Papers by Keyword: Self-Compensation

Abstract: This work deals with the design of fringe capacitance based non-contact type liquid level sensor employing self-compensation feature. The existing capacitive type sensors require additional compensation to overcome the problem of various stray capacitances, specifically due to atmospheric corrosion. This paper emphasizes on the selection of suitable material to accomplish the self-compensation feature in corrosive environment. Rate of attack of corrosion is studied on Copper (Cu) and Aluminium (Al) samples under drizzling environment. Visual Analysis of SEM images of samples exposed for different durations reveal that Al protects itself from the corrosion. Further, performance evaluation of two sensor units with Cu and Al electrodes under the same drizzling environment beside the respective samples indicate that sensor with Al electrodes facilitates the feature of self-compensation in corrosive environment. Further, the sensor is interfaced with Siemens PLC-S200 for liquid threshold level monitoring.

Abstract: The configuration of the system combines a liquid-filled lens, a flexible sensor membrane and a self-adjusted optical compensation device. We focus on optical compensation between the liquid-filled lens and the sensor membrane to make the system has good optical characters. For a single lens optical system, the curvy sensor membrane has better performance than flat type sensor in both the image quality of MTF, aberration and angle of view. To prove the idea, an optical measure system is developed and the optical system is also made. The experimental results show that this system do has a better performance in optical character.

Abstract: NC machine tools are generally thought to be with a high degree of automation, high precision, high reliability and high efficiency characteristics. But because of the inherent flaws of the machine mechanical structure, such as screw wear, assembly errors or repeated positioning error, the machining accuracy may reduce. Therefore, this paper describes a self-compensating system design FPGA-based NC machine tools. Using Programmable devices(FPGA) and Hardware description language(VHDL) to achieve self-compensation system controller development, Position measurement from absolute encoder in real-timing, Comprehensive building of NC machine tools since compensation control system.

Abstract: Butterfly pivot is a large-travel rotational flexure pivot, which can provide elastic support for the rotational shaft in several ten degrees. Rotational precision is of great important for its application. Because of the complex structure, rotational precision is always taken with Finite Element Method (FEM), which is not suitable for design and optimize parametrically. The structure property of the butterfly pivot is analyzed before the precision analysis. Four-Blade Isosceles-Trapezoid Element is present as the basic structure unit of the Butterfly Pivot. And then, Rotational precision of the Four-blade Isosceles-Trapezoid unit is calculated and analyzed. The Self-Compensation performance of the butterfly Pivot is also studied. Work in this thesis can validate the high rotational precision of the butterfly pivot.

Abstract: The static performance of an aerostatic bearing with angled surface self-slot-compensation is analyzed. The consistent condition was applied to unitize the Reynolds equation of different forms and the finite element method (FEM) was used to solve the equation. The load carrying capacity (LCC) and the stiffness of the bearing was obtained and the influence of the geometric parameters was discussed. It is concluded that this self-compensating aerostatic bearing can achieve a good performance; the geometric parameters of the gap are interactive, and should be rationally matched.

Abstract: A theory of time-space coordinate transformation is presented for measuring space with time. A novel type of displacement sensor named time grating is developed, and methods of electronic rectifying, self-compensation and self-correction are proposed to intelligentize the sensor. Experiment results coming from applications conform to the validity of the proposed theory and methods. The experiment and test results show that high-precision measurement is achieved without high-precision manufacture and that angular displacement is measured very accurately without a dividing scale, which embeds the remarkable characteristics of low cost but high accuracy to the time grating sensor.