The reason of boundary condition of movement in the objective optimization of the mode swing operation of a jib crane

Autors
Loveykin, V. S., Romasevich Yu. A., Kadykalo I. O.
Issue
Hoisting and transport equipment, 2019, №2(61)
Pages
45-59
DOI
10.15276/pidtt.2.61.2019.04
Abstract
In this article it is given one of the ways to solve the problem of eliminating fluctuations of cargo on a flexible suspension during the operation of the rotation mechanism of the jib crane and minimization of dynamic loads. The solution of the problem consists in optimization of the transition modes for starting the rotation mechanism of a jib crane. The optimization was carried out according to the criterion of the RMS (root mean-square) value of the rate of change in the elastic moment in the drive mechanism. For the solution of this problem, the calculus of variations methods were used. The optimization criterion is presented in the form of an integral functional, which displays undesired system properties - dynamic loads in the drive mechanism, so its value was reduced to a minimum. The solution of the variational problem is obtained in the form of functional dependencies of the motion mode of individual parts of the rotation mechanism of a tower crane and is presented in graphical form. The obtained optimal mode of motion of the rotation mechanism of a crane allows to eliminate the fluctuations of the load on the flexible suspension during the rotation mechanism operation, as well as to reduce the dynamic loads in the drive and metal framework of a crane. During the solution of the optimization variational problem of motion of the rotation mechanism of a crane, it has been justified the boundary conditions of motion, which minimize the dynamic loads in the drive mechanism. The use of optimal laws of motion makes it possible to significantly increase the reliability and performance of the crane operation and reduce emergencies during loading and unloading procedures. The realization of the optimal modes of motion is achieved with the help of the mechatronic devices of the control system of the drive mechanism. The results obtained in this study can be further used for specification and improvement of existing engineering methods for calculating the rotation mechanisms of cranes with a cargo on a flexible suspension both at the stages of their design / construction, and in conditions of real exploitation.
Keywords
jib crane, rotation mechanism, load, dynamic load, minimization, criterion, optimization, oscillation, elastic moment, speed change, boundary conditions
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