ALGORITHM FOR SELF-TUNING THE PID CONTROLLER

An algorithm for self-tuning the PID controller to the second order systems is proposed in this paper. The proposed self-tuning procedure was developed according to the maximum stability degree criterion, the criterion that permits to achieve the high stability degree, good performance and robustness of the system. According to the proposed algorithm, the controller can be tuned according to the parameters that characterize the process and they can be determinate from the experimental response of the open loop system. To demonstrate the efficiency of proposed procedure of self-tuning the PID controller, the computer simulation was performed and the obtained results were compared with Haeri’s method, maximum stability degree method with iterations and parametrical optimization method. According to the developed algorithm, it was performed the control of the thermal regime in the oven.

Numerical studies of steel pipe sheet pile

The sheet pile wall (SPW) is carried out from pipes of big diameter which plunge into soil very deeply. Depth of pipes is the settlement size depending on a set of parameters. Depth of pipes provides rigidity and reliability of a construction. SPW has a high rate of a consumption of steel on his production. Authors of the present article suggest to reduce a material capacity of SPW at the expense of reduction of depth of blockage of every second pipe. Decrease in depth of blockage of separate pipes is carried out at preservation of the maximum depth of blockage of other pipes. The design similar to a «comb» because of alternation of long and short pipes turns out. Such decision allows to reduce the total depth of blockage of pipes and as a result leads to decrease in a material capacity and cost of a construction in general. The problem of search of possible reduction of length of a part of pipes is the purpose of the real research. As solutions of the put problem we suggest to execute numerical experimenting in iterative statement with use of modern software. Results of numerical researches of SPW are presented in the present article. The presented results allow to draw a conclusion on efficiency of the solution on decrease in a material capacity of SPW proposed by authors. For obtaining the generalized decision and obtaining undoubtedly the best result of a design of SPW authors consider necessary to execute problem definition in the form of parametrical optimization.

Structurally-Parametrical Optimization Technological Process by Dijkstra's Method in System Mathcad

The article describes the procedure of structurally-parametrical optimization of technological process by Dijkstra's method with using of Dijkstra’s functional (recurrent) equation and Mathcad system. The technological process includesnof operations and each operation can be executed by various types of equipment. Expenses (cost, time, ...) on execution ofioperation bykequipment after execution byjequipment (i-1) operation are known -c(i, j, k). The algorithm of the decision of a problem by Dijkstra’s method includes two phases.The firstphase is calculations of the minimum expenses for execution of all partial technological processes, from first operation of process to the last.The secondphase is definition of the required optimum set of equipment which is carrying out all technological process with the minimum expenses from last operation of process to the first. The proposed procedure of structurally-parametrical optimization of technological process using Dijkstra’s method and Mathcad software significantly decreases time and labour costs on execution of such calculations and efficiently to execute investigations related with change of equipment parameters.

THE PROBLEM OF PARAMETRIC OPTIMIZATION AND SECURITY OF FUNCTIONING OF HYDRAULIC SYSTEMS

Problem definition of parametrical optimization of hydraulic systems is considered. The general problem of parametrical optimization for systems of water supply and gas supply is presented in the form of a problem of mathematical programming. As a result of the solution of the considered task optimum parameters of the studied systems have to be determined, the required levels of reliability and safety when functioning are ensured.

Investigation of vibroisolating device reliability in grinding machine

For the search of rational engineering solutions on the design of vibroisolating devices of a machine functioning under conditions of a floating shop there is used a method of a morphological analysis. The undertakings carried out allowed solving a problem at the level of a structural arrangement optimization and parametric synthesis and creating new designs of a vibroisolating support and a vibroisolating device. On the basis of the regulations of a mass service theory there is offered a method for the operation reliability estimation of a machine vibroisolating device with the use of a graduated graph of states taking into account failure and restoration flows. The state of the system is determined by a set of equations of final likelihoods. A machine experiment has shown maintainability high enough of a vibroisolating device (more than 96 % of its life the device is in its operational status, and about 4% - in the repair (restoration) state of its subsystems). To the least reliable subsystem it should be related a drive (failure probability – 2.11%), further – vibro-isolator (failure probability – 1%), then – a body – (0.52%) and a fastening device (0.26%). The method allows defining device maintainability with the aid of a machine experiment and revealing least reliable subsystems and elements and also an expediency of their parametrical optimization.