Abstract
In recent years the design trend in industry has been to work in a concurrent way to unify and simplify the data models and the work flow. In this way, computer data models are being used as the core part of the whole process where the users can work on the same model and perform several analyses to validate the model. Now Digital Mock-Ups are replacing the use of physical models. This allows reduced cost, lead time and better competition.
The possibility of carrying out several assembly simulations during the design process of a 3D mechanical assembly allows to detect a number of problems at an early stage (for example, the parts of the assembly do not fit or the functional requirements are not fulfilled), and thus it is possible to search for alternative design solutions or manufacturing methods, avoiding a strong increment in the product cost.
This paper presents two complementary assembly simulation tools: tolerance analysis and a haptic virtual environment.
TASys is a Tolerance Analysis System based on a 3D non-manifold variational geometric modeller DATum developed by LABEIN. It includes both dimensional and geometrical tolerances, several assembly methods, the two types of tolerance analysis, that is, worst case and statistical analysis (linear stackup, quadrature technique, Taguchi's method and MonteCarlo simulation) and postprocessing tools.
In the haptic environment the user can manipulate 3D virtual prototypes. It has been done by the link between PHANToM, a 3 degree of freedom force feedback haptic device (SensAble Technologies, Inc.) and DATum. The integration of both systems allows the user to interact with the 3D designs in a new and more realistic way: now he can not only view the objects, but also touch, grasp and manipulate any 3D object designed in the CAD environment with collision detection. This may have multiple applications, but this work is focused in the simulation of assembly and maintenance operations of mechanical components.