Boris Rozin

Optimization of Multi-tool Cutting Modes for Batch Manufacturing in Large Series Machining Environment

The problem of optimization of cutting modes for multi-position machines with multi-spindle heads is considered. Parts of several types are groped into batches. Each tool can be used for machining different parts of a batch. Cutting modes to be defined should provide the required throughput, meet the constraints on the cutting process characteristics and minimize the production cost. Decomposition techniques are proposed. These techniques are based on the method of Lagrange multipliers and the concept of fragmentary parameterization.

Cost optimization for series–parallel execution of a collection of intersecting operation sets

A collection of intersecting sets of operations is considered. These sets of operations are performed successively. The operations of each set are activated simultaneously. Operation durations can be modified. The cost of each operation decreases with the increase in operation duration. In contrast, the additional expenses for each set of operations are proportional to its time. The problem of selecting the durations of all operations that minimize the total cost under constraint on completion time for the whole collection of operation sets is studied. The mathematical model and method to solve this problem are presented. The proposed method is based on a combination of Lagrangian relaxation and dynamic programming. The results of numerical experiments that illustrate the performance of the proposed method are presented. This approach was used for optimization multi-spindle machines and machining lines, but the problem is common in engineering optimization and thus the techniques developed could be useful for other applications.

Optimization of Multi-tool Cutting Modes in Multi-item Batch Manufacturing System

The problem of optimization of cutting modes for multiple position machines and transfer lines equipped with multi-spindle heads is considered. Parts of several types are grouped into batches. Each tool can be used for machining different parts of a batch. The cutting modes to be defined should provide a required throughput, meet the constraints on the cutting process characteristics and minimize the batch production cost. Decomposition techniques are proposed. These techniques are based on the method of Lagrange multipliers, the concept of fragmentary parameterization and techniques for separable programming problems.

Optimization of Machining Modes for Multi-head Machines under Group Replacement of Tools

Abstract A problem of defining of machining modes for paced multi-station transfer lines composed of workstations with multi-spindle heads is considered. Each spindle head performs some block of operations with its tools. Each tool of a spindle head has its own spindle speed. All tools of a spindle head have the same feed per minute. All spindle heads of all workstations are activated simultaneously. Constraints on ranges of cutting parameters, cutting process characteristics, required productivity, as well as dependences of tools life time on the cutting parameters are given. To decrease the idle time of the equipment the tools are grouped to implement their replacement simultaneously. All tools of each group are replaced after processing the same number of parts, where the number is taken from the given set. The problem consists in finding the cutting parameters and the tools grouping to minimize the unit production cost under the above constraints. The proposed method is based on the combination of fragmentary parameterization concept and the coordinate-wise descent over groups of variables of the parameterized problem. A numerical example is presented.