2D Geometric Constraint Optimum Solving Based on Problem Decomposition

Constraint solving is widely applied to many fields including computer aided design, 2 dimension (2D) model design and computer aided manufacturing. Geometric constraint solution is a difficult problem because there are a large number of entities and related parameters in 2D sketches. In this paper, a new method which decomposes geometric constraint relations based on entity-parameter graphs is proposed for reducing the size of constraint solution. A geometric constraint problem is decomposed into many independent sub-problems. Then, particle swarm optimization algorithm is used to solve constraint equations in each sub-problem. Solutions of all sub-problems are integrated to obtain the original problem’s solution. In experiments, the proposed method is applied to HUST-CAID system. Experimental results show that the method can effectively solve 2 dimension geometric constraints.