High-Precision Fabrication of Micro Monolithic Tungsten Ball Tips via Arc Discharge and the Taguchi Method

A micro ball tip is a core component of high precision coordinate measuring machines. The present micro ball tips cannot satisfy the high-precision measuring requirements of high aspect ratio microstructures due to their large diameter and low accuracy. In the previous study, we fabricated a micro monolithic tungsten ball tip by using arc discharge and surface tension principles. However, the fabrication success rate of forming a micro ball tip is less than 10%. In the present study, the Taguchi method has been applied to increase the fabrication success rate, and it has increased to 57.5%. The output response is evaluated in terms of the diameter, roundness, and center offset of the tungsten probe ball tips. The smaller-the-better signal-to-noise ratio is applied to analyze the influence of various parameters. The proposed parameters can be used to increase the fabrication success rate and accuracy of the monolithic probe ball tip.

A Study on Optimal Voltage of Electromagnet for Precision Measuring Robot During Surface Roughness Measurement by Vibration Analysis

In electric power stations, precision surface roughness measurements are performed for environmental loading reduction, quality assurance, and safety. These measurements are performed manually at high places, narrow places, uncomfortable environments, etc. Therefore, workers in power stations experience a lot of hardship and are exposed to danger. To solve these issues, this study researched and developed a crawler-type robot with high measurement accuracy. Conventionally, robots that supply workpieces for surface roughness instruments have been developed. However, to the best of our knowledge, robotization and self-propelled precision measurement instruments have not been developed. Usually, a precision measurement instrument is designed for increased stiffness and stability because high measurement accuracy is the highest priority. However, if the stiffness and stability of the robot are as high as those of the precision measurement instrument, a problem occurs in the robot operation. Therefore, we propose a precision measurement unit using electromagnets and a crawler-type self-propelled robot to equip the unit. In a previous study, vibration analysis experiments using the impulse response method were performed on a precision measuring robot. In this study, the relationships between the voltages applied to the electromagnet and the reductions in the vibration magnitudes were determined by analyzing the vibrations of the robot during measurement. Furthermore, an optimal voltage of the electromagnets of the precision measuring robot to reduce vibrations was determined. From the results of the vibration analysis, the authors demonstrated that the optimal voltages were 9 and 12 V, and the precision measurement unit confirmed the effectiveness and validity of vibration reduction and improved measurement accuracy.

Extraction Methods and Implementation Technologies of Fuel Injection Pump Cam Profile Characteristics

Because the traditional camshaft measurement methods cannot be applied to the injection pump cam, in order to improve the measurement automation of injection camshaft, an accurate extraction method of the characteristic parameters of the injection cam profile is proposed in this paper. In this method, the phase error optimization is realized by the angle precise rotation matching of the actual lift data. The optimization is realized by the Lagrangian polynomial interpolation algorithm based on the moving window. The goals of precise measurement of the peach point phase of single high point cam and accurate acquisition of the back dead point phase of high point arc segment cam are realized. Compared with the precision of high-precision measuring equipment, the method can extract the lift and phase angle error of the cam accurately and stably.

Multi-objective Optimization of Linear Proportional Solenoid Actuator

This paper employed a multi-objective Genetic Algorithm (GA) process to optimize the structure parameters of Linear Proportional Solenoid (LPS). And designed objectives include magnitude of static push force, stability of push force with displacement in working range and push force to mass ratio. A two-dimensional finite element analysis model is presented to reduce the large calculation time generated by GA process. The optimization process result of LPS shape parameters is obtained and the optimal LPS is manufactured. Through using a high-precision measuring device in the static push force test, a comparison result between conventional shape and optimal shape shows that the proposed optimization strategy is feasible.

Half division two-dimensional method for simple sinusoidal quantities parameters accurate measurement

Several variants of half division two-dimensional method are proposed, which is the basis of a fundamentally new approach for constructing measuring instruments for sinusoidal or periodic electrical quantities. These measuring instruments are used in the diagnosis of electric power facilities. The most general variant, called midpoint method, is considered. The proposed midpoint method allows you to measure much smaller than using widespread methods, alternating currents or voltages, especially when changing the amplitude of the measured signal in very wide ranges, by 1–2 orders of magnitude. It is shown that using the midpoint method it is possible to suppress sinusoidal or periodic interference in the measuring path, in particular, to measure small alternating current when sinusoidal or periodic interference is 1–2 orders of magnitude higher than the useful signal. Based on the results of comparative tests, it was found that the current measuring device implementing the midpoint method is an order of magnitude more sensitive than the currently used high-precision measuring instruments.

