Alba Perez Gracia - Research


Links to related research

Synthetica (UCI)


See a Bennett's net


Mathematica animation of a heterogeneous network mechanism by RaNae Isaak (QuickTime, big)

 Network mechanisms

Network mechanisms with one degree of freedom can be created using parallel overconstrained spatial and planar linkages. In particular, we have studied the simplest closed linkage, composed of four revolute joints, which is movable only in three particular cases: planar four-bar linkage, spherical four-bar linkage and Bennett linkage. We have created some movable structures using a homogeneous network of Bennett linkages and heterogeneous networks of both Bennett and planar four-bar linkages.

Some information about this project:
- Isaak, R., "A Study of Overconstrained Linkage Networks", Master's Thesis, College of Engineering, Idaho State University, June, 2006.
- Construct and visualize a Bennett's linkage.

These results are for a simplified definition of a human skeleton consisting of five serial chains with revolute and spherical joints.

Kinematic identification of structures from visual data

- We applied the dual quaternion synthesis theory to identify the kinematic structure underlying moving images. Graphic data from human subjects can be used to identify the kinematic skeleton. This may be used to create a 3d movable avatar representing the subject. This research was developed as a main researcher by Mari Cruz Villa Uriol, at the Department of Electrical Engineering and Computer Science at the University of California, Irvine.

- Current research project in the same direction involves the identification of human hand motion

Implementation in Synthetica1.0 of the dual quaternion synthesis for the RPC robot (Main developer of the Synthetica software: Hai Jun Su).

Dual quaternion synthesis of constrained serial robots

- The following Mathematica notebooks can be adapted to design any serial robot with less than six degrees of freedom. These are the results of the research developed in my dissertation. I include here several examples.
Spatial RR Robot,
Spatial RPP Robot,
Spatial RRP Robot,
Spatial RRRR Robot

- I developed a general solver (Java) for the finite-position dimensional synthesis of serial robots with up to five joints and up to ten degrees of freedom.

- We added this solver to Synthetica 2.0. Go to the Synthetica webpage to download the latest version of Synthetica, which can be used in Mac, Unix and Windos O.S. Synthetica was developed at the Robotics Lab of the Univ. of California, Irvine. Contact also Hai Jun Su, at Iowa State University, for questions or comments about Synthetica.

Visualization of a protein using robot kinematics

Use of robot kinematics to model macromolecules

- Project under development: apply Clifford algebra robot kinematics to model the motion and pose of macromolecules.

Surface of the joint

Modeling of 3-D meshing surfaces in human foot joints

- Project under development: develop criteria to assess the motion of the midtarsal joint complex in the evolution of human locomotion.