Based on the analysis of characteristic of cable harness planning in virtual environment,a discrete control node modeling(DCNM)method of cable harness in virtual environment and the cable harness assembly routing tech...Based on the analysis of characteristic of cable harness planning in virtual environment,a discrete control node modeling(DCNM)method of cable harness in virtual environment and the cable harness assembly routing technique based on it are proposed.DCNM converts a cable harness into continuous flexed line segments connected by a series of section center points,and the design can realize cable harness planning through controlling those control nodes.This method of cable harness routing in the virtual environment breaks the status that virtual assembly process planning is just suitable for the rigid components at present,and impulse the virtual assembly process planning to be more practical.Relation algorithms have been verified in a self-developed system named virtual cable harness assembly planning(VCHAP)system,and this VCHAP system has been applied in assembly process planning of aerospace-related products.展开更多
This paper deals with the problem of planned lead time calculation in a Material Requirement Planning （MRP） environment under stochastic lead times. The objective is to minimize the sum of holding and backlogging co...This paper deals with the problem of planned lead time calculation in a Material Requirement Planning （MRP） environment under stochastic lead times. The objective is to minimize the sum of holding and backlogging costs. The proposed approach is based on discrete time inventory control where the decision variables are integer. Two types of systems are considered： multi-level serial-production and assembly systems. For the serial production systems （one type of component at each level）, a mathematical model is suggested. Then, it is proven that this model is equivalent to the well known discrete Newsboy Model. This directly provides the optimal values for the planned lead times. For multilevel assembly systems, a dedicated model is proposed and some properties of the decision variables and objective function are proven. These properties are used to calculate lower and upper limits on the decision variables and lower and upper bounds on the objective function. The obtained limits and bounds open the possibility to develop an efficient optimization algorithm using, for example, a Branch and Bound approach. The paper presents the proposed models in detail with corresponding proofs and se＇~eral numerical examples. Some advantages of the suggested models and perspectives of this research are discussed.展开更多
基金Sponsored by the National Natural Science Foundation,China(No.50475162)
文摘Based on the analysis of characteristic of cable harness planning in virtual environment,a discrete control node modeling(DCNM)method of cable harness in virtual environment and the cable harness assembly routing technique based on it are proposed.DCNM converts a cable harness into continuous flexed line segments connected by a series of section center points,and the design can realize cable harness planning through controlling those control nodes.This method of cable harness routing in the virtual environment breaks the status that virtual assembly process planning is just suitable for the rigid components at present,and impulse the virtual assembly process planning to be more practical.Relation algorithms have been verified in a self-developed system named virtual cable harness assembly planning(VCHAP)system,and this VCHAP system has been applied in assembly process planning of aerospace-related products.
文摘This paper deals with the problem of planned lead time calculation in a Material Requirement Planning （MRP） environment under stochastic lead times. The objective is to minimize the sum of holding and backlogging costs. The proposed approach is based on discrete time inventory control where the decision variables are integer. Two types of systems are considered： multi-level serial-production and assembly systems. For the serial production systems （one type of component at each level）, a mathematical model is suggested. Then, it is proven that this model is equivalent to the well known discrete Newsboy Model. This directly provides the optimal values for the planned lead times. For multilevel assembly systems, a dedicated model is proposed and some properties of the decision variables and objective function are proven. These properties are used to calculate lower and upper limits on the decision variables and lower and upper bounds on the objective function. The obtained limits and bounds open the possibility to develop an efficient optimization algorithm using, for example, a Branch and Bound approach. The paper presents the proposed models in detail with corresponding proofs and se＇~eral numerical examples. Some advantages of the suggested models and perspectives of this research are discussed.
