4 more papers accepted!!

So happy to have 2 conference accepted in IEEE SMC 2013, 1 in IROS 2013 and a journal paper in Robotics and Autonomous Systems!!!

All will be published shortly, keep ’em coming!!

Research Seminar given by yours truly!

Yesterday I presented my previous and current research at New York University Abu Dhabi. The seminar was the last date in a series of CSE (Center for Science and Engineering) Research Rounds, which are a weekly forum to learn about the researchers at the CSE and their exciting work and facilitate connections among the research staff at the CSE. Following, you can have a glimpse at my presentation.

New journal paper accepted!!

This time we have submitted a manuscript to the International Journal of Advanced Robotic Systems and it was accepted!

The paper is about a novel wearable alarm system of approaching objects for the hearing impaired using laser range sensors and vibrating motors.

If interested, refer to publications section for pre-print.

RAS journal paper accepted!!

My first ever journal paper was accepted for the Journal of Robotics and Autonomous Systems!!

Title: Joint Origin Identification of Articulated Robots with Marker-based Multi-Camera Optical Tracking Systems

Refer to publications section for pre-print.

Back in Abu Dhabi!!

HI! So after ~1 month of vacation, going back to my home country (Mexico) and traveling around Europe I am back in Abu Dhabi. I was offered a Research Assistant position at the Interactive Robots and Media Lab (IRML++) at the CSE Labs of NYU Campus Abu Dhabi under the supervision of Dr. Nikolas Mavridis http://www.dr-nikolaos-mavridis.com

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Finally done with Ripley’s kinematics!

In order for the Ripley framework to work with a new robotic arm (ST Robot R17) I had to find the kinematic model of that arm. This was fairly simple, the manufacturers gave me the link lengths and they compute forward and inverse kinematics using triangle trigonometry, as explained in the following link:

The difficult part was that I didn’t know where the Origin of the first joint of the robot was wrt. the table, as well as the position and orientation of the camera that I mounted on the robot end-effector.  The identification of these parameters was crucial to adapting the new robot to the ripley model of it.  Therefore, I used the VICON Motion Capture system to identify the origins of the first joint of the robot (ie. the base) and the last joint of the robot (ie. end effector). Knowing these two parameters we can compute the relative pose of the robot wrt. the table and the camera wrt. end effector. I had done something similar in my master’s thesis. There I used markers in a tracking system to identify the pose of the head’s joint and the hand’s joint of the humanoid robot ‘rollin Justin.

The identification of the origin of kinematic joints is based on the fitting of spheres and planes to a series of measurements created by rotating the joints around their DOF. In my thesis I evaluated several methods, and finally chose a “Constrained least-squares optimization for robust estimation of center of rotation.” by Chang and Pollard. I adapted their proposed method to be used for the estimation of a robotic joint’s center of rotation. This can be seen in the following picture:

This lead me to identify the missing parameters of the complete environment:

  1. Relative pose of robot origin frame to table center.
  2. Relative pose of camera to end effector origin.
  3. Relative pose of robot origin frame to end effector (This I used to verify the accuracy of the Robot Controller’s forward kinematics.)

Once I knew all the kinematic parameters of the robot and it’s environment, I modified ripley’s kinematic model from the original framework and came up with this 🙂 …