Minimization of oscillations of the tower crane slewing mechanism in the steady-state mode of trolley movement

In the present study, the problem of optimization of the motion mode of the tower crane's slewing mechanism in the steady-state mode of trolley movement is stated and solved. An optimization criterion, which includes the RMS values of the drive torque and the rate of its change over time, is minimized. The optimization is carried out taking into account the drive torque constraints, and under the specified boundary conditions of motion. Three optimization problems at different values of the weight coefficients are solved. In the first problem, priority is given to the drive torque, in the third – to the rate of the drive torque change, and in the second problem, the significance of both components is assumed equal. The optimization problems are nonlinear, thus a VСT-PSO method is applied to solve them. The obtained optimal start-up modes of the crane slewing mechanism eliminate pendulum load oscillations and high-frequency elastic oscillations of the tower. Most of the kinematic, dynamical, and power parameters at different values of the weight coefficients are quite close to each other. It indicates that the optimal modes of motion are significantly influenced by the boundary conditions, optimization parameters, and constraints