Papers by Keyword: Compensation

Abstract: With the aim of enhancing the precision and quality of turning processes, this study investigated cutting stress and thermal deformation induced by friction between the tool and chip of a Wolfram carbide (WC) tool cutting AISI-1045 carbon steel. Analysis of cutting stress and thermal deformation using COMSOL Multiphysics software is useful for evaluating the compensation for machining errors and reducing tool wear. Three cutting loads were adopted for the simulation of the thermal conduction, and changes in temperature and the stress field. Simulation results show that thermal deformation in the tool tip is proportional to cutting speed and time. As long as the temperature of the tool remains below the quasi-steady-state temperature, the amount of deformation does not change significantly. An understanding of the thermo-mechanical coupling effect during turning can help to improve the accuracy of compensation for thermal deformation in turning tools.

Abstract: Numerical modeling and a tracking control of angular velocity of a rotor measured in the assumed sliding contact bearing subject to a discontinuous dynamical loading has been performed in this contribution. A contact interface in the direct current motor’s sleeve bearing has been treated as a dynamical system with dry friction, including a few sources of the stick-slip and creep-slip effects. The object of control is subject to an irregularly changing torque generated by another discontinuous dynamical system with friction. The loading comes from a block-on-belt model of a conveyer system with intensification of friction force, which has been elastically coupled with the direct current rotor’s shaft by means of the transmission belt. Therefore, the dynamic loading of the DC motor changes because of time-varying linear velocity of two belts. If such additional torque oscillates while the rotational velocity of the motor’s shaft is small due to a requirement, then it significantly affects the entire system’s dynamics producing stronger nonlinear response of the motor’s speed.

Abstract: Employees are very important to every organization. This study attempts to examine the effectiveness of current human resource management utilization and practices in oil and gas projects in Malaysia, as well as to study the importance of having effective human resource management practices utilization. The human resource management practices namely training and development, performance appraisal, compensation, employee empowerment and ownership as well as work environment are the main practices that has being focused. A questionnaire form has been distributed to the employees of PETRONAS Carigali SDN BHD (PCSB), a leading oil and gas operator in Malaysia including their contractors.

Abstract: This paper gives a description of the challenges in the development of a generalized approach for the structure model based correction of thermoelastic errors of machine tools. The correction approach can be divided in modules. The challenges are described on the requirements of the modules.

Abstract: Error compensation is a key to reach the geometric accuracies required for high precision machine tools. To prevent errors from affecting the machining process, compensation values for the feed axes can be used. However, conventional feed axes can only compensate deviations in their feed directions. By controlling its integrated hydraulic guiding system, the feed axis presented in this paper is capable of compensating errors in all other degrees of freedom as well. Using a specifically developed program, ideal parameters for the compensation of errors in a realistic 3D-axis-system were calculated. The axis’ characteristics were examined on a test rig for different types of controllers and compared to those parameters. It could be shown that the presented highly integrated hydraulic feed axis is capable of compensating typical errors resulting from such a 3D-setup.

Abstract: Effects of electron irradiation in n-4H-SiC have been studied by the methods of the capacitance--voltage characteristics and photoluminescence. It was found that the carrier removal rate (Vd) reached a value of ~0, 25 cm^{- 1}. Full compensation of samples with an initial concentration of 1.2 10¹⁵ cm ^-3 was observed at doses of about 5 10¹⁵ cm ^-2. Simultaneously with the increase in the degree of compensation, the intensity of the “defect luminescence”, typical of 4H SiC, became higher. The physical compensation mechanisms were analyzed for the samples under study.

Abstract: Theregulations of the land access for mineral exploration in China are so inattentive thathindered the realization of the interests of the holder of mineral explorationright. Using the provisions of the land access of mineral exploration andcompensation system in Western Australia, Queensland, New South Wales for reference. In order to realize theright of the holder of mineral exploration right, the compensation systemsshould clear the landlord , enlarge the scope of the compensation.

Abstract: In recent years, the problem of customer focus in power engineering is gaining more and more attention. The authors offer a mechanism for implementation of customer-oriented approach in power supply reliability ensuring. It is proposed to decompose power supply reliability into the system and address ones. Address reliability of power supply ensuring is presented in the form of the separate service provided on the basis of free bilateral contracts between the electric grid company and end users of the electric power. Customers are expected to determine reliability level according to the estimation of adequate indemnity in case of interruption or power limitation.

Abstract: By presetting correcting device transfer function D(z), this paper puts forward series compensation design approach of minimum beat system. Compared with tradition design method, this way is much simpler and easier.

Abstract: As for MEMS Micro machined accelerometer, biases characteristic always varies with temperature fluctuations. Through establishing the error model between the MEMS accelerometer biases and the temperature variation in the temperature range of-20 °C ~ 60 °C, studying on the bias changed with thermal variation of MEMS accelerometer, and the test results show that MEMS accelerometer bias caused by temperature change have decreased from more than 5mg to lessen than 1mg before and after compensation. Also based on the temperature error model of the MEMS accelerometer bias in static and dynamic condition, the whole temperature characteristics have been improved to some extent, which would improve the precision in the inertial navigation systems.