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 obtained from the Matlab system. The initial problem has been solved by the Runge–Kutta method. The numerical program has been developed on the basis of the presented model which allows analyzing the motion of load arising from crane operating mechanisms.

No abstract

In the paper, the authors present construction stages of simulation models worked out using SolidWorks and Matlab/Simulink environments. As examples of simulation models, a laboratory truck crane and a forest crane have been shown. These models allow for visualization of movements, tracking of the trajectory, velocity and acceleration of any point of the system.

In this work the problem of motion modeling and work cycle optimization of manipulator with revolute joints has been considered. The motion equations of the manipulator elements under any spatial work cycle conditions have been formulated. The formulation has been completed by using the classic vector mechanics and Lagrange equations of second kind. The equations of motion of the system have been obtained using commercial software. The chosen motion model for each considered actuator is point-to-point motion model with quasi-trapezoid velocity profile. Additionally, the problem of optimization of a particular work cycle has been presented. The optimization objective has been chosen as minimization of loads (torques) in actuators. The objective function has been formulated using performance indexes and the design variables are rated velocity value and initial time value of work cycle in each considered actuator. The formulated optimization problem has been solved using constrained Multi-Objective Particle Swarm Optimization algorithm. A numerical computation has been completed using specially performed software and results of the computation have been attached to the paperwork.

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.