Key Engineering Materials Vol. 613

Abstract: The minimum achievable residual unbalance ratio e_mar is the index for evaluating the balancing capability of dynamic balancing machine. When the e_mar is expected to achieve to 0.1um grade or higher, to tap potential solely from the design of the signal conditioning circuits or the digital signal processing algorithm could not settle problems completely, equal importance should be paid on eliminating the influence of machine intrinsic interference vibration. Unfortunately, compared with much effort on the research and implementation of circuits and algorithm for unbalance signal extraction, little attention has been paid on the latter. This paper puts forward an interference vibration separation approach based on multi-point test-mass circulation calibration, to the purpose of improving the overall performance of balancing machine.The measurement system of a dynamic balancing machine composed of vibration mechanism, vibration pick-up sensor, signal conditioning circuits and the digital signal processing module, wherein the vibration mechanism locates on the front end and is of great importance. In the current design of dynamic balancing machine, there is a hypothesis that the vibration mechanism vibrates in the manner of simple harmonic oscillation forced by the unbalance of the under test rotate work piece and the amplitude and initial phase of that vibration are only related to the magnitude and angle position of the unbalance. In a practical balancing machine, however, the unbalance of driving devices, the coaxial error of the coupling or the vibration of the driving belt will incur additional vibrations to the vibration mechanism. Being of the same frequency or nearby frequency with the unbalance vibration, those interference vibrations are difficulty to remove by the signal conditioning circuits or the digital signal processing approach.Based on the invariability of the machine intrinsic interference vibration, this paper developed a circumference multi-point measurement and compound calibration method. The principle of the method will be introduced and analyzed in detail in the paper. Based on the vector operation and least square fitting to the unbalance vibration response with the obtained compound vibrations, the interference vibration can be separated to a satisfied extent. Experiments investigation is carried out on a hard bearing dynamic balancing machine, and the experiment results demonstrate the feasibility of the said method.

Abstract: This paper presents an approach for the selection of methods for the proof of capability of measurement processes according to the risk connected to a false decision. High risks demand more reliable and therefore cost-intensive methods, a low risk allowing for cost-efficient methods with lower reliability. This approach, which is incorporated into the upcoming guideline VDI/VDE 2600-1, allows manufacturers to reduce efforts and costs associated with measurement process evaluation according to the risks and consequences of erroneous decisions deriving from measurement results. To be able to decide for the economically optimal measurement process solution, a cost model for the processes described in the VDI/VDE 2600-1 is presented.

Abstract: Based on a novel handling concept, the reconfigurable modular multi-arm robot system PARAGRIP is able to handle objects with six DOF by including them into a parallel kinematic structure. The properties of this repeatedly new created parallel structure can be adjusted by appropriate choice of the grasping-and base points to gain optimal performances for a given task. As kinematic parameters determine the transmission behavior and properties of the structure, deviations in the kinematic control model induce positioning errors of the object. In this work, the reduction of these positioning errors is investigated by parameter identification of the implemented kinematic parameters for a single robotic arm. After deriving the kinematic relations of the system, the pose is measured using an external referencing system. Meaningful kinematic parameters are identified and it is shown that the accuracy of each arm can be increased significantly.

Abstract: The dimensions of a workpiece have been measured during the milling process using a 3D laser inspection system. Re-clamping of the work piece has been avoided but a short interruption of the milling process took place. All three dimensions of the part have been measured, height and width using a profile scanning devise based on the laser triangulation method and the length using also the displacement features of the machine tool. Gauge blocks with the reference dimension of 4, 8, 10, 14, 18 and 23 mm have been used for the verification of the measurements. The measured values for the height deviate from the real value between 0 to 19 μm. The deviations of the length lie between 0 and 33 μm. The deviations of the width are higher and they lie between 0 and 150 μm, because of the scanning steps of the devise. The measurement of the width could be improved using a second scanner perpendicular to the first one in order to achieve an overall part inspection with deviations lower than 33 μm.

Abstract: In cutting procedures a possible reason for deviations from the predefined dimensions of the workpiece are deformations caused by the clamping. The deviations are usually measured after process using for example a coordinate measuring machine (CMM). It would be very much advantage to detect such deformations in process. Then, it could be possible to avoid, compensate or repair them before finishing. In the present work, four strain gauges have been applied into a four-jaw chuck in order to measure the clamping forces during milling and correlate them with deviations in the dimensions of the workpiece. A correlation between the clamping forces and deviations in the roundness of the workpiece has been verified. These investigations allow for the next step the development of an active clamping system for adaptive corrections during the cutting process.

Abstract: The changing world economy makes high demands on today's production systems. In order to stay competitive, companies, especially in high-wage countries, have to adjust their production for enabling customer individual wishes. The human operator provides meaningful skills including sensorimotorical skills and the capability of creative thinking from which the production system can significantly benefit. For establishing effective human-machine cooperation, both the employee and the technical system need to have an understanding of each other so that they can estimate the counterpart. In this paper, the requirements for introducing the human operator in technical models of production systems are described. Furthermore, first solutions are presented to implement effective human-machine cooperation.

Abstract: This research study two performances of one piano work. It includes charts tracking changes in tempo and dynamics, distribution histograms, statistical parameters. These numerical and graphic values are compared with the text of which is given a description of these performances.

Abstract: There exist various sociological (and pseudo-sociological) legends about distribution of the population of different countries over the level of mental development, cultural activeness, and related matters. Some of these distributions are supposed to deal with sharp social inequality within the population; on the contrary, other legends treat such distributions as rather homogeneous. So it is desirable to compare appropriate distributions in different countries, the method of measurement being free of concrete cultural peculiarities capable of distorting the results (the phenomenon which is usual in sociological and psychological cross-cultural studies). Exactly such method of measurements was derived in the framework of the systemic-informational approach. The model comes to a certain index measured in the ratio scale. So the sociological investigation involving a sample of the population, should be realized, permitting to build the so-called Lorenzs curve dependence of the share of the population with the given value of the index, on the values of the index. The difference between this distribution and absolutely democratic one (homogeneous, responding to equal mental wealth of all respondents), is Gini coefficient, which can be used to measure the degree of mental inequality within the population of each region or country, irrespective of its national cultural peculiarities. Such measurements were realized in several sociological investigations involving about 50 000 respondents; this approach can be used to compare cultural inequality in different countries.

Abstract: Out of various standpoints concerning social development, systemic-informational approach should be singled out, because it is common both for physical world and mental one. One of its partial models deals with the so-called vertical dimension responding to progressive way from Low to High, i.e., increasing energy (in physical systems), more noble behavior (in psychology), perfect works of art, etc. The criterion of the Height of the state of any system (or its element) is entropy. The equation for mutual information between the system and its environment consists of a sum of three free items, optimization of each of them being capable of deducing indicators of vertical growth. A set of 16 groups of indicators gives an opportunity to identify the direction and to measure the rate of the movement of the social system studied, in any given moment toward either High pole or Low one. In application to Russia, evidences were obtained in favor of rather regressive trajectory of its social system during last two decades.

Abstract: The link between the origin and development of music, on one hand, and appearance and development of emotional intelligence, on the other hand, is considered. It is shown that at present the prerequisites exist to create a measuring instrument that could enable the level of emotions in acoustic signals to be recognized and evaluated. The prospects of future studies in the field are observed.