Fuzzy comprehensive evaluation of green closeness

There are many methods that can be used to evaluate the green closeness of green tools, such as weighted scoring method, cost-benefit method, analytic hierarchy process, value engineering method, expert consultation method, fuzzy comprehensive evaluation method, etc., among which the fuzzy comprehensive evaluation method is more representative. Fuzzy comprehensive evaluation is a comprehensive evaluation method that applies fuzzy set theory to comprehensively evaluate the system composed of things affected by multiple factors. Because it breaks through the limitations of precise logic and language, emphasizes the fuzziness of the influencing factors of things, and can more truly and deeply describe the objective attributes of things, it is widely used in engineering evaluation

2 characteristics and attributes of green tools in the whole process of its life cycle, green tools should fully reflect the guiding ideology of reducing pollution, protecting the environment, optimizing the use of resources and saving energy (i.e. the principles of environmental protection, consumption reduction and energy conservation). The main attributes of green tools can be summarized as follows: environmental attributes: Green tools should be environment-friendly in the whole life cycle without endangering personal safety and health, It will not cause environmental pollution (including material, physical, chemical and other pollution), and it should have good disassembly and recyclability after scrapping, and have a certain degree of reusability

material properties: Green tools require that tool materials have significant green characteristics, that is, they should not cause pollution and harm in the acquisition, production, processing and use of tool materials, and they should be easy to be recycled and treated after scrapping, and should not cause secondary pollution to the environment; At the same time, it requires high utilization rate of materials and less waste; In addition, the types of materials used should be reduced, and materials that are easy to obtain should be selected, so as not to use or cause general enterprises to have difficulty in entering, and rare and precious materials should be used less

energy attribute: Green knives should consume the least energy in all links of their life cycle, make full and effective use of materials and energy, and realize the reliable recovery and reuse of energy at the least cost

function attribute: the green tool should have good cutting function and reliable quality assurance, which can achieve higher cutting efficiency and better technical performance, suitable for dry cutting and high-speed cutting

man machine attribute: the green tool should meet the requirements of man-machine engineering, have good man-machine interaction, simplify operation, reduce labor intensity, and ensure the personal safety and physical and mental health of users

3 mathematical model of multi-level fuzzy comprehensive evaluation fuzzy comprehensive evaluation method can apply the principle of fuzzy exchange and the principle of maximum membership to comprehensively analyze various factors related to the evaluated things, Through fuzzy exchange and operation, determine the "close to reality. When applying the fuzzy comprehensive evaluation method, if there are many influencing factors, the factor set u can be classified according to some characteristics. First, comprehensively evaluate each type of factors, and then evaluate the evaluation results" "High level comprehensive evaluation between. The specific steps are as follows: set the factor set u=ml, M2,..., u*, and the alternative set v=vi, V2,..., vp. first, according to the relationship between the factors in the factor set, u is divided into n categories, and establish the factor set, that is, u=mi, M2,... Mn, milmi2,..., Mimi. Mi factors in the factor set are comprehensively evaluated according to the first-level fuzzy comprehensive evaluation model, which can be obtained (3) The total evaluation matrix R of the two-level fuzzy comprehensive evaluation u is -bn. According to the weight distribution corresponding to private, calendar,..., H5, the weight can be obtained. According to the importance of various factors, each factor class is given the name = (0.3, 0.20.20.1, 0.2). From this, the evaluation result of the environmental characteristics is d=c*r, which can be determined as 005 according to the principle of maximum membership)

if there are many factors in factor set u, three or more levels of fuzzy comprehensive evaluation can be carried out by imitating the above steps

4 fuzzy comprehensive evaluation of green closeness of green tools the green closeness of green tools is evaluated by multiple fuzzy comprehensive evaluation methods. The specific steps are as follows: (1) establish the evaluation characteristic factor set U of green tools. According to the properties of green tools, establish the vertical characteristic factor set u=h, cngr, which causes the error of the pressure testing machine. Among them, the factor categories are: environmental factor H includes tool manufacturing The amount of solid waste hi produced in the process of use, the use and pollution history of cutting fluid during tool processing, the impact of cutting noise H3, the disassembly H4 after tool abandonment, and the recyclability and reusability history after tool abandonment

material factor C includes material accessibility Ci, material utilization C2, material processability C3, number of types of materials C4, recycling and disposal of waste materials c5 Energy factor n: including energy type N1, efficiency ratio N2, energy utilization rate N3, clean energy utilization rate N4, renewable energy utilization degree n5 Functional factors g include cutting performance G1, quality reliability G2, cutting parameter optimization G3, cutting power G4, and service life G5 Human machine factor R includes simple structure R1, convenient operation R2, interactivity R3, safety R4, and aesthetic rule r5 (2) The first level fuzzy comprehensive evaluation of characteristic factors first carries out the first level fuzzy comprehensive evaluation of the influencing factors of green cutting tools, that is, each single factor in the characteristic factor set is evaluated separately. According to relevant national or industrial regulations and standards, the green closeness of this factor is evaluated by relevant institutions and experts. The closeness can be divided into five grades, namely excellent (a), good (b), medium (c), poor (d) and poor (E)

(0.5, 0.20.20, 0.1) similarly, we can get the two-level fuzzy comprehensive evaluation of the evaluation characteristic factors of other single factors. Similarly, we can evaluate the characteristic factors of C, N and GR respectively. We can get the evaluation matrix of the factor set u, which is to determine the corresponding weight of each characteristic factor H, C, N and GR at the same time. To this end, we can get the two-level fuzzy of the tool will pay more attention to the consumer experience. The comprehensive evaluation result is d=w ° R =0.298, which is the green closeness value of the tool. Compare the green closeness value of the tool with the standard closeness value determined according to relevant standards and regulations. If it is higher than the standard value, it can be determined that the tool is green

the green characteristics of green tools are mainly composed of environment, materials, energy, function, human-machine relationship and other factors. Whether they are green tools can be determined by applying the fuzzy comprehensive evaluation method to determine the green closeness of tools. Because the characteristic factors of different types and functions of tools may be different, different characteristic factors and their weight distribution can be determined according to the specific evaluation object, so as to fully and reasonably reflect the green characteristics of the tool