International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

In this paper is presented the optimal design of quarter car vehicle suspensions. During the optimisation the three design criteria which have been used are; vertical vehicle body acceleration, dynamic tire load and suspension working space. For implementing a optimization a comparison of two optimisation algorithms: Sequential Quadratic Program (SQP) and Genetic Algorithms (GAs). will be chosen five design parameters: sprung and un-sprung mass, spring stiffness, damping coefficient and tire stiffness. Through the simulation in Matlab it will be shown that GA is more powerful tool to find the global optimal point, without any restrictive requirements on the gradient and Hessian Matrix, while SQP has local convergence properties. The main focus of this research will be on minimising the vertical vehicle body acceleration subjected to a suspension working space and the dynamic tire load. At the end of this paper, it will be shown the comparison between the simulation carried out with nominal and optimal values of design parameters.

This paper deals with the comparison of Control of quarter car vehicle suspension using Linear Quadratic Regulator (LQR) and Fuzzy Logic Controller (FLC) which are considered to control quarter car suspension and computer simulation is done on the nonlinear quarter-car model with actuator dynamics. The Linear Quadratic Regulator (LQR) and Linear Quadratic Gausian (LQG) methods are the most used control approaches. LQR and FLC provide the possibility to emphasize quantifiable issues of vehicle suspensions like; ride comfort and road holding for varying external conditions.

In this paper is presented Synthesis of a for-bar linkage mechanism of the lift car extrusion. In this mechanism are introduced even higher kinematic pairs. The movement of the mechanism is repeated periodically and it is sufficient to do its kinematic study for an angle 75 [deg]. The description of the mechanism movement can be performed in the grafoanalytical or analytical path by centers of speed moments, which belong to a narrow link and a loop of the center mechanism, and the instant centers belonging to the two related movements. In the kinematic analysis of the forward mechanisms are used graphical methods. These are simple and universal, making it possible to determine the positions, velocity and acceleration of the links of any structure. With the application of contemporary calculating technology, the graphical methods in the analysis of mechanisms take the right place. The velocity of each link of the mechanism linkage that performs the movement of the plane can be shown as very geometric of the instant center speed and the speed of rotation around the center of the instantaneous. The analysis will be performed by Math Cad software, while kinetostatic analysis will be carried out using Contour Method, comparing results of two different software‘s Math CAD and Working Model. The simulation parameters will be computed for all points of the contours of mechanism. For the simulations results we have use MathCad and Working Model software’s.

This paper deals with the simulation of vertical displacement vehicle car body with one and two DOFs by using and comparing results of two softwares Working Model and MatLab. The aim of this paper was to show that is very easy is to solve the differential equations that describe both models of vehicle system with one and two DOFs. The results simulations performed with both software’s are almost the same for calculating displacement and velocity of sprung and unsprung mass and for different road excitations. The results of simulations have been analysed in terms of stability and road holding since sprung mass or vehicle body oscillations have direct impact on the passenger comfort.

In this paper is presented a six-bar linkage mechanism of the pump for oil extrusion. In this mechanism are introduced higher kinematic pairs. Dimensions and other incoming links are adopted as necessary. For the six-bar linkage mechanisms is carried out the kinematic analysis and for all linkages are shown the displacement, velocity and acceleration. The analysis is performed by Math Cad software, while kinetostatic analysis is carried out using Contour Method, comparing results of two different software‘s Math CAD and Working Model. The simulation parameters are computed for all points of the contours of mechanism.

This paper deals with the comparison of analysis of two legged humanoid robots during walking. This research area is characterized by the fact that there are a lots of publications, most of which are based on the classic Zero-Moment-Point (ZMP) method. First, a brief overview is provided on humanoid robots, and also models for the dynamic behavior are discussed. As base for these models these two methods Denavit Hartenberg and the Newton-Euler are used. Main aim of this work is to investigate the stability of humanoid robot developed. There is currently the low base of robot – consisting of feet, legs, hips and upper part of robots body. First, the existing low base of humanoid robot was simulated using Matlab / SimMechanics, where the derived by Newton-Euler model was used.

This paper deals with the safety, modeling, simulation and the possibility of automation of a production warehouse as a key component on CIM systems. The manufacturing has been changed significantly by using information systems. Using electronic data processing in the production systems and beyond, automatic protocols are derived and flow both on confirmation of the order and in economic aspect of the raw material. Also, information systems are used in planning and controlling the production, including machines, equipments and entire production process, as well as a lot more opportunities have been provided for the operator. But, security of the production systems is one of the concerns which are elaborated in this paper. Production systems play an important role in industrial and economic development of a country. Recent years, there was a tremendous change in the technology of production systems. Such changes happened as a result of advances in the field of hardware and software technology, which are directly or indirectly related to modeling and simulation of production systems. In this paper, we will investigate the possibility of automation of a production warehouse as one of the key components of CIM technology. Simulations are new and very attractive area. Nowadays they have become indispensable engineering tools for solving engineering tasks, leaving behind the traditional analytical methods. They include design, analytical and optimisation tasks of complex production systems, computer architecture, biological and military systems etc. This is made possible, because of failure to gain good results by the analytical methods, which is the case also for simple systems too. In the group of traditional methods are distinguished: arrays method (querying theory), different heuristic mathematical methods etc.This paper also deals with modelling and simulation of flexible system for electrical machine assembling by ARENA software.