No abstract

The paper deals with the structural synthesis of bi-mobile mechanisms based on six links passive modular groups and used in robotics and other industrial equipment [1]. Such mechanisms are useful in any practical situation when a suitable curve is necessary to be described in manufacturing processes. Even if the passive complex modules with six links are mentioned in the literature these are rarely encountered in construction of mechanisms and in design due to the difficulties to achieve their mathematical models.

Biomechanical systems for human upper limb have been studied and developed for more than 60 years, due to requirements of improving life quality for people who cannot partially, or totally, use their hand. This paper presents aspects related to preliminary research (kinematic model of thumb, 3D mechanic model, hard-software platform) of a bionic hand that will be done and is intended to be of high sensitivity, good accuracy, low weight, friendly user interface, with efficient command and control system.

The passive modular groups mentioned in the classical theory of mechanisms are the basis modules in the construction of planar mechanisms with one degree of mobility corresponding to their linkages with four degrees of freedom. Even if thirteen solutions are presented [3,4,5,6] only some of them are found in practice and apparently there are groups never met in the mechanisms structure.The effectors extremity of bi mobile mechanisms describes any curve in an adequate domain. When the bi mobile mechanisms become main mechanical structures for robot arms and legs for mobile platforms two new notions are put into evidence -the inverse and the direct modelling. The inverse structure modelling of bi mobile mechanisms is based on the passive modular groups. By using the numerical operators such new structures with zero degree of mobility obtained from Baranov trusses may be obtained. In the paper there are also presented such new groups and their applying for the design of optimal bi mobile mechanisms. The paper is the result of intensive research to obtain new solutions applied and designed for various branches of robotics. The bi mobile systems thus obtained are patentable.

The research of the optimal conditions of achievement of robotic assembling requires the determination of the restrictions imposed by the characteristics of the desired assembling. To analyze the requirements imposed to the assembling robot in the elaborated paper there have been considered Petri Graphs with dynamic markings. These schemes permit a synthetic representation of the assembling process and they praise clearly the active phases of the robot.