Papers by Author: Shun De Gao

Abstract: Scientific and practical crane evaluation index system is expected to obtain by screening of indices in this paper. The initial comprehensive evaluation indices are selected by stratification. Then the quantitative indices are screened by entropy method and Pearson correlation coefficient method, and the qualitative indices are screened by Delphi method and Spearman correlation coefficient method. The little effect indices on the evaluation result are deleted and the redundant information between the indices are got rid of. The index system simplified is comprehensiveness and representative, which is convenient to compare and evaluate cranes.

Abstract: This paper presents the work done towards searching a collision-free path for mobile crane based on C-space in the complex 3D working environment. The crane is simplified into three degrees of freedom (DOFs) robot, each of which is represented as an axis of configuration space (C-space). In this paper, we propose an improved ant colony approach for crane path planning, which takes into full account of not only the factor of the shortest path but also the factor of safety. In this approach, we employ more complete heuristic information, introduce adaptive pheromone volatilization coefficient and pheromone penalty factors, and prevent ants from falling into trap and the stagnation. The reasonability and practicability of the proposed approach for automated path planning is verified by comparing the performances of the present approaches in the practice case, and the comparison results show that the algorithm can gain a relatively optimal solution in short time and have a great value of engineering application.

Abstract: Modeling System for Construction task Simulation (MSCS) presented in this paper is a 3D computer-aided drawing tool which is designed for construction task planners. It is based on OGRE (Object-oriented Graphics Rendering Engine) and Bullet Dynamic Engine, therefore the model created by MSCS has both geometric and dynamic properties. MSCS has already been used in Crawler Crane’s Lifting Simulation System which is developed by Dalian University of Technology in China to draw the work environment and the loads to be lifted.

Abstract: According to the crawler crane’s structure and the scene management principle of OGRE (Object-Oriented Graphics Rendering Engine), this paper presents a new 3D parameterized modeling method of crawler cranes. By integrating the interactive modeling using 3DSMAX and the geometrical graphics modeling, the new method can solve the problem about rendering speed, vivid and parameterized models and how to obtain the position of key points. A case is described in order to demonstrate the use of the developed method and to illustrate its reliability.

Abstract: Crawler cranes are the most expensive and frequently shared resource on construction sites, industries, etc. According to the characteristics of crawler crane, this paper presents a multiple modeling method of crawler crane based on OGRE (Object-oriented Graphics Rendering Engine) and Bullet Dynamic Engine. The multiple model is composed of rendering model, collision model, skeleton model and dynamic model. Based on this modeling method, not only vivid figuration and motion of the crane but also real-time collision detection and distance computation can be achieved.

Abstract: Though rule-based reasoning system is easy to create and convenient to extend, it is not flexible because of the demand for precise matching. Geometric reasoning system can obtain engineering semantic from CAD model and connect geometric topology with design knowledge, but it can not drive product design directly. Utilizing the complementary of rule-based reasoning and geometric reasoning, a product design method based on integrated geometric and rule-based reasoning is presented. The method can standardize the expression of design scheme which is from geometric reasoning, and dock seamlessly design scheme and input condition in rule-based reasoning system. Furthermore, the result of rule-based reasoning can drive product design directly. The operation of human-computer interaction and designer’s experience needed are decreased greatly. Digital target in locater is significant to harmonize aircraft tie-in. there are different types in it, and the amount of it is huge, so its design process is complicated and fussy. On the basis of the method, a rapid design software package for locator digital target design is developed and has been applied in aircraft assembly tooling design. The application has proved the method can improve design efficiency, standardization and intelligence.

Abstract: Along with the development of simulation technology, systems of three-dimensional simulation are being used in more and more domains. The distance of objects is one of the important measures which are used to estimate the relationship of object’s position and to weigh the attributes of their own movement. The distance computing places an important role in the system of 3D simulation. In this paper, the two-phases (broad-phase and narrow-phase) algorithm for computing distance is presented. Using the algorithm, finally we have got the minimum distance of objects, and the feasibility and veracity of the algorithms are proved by an example.