Reliability allocation of rotary ultrasonic vibration-assisted EDM machine tool based on maximum entropy ordered weighted average and constraint under the index of overall cost

Abstract

Rotary ultrasonic vibration-assisted EDM is a composite machining method which uses EDM technology to process metal surface and adds rotation and ultrasonic vibration. In this paper, the failure rate of each module of the rotary ultrasonic vibration-assisted EDM machine tool can be accurately predicted by the maximum entropy ordered weighted average algorithm so that the corrected maintenance cost can be predicted. And effective control of preventive maintenance costs can be achieved by selecting the best maintenance times under the premise of reliability. The results showed that the reliability of rotary ultrasonic vibration-assisted EDM machine tool is smoother at nonfixed maintenance intervals by varying the maintenance interval according to the comparison between non-fixed and fixed maintenance cycle. The cost of corrective maintenance can be reduced by varying the measurement to achieve cost optimization in the context of reliability with an optimum number of maintenance cycles and reliability.

A preventive maintenance scheme for rotary ultrasonic vibration EDM machine tool based on particle swarm optimization algorithm under reliability constraints.

“…Where, is preventive maintenance(PM) costs, is the cost of repair after failure, and is the total maintenance cost. Assuming that the average cost of PM cost for the m-th component of the machine tool is , the average cost of repairing the m-th component after failure is , the reliability level of the accessory after each repair is the same, the probability of performing preventive maintenance during the preventive maintenance interval is and the probability of performing post-failure restorative repair is , so the total maintenance cost during the preventive maintenance interval is calculated by formula (14): Substitute formula (11) and formula (12) into formula (14), C(T) is calculated by formula (15): Also, in order to ensure that T is within the permissible pre-repair interval for each component, the upper limit of the preventive maintenance interval for the m-th component is calculated by formula (16):…”

“…In order to reduce the above unnecessary losses, the preventive maintenance(PM) of the machine tools is particularly important. Minggang Xu and Hao Fu et al [14] predict the failure rate of each component of CNC machine tools and effectively control preventive maintenance costs. For the various types of preventive maintenance, there are signi cant differences in repair time and repair costs between the different repair types [15].…”

Variances and Logarithmic Aggregation Operators: Extended Tools for Decision-Making Processes

“…In this sense, the system weights the introduced values in relation to a given order, thereby measuring the importance of the introduced values with independence to the origin of the information [46]. This characteristic design has been widely applied in automation control systems [47], computer science and information systems [48], and telecommunications [49] among a wide variety of applications. The increasing appeal of the OWA operators' design can be observed in wide ranging reviews such as [17].…”