Objectives

  • UR3 model must be mounted on the linear rail
  • Model and simulate the gripper
  • Simualte the environment and safety features
  • Display and log transforms and process status during task completion
  • Calculate and plot workspace radius & volume

    • Linear UR3 with custom gripper model

  • The linear rail act like a prismatic link for the UR3, I need to adjust the DH parameters a bit to fit with the linear rail.
  • The gripper contains 2 fingers, each finger act like a 2D plannar robot with 2 joints.

    • Working volume calculation

  • The red pointcloud are generated by iterate each link of the UR3 from the start to the qlim with the proper steps. The working volume of the UR3 on the linear rail is estimated by assuming it an ellipsoid and I used the formula for the volume of the ellipsoid to calculate it.
  • Visualizing the working volume in a pointcloud helps me to identify where should I place the fence to protect it from the other people.

    • Simulation video

    You can click to the video to go to youtube, it would be easier to see it more clearly.

    Pick and place task simulation on the real UR3

    It was not very fancy :) as I need to send separate rossubcriber command to maintain the safety for the robot. However, I did learn how the ROS work in MATLAB and later I can apply it into many other robots in the mechantronics lab.

    Conclusion

    After this project, I have acquired many invaluable knowledge and skill:

  • 1. Inverse kinematic with jont guess and foward kinematic and foward kinematic. Trajectory generation with trapezodial velocity profile.
  • 2. Functions and classes in MATLAB
  • 3. Documenting the safety and risk assessment before working with the real robot.