Papers by Keyword: High-Accuracy

Abstract: This paper describes the development of an embedded SNTP clock which applies NTP Protocol to embedded clock to realize the high accuracy and precision SNTP client clock. It consists of three parts which are the communication part to communicate between NTP Server and SNTP client clock, the data processing part to process data packet, and maintain accuracy, precision of time, and the result displaying part to show time together with the reliability status of the clock. This article explains the concept of applying and analyzing NTP packet, process of maintaining accuracy and precision of time and displaying the result, and hardware, software designs. This paper will provide the introduction of NTP, the development of NTP on the embedded clock, the simulation, and results of the experiment.

Abstract: In view of the risk to use the traditional rheostat Slide Rheostat and the contradiction between its range and accuracy, in this paper, designed automatically adjust the rheostat of resistance based on the traditional rheostat, and further study on combination relationship between different range and precision resistor. The host controller and the under controller was designed too. The slide rheostat can solve the existing problems between range and resistance and operational safety, and improve the safety and adjusting speed during operation.

Abstract: This paper discusses the realization of the cascade of two stage rotary coder. It is aimed to establish a coordinate system to apply in the continuous and precision measurement of the displacement and rotary angle in a large scale. This coordinate system can be used for any industrial control process in which there are particular demands for the measurement of the displacement and rotary angle. It has characteristics of high resolution, large scale and non-volatile.

Abstract: In this paper, one-dimensional heat conduction equations is studied, many difference Schemes have been proposed to solve it. In order to find a high accuracy difference scheme in all the methods, we give a numerical experimentation in this paper. by numerical experimentation, a high accuracy difference scheme for solving Heat conduction equations initial boundary value problem is found, according to the truncation error and stability analysis ,we find its accuracy is better-then- third-order in time and space direction. this is a valuable method and better then the others this is a high accuracy difference Scheme. this scheme is a valuable method in Heat conduction and Fluid mechanics.

Abstract: HBWSL-1 type photosensitive resin for Stereolithography was prepared with bisphenol A type epoxy diacrylate (EA-612), polyethene glycol (200) diacrylate (PEGDA), ethoxylated trimethyolpropane triacrylate (EO₃TMPTA), cycloaliphatic diepoxide (ERL-4221), polycaprolactone polyol(Polyol-0301), 1-hydroxycyclohexyl phenyl ketone (Irgacure184) and a mixture of triarylsulfonium hexafluoroantimonate salts (UVI-6976). The main parameters of the photosensitive resin were as follows: the penetration depth was 0.15mm, the critical exposure was 16.6mJ/cm², the viscosity at 30°C was 215mPa.s, and the density at 30°C was 1.13g/cm³. With the photosensitive resin as the processing material, cuboid parts and double-cantilever parts were fabricated by using a stereolithography apparatus, and the dimension shrinkage factor and the curl factor were studied. The shrinkage factor was less than 1.00%, and the curl factor was less than 8.00%, which showed that the accuracy of the fabricated parts was high with the photosensitive resin for stereolithography.

Abstract: A new sensor-based temperature measuring system with high accuracy is presented in this paper. The temperature accuracy smaller then 0.02K is the measured performance of the measuring system after calibration at ten temperatures, over the -50°Cto 300°C targeted temperature range. Comparing with the traditional temperature measuring system, the advantages of the new sensor-based temperature measuring system are the high precision, immunity to noise, independent with the length of sensor wires and remote operation. And all these are at a low cost with less then 36mW of power consumption. Therefore the sensor-based temperature system is suitable for any field where reliable and accurate temperature measurement or a wide measurement range is necessary.

Abstract: The micro-motion stages are critically important in modern manufacturing technology. In this paper, an integrated approach for measuring micro-displacement of micro-motion stage that incorporates micro-motion measurement algorithm into the computer microvision is proposed. At first, the basic principle of the computer microvision measurement is analyzed. Then, an algorithm for micro-motion measurement is proposed. Finally, the micro-displacement of the micro-motion stage is measured using the integrated approach. The maximal bias of this proposed combined approach reached 12.5 nm. Experimental results show that this method can measure micro-displacement with nanometer accuracy.

Abstract: Micro-displacement measurement with high accuracy plays a vital role in micro/nano manufacturing technology. In this paper, three low-cost techniques for micro-displacement measurement with high accuracy are discussed, and they are the methods based on DVD optical head, burred images and stop-action images. The techniques based on the DVD optical head and burred images are very attractive for many applications where the low cost is indispensable, and the method based on stop-action images has also better performance when measuring the static micro-displacement. Then, an application based on the stop-action images approach is given, and this method can measure the micro-displacement with nanometer accuracy. In addition, these discussions show that the methods based on the DVD optical head and burred images are a possible direction for low-cost micro-displacement measurement with high accuracy.

Abstract: Motion profile smooth control is significant to reduce the obvious impact on machine tool in high speed and high accuracy CNC machining. However, the jerk is discontinuous and brings about flexible impact on machine tool in the linear Acceleration/Deceleration (ab. Acc/Dec), exponent Acc/Dec and S curve Acc/Dec approach. In the paper, the CNC machine tool dynamic model is built up to analyze the cause of machine impact, to describe the mathematics and physics meanings of jerk. Then a new Acc/Dec approach in which the jerk is continuous is put forward. And the motion profile smooth control algorithm based on continuous jerk is developed in details according to the permissible maximum acceleration, the permissible maximum jerk, the machining program segment displacement and the instruction feedrate. The motion profile smooth control algorithm can achieve continuous jerk, reduce impact on machine tool effectively, and be important to high speed and high accuracy CNC machining.

Abstract: A feeding table system is set up to meet the need for high motional precision and super-slow speed in micro-electron discharge machining (micro-EDM). It is composed of a resonant piezoelectric ceramics motor, a linear bearing and a linear encoder . It features high accuracy due to the application of linear driving, closed-1oop feedback and elimination of abbe’s errors. The characteristics of fine motion , slow speed and load capability are investigated. The results of the experiments show that the stable fine motion of this system can be as little as 100 nanometer and its speed can be as slow as 0.5 micron per second which is proper for feeding table of micro-EDM.