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PID based SCARA Robot Position and Velocity Control And Manipulation

Developed at: Worcester Polytechnic Institute

Project date: December, 2022

GitHub URL: parth-20-07/PID-based-SCARA-Robot-Position-and-Velocity-Control-And-Manipulation

Introduction on Project

The aim of the assignment is meant to get a better understanding of basic concepts of Robotics using tools like ROS2 Humble Hawksbill, Gazebo Sim, RVIZ and MathWorks® MATLAB The final project is divided into three seperate assignments:

Assignment 1: Build Model URDF, Forward Kinematics Node and Inverse Kinematics Node

  • Setup the dynamically accurate model of robot in Gazebo by editing the model URDF.
  • Calculate the DH Parameters of the Robot to build a node that:
    • Subscribes to the joint states of the robot and calculates the Pose of the robot by using Forward Kinematics.
    • Publishes the Pose of the Robot to a new topic using a publisher.

  • Create an Inverse Kinematics Calculation Node that:

    • Uses a custom service to take input of the (x,y,z) coordinates of the robot end-effector.
    • Calculate the Joint States from the end-effector position and return it as a response to the service.

    Gazebo Model-pid.png

    PlotJugger Set Canvas.png

Assignment 2: Build a node to control Joint States

  • Create a node that takes Reference Values for Joint Position as input through a service.
  • Build a Proportional-Derivative Controller that takes the current Joint States and Reference joint state to publish the control torque values to the /forward_effort_controller/commands topic.
  • Ensure that the model reaches the reference joint states in Gazebo.

vel.gif

Assignment 3: Build a node to control Joint or End-Effector Velocity

  • Create a node with 2 services:
    • Service 1 takes Joint Velocity as input to convert it to End-Effector Velocity as output.
    • Service 2 takes End-Effector Velocity as input to convert it to Joint Velocity as ouput.
  • Based on the input, build a Proportional-Derivative controller that takes the current Joint Velocity and the Reference Joint Velocity to publish the torque values to the forward_effort_controller/commands topic.
  • Ensure that the model reaches the desired end-effector or joint velocity in Gazebo.

eff.gif