Papers by Keyword: Control

Abstract: This article provides an overview of Direct Energy Deposition – Arc technology (DED-Arc), also known as Wire Arc Additive Manufacturing (WAAM), which involves the deposition of metal wire using an arc power source and a CNC or robotic manipulator. The high deposition rate of WAAM justifies its use for the manufacturing of small to large-size components with lower resolution and less complex geometry. However, the use of wire as feedstock in the WAAM process has certain advantages and disadvantages, which are explained in detail. The WAAM specialties are in-situ alloying and the production of functionally graded materials (FGMs). Various sensors, path planning, process control, and FEM simulation from WAAM are used to reduce material and energy consumption and make the process more sustainable. Post-processing techniques are also discussed as a method of improving the quality of the final product. Finally, the prospects of the WAAM process are presented.

Abstract: This research is an invention of a non-linear sensor measurement process with a non-linear interpolation technique using a method with the Goen constant equation. This invention is not a linearization technique, so a comparison signal technique is not needed from the output of the non-linear sensor. Therefore, the advantage of this technique without a comparison signal is that it is more responsive. In addition, the costs incurred are cheaper because if the non-linear sensor uses a linearization technique, it will require additional electronic devices to support the use of the comparison signal technique. Two-way non-linear sensor measurements can be done simply using one-way measurement techniques using Ivan Newton Interpolation (INI). There are two non-linear sensor measurement process techniques. The first technique measures conditions outside the sensor that are non-linearly correlated to the sensor's characteristic values. The second technique measures sensor characteristic values non-linearly correlated to the condition values outside the sensor. This second technique can be done indirectly using the trial and error (TE) interpolation technique. The non-linear sensor measurement technique using INI will produce a two-way non-linear correlation between the conditions outside the sensor and the sensor characteristic values. This measurement technique will produce a non-linear correlation, so a comparison technique is unnecessary for the linearization process. The output response results from the non-linear sensor measurement process technique with INI can be more responsive when used as a control sensor. More responsive when compared to non-linear sensors using linearization techniques. This can happen because the linearization technique requires a slope comparison process using a comparison signal first.

Abstract: The effectiveness of the functioning communication management systems with the information security system is analyzed on the example critical information infrastructure objects. Based on the study, a new approach is proposed to obtain analytical estimates security and reliability indicators hardware and software complexes critical information infrastructure management systems. The given formulas for calculating the intensities of the states telecommunication systems allow to expand the number indicators information security and reliability functioning, if necessary.

Abstract: The issues of constructing a control subsystem for adaptive control of technological processes on metal-cutting machines are considered. The implementation of control functions is carried out within the framework of adaptive control systems for cutting processes through the use of information about the power parameters of the cutting process, obtained on the basis of universal measuring converters. Measuring devices are an essential part of any adaptive control system and, in addition, have independent significance, since they can be used in systems for protecting equipment and diagnosing its condition. The quality of control and the reliability of measuring devices largely determine the effectiveness of the control system.

Abstract: The work addresses the issues of increasing processing accuracy and productivity by controlling technological connections that act during the formation of shaped surfaces by grinding and plastic deformation, presents the main indicators of the quality of teeth on the working surface, provided by the developed technology, with a decrease in the maximum value of the actual cutting depth by more than 1.5 times when grinding toothed surfaces by copying, determined influence of the position of the workpiece on the accuracy of the pitch and half-angles of the profile for rolling threads of high precision by radial feed, the purpose of which is movement and measurement, design features determined of rollers for thread rolling on workpieces with low rigidity with tangential feed, the parameters of their threads, including the functional and structural relationship of the helix angles with the dimensions of the rolled thread.

Abstract: It is natural to define marine corrosion in terms of the different zones in which the corrosion occurs such as atmosphere splash, tidal and sea mud etc. However, this study focused on issues affecting the marine structures, different types of corrosion and their impact on the marine steel structures as well as the machinery/equipment. Furthermore, several control measures of corrosion necessary to avert corrosion in marine environments were discussed. However, it was established that prolonged contact of marine structures with seawater would lead to corrosion as well as ruing the safety elements present. Thus, the study provides potential information to material scientists on the need for using structural steels of adequate mechanical properties.

