Hierarchical Collision Detection Research Articles

Research on Collision Detection Method of Contact On-line Measurement

In order to avoid collision and improve the safety of on-line measurement, a contact on-line measurement collision detection method is studied. Firstly, according to the structural characteristics of the probe and workpiece, the dynamic collision detection between the probe and workpiece is transformed into static collision detection by using the discrete method, and then the grid division of the collision detection space is carried out by using the space division method. Finally, the dynamic collision detection between the probe and workpiece is transformed into the intersection judgment between simple geometry, and according to different collision accuracy requirements, Hierarchical collision detection combining rough detection and fine detection is carried out. Experimental results show that the hierarchical collision detection algorithm has high detection speed and accuracy.

Design and preliminary realization of component installation scheme generation system in virtual EAST

In the experimental advanced superconducting tokamak (EAST) experiment, the properties, states of plasma and the engineering parameters of the EAST device are measured and analyzed by various diagnostic methods. The approaches of diagnosis and measurement are constantly updated, and the diagnostic systems should be updated accordingly. However, position conflicts would inevitably occur due to the traditional diagnostic marker from diagnosis personnel according to the installation location of the part drawing, leading to modification after the rediscussion with other diagnosis personnel. In addition, the confined environments of EAST result in inconvenient installation. Therefore, the technology of scheme generation of an immersive component installation should be urgently pursued. Aimed at the actual requirements of physical experiments, the digital technology of component installation and design process based on multiuser and multidetail level, as well as the technology of virtual installation and cooperative discussion based on hierarchical collision detection are proposed. Taking the electromagnetic measurement diagnosis system as an example, the scheme generation system of immersive virtual EAST component installation is established to provide a reference for researchers to access the actual installation process, reduce the conflict of component positions, and improve the installation efficiency of the components. Preliminary realization and design of component installation scheme generation system are described.

Design on Experience Virtual Tour System

According to the characteristics and needs of virtual scenic roaming system, select the appropriate modeling techniques. By using the modeling platform scenic entity object model structure, and then build virtual tourist attractions, we propose hierarchical collision detection methods. This method actually meets the accuracy requirements under the premise, greatly reducing the number and complexity of collision detection; effectively improve the system in real time.

Proximity Queries Between Convex Objects: An Interior Point Approach for Implicit Surfaces

This paper presents a general method for exact distance computation between convex objects represented as intersections of implicit surfaces. Exact distance computation algorithms are particularly important for applications involving objects that make intermittent contact, such as in dynamic simulations and in haptic interactions. They can also be used in the narrow phase of hierarchical collision detection. In contrast to geometric approaches developed for polyhedral objects, we formulate the distance computation problem as a convex optimization problem. We use an interior point method to solve the optimization problem and demonstrate that, for general convex objects represented as implicit surfaces, interior point approaches are globally convergent, and fast in practice. Further, they provide polynomial-time guarantees for implicit surface objects when the implicit surfaces have self-concordant barrier functions. We use a primal-dual interior point algorithm that solves the Karush-Kuhn-Tucker (KKT) conditions obtained from the convex programming formulation. For the case of polyhedra and quadrics, we establish a theoretical time complexity of O(n <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1.5</sup> ), where n is the number of constraints. We present implementation results for example implicit surface objects, including polyhedra, quadrics, and generalizations of quadrics such as superquadrics and hyperquadrics, as well as intersections of these surfaces. We demonstrate that in practice, the algorithm takes time linear in the number of constraints, and that distance computation rates of about 1 kHz can be achieved. We also extend the approach to proximity queries between deforming convex objects. Finally, we show that continuous collision detection for linearly translating objects can be performed by solving two related convex optimization problems. For polyhedra and quadrics, we establish that the computational complexity of this problem is also O(n <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1.5</sup> ).

