Research and Practice of Intelligent Tool Setting Device for CNC Milling Machine

The utilization of intelligent tool setting device of CNC milling machine can reduce the probability of tool setting error, better guarantee the normal operation of CNC milling machine and the safety of relevant operators, and avoid unnecessary losses. Based on this, this paper first analyses the coordinate system of CNC milling machine and the concept of tool setting, then studies the operation method of tool setting device of CNC milling machine, and finally gives the design and practice of intelligent tool setting device of CNC milling machine.

Reducing the manual length setting error of a passive Gough-Stewart platform for surgical template fabrication using a digital measurement system

As recently demonstrated, a passive Gough-Stewart platform (a.k.a. hexapod) can be used to create a personalized surgical template to achieve minimally invasive access to the cochlea. The legs of the hexapod are manually adjusted to the desired length, which must be read off an analog scale. Previous experiments have shown that manual length setting of the hexapod’s legs is error-prone because of the imprecise readability of the analog scale. The objective of this study is to determine if integration of a linear encoder and digitally displaying the measured length help reduce the length setting error. Two experiments were conducted where users set the leg length manually. In both experiments, the users were asked to set the leg length to 20 nominal values using the whole setting range from 0 mm to 10 mm. In the first experiment, users had to rely only on the analog scale; in the second experiment, the electronic display additionally showed the user the actual leg length. Results show that the mean length setting error without using the digital display and only relying on the analog scale was (0.036 ± 0.020) mm (max: 0.107 mm) in contrast to (0.001 ± 0.000) mm (max: 0.002 mm) for the experiment with the integrated digital measurement system. The results support integration of digital length measurement systems as a promising tool to increase the accuracy of surgical template fabrication and thereby patients’ safety. Future studies must be conducted to evaluate if integration of a linear encoder in each of the six legs is feasible.

Wheel Setting Error Modelling and Compensation for Arc Envelope Grinding of Large-aperture Aspherical Optics

Precision grinding is the key process to meet the heavy demands of large-aperture aspherical optical elements in the fields of laser nuclear fusion devices, large-aperture astronomical telescopes and high-resolution space cameras. In this study, the arc envelope grinding process of large-aperture aspherical optics was investigated using the CM1500 precision grinding machine with a maximum machinable diameter of Φ1500 mm. The analytical form error models of aspherical workpiece induced by wheel setting errors were established for both parallel grinding and cross grinding. Result show that the form error is much more sensitive to the wheel setting error along the feed direction than that along the lateral direction. It is a bilinear function of the feed-direction wheel setting error and the distance to optical axis. Based on the above analysis, a method to determine the wheel setting error is proposed. The grinding tests were then performed with the wheel accurately aligned. By using a newly proposed partial error compensation method with an appropriate compensation factor, a form error of 3.4 µm PV for a Φ400 mm elliptical K9 glass surface was achieved.

An Improved Power Management System in Electrosurgery Unit Monopolar Design

In using the Electrosurgery unit, improper power settings and modes can cause tissue damage, so it is necessary to adjust the cutting mode and power settings needed. The purpose of this research is to design power control and cutting mode in Electrosurgery using Arduino nano as a regulator of power and pulse or duty cycle. The contribution of this research is the creation of power control and mode in the Electrosurgery unit to increase power and cutting mode. This is to control the electrosurgery power. The LM2907 IC frequency to voltage circuit is used as a voltage regulator, which is issued according to the frequency with the power selection LOW, MEDIUM, HIGH. The method used is the CMOS 4069 device as a frequency generator at 250 kHz, then the driver pulse is passed and controlled by the ATmega328 IC, then forwarded to an inverter circuit that functions to increase the voltage and output in the form of power. After the measurement process is carried out on the inverter input with a Blend mode three value, the voltage value is obtained at the low setting 100 V error 0.03%, medium setting 110V error 0.02%, High setting 120 V Error -0.02%. While the measurement results in the coagulation mode are the low setting error of 100 V 0.05%, the medium setting error is 110V 0.08%. High setting error is 130 V 0.003%. The measurements show that the error in power management is lower than 1%. The results of this study can be implemented in the electrosurgery unit to reduce tissue damage due to a lack of cutting modes and power management.

IMPLEMENTASI MANAJEMEN MUTU DI SEKOLAH

This paper explains about Implementation of quality in Philip B. Crosby's perspective in school educational institutions. School ducational institutions are a forum that has the function to produce quality individuals. To be able to produce a quality generation, of course an educational institution must be quality. The quality concept offered by Crosby to be implemented in educational institutions is to have fourteen stages, namely Management Commitment, Quality Improvement Team, Quality Measurement, The Cost of Quality, Quality Awareness, Corrective Actions, Zero Defects Planning, Supervisor Training, Zero Defects day, goal setting, Error-Cause Removal, Recognition, quality councils and do it over again. The fourteen stages will be implemented in school educational institutions as an effort to achieve quality school educational institutions.

Improved Position Error Model for Airborne Hyperspectral Imaging Systems

An improved position error model for airborne hyperspectral imaging systems is proposed to quantify the position errors caused by the deficiencies of instruments and the manual installation of integrated systems. The model is based on a thorough analysis of position error sources, which include uncertainties caused by camera position and altitude, interior camera parameters, gyro stabilized mount, position setting error of the global positioning system antenna, and boresight angle error. An improved position error model that describes these error sources is established based on collinear equations. This model is then expanded into the first-order Taylor series. Finally, the error propagation law is applied to estimate the position errors. The performance of the proposed method is evaluated based on real hyperspectral images of Hymap. Results show that the mean square error of the position error is better than 2.1 pixels, which is almost the same as that of ground truth.