Dawid Cekus

THE DYNAMICS OF THE FOREST CRANE DURING THE LOAD CARRYING

In this paper, the theoretical and calculation model of the forest crane and the lifted load is presented. The model enables the simulation of the motion of the load carried by a forest crane while taking into account the elastic deformations of the boom. The lifted load has been modeled as a 3D rigid body. The application of such a load model enables the simplification and enhancement of the calculation algorithm. The equations describing the coupled motion of the system load and machine elements are presented. The kinematic model enables the analysis of the basic motion of the load as a response of the system to operational control of the forest crane. In order to determine the motion parameters it was assumed that all system elements are rigid. The lifted load is also treated as a rigid body and its motion is the result of the movement of the load suspension point and the dynamic interactions generated during the motion of the system. The presented sample results from the numerical calculations were ob...

VIBRATION MODEL AND ANALYSIS OF THREE-MEMBER TELESCOPIC BOOM WITH HYDRAULIC CYLINDER FOR ITS RADIUS CHANGE

In this paper, the free vibration problem of a system consisting of a three-member type telescopic boom of the laboratory crane, the hydraulic cylinder of crane radius change and the elastic support system has been presented. The model has been formulated in order to represent the vibrations in the lifting plane of the laboratory crane. The transverse vibrations of the boom, longitudinal and transverse vibrations of the hydraulic cylinder have been considered in the coupled model of the system taking into account the elasticity of the support system. In the computational model, the analyzed system has been replaced by the discrete-continuous model. The free vibration problem of the analyzed system is formulated and solved on the basis of Lagrange multiplier formalism. The experimental modal analysis is done and the genetic algorithm worked out with the aim of identifying spring constants of the support system elements. The analysis of the influence of the hydraulic cylinder and the length of the telescopic boom on the free vibration frequencies is carried out on the basis of the identified vibration model of the considered system. The examples of the experimental and numerical results are presented.

Identification of parameters of discrete-continuous models

In the paper, the parameters of a discrete-continuous model have been identified on the basis of experimental investigations and formulation of optimization problem. The discrete-continuous model represents a cantilever stepped Timoshenko beam. The mathematical model has been formulated and solved according to the Lagrange multiplier formalism. Optimization has been based on the genetic algorithm. The presented proceeding’s stages make the identification of any parameters of discrete-continuous systems possible.

The Influence of the Type of Used Connections on the Results of Analyzes Carried Out in CATIA System

In the paper the existing in CATIA system the types of connections that may occur between the components have been characterized. These connections specify the boundary interaction between bodies and can simulate the real connection behavior. Use in the same place another connection has a significant impact on the results of analyzes. The stress analyses of the excavator jib together with the bucket for the different types of connection properties have been presented as the examples.

Modeling and Stress Analysis of an Industrial CNC Plotter

In the paper a geometrical and computational model as well as results of stress analysis of an industrial CNC plotter have been presented. The research of the designed device have been divided into two parts: the static analysis of a frame with a plotter gate, and the static analysis of an axle assembly Z. The obtained results have been used in the design stage of an industrial plotter for a Polish company producing CNC machines.

Simulation of Riding a Real Mobile Robot Following the Defined Path

The paper presents a method that enables a race of a real mobile robot following the path defined by Catia software. On the basis of the performed simulation, the parameters necessary for task realization have been obtained and combined into a matrix, then importing and implementing them into the mobile robot. Exemplary experimental research on P, PI and PID regulators with a turbine switched off and on P regulator with a turbine switched on has been carried out.

Kinematic Analysis of a Four-Degree-of-Freedom Manipulator

The paper deals with the kinematics problem of a four-degree-of-freedom manipulator and derives equations for forward and inverse kinematics. A simulation model has been created applying SolidWorks program. On the basis of modelling, a real object used for experimental research has been built. Numerical, analytical and experimental results have been compared.