Based on the previous dynamic analysis, it was discovered that during the operation of the rotation mechanism of the tower crane, there are fluctuations of the load and significant dynamic loads in the elements of the structure and drive. These phenomena arise during the transitive modes of motion (starting and braking). For their minimization, the optimization of the start-up process was performed according to a certain optimization criterion. In this article, the problem of optimizing the mode of rotation of the jib crane is solved by the criterion of the RMS (root mean-square) value of acceleration of the change in force in the drive mechanism. 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 laws of motion according to the criterion of the RMS value of acceleration of the change in force in the drive mechanism (mode 2) have significant advantages compared to the laws of motion based on the criterion of the RMS value of the rate of change of the elastic moment in the drive mechanism (mode 1). As a result of the analysis, it was found that under mode 2, the maximum and RMS values of most kinematic and power characteristics have less values than under mode 1, for some indicators these parameters are equivalent. However, the nature of the change of these indicators under mode 2 is smooth. 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. It should be noted that 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.
tower / jib crane, rotation mechanism, load, rotation, dynamic load, optimization, minimization, criterion, force, oscillation, elastic moment, speed change, acceleration, optimal control