EXPERIMENTAL STUDIES OF THE INFLUENCE OF WAVES ON THE BREAKWATER OF A PARTIAL VERTICAL PROFILE

The article is devoted to the issues of physical experimental researches connected with the determination of the parameters of wave quenching when overflowing them through the superstructure of enclosing hydraulic structures (ENS) of incomplete vertical profile. The research was conducted in the hydrowave laboratory of the Department of Hydraulic Engineering of the Odessa State Academy of Civil Engineering and Architecture. The article presents partial results of experiments performed on ENS of incomplete vertical profile. The models were made on a geometric scale and were subjected to wave effects similar to the conditions of the natural section of the coast of the Odessa Bay in compliance with the criteria of similarity. The construction of new structures of enclosing hydraulic structures requires careful primary experimental research. These researches mostly often carried out on physical models in specialized hydrowave laboratories, allow to get rid of risks of financial losses at the wrong choice of types and elements of the designed objects. The carried out researches allow estimating with a high degree of reliability, according to scale conditions, physics of the processes proceeding on models which will also be observed at the operation of real construction. The physics of the process of hydrodynamic impact on hydraulic structures is often difficult to describe only with the help of a mathematical model, which confirms the high degree of importance of physical experiments. The progress of technical science largely depends on the ability to make more accurate measurements. High-precision measuring equipment was used in laboratory tests. This paper describes the method of conducting experiments that were performed on one physical model, under three different conditions of the location of the superstructure relative to the quiet level, as well as different values of the initial wave heights. The use of structures of incomplete vertical profile, in order to protect the waters of seaports, as well as elements of the coastal infrastructure of maritime cities will increase economic attractiveness by reducing financial costs, thanks to the reduction of the topside of the enclosing structures.

ACCURACY OF MEASURING SYSTEMS BASED ON LASER MODULES

Measuring systems using the design of laser module beams on the surface of the object under study are considered. A technique is proposed for experimental studies of the brightness structure of the study of laser modules for their subsequent testing. Adaptive algorithms for determining the type of module and distance have been developed for determining the coordinates of light marks on the surface of controlled products, ensuring the accuracy and reliability of the measurement. The need for high-precision measuring systems to carry out their preliminary selection and calibration of laser modules according to the proposed method, taking into account the range of design of light marks, is shown. It is shown in the work that the accuracy of determining the relative coordinates in the trajectory of the light marks of laser modules at a distance of 5 m for plain surfaces of the observed objects can be several times higher (0,2…0,3 mm) of the accuracy of determining their absolute coordinates (»1 mm).

Prospects for Using Carbon Nanotubes in Precision Instrument Engineering

This research deals with the prospects for application of modern nanomaterials as exemplified by carbon nanotubes for development of new classes of precision measuring instruments or for significant improvement of the performance of existing sensors and systems based on sensors. Carbon nanotubes have been known since the end of the 20th century, but production of high-quality carbon nanotubes on a commercial scale has become possible relatively recently, owing, inter alia, to researches of Russian scientists. Carbon nanotubes have unique properties which hold much promise for their use in different areas of science and technology. Thus, use of nanotubes in precision instrument engineering can solve a number of problems, such as increase in reliability, accuracy, durability, weight and size reduction, etc. Fiber optic gyroscopes based on microstructured optical fiber are considered in this research as an example to demonstrate that use of carbon nanotubes allows significant reduction of the temperature differences in the fiber and that such reduction, in its turn, leads to lower dependence of the FOG characteristics on the temperature effects under actual operating conditions. A mathematical model of the equivalent thermal conductivity of a microstructured fiber loop, all or some channels of which are filled with carbon nanotubes, has been developed in this research. A comparative analysis has been made of the distribution of heat in coils with the considered and traditional fibers under different temperature effects – harmonic, random and stepped.