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

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.

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.