EV3PathBot

📖 Introduction

EV3PathBot is a python package that is used to control the EV3 robot to follow a path, pre-defined by the user.

The motivation for this project is to provide a simple and easy to use control system for the EV3 community to use in their projects.

The EV3PathBot package is developed generates a script that is modifiable by the user to add more functionality to the robot, which saves the user time and effort.

The package is developed using ev3dev2 library.

⚒️ Requirements

1- Python3 2- Anaconda or Miniconda 3- Git bash for Windows Users -Optional but recommended-

⚠️ Note: This package is tested on Windows machine. It should work on Linux and Mac machines as well.

💻 Installation

Unix (Linux & Mac)

Creating Virtual Environment

by running this command:

$ make virenv

then activate the virtual environment

$ conda activate ev3pathbot-env

Install & build the package:

$ make install

Windows

Creating Virtual Environment

run these commands in git bash:

$ conda env create -f environment.yaml

then activate the virtual environment

$ conda activate ev3pathbot-env

Install & build the package:

$ ./install.bat

📚 Glossary

• X and Y are the coordinates of the robot in the Cartesian coordinate system. As shown in the figure below:

▶️ Usage

⚠️ Note: you are running the EV3PathBot package on python3, and running the generated script on the microPython on the EV3 brick. Just follow the instructions below.

1. Configuring the EV3 robot and the environment

fill in the config.yaml file with the following information:

Parameter	Description
robot dimensions
length_x	The length of the robot in the x-axis in stud
width_y	The width of the robot in the y-axis in stud
wheel_diameter	The robot outer wheel's diameter in mm
mat_dimensions
length_x	The length of the mat or the arena in the x-axis in mm
width_y	The width of the mat or the arena in the y-axis in mm
mat_image_path	The path to the mat image
robot_motors
port_A	Type of the motor connected to port A (Medium or Large)
port_B	Type of the motor connected to port B (Medium or Large)
port_C	Type of the motor connected to port C (Medium or Large)
port_D	Type of the motor connected to port D (Medium or Large)
robot_sensors
port_1	Type of the sensor connected to port 1 (Color or Gyro)
port_2	Type of the sensor connected to port 2 (Color or Gyro)
port_3	Type of the sensor connected to port 3 (Color or Gyro)
port_4	Type of the sensor connected to port 4 (Color or Gyro)
pid_constants
kp	The proportional constant of the PID controller
ki	The integral constant of the PID controller
kd	The derivative constant of the PID controller
log_file_append	to append to the log file or not (True or False)
steps
delta_theta	the rotation angle of the robot in degrees
delta_pixels	the distance the robot will move in pixels
additional_motors_steps	the medium motors speed steps in degrees
speed_steps	the step size of the robot movement speed

2. Connecting the EV3 robot to the computer

follow the instructions in the ev3dev2 to install the image on the EV3 brick, and connect it to the computer.

3. Run the EV3PathBot package

use the following command to run the package on mac or linux:

$ python src/main.py

or use the following command to run the package on windows:

$ python src\main.py

4. Follow the control instructions

to control the robot, use the following keys:

Key	Description
w	move forward
s	move backward
a	turn left
d	turn right
q	quit the program and generate the script
,	rotate the robot's head left
.	rotate the robot's head right
p	save the robot current position, orientation and speed
z	increase the additional motors 1 degrees
x	decrease the additional motors 1 degrees
c	increase the additional motors 2 degrees
v	decrease the additional motors 2 degrees
r	change the additional motors mode to Parallel
t	change the additional motors mode to Series
m	increase the robot movement speed
n	decrease the robot movement speed
y	reset the gryo sensor angle value

⚠️ Note: Make sure that you are on English keyboard layout.

5. Edit the generated script

Now you will have a generated script in the ev3dev-codes directory, you can edit it to add more functionality to the robot.

Each time you run the EV3PathBot package, it will generate a new script with a new name, so you can keep the old scripts and compare them.

🔁 Control System

The EV3PathBot package uses a PID controller to control the robot movement. The PID controller is a closed-loop control system that uses the current error, the integral of the error, and the derivative of the error to calculate the output.

The control function is: $u(t) = K_pe(t) + K_i \int_0^t e(\tau)d\tau + K_d\frac{de(t)}{d(t)}$

where:

• $K_p$ is the proportional constant
• $K_i$ is the integral constant
• $K_d$ is the derivative constant
• $e(t)$ is the error at time $t$
• $u(t)$ is the output at time $t$

✍️ Authors

• Ali Albustami

• Waleed Abu Blan

• Hazem Al Btoush

🙌 Acknowledgments

Big thanks to Zaid Ghazal for sharing his knowledge and experience with us.

Contributing

To contribute to EV3PathBot, follow these steps:

1. Fork this repository.
2. Create a branch: git checkout -b <branch_name>.
3. Make your changes and commit them: git commit -m '<commit_message>'
4. Push to the original branch: git push origin <project_name>/<location>
5. Create the pull request.

Contact

If you want to contact me you can reach me at my LinkedIn Account