Master’s Thesis

Robot teleoperation through Impedance Control

Objective: Develop a Control Law that works in position and force subspaces using kinematical and dynamical models in order to replicate Master Robot movement to the Slave Robot.

Summary:

  • Develop Direct and Inverse Kinematical Models.
    • Develop Kinematic Simulator.
  • Develop Direct and Inverse Dynamical Models.
    • Models Validation.
  • Develop Control Law in Force and Position Subspaces.
  • Conclusions.

Remarks:

  • Master Robot is 6 DoF
  • Slave Robot is redundant (7 DoF)

Results:

Phantom Omni (Master Robot)

Loading file
  • Fullscreen
  • Wireframe
  • Zoom In
  • Zoom Out
  • Rotation
  • Screenshot
  • Help

Controls

×
  • Rotate with the left mouse button.
  • Zoom with the scroll button.
  • Adjust camera position with the right mouse button.
  • Double-click to enter the fullscreen mode.
  • On mobile devices swipe to rotate.
  • On mobile devices pinch two fingers together or apart to adjust zoom.
  • On mobile devices 3 finger horizontal swipe performs panning.

Robai Cyton Gamma 1500 (Slave Robot)

Loading file
  • Fullscreen
  • Wireframe
  • Zoom In
  • Zoom Out
  • Rotation
  • Screenshot
  • Help

Controls

×
  • Rotate with the left mouse button.
  • Zoom with the scroll button.
  • Adjust camera position with the right mouse button.
  • Double-click to enter the fullscreen mode.
  • On mobile devices swipe to rotate.
  • On mobile devices pinch two fingers together or apart to adjust zoom.
  • On mobile devices 3 finger horizontal swipe performs panning.

When trying to track a given trajectory with inverse kinematics algorithm of both robots, I got the following result.

Master Robot Inverse Kinematics Test
Slave Robot Inverse Kinematics Test

Inertia Ellipsoids of both robots are shown in the following images

Front View
Right View
Upper View
Master Robot Inertia Ellipsoids Representation
Front View
Right View
Upper View
Slave Robot Inertia Ellipsoids Representation

Next I’ll show dynamics result. There’s a delay in the graphs, however, it’s because I don’t have a control law acting in the simulation, it’s just the robot dynamics in open loop.

Reference and Output
Joint Velocities
Joint Acceleration
Torque
Master Robot Joint Space Dynamics
Reference and Output
Joint Velocities
Joint Acceleration
Torque
Slave Robot Joint Space Dynamics

Finally, I’ll show robots dynamics with the control law. In the case of the Master Robot I have a PD with gravity compensation, and in the case of the Slave Robot I have the Impedance Controller in Task Space.

Reference and Output
Task Space Velocities
Task Space Accelerations
Control Law
Master Robot PD Task Space
Reference and Output
Task Space Velocities
Task Space Accelerations
Control Law
Slave Robot Impedance Control Task Space