Investigation into non-destructive testing and evaluation of 3D printing quality is relevant due to the lack of reliable methods for non-destructive testing of 3D printing defects, including testing of the surface quality of 3D printed parts. The article shows how it is possible to increase the efficiency of online monitoring of the quality of the 3D printing technological process through the use of an optical contactless high-performance measuring instrument. A comparative study of contact (R130 roughness tester) and non-contact (LJ-8020 laser profiler) methods for determining the height of irregularities on the surface of a steel reference specimen was performed. It was found that, in the range of operation of the contact method (Ra 0.03–6.3 µm and Rz 0.2–18.5 µm), the errors of the contactless method in determining the standard surface roughness indicators Ra and Rz were 23.7% and 1.6%, respectively. Similar comparative studies of contact and non-contact methods were performed with three defect-free samples made of plastic polylactic acid (PLA), with surface irregularities within the specified range of operation of the contact method. The corresponding errors increased and amounted to 65.96% and 76.32%. Finally, investigations were carried out using only the non-contact method for samples with different types of 3D printing defects. It was found that the following power spectral density (PSD) estimates can be used as diagnostic features for determining 3D printing defects: Variance and Median. These generalized estimates are the most sensitive to 3D printing defects and can be used as diagnostic features in online monitoring of object surface quality in 3D printing.
The article focuses on a new way to solve the problem of cutting processing due to the appearance of a wide range of super hard and hard-to-machine structural materials for aircraft, automobile, ship and engine construction, as well as for spacecraft, medi cine (orthopedics, dentistry), nuclear and military equipment. Such materials have an organized regular structure, high strength, super hardness. As a result, there is a problem of defect-free machining of these materials without damaging their balanced structure. The article describes a new approach and formulates innovative principles for creating a new class of mechatronic technological systems for precision machining of parts made of these materials using the example of drilling small diameter deep holes. The core of the mechatronic technological system is a mechatronic parametric stabilizer of the power load on the cutting tool. The mechatronic tech nological system provides a program task, automatic stabilization and maintenance in the tracking mode of the power load on the cutting tool with “disturbance control”. For example, in the technological cycle of drilling small diameter holes, such a system pro tects the drill bits from breakage. An integrated technological system is proposed with the following three levels of control: intelli gent (upper), adaptive (middle) and robust (lower). The basis of the multi-level system is a high-speed robust automatic control sys tem “by the disturbance”. The disturbance is the load torque, which is either automatically stabilized, or tracked when setting a pro gram from a computer, or changes according to the program that sets the mechatronic technological system the functioning (opera tion) algorithm. This algorithm can vary widely with different methods of machining parts by cutting (grinding), including shaping free 3D surfaces according to their digital models. The mechatronic technological system proposed is easily integrated into the cut ting (grinding) system of CNC machines, expanding their capabilities by transferring the standard control program of the CNC to a higher level of the control hierarchy. This allows machining any complex-shaped parts, including “double curvature” parts, namely impellers, turbine blades, rowing screws, etc.
Information support for modern computer-aided design of products and processes is considered in this review in accordance with the methodology of the integrated CAD/CAM/CAE system. Three levels of the management hierarchy at the design and production stages are considered. At the top (organizational) level, computer-aided design of the product structure and its manufacturing technology is performed. At the middle (coordinating) level, a binding to existing technological equipment and debugging of individual fragments of the control program are performed. At the lower (executive) level, the control program is finally created, debugged and executed. A distinctive feature of the proposed automation methodology at the design and production stages is the use of feedback from the lower level to the middle and upper levels to correct the decisions made there, taking into account the existing management powers at these levels of the hierarchy. Thus, the indicated levels of the hierarchy of the intelligent system correspond to the hierarchy of objects and subjects of management and control, taking into account the powers (and capabilities) of management and control at each level. Information is a basic category not only in information (virtual) technology for its transformation and transmission, but also in physical technology of material production in the manufacture of a corresponding material product. Such technology as a rule, contain preparatory (pre-production) and executive (implementation) stages. At the preparatory stage, a virtual product is created (an information model of a real product in the form of virtual reality), and at the executive stage, a real (physical) product appears that has a use value (possession utility). This research describes the features of information processing at both stages of production in order to increase its efficiency.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.