In this article we present a symbolic closed-form matrix formulation to obtain the dynamic equations of branched articulated multibody systems (AMS)s. The proposed approach uses geometric mechanics based on Screw Theory and Lie groups. Both Lagrange's and Newton-Euler's equation of motion are derived. Furthermore, the structure of the proposed set of geometric equations holds the intrinsic robot parameters explicitly arranged like symbolic matrices. The formulation is valid for any branched AMS without closed kinematic chains and whose joints have one degree of freedom (DoF) (revolute and/or prismatic). All these properties allow the use of these equations in different algorithms such as identification, simulation and control of branched AMSs like hands or humanoids. Finally, the proposed equations have been validated and verified with the multi-body simulation software package MSC=ADAMS©by computing the inverse dynamics of a two arm torso of 16 DoF.

The modeling of a modular robot system is complex due to its capability of changing and forming countless robot configurations with a set of modules. The greater the number of modules added to the structure, more complicated is the robot and its modeling. A methodology to represent modular robot configurations as a fixed shape robot is presented. The equivalent model is obtained through the characterization of the module, graph theory and geometric modeling of robots. After the transformation, the resulting kinematic and dynamic parameters are similar to the traditional model of a single configuration robot. Once the equivalent model is obtained, it can be used within different robot applications.

This paper shows the advantages of having a modular system with 3-DoF spherical actuator in the base module to perform tasks that require displacement and object manipulation. Having 3-DoF actuator improves the complexity of coordination patterns and control algorithms of the modular system more relevantly as compared to having only 1 or 2DoF actuator in the module. Nevertheless, modules with actuators of only 1 or 2DoF require more modules to be assembled together in order to achieve complex tasks. Experiments performed with RobMAT modular system proves that a 3DoF actuator in the module is better, because tasks such as displacement, obstacle climbing and object manipulation, can be efficiently carried out with systems of 2 modules, 4 modules and 6 (maximum) modules connected together.

This paper presents the operations of a 3-D camera and a video processing device aiming at the improved performance of teleoperated tasks. The video processing device has two operation modes: a) one for the stereoscopic image visualization, and b) other for the blending of video and graphic images. Main results are shown; considering specially the influence of the different video frequencies, corresponding to PAL and VGA formats. Finally, two telerobotic applications, on which these devices have been successfully applied, are described.