Collision of Convex Objects for Calculation of Porous

PresentationWe investigate the coupling of the flamelet combustion model with the collision distance algorithm for entertainment games. The collision algorithm is coded to calculate the porosity of the geometry based on the PDR (Porosity Distributed Resistance) approach for modelling of complex geometries. The turbulent field generated by the interaction of the flow with the porous objects is used to calculate the wrinkling length scale of the flame via the fluctuating velocities. The turbulent fluxes are amended in accordance with assigned porosities at the cell faces. The combustion and porosity models are implemented in the framework of an in house Fortran code that solves the full set of Navier-Stokes equations. Results are presented for non-reacting flows and reacting flows over a bluff body for Re=44,000 and Ka=1 (Reynolds and Karlovitz numbers, respectively). Numerical findings are compared with standard commercial CFD tools

Distance estimation and collision prediction for on-line robotic motion planning

An efficient method for computing the minimum distance and predicting collisions between moving objects is presented. This problem has been incorporated in the framework of an in-line motion planning algorithm to satisfy collision avoidance between a robot and moving objects modeled as convex polyhedra. In the beginning the deterministic problem, where the information about the objects is assumed to be certain is examined. If instead of the Euclidean norm, L(sub 1) or L(sub infinity) norms are used to represent distance, the problem becomes a linear programming problem. The stochastic problem is formulated, where the uncertainty is induced by sensing and the unknown dynamics of the moving obstacles. Two problems are considered: (1) filtering of the minimum distance between the robot and the moving object, at the present time; and (2) prediction of the minimum distance in the future, in order to predict possible collisions with the moving obstacles and estimate the collision time

A Collision Detection Algorithm For Virtual Robot-Centered Flexible Manufacturing Cell

Collision detection is crucial in virtual manufacturing applications such as virtual prototyping, virtual assembly and virtual robot path planning. For accurate simulation of manufacturing systems and processes in virtual environment, physical interaction with the objects in the scene are triggered by collision detection. This thesis presents a collision detection algorithm for accurate simulation of a virtual flexible manufacturing cell. The technique utilizes the narrow phase approach in detecting collision detection of non-convex object by testing collision between basic primitive and polygon. This algorithm is implemented in a virtual flexible manufacturing cell for the loading and unloading process performed by the robot. The robot’s gripper is treated as non-convex object and the exact point of collision is represented with a virtual sphere and collision is tested between the virtual sphere and the polygon. To verify the collision detection algorithm, it is tested with different positions and heights of the storage system during simulation of the virtual flexible manufacturing cell. The results showed that the collision detection algorithm can be used to support the concept of hardware reconfigurablility of FMC which can be achieved by changing, removing, recombining or rearranging its manufacturing elements in order to meet new demands such as introduction of new product or change

A collision avoidance system for a spaceplane manipulator arm

Part of the activity in the area of collision avoidance related to the Hermes spaceplane is reported. A collision avoidance software system which was defined, developed and implemented in this project is presented. It computes the intersection between the solids representing the arm, the payload, and the objects. It is feasible with respect to the resources available on board, considering its performance