Shun Jia

Therblig-based energy demand modeling methodology of machining process to support intelligent manufacturing

Energy efficiency has become an important factor that should be included in Intelligent Manufacturing due to the increasingly rising energy price and severe energy shortage issues. Energy demand modeling method is the foundation of improving the energy efficiency of manufacturing; therefore, an energy demand modeling methodology for machining processes is proposed. In this method, machining processes are divided into a series of activities, and Therblig, as one of the basic concepts of Motion study, is introduced to represent the basic energy demand unit. Moreover, a mathematical model of energy demand of machining processes is established by linking the activity and Therblig with machining state. Finally, case studies are performed to illustrate the validity and feasibility of the proposed methodology.

Machining activity extraction and energy attributes inheritance method to support intelligent energy estimation of machining process

An energy-efficient intelligent manufacturing system could significantly save energy compared to traditional intelligent manufacturing systems that do not consider energy issues. Intelligent energy estimation of machining processes is the foundation of the energy-efficient intelligent manufacturing system. This paper proposes a method for machining activity extraction and energy attributes inheritance to support the intelligent energy estimation of machining processes. Fifteen machining activities and their energy attributes are defined according to their operating and energy consumption characteristics. Activities and energy attributes are extracted mainly from NC program supplemented with blank dimensional information. An effective extraction method of activities and energy attributes is the basis for the intelligent energy calculating of machining process. Based on an investigation on the extraction procedure of activities and energy attributes, energy attributes inheritance method is further discussed. Four types of energy attribute inheritance rules are summarized according to the different inheritance characteristics. Based on these four types of inheritance rules, the energy attributes can be transmitted from activity to Therblig as effective inputs of Therblig-based energy model of machining processes. The proposed methodology is finally demonstrated through two machining cases.

Methodology for Calculating Energy Consumption of a Machining Process

Due to significant environmental impact and constantly rising prices, energy consumption gets more and more attention by governments and companies. Understanding and calculating the total energy requirements as well as detailed energy breakdown of a machining process are essential tasks as machining is responsible for a large amount of energy consumption in manufacturing industry. The aim of the work reported in this paper is to develop a methodology to estimate and analyze energy consumption of a machining process. This methodology is based on the representation of a machining process as a series of activities. The energy consumption of activities is calculated combined with the energy behavior of machine tool components, and formulas for calculating total as well as detailed breakdown of energy consumption for a machining process are given. The application of the methodology is demonstrated on the turning of a simple shaft.