Hydraulic Manifold Hole Checking Using Real-coding Genetic Algorithm

Hydraulic Manifold Hole Checking Using Real-coding Genetic Algorithm

Abstract
This research is the first attempt to use Real-coding Genetic Algorithm (RGA) approach for physical interference checking of hydraulic manifold hole with wall thickness and drill cone consideration. Typical computer-aided technique for hydraulic manifold hole checking is the 3D constructive solid geometry method, which treats two holes as two entities, and checks them by Boolean pattern UNION. The disadvantage of this method is that it requires the user to convert the traditional 2D drawing into 3D. This operation is also very time consuming and takes up a lot of computer memory and storage space for the 3D drawing. Moreover, this model is not mathematical-based; it can only check whether the holes are open or short, but it cannot tell the user the minimum wall thickness between a pair of holes and drill cones. In practice, wall thickness is very important for hydraulic manifold design. To facilitate the design processes, an automatic system for this problem is therefore studied. RGA is an evolutionary algorithm to identify global maximum and minimum points of multivariable functions or optimal point in system equations without solving complex mathematical equations. In this paper, RGA calculates the nearest distance between two hole entities, says "d". If d is less than the minimum wall thickness, then the two holes interfere with each other. Otherwise, it passes. With iterative process, RGA can check all hole entities in the manifold block using one simple mathematical model. A prototype computer-aided manifold block design and hole checking system, written in C++ and running on an AutoCAD platform, has been built to implement the concept. The system can concurrently draw and record the locations and sizes of the holes in a 2D drawing. The data recorded can serves as the input variables of the mathematical models. Experimental results show the program actually shortens the checking process, and the CAD environment can be simplified from the traditional 3D to 2D.

Keywords
Genetic Algorithm, Hydraulic manifold blocks, Hole interference checking