster node too:
```
cd ~/walkerbot_ws/
source devel/setup.bash
roslaunch turtlebot3_gazebo turtlebot3_house.launch
```

To run the ros_walker_bot_node run the following in a new terminal:

cd ~/walkerbot_ws/
source devel/setup.bash
rosrun ros_walker_bot ros_walker_bot_node

Setting the logger level

To set the logger level of ros_walker_bot to info/debug:

rosservice call /ros_walker_bot/set_logger_level "{logger: 'rosout', level: 'debug'}"

Rosbag record and play

To run rosbag recording run the following in a new terminal (assuming the above nodes are running):

cd ~/walkerbot_ws/
source devel/setup.bash
rosbag record -O record_topics.bag -a -x '(.*)/camera(.*)' --duration 30

# -O record_topics.bag: name of the output bag file
# -a: to record all topics
# -x: to exclude certain topics. here, /camera topics will not be recorded
# --duration 30: record for 30 sec

To verify the recording:
- Examining the bag file:
```
rosbag info <your bagfile>
```
- Stop/close the gazebo world and only start the ros_walker_bot_node:
```
# in a new terminal run:
cd ~/walkerbot_ws/
source devel/setup.bash
roslaunch ros_walker_bot ros_walker_bot.launch launch_gazebo:=false
```
- Replay the bag file in a new terminal:
```
rosbag play record_topics.bag
```
- You can verify that the ros_walker_bot_node is now subscribing to the recorded messages (/scan topic).
Run a sample recorded rosbag file.
- Download the recorded bagfile from here.
- Copy and paste the file in ~/walkerbot_ws/src/ros-walker-bot/results/bag folder.
- In a new terminal start the ros_walker_bot_node to subscribe the /scan topic. This time gazebo will not be launched.
```
cd ~/walkerbot_ws/
source devel/setup.bash
roslaunch ros_walker_bot ros_walker_bot.launch launch_gazebo:=false
```
- In a new terminal replay the bag file. This is a 30 sec recording of many topics including /scan topic.
```
cd ~/walkerbot_ws/
source devel/setup.bash
roscd ros_walker_bot/results/bag
```
- Examining the bag file: Sample output.
```
rosbag info record_topics.bag
```
- Play the bag file: Sample output.
```
rosbag play record_topics.bag
```

Run cppcheck and cpplint

Run cppcheck: Results are stored in ./results/cppcheck_process.txt, ./results/cppcheck_result.txt

cd ~/walkerbot_ws/src/ros-walker-bot

sh run_cppcheck.sh

Run cpplint: Results are stored in ./results/cpplint_result.txt

sh run_cpplint.sh

anubhavparas / ros-walker-bot