Xiaoping Liao

Surface segmentation based intelligent trajectory planning and control modeling for spray painting

A critical technology of automatic trajectory planning and control system for spray painting is segmenting complicated surfaces into multiple simple patches. This paper develops a new surface segmentation approach based on triangulated CAD model of part and deposition model of spray painting. First, the foremost segmentation generates the patches that are connected and can be covered by paths uniformly, which is based on determining the maximum deviation angle of vertexes in spray stroke. Next, considering different figure of one patch, the region expanding curve (REC) and the orientation of sub-paths, we present the segmentation based on obstacle avoidance (SBOOA) to settle the further segmentation of one patch containing obstacles. The simulation results demonstrate the effectiveness of proposed approach. It shows that this paper provides the approach support for the surface segmentation handling complicated shape or topological structures, and intelligent trajectory planning and control system for spray painting.

Visual nesting system for irregular cutting-stock problem based on rubber band packing algorithm

This article deals with the packing problem of irregular items allocated into a rectangular sheet to minimize the waste. Conventional solution is not visual during the packing process. It obtains a reasonable and relatively satisfactory solution between the nesting time and nesting solution. This article adopts a physical method that uses rubber band packing algorithm to simulate a rubber band wrapping those packing irregular items. The simulation shows a visual and fast packing process. The resultant rubber band force is applied in the packing items to translate, rotate, and slide them to make the area decrease and obtain a high packing density. An improved analogy QuickHull algorithm is presented to obtain extreme points of rubber band convex hull. An adaptive module could set a variable rubber band force and a variable time step to make a proper convergence and no intersection. A quick convex decomposition method is used to solve the problem of concave polygon. A plural vector expression approach is adopted to calculate the resultant vector of the rubber band force. Several cases are compared with the benchmark problems to prove rubber band packing algorithm performance.

Collision Detection Analysis of 2D Layout Based on Convex Hull Plus Rubber Band Simulation

It is an innovative design method in physics that product layout design is abstracted into convex hull plus rubber band simulation layout mode by setting up the optimized model. Based on the physics model of Newtons Second Law, this paper analyzed collision detection methods during the process of realizing reasonable layout, and it is founded that real-time collision detection and collision response during movement, produced components within the given beat, appeared to be the key content of resolving digital model design. In this paper, Area Difference method was adopted to detect when the collision occurred during component movement and what kind of state the component tended to be in collision. At the same time, it also determined the interference degree, solved critical point pose for collision response as well as its generation time and related torque and force, which can confirm the components continued movement model of rotation and sliding. Meanwhile, it employed the Judgment Matrix method to analyze collision response so as to confirm the collision interference relationship and collision action state, movement possessing mode (rotation, sliding and retraction, etc.) within the remaining time after collision with given beat during the layout process. All these provided with a practical solution for digital design of optimized model based on convex hull plus rubber band simulation compact layout.

Research and Motion Analysis of Multi-Object Compact Layout Based on CPR in 2D

Compact layout is a problem widely faced in many branches of science, engineering, is also the key point in lightweight design of product. With the perspective of digital design we divided the layout procedure into three stages-only outers, outer-inner, more objects involved-based on (convex hull plus rubber band) CPR. Motion analysis in each stage is done respectively according to physics principles. Rules of Multi-Object collision response are built in two forms, vertex-edge and edge-edge. Objects motions are determined by their motion analysis and collision response rules. An example of Multi-Object compact layout in stimulation platform is given and feasibility of the method is confirmed.

Digital Modeling and Movement Resolution of Rubber Ballon Analogy for 3D Packing Problem

Packing problem is how to arrange the components in available spaces to make the layout compact. This paper adopts a digital modeling algorithm to establish a novel rubber ballon convex hull model to solve this problem. A visible point puls maximum distance method analogy QuickHull algorithm is presented to get extreme points of rubber ballon convex hull. Movement resolution aim at force analyze and calculate the resultant vector to translate, rotate and slide the component to make the volume decrease in detail. An experiment proved this digital modeling algorithm effective.

The Study and Application of Gaussian Process Surrogate Model Based on Gradient Particle Swarm Optimized Hyper-Parameters

Constructing a high-fidelity surrogate model to optimize production process is often required to meet the requirement of manufacturing process programming ,one of the most popular techniques for the construction of such a surrogate model is that of Gaussian process surrogate model. In this paper, the development of a gradient particle swarm optimization is described, which aims to reduce the cost of this likelihood optimization by drawing on an efficient adjoint of the likelihood, and improve the precision of the model. A multimodal benchmark function was used to test, show that the tuning strategy can provide an accurate Gaussian process surrogate model. Based on LHS ,Gaussian process surrogate model (GP) and gradient particle swarm optimization algorithm (GPSO), a optimization model which is used for improving the quality of Al profile welding is built and utilized to obtain optimal multi-parameters of Al alloy profile extruding processes and moulds. Optimal solution is validated by experiment.

Process simulation modeling for sequence switching strategy in substations

Automatic sequence switching has been an important pursuit in the field of substation automation. This paper presents a software process simulation modeling representation and method for sequence switching strategy in substation. It starts with a presentation of sequence switching problem, then, suggests a component-driven pattern recognition model of a substation switch network organized in a logic relationships structure of constraint objects, and reachability of Petri nets suitable for constraint satisfaction. An intelligent optimal sequence switching strategy and component-driven knowledge representations of sequence switching are presented. The software process simulation modeling method provides a platform for further research in terms of intelligent decision-making of switching processes.