Title: Multipurpose grasping system
Author: prof. Alberto Rovetta N. AA-2 


A further characteristic of the prehension system is the palm, its mechanical properties are connected with the angular disposition of the fingers. The palm presents some configurations and shapes which are different in the form of the contact plate and in the elastic and dynamic features of its mechanical elements.

An analytical-geometrical algorithm which appears to be suitable for an approach to the analysis of the prehension of a generically shaped workpiece is here introduced:

  • analysis of the object shape and schematisation of the object by composition of geometrical elementary forms;
  • analysis of the validity of an approximate geometrical model;
  • transformation of the model in a geometrical analytical algorithm;
  • definition of spatial working points of the mechanical hand and of the possible contact and grasping surface in geometrical-analytical form;
  • comparative analysis between the object surfaces and possible grasping contact surfaces for the identification of the actual common grasping line-surface;
  • analysis of grasping sequence with control of kinematics and dynamics of contact;
  • modification of contact surfaces and evaluation of prehension efficiency with reference to the stability.

The control requires:

  • sensors which give position and force signals for each finger;
  • palm signal;
  • the A/D converter;
  • the microcomputer for data processing, for calculation and control reference to selected values setup;
  • the D/A converter for actuators control;
  • the motors control

Future possible developments
Experimental programs about the software, through computation control implementation, and the hardware in its mechanical structure (modifying springs, drive elements, pins, fingers, components) and in its electrical composition (motors, transducers, feeders, converters).