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Ambient temperature has a significant effect on the electrical and luminous parameters of light-emitting diodes (LEDs), which include forward and reverse current, forward voltage, and luminous flux. This paper gives insight into the influence of ambient temperature on the electrical and luminous parameters of LEDs powered by a rectangular pulsed voltage source versus those powered by a constant voltage source. The characteristics of LEDs in LED lighting devices were studied to determine their optimal operating conditions. To this end, rectangular pulse voltages with different pulse filling factors D were considered against the DC voltage source. Characteristics were obtained for the current stabilization mode and for the LED voltage stabilization mode. In both modes, the temperature dependence of the luminous flux, current, voltage, power consumption, and luminous efficiency of the LEDs was studied in the 20 °C to 60 °C range. The optimal LED operating conditions were determined, of which their luminous flux and luminous efficiency are least dependent on ambient temperature. When powered by a rectangular pulse voltage, the LED device drivers' optimal pulse filling factor and operating frequency were determined. [ABSTRACT FROM AUTHOR]

This article is focused on the problematics of path planning, which means finding the optimal path between two points in a known environment with obstacles. The proposed path-planning method uses the wavefront algorithm, and two modifications are implemented and verified. The first modification is the removal of redundant waypoints. The first modification is applied because the wavefront algorithm generates redundant waypoints. These waypoints cause unnecessary changes in the direction of movement. The second one is smoothing the generated trajectory using B-spline curves. The reason for applying the second modification is that trajectory generated by the wavefront algorithm is in the form of the polyline, which is inadequate in terms of the smoothness of the robot’s motion. The verification of the proposed method is performed in environments with different densities of obstacles compared with standard Dijkstra’s and A* algorithms.

The electrical and light characteristics of light-emitting diodes (LEDs), upon which modern lighting devices are constructed, are significantly influenced by ambient temperature. As the temperature rises, the luminous flux of LEDs diminishes, and the lifespan of LED devices also decreases. The control devices (drivers) used in LED lighting systems, built based on current stabilization schemes, do not effectively stabilize the luminous flux when the ambient temperature fluctuates between +15 to +60 °C. The luminous flux declines as the temperature increases, even if the current supplied to the LEDs remains constant. This paper presents a comparative analysis of LED lighting devices equipped with drivers featuring current stabilization and those with drivers employing voltage stabilization for operation in higher temperature conditions. [ABSTRACT FROM AUTHOR]

Gripping and manipulating objects using non-contact and low-contact technologies is becoming increasingly necessary in manufacturing. One of the promising contactless gripping technologies is Bernoulli gripping devices for industrial robots. They have many advantages, but when changing the nozzle geometry, it is difficult to find the optimal parameters of the outer diameter of the gripper and its operating parameters. Therefore, the article presents a model for numerical simulation of the dynamics of airflow in the nozzle of the Bernoulli gripping device and in the radial gap between its active surface and the surface of the object of manipulation. Reynolds-averaged Navier–Stokes equations of viscous gas dynamics, SST-model of turbulence, and γ-model of laminar-turbulent transition were used for this purpose. The technical requirements for the design of the nozzle of Bernoulli jet gripping nozzles are determined and variants of their constructive improvement are offered. According to the results of numerical simulation in the Ansys-CFD software environment, the optimal diameter of the Bernoulli gripping device and the influence of the geometric parameters of the nozzle on the nature of the pressure distribution in the radial gap and its lifting force were determined. Determined the optimal parameters of the height of the gap between the object of manipulation and the Bernoulli gripping device using C—Factor, which will allow efficient operation of Bernoulli gripping devices during automated handling operations using industrial robots. [ABSTRACT FROM AUTHOR]

The assessment of the viscous medium flow's transformations under the influence of a component of the technological process and equipment during the redistribution of the formed local injection zones constantly requires the search for areas of improvement in both the process and the machine with rollers. Forecasting of structural and technological parameters, considering possible overloads at the change of rheology and flow of the medium, are based on research, analytical models, and computer simulations. The analysis of the action of working bodies at various loadings on the environment is carried out and the possible flow between rotating rolls with changes of structural and mechanical properties in processes of formation of a product is considered. The interaction of constructive factors with technological ones under the conditions of observance of all operating modes of the machine during its operation is established. The optimization of the parameters of this class of machines with the choice of analytical methods under the conditions of the necessary models and their development, taking into account a number of factors influencing the processes of unloading, injection, transportation of viscous media, is discussed. This is based on the result of the processes of transfer of a large enough volume with a directed flow and the pulsating motions of different scales of variables applied to it, both in time and space mathematical modeling of the influence of rheology and design parameters of forming rolls on the flow in the gap between rotating rolls and determination of useful specific power when rolling and forcing the dough. The proposed techniques allow establishing the quality of rolling the mass of the medium to the appropriate thickness when injecting roller working bodies and determining the speed and pressure formed, which depends on its physicochemical properties, the shape and location of the rolls. [ABSTRACT FROM AUTHOR]

The paper deals with the kinematic analysis of the robot model. The matrix method of kinematic analysis is used. The robot mechanism is an open kinematic chain. The position, velocity and acceleration vector of the end point of the robot arm is determined in the Matlab program. Computer simulation is also performed in the MSC Adams program. [ABSTRACT FROM AUTHOR]