Papers by Keyword: Precision

Abstract: As with any measuring device, it is important to install and operate water meters that are calibrated within an acceptable international standard (ISO) and regulatory acceptable relative error, in accordance with the requirements of the international standard. The article deals with the issue of correct installation of measuring devices during operation and checking on high-precision equipment. Production In order to increase the technical level and meet people's needs, there is a need to use the latest modern measuring tools of equipment and technology in the economy and production. For this reason, it is important to provide citizens with new measuring devices and provide them with regular technical service in our country. It is necessary to create modern equipment and laboratories for checking measuring instruments. As the devices are used, their life ends after a certain period of time, and they need to be checked. A malfunctioning device leads to incorrect information, incorrect calculations and losses, depending on where it is used for its intended purpose. By checking the measuring devices in modern laboratories with high accuracy, removing the defect and re-using it after calibration, we get correct calculations, correct information exchange, and elimination of losses. For example, the correct installation of water measuring devices was also checked on the error determination stand, and the results of their errors at different values ​​were automatically displayed in the error curve table.

Abstract: The development of lithium batteries as an energy storage system is getting higher equal to the development of eco-friendly energy needs. However, lithium batteries have disadvantages in electrical and temperature interference. Series and parallel configuration causes voltage imbalance and leads to degradation performance of the battery. The focus of the research is the development of BMS with voltage monitoring and balancing features for the 12-series battery pack configuration. Monitoring can be done by observing electrical parameters, are cell voltage and battery temperature. The results of the simulation and modeling of BMS and Lithium-ion Battery show that the flat-zone voltage on the LFP UNS battery is in the 10-90% SoC range (generally SoC 20-80%), and the characteristics of lithium battery are current affects the battery voltage curve (high current causes a high voltage drop), while temperature affects the internal resistance (low temperature causes an increase in internal resistance). The BMS hardware monitoring test shows the accuracy and precision of the voltage sensor at 99.7064% and 99.9998%, while the temperature sensor performs the accuracy and precision of 95.4909% and 100%, respectively. The passive balancing method with Switched Shunt Resistor shows a nominal balancing current of about 170mA with a 20mV voltage drop.

Abstract: In this scientific study, the problem of automation of machine-building production is justified. A 3D model of the lathe is presented and its design is improved. Standard layout schemes based on the upgraded spindle assembly have been developed, which make it possible to increase the speed of this type of machine. The results obtained make it possible to achieve the desired cutting speed, which has significantly increased by 2-2,5 times. The constructed dependence of the deviation on the roundness of samples by the finite element method allows predicting the main indicators: feed rate, spindle speed, cutting depth, static imbalance, initial and final pressure. Also, the obtained analytical results allow us to establish the main regularities of forming the accuracy of this lathe.

Abstract: Offline programming is a critical step in the implementation of various robotic tasks such as pick-and-place, welding, cutting, and milling. This paper describes a simulation study that analyses the accuracy of the robot's path tracking, during tasks that require the robot tool to interact with the environment, while considering the current operating conditions. To accurately determine the actual position of the Tool Center Point (TCP) and the associated orientation of the end effector, the study will first establish a robot model that takes into account the elasto-static behavior during the milling process that generates significant contact forces on the end effector. Then, an offline simulation tool is developed within the SolidWorks^® CAD environment. The analysis of simulation results from multiple scenarios revealed that the tool/material contact forces were the main source of the robot's deviation from its nominal trajectories. Moreover, the range of positioning errors varies according to the architecture of the robot and the workpiece emplacement. Depending on the working conditions, the tool deflection ranges from 0.1 mm to 0.75 mm in the or cutting directions and increases as one moves away from the reference frame, while the Cartesian orientation deviation is negligible (less than 1°).

Abstract: The validation method for determination of chemical oxygen demand (COD) with indirect UV-Vis spectrometry have been done. This method enable to easily perform highly sensitive, considerably faster and easier, and minimize the use of digestion solution. This method is the development of standard method of COD determination by closed reflux using UV-Vis spectrometry so it requires the method validation stage. The validation is used to ensure linearity, limit of detection, limit of quantification, precision, and accuracy values in accordance with quality control. This study was also carried out to formulate the uncertainty calculation modeling of COD on water analysis. The result of validation method show that the calibration curve linearity is 0.9994 with the linear regression equation Y = 0.0003X + 0.0005. The method is able to have high sensitivity in measuring COD value with low concentrations with limit of detection and limit of quantitation of 9.78 and 32.59 mg O₂/L. Indirect UV-Vis spectrometry has high precision with relative standard deviation of 0.66% and high accuracy with the percentage of recovery of 91.35%. The uncertainty formulation model on determination of COD from the source of standard uncertainty of sample volume, calibration curves, and repeatability.

Abstract: The article presents the results of the analysis different methods to enhance theaccuracy, sustainability and energy efficiency of automatic control systems. Shows the constraints on the possibility of increasing the accuracy and stability of automatic control systems. The necessity of the use of self-tuning systems for control of nonstationary objects, which include the installation of thermal processing of building materials and products. Theblock diagram of the analytical self-tuning system optimal reference model.

Abstract: The results of the theoretical research and the computer simulation, aimed at increase in accuracy of robotic milling, are presented in the article. An analysis of the mathematical models of the system «technological robot – milling process» is conducted. The prospects of the usage of precision geared dual motor servo drives and trajectory-impedance control systems are underlined. A computer research of the tool movement accuracy during the robotic cylindrical up-milling process, depending on path velocity of the milling cutter and rated value of the cutting depth, has been carried out. Two types of manipulators have been considered: a manipulator with traditional geared servo drives with one motor and a manipulator with the suggested precision dual motor drives. In order to measure accuracy of movements during the computer simulation process a deviation of the tool, normal to the desired trajectory of its movement, has been defined. The results testify the facts that dual motor servo drives allow us to significantly increase dynamic stiffness of technological robots and they promote increasing accuracy and performance of robotic milling.

Abstract: For general dynamic pick and place tasks that the objects are transferred with high speed by the conveyor belt, the capability of a delta robot to track the traveling objects is very important for the efficiency. To meet the needs of precision and smooth control, a computed-torque control scheme for conveyor tracking is implemented in this paper. For higher efficiency and accuracy, computer vision system, encoder and conveyor belt region are incorporated into the control scheme. Dividing the conveyor belt into three regions, the robot is commanded to track, pick and give up according to the subregions. Conveyor belt is equipped with an encoder that provides the controller with real-time position and speed of the belt. Based upon those informations, the controller automatically compensates the end positions with respect to the belt to adjust for the position of the conveyor. Then, the conveyor tracking problem is converted to a subregional tracking problem.

Abstract: An innovative cutting method, constant load feeding method, is proposed as a high precision secondary working tool in CFRP cutting. The constant load feeding can restrain the occurrence of cutting defects such as burr and scuffing in a diamond saw cutting. The combining of constant load feeding with point contact eliminated most of the cutting defects even in the CFRP cutting with a low rigidity cutting tool like the diamond saw blade. In addition, there was no apparent cutting damage on the cutting surface obtained from the drilling with constant load feeding. These facts indicate that the self-generated feed rate in the constant load feeding would be the optimal feed rate to realize a defect-free drilling of CFRP composites.

Abstract: The objective of this paper is to analyze the precision of plastic parts made by using robot milling. Currently, the robots have good precision, rigidity, flexibility and they are able to machine parts. By using a six axis Kuka robot and an electric spindle, a plastic part was milled. The paper presents the advantages and disadvantages of this new technology, analyzing the dimensional accuracy, surface quality and costs.