Papers by Author: Jacek Kłosiński

Abstract: A strategy for control of a system of two electrical vibrators mounted onto the vibrating plate of a typical small table vibrator was discussed in the present paper. The aim of the considered control system is rapid positioning of counterbalances for ensuring achievement of the assumed directions of vibrations and loading forces (where , m is unbalanced mass, ω is angular velocity of the vibrator shaft, e is distance between the unbalanced mass and the vibrator rotary axis). The strategy of the control consists in setting of different directions of vibrator rotations together with controlled change of vibration frequency and amplitude. Numerical analysis was performed. The obtained results are presented in a graphical form.

Abstract: Dynamics of two models (simplified and complex) of a small, typical vibrating table is considered in the paper. The table consists of vibrating plate and electrical vibrator, mounted in the central position of the plate, which excites the vibrations of the table. The coefficient of transversal stiffness of the spring has been determined on the basis of numerical simulation. The spring is an essential element of the system. The results of performed numerical simulations are presented in the graphical form.

Abstract: A payload displacement in mobile cranes is performed via an adequate composition of working movements. Hoists are used for lifting and lowering of a payload. The following devices are used for displacement of a payload from initial point to another one: a mechanism for generation of crane slewing motion and a mechanism of reach variation. Displacement of heavy payloads by mobile cranes in some conditions can lead to a loss of stability. In this paper authors propose assessment of a stability surplus via: monitoring of values of stress forces of the supports on the ground, calculation of the vertical resultant force of these stress forces and determination of the acting point of the resultant force. The mathematical model of the control system (regulating chassis slewing motion) integrated in the intervention system of a jib reach is presented. Finally, some representative results of numerical simulations are provided.

Abstract: A mathematical model of the control system of a mobile crane is presented in the paper. The system controls the slewing motion of the chassis as well as it is applied in the model of the emergency subsystem which changes the jib reach. The latter one is initiated at the moment when the threat of loss of stability occurs. Some results of numerical analysis are presented in this paper. The results are related to different strategies of control of the slewing motion as well as to different types of controllers applied in the main loop of control and emergency subsystem. The results of experimental studies are reported as well. The experiments were performed using custom-built testing setup, which represents a kinematic model of a crane.