BOSCH BITES Hackathon

Team Members

• Archana A Chandaragi
• Arjun Achar
• Pradeep J
• Sanraj Lachhiramka

Problem Statement

Using ROS, Build a two-PC communication model that will acheive the following

We define 2 PCs(Linux Machines) as follows: PC1 and PC2

• PC1 will send out data to the PC2 (either as ROS topic or Request/Response model)

• Data sent out by PC1 contains following data:

• An array of structures called location_list of size NUMBER_OF_LOCATIONS with structure as shown below

  Single_location:
  	Radius
  	Azimuth angle
  	Elevation angle
  

• The data from PC1 must be sent cyclically( period can be defined by the teams, suggest to keep the period within 1 second)

• Verify the published data using Wireshark tool.

• PC1 must process based data as per the Algorithm mentioned in below section

• PC2 must be capable of receiving the data published by PC1 (Teams are allowed to use publisher-subscriber or server-client methods)

• PC2 ROS Node should convert data into x, y, z and use specific ROS message type to visualize the same in RVIZ

  • Hint : Teams are free to look up open source and understand.
    • Double-Hint ** Pcl-classes

• Once conversion is done, another topic of the type as described above must be published and using RVIZ, it mist be visualized.

Algorithm development:

We came up with a way to achive the following in well-defined steps:

Step1:

• Each location must have different azimuth and elevation angle and initially all locations must be at origin.
• For every cycle, change the elevation and azimuth angles in a specific pattern(can be decided by teams).
• Send out this data for all locations from PC1 and receive this at PC2. Convert this data into x, y, z and visualize it in RVIZ.

Our Approach

1. Utility Functions: The utils.py module contains helper functions for converting between spherical and Cartesian coordinates. These functions are used by both the publisher and subscriber scripts to ensure consistent coordinate transformations.

2. Data Generation and Publishing: The spherical_coord_pub_mv_temp.py script is responsible for generating and publishing temperature data along with spherical coordinates. We simulate a moving object that emits temperature data at different points in space. The temperature data is randomly chosen within a specified range, and the object's position is updated based on predefined spherical coordinates. The data is published on the /spherical_coord topic using a custom message type spherical_coord_mv_temp.

3. Data Visualization: The rviz_visualizer_mv_temp.py script subscribes to the /spherical_coord topic and visualizes the temperature data in RViz. It converts the spherical coordinates to Cartesian coordinates using the utility function rad_az_ele_to_xyz from the utils.py module. The temperature data is represented as colored spheres in 3D space, with the color indicating the temperature level (e.g., red for high temperatures, green for moderate temperatures, and blue for low temperatures). Additionally, the script displays a text marker showing the current temperature value. The script continuously runs in a loop, updating and republishing markers as new data is received, ensuring real-time visualization of the spherical coordinates and their temperatures.

Tech Stack

• Python
• C++
• ROS
• Rviz

Steps to run the project

1. Clone the repository in the src directory of your catkin workspace using the following command

git clone https://github.com/Space-Gamer/bites-hackathon.git

2. Navigate to the root of your catkin workspace and build the project using the following commands

catkin_make
source devel/setup.bash

3. Running the project

• To run the basic implementation of the project, run the following commands

  roslaunch bites_hackathon bites_hackathon.launch ros_service:=false ## For using Publisher-Subscriber model

  or

  roslaunch bites_hackathon bites_hackathon.launch ros_service:=true ## For using ROS Service model

• To run the improvised implementation of the project with moving obstacle and varying frame rate, run the following commands

  roslaunch bites_hackathon bites_hackathon_moving_obj.launch python:=true ## For running the python implementation

  or

  roslaunch bites_hackathon bites_hackathon_moving_obj.launch python:=false ## For running the C++ implementation

4. To visualize the data in RVIZ, navigate to the rviz tab and add a new display of type Markers.