Journal of Machinery Manufacture and Reliability最新文献

A method for the optimal design of adaptation units for changing the reflective surface shape of a millimeter-range reflector has been developed in order to provide the specified requirements for the accuracy and shape stability of the working surface in the course of operation for the intended purpose. The reliability of the developed method is provided by a detailed mathematical description of the reflector design and adaptation units. The use of a multistaged control algorithm makes it possible to adjust the reflector shape with the required accuracy with the use of the chosen arrangement of adaptation units and their design. The results of this work are used in the course of an a priori adaptation of the reflector in the scope of ground operation and can also be used as a basis for a method for autonomous orbital adjustment of the reflector.

At present, one of the pressing issues in mechanical engineering is the automation of production processes. Automation helps partially address the problem of personnel shortages and increase labor productivity. High-speed cyclic and positional manipulators developed at the Blagonravov Institute of Mechanical Engineering of the Russian Academy of Sciences (IMASH RAN), based on the use of high-coercivity permanent magnets, are presented. These developments can serve as a basis for creating manipulators with low and ultra-low lifting capacities for use in various industries.

A calculation scheme for vertical oscillations of a 2a–2a type underframe is proposed. A system of six second-order differential equations describing oscillations in the vertical longitudinal plane is derived. A model of a locomotive section is built in the MathLab program using the Simulink application. The functions of body oscillation in the longitudinal vertical region of locomotive movement over time and the body tilt in the longitudinal vertical region of locomotive movement over time are determined.

A problem of tank equipment diagnostics in the oil-and-gas industry is considered, and existing robotic solutions are analyzed. A methodology of robot designing is presented, including the development of an information model, the simulation of the supporting structure, and studies on the pressing force of wheel movers to the ferromagnetic surface depending on the remoteness thereof. As a result, an innovative robotic facility for the diagnostics and stress mapping of the walls of tanks and reservoirs with the use of nondestructive testing methods has been developed. The facility is intended to inspect both horizontal and vertical surfaces, providing industrial safety, a decrease in environmental risks, and money saving.

A technique for recording tangential displacements in the zone of a hole-indicator of residual stresses by electronic digital speckle interferometry using phase-shifting interferometry is developed, which provides for the possibility of effective practical application of “large hole” drilling for studying nonuniform fields of residual stresses in flat parts. A circuit of an interferometer for electronic digital speckle interferometry is proposed, in which a step-by-step (up to 20 steps) phase shift of the object beam is set using a special unit—a phase modulator. This allows recording many interferograms that are different from each other in the form of intensity patterns with known phase shift values, providing for the possibility of obtaining highly accurate information on displacement fields in a wide range of displacements. Using the “large hole” drilling method, residual stresses in the weld butt seam zone and the weld-affected zone of a steel sample have been studied. The results of such study for four cases of successively increasing hole diameters showed that the developed technique ensures high accuracy of results in studies of nonuniform high-gradient distributions of residual stresses.

A program developed for increasing the efficiency of keeping track of the production process by automating parts identification in production containers and using QR codes is described. To detect tags and objects in containers, a cascade algorithm is developed that uses trained convolutional neural networks YOLO and VGG19, increasing the accuracy of recognition while significantly reducing the size of the training sample for neural networks. The developed program is tested using production equipment at Samara University. The experimental results show 93% accuracy in identifying parts when using the algorithm developed.

This article is devoted to the development of a system solution for new automation tools based on the concept of a digital twin for managing a manufacturing enterprise. The field of digital twins is explored, including the theory, standards, and software platforms for implementation. An analysis and the development of an architecture was carried out to ensure the possibility of creating and using target industrial digital twins of enterprises depending on the goals and chosen strategy of conducting business.

Since one of the most pressing production tasks today is to improve the quality and speed of manufacturing products using robotic systems, this article examines the technological process of drilling holes based on the KUKA LBR IIWA 7 R800 collaborative robot. This article presents the results of a study of the influence of interpolation methods in the trajectory control of a robot on the performance indicators of the technological process: the time to calculate the trajectory of bypassing an obstacle, the time to implement the movement, and the energy required to implement the movement. Recommendations have been developed for choosing an interpolation method for an intelligent control system in the presence of technological requirements—eliminating or minimizing pauses for operational design of movements.

A task of utmost importance in the manufacturing of competitive products is to enhance the efficiency of automated control based on optimization of the operating parameters and improvement of technologies. Considered below are the options for optimizing the control of operations directly related to material processing. The efficiency of control depends on the change in the trajectory of the processed material in the space of variable states and the synergistic effects that arise due to the complex mutual influence of input parameters on the control object. It is proposed to control the process of applying high pressure to liquid metal using a “reference model,” which is considered to be the law of pressure change over time providing the maximum density of the metal.

Increasing the reliability and durability of machine parts is a decisive factor in solving the problem of highly efficient designs. The use of design improvements and the creation of favorable operating conditions make it possible to create highly reliable hydraulic rotary joints. The distribution of specific pressures on the seal contact surfaces and the amount of fluid leakage are determined. Experimental studies of the operability of hydraulic rotary joints are conducted, and designs are developed that are distinguished by the greatest resource, wear resistance, and maintainability. An approximate estimate of the specific pressure on the surfaces of contact sealing elements is developed. A study is conducted to compare the calculated and experimental values of the amount of fluid leakage. A change in the values of the force and the friction coefficient in various seals is established depending on the pressure of the sealed liquid.