Abstract: Because of The low complexity of passive filters (PF) compared to the active filter, their high efficiency, their ease of installation and their different topologies,theyremained the devices required in the power system. In order to minimize the harmonic distortion produced by the large industrial loads, harmonic filters should, therefore, be designed with the utmost rigor, because a poorly designed filter may amplify the undesired harmonics. The determination of the PFcomponents requires both adetailed study ofthe power system parameters, which influence the efficiency and economic viability of the harmonic compensation and the reactive power required by the load.This article studies the use of the Cuckoo optimization algorithm (COA), in order to designpassive filters with an improved power quality and reduced cost. The optimal filters are connected concurrently to the power system so that each individual Harmonic distortion respects the recommended limits. The results show that the optimized (PF) is effective, and has a lower cost.

Abstract: In this study, the nonlinear dynamic analysis of the motion and control of the lower limb exoskeleton using differential transform method is presented. Devices for medical processes are continuously undergoing improvement such as enhancing and assisting automatic therapies with flexible and configurable programs for treating people with partial disability in lower limbs as applied in lower-limb exoskeleton. The configurable programs in this exoskeleton can be applied to observe and control the motion of the exoskeleton for effective physiotherapy and reduced rehabilitation time for patients with such disability. Hence, a two degree of freedom nonlinear dynamic model for the motion and control of the lower limb exoskeletons was developed for two links. The nonlinear dynamic models are solved by applying the differential transform method (DTM) and verified with the forth order Runge-Kutta numerical method (RK4). The effects of the applied torque on the two links are investigated and it is observed that Link 1 has large negative deflection amplitude that drives link 2 towards the opposite positive direction. An increase in the applied torque resulted in increase in the amplitude of the system for all initial condition considered. This in turns increases the nonlinear dynamic behavior of link 2 due to its lower mass value. The speed of both links dampens out over the history due to the presence of damping term. At equilibrium, both links are in phase and have the same amplitude over the time history. This study provides an analytical tool for observing and controlling the motions of the lower limb exoskeleton and for improving the designs of the medical device.

Abstract: Mechanized arc welding is divided into two main varieties: with self-regulation of the electrode melting process and with automatic process control. The common thing between self-regulating mechanized arc welding and manual arc welding is that in the welding equipment there are no means for automatic control with feedback from the arc. The difference between them is that stabilization of the electrode melting process in mechanized welding is carried out by the source itself, which has a particular volt-ampere characteristic (CVC), by a corresponding spontaneous reaction to a change in the situation in the arc. This method is significantly inferior to the method with automatic process control in precisely maintaining the specified parameters and has a limitation on the minimum current density on the electrode. The method of pulse self-regulation of the electrode melting process proposed in the E.O.Paton EWI removes this problem. However, it requires the use of power sources with a complicated, multi-link CVC curve. Further improvement is revealed through the use of digital controlled, programmable power supplies that have an automatically generated CVC. The combination of automatic source control and self-regulation by the spontaneous reaction to the situation in the arc creates a new hybrid way to stabilize the process of arc welding with a consumable electrode and other related arc processes (surfacing, soldering, re-melting).

Abstract: Anti-locking brake systems (ABS) are well established in the automotive industry as a safety feature. ABS generally offers superior vehicle safety by limiting the longitudinal wheel slip in a braking event with deep slip condition. The study presents a creative solution for the elastic element included in the electromagnetic valve meant to reduce the noise and vibration associated with the use of the hand brake. At the same time, the suggested solution improves the dynamics in vehicle’s ABS regulator device by allowing its working frequency to be increased and the braking space to be implicitly reduced. Drivers would have better directional control of the vehicle equipped with ABS. The performance of this constructive solution, materialized in the creation of its own high frequency, is showcased and confirmed in this study by the results obtained experimentally.