Fast collision detection based on nose augmentation virtual surgery

Collision detection is the key technology in nose augmentation surgery simulation system, which can avoid incorrect intersection between bones and the implant model. In this paper, we present a sphere-tree-based hierarchical collision detection algorithm (STHCD) for surgery simulation. Each model is represented as a clustered hierarchy of sphere tree (CHST). Graphics processing unit (GPU)-based occlusion queries were used for fast collision culling between massive models. Furthermore, we are able to generate these hierarchies and perform collision queries using out-of-core techniques on all triangulated models. Experimental results show that STHCD performs real-time collision detection between massive bones and implant models, consisting of millions of triangles at interactive rates on a commodity PC.

Efficient updates of bounding sphere hierarchies for geometrically deformable models

We present a new approach for efficient collision handling of meshless objects undergoing geometric deformation. The presented technique is based on bounding sphere hierarchies. We show that information of the geometric deformation model can be used to significantly accelerate the hierarchy update. The cost of the presented hierarchy update depends on the number of primitives in close proximity, but not on the total number of primitives. Further, the hierarchical collision detection is combined with a level-of-detail response scheme. Since the collision response can be performed on any level of the hierarchy, it allows for balancing accuracy and efficiency. Thus, the collision handling scheme is particularly useful for time-critical applications.

GPU‐based Collision Detection for Deformable Parameterized Surfaces

Abstract Based on the potential of current programmable GPUs, recently several approaches were developed that use the GPU to calculate deformations of surfaces like the folding of cloth or to convert higher level geometry to renderable primitives like NURBS or subdivision surfaces. These algorithms are realized as a per‐frame operation and take advantage of the parallel processing power of the GPU. Unfortunately, an efficient accurate collision detection, that is necessary for the simulation itself or for the interaction with and editing of the objects, can currently not be integrated seamlessly into these GPU‐based approaches without switching back to the CPU. In this paper we describe a novel GPU‐based collision detection method for deformable parameterized surfaces that can easily be combined with the aforementioned approaches. Representing the individual parameterized surfaces by stenciled geometry images allows to generate GPU‐optimized bounding volume hierarchies in real‐time that serve as a basis for an optimized GPU‐based hierarchical collision detection algorithm. As a test case we applied our algorithm to the collision detection of deformable trimmed NURBS models, which is an important problem in industry. For the trimming and tessellation of the NURBS on the GPU we used a recent approach [GBK05] and combined it with our collision detection algorithm. This way we are able to render and check collisions for deformable models consisting of several thousands of trimmed NURBS patches in real‐time. Categories and Subject Descriptors (according to ACM CCS): I.3.5 [Computer Graphics]: Computational Geometry and Object Modeling—Geometric algorithms, languages, and systems; Splines; I.3.7 [Computer Graphics]: Three‐Dimensional Graphics and Realism—Virtual reality

Efficient collision detection for models deformed by morphing

We describe a fast and accurate collision-detection algorithm specialised for models deformed by morphing. The models considered are meshes where the vertex positions are convex combinations of sets of reference meshes. This new method is based on bounding-volume trees that are extended to support efficient tree-node updates by blending associated sets of reference bounding volumes. With our approach, it is possible to use either axis-aligned bounding boxes, discrete-orientation polytopes, or spheres as bounding volumes. The expected performance of our algorithm is of the same order as for rigid hierarchical collision detection. In our tested scenarios, the speed-up we achieved ranged from 1.5 to 58, compared to another more general algorithm for deforming bodies. (Less)

An Intelligent Procedure for Collision-Detection in Robotic Systems

This paper presents a great improvement in the collision-detection problem by considering: 1.- A simple description of the objects in the world, 2.- A fast distance computational technique and 3.- A collision-detection procedure which reduces the number of distance computations required. A multi-level hierarchical structure and a novel three-dimensional object representation technique based on spherical objects are adopted for modeling the world. Fast algorithms for distance computation, based on geometrical considerations, have been developed and used in the hierarchical collision detection procedure. This technique has been applied to a complex robotic system consisting of two PUMA robots, each mounted on a three-degree of freedom platform used in order to study robotic assembly of structures in space.