In this paper a mechatronic model for an electromagnetic-force-compensated (EMC) load cell is presented. Designed in MATLAB® Simulink® the model consists of four main modules: a rigid-body model delineating ...
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ISBN:
(纸本)9781618390219
In this paper a mechatronic model for an electromagnetic-force-compensated (EMC) load cell is presented. Designed in MATLAB® Simulink® the model consists of four main modules: a rigid-body model delineating the mechanical behaviour of the load cell, an analytical model characterising the electrodynamic actuator consisting of a voice coil and a permanent magnet, a characteristic curve modelling the position detector, and a continuous or discrete model describing the operation of the controller. Optimization of the mechanical, electromagnetic and controller components can be performed using this model;furthermore experiments can be performed to determine the sensitivity of the complete system to changes of defined parameters.
In order to further improve the metrological properties of weighing systems based on the principle of electromagnetic force compensation (EMFC) as well as quality assurance, it is necessary to determine the parameters...
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ISBN:
(纸本)9781618390219
In order to further improve the metrological properties of weighing systems based on the principle of electromagnetic force compensation (EMFC) as well as quality assurance, it is necessary to determine the parameters relevant for the dynamic operation, such as measurement time and controller behavior. This determination is carried out by loading the balance system and observing the indication. Typically this is done by a load changer using different metrological weights. This method is inevitable if metrological traceability is required. However, the conventional procedure of load changing also entails several disadvantages. The number of possible load changes per unit time is limited and the force characteristic during loading is usually unknown and relatively difficult to reproduce or manipulate. Furthermore the fast and sudden exchange of the weights causes mechanical vibrations and a movement of the surrounding air, both of which act as additional disturbances. In this paper we propose an alternative loading method, with which these shortcomings can be improved and compare it to a conventional system. This method is based on loading the weighing system in a defined manner using a Lorentz-force, allowing the tester to generate a known, virtually arbitrary force characteristic during loading. It is shown that the Lorentz-force generated load represents a practical alternative to classical weights, offering advantages in reproducibility, dynamics and ability to be automated. Since the proposed method applies a known Lorentz-force to the weighing system it becomes possible to exactly determine the relationship between the force acting on the weighing pan and the resulting behavior of the weighing system.
This paper discusses an optical position sensor which can be used in balances based on the principle of electromagnetic force compensation (short used EFC) for example. Other applications are zero point detection as w...
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ISBN:
(纸本)9781618390219
This paper discusses an optical position sensor which can be used in balances based on the principle of electromagnetic force compensation (short used EFC) for example. Other applications are zero point detection as well as high precision positioning in the range of ± 200 μm. The position sensor consists of two infrared-LED (IR-LED) which illuminate a single photodiode via an aperture. The aperture is movable and performs a shadowing of the beams, thus shadowing changes due to the position of the aperture. The photodiode detects light from both LED. Both light sources have to be modulated and phase shifted to distinguish them in the photodiode signal. The evaluation of the position of the aperture is done by demodulating the received signal. A major advantage of this method is that the aperture's operating point is in the centre of the beams. Hence higher sensitivity is achievable and the beams can be focused onto the photodiode. Furthermore standard components are used and thus expensive differential photodiodes are no longer necessary.
We present a simple method to synthesize Pb（OH）2 nanorods by solution-phase reaction. Rod-like lead hydroxide precipitates are obtained by mixing lead nitrate with a concentration of about 0.01 M and potassium hydro...
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We present a simple method to synthesize Pb（OH）2 nanorods by solution-phase reaction. Rod-like lead hydroxide precipitates are obtained by mixing lead nitrate with a concentration of about 0.01 M and potassium hydroxide with concentration of about O.03 M in an aqueous solution. Sodium chloride as an additive is premixed with the lead nitrate aqueous solution. The presence of chloride ions in the precursor solution results in the rod-like morphology of lead hydroxide precipitates. The growth mechanism of the lead hydroxide nanorods is discussed.
The Vacuum Transfer System (VTS) is designed for fully automatic loading of weights into the Sartorius Prototype Mass Comparator CCL1007. The system enables the user to transfer weights from air to air/neutral gas, ai...
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ISBN:
(纸本)9781618390219
The Vacuum Transfer System (VTS) is designed for fully automatic loading of weights into the Sartorius Prototype Mass Comparator CCL1007. The system enables the user to transfer weights from air to air/neutral gas, air to vacuum and back, as well as from vacuum to vacuum conditions. A detailed description of the technical parameters and the different operation modes will be presented.
In metrology eddy current non-contact transducer have been widely used for measurement of position, displacement, cracks, vibration, proximity and alignment, as well as parts sorting applications over the past years. ...
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A positioning system is introduced which overcomes the limitations of existing indoor positioning systems by the use of artificial quasi static magnetic fields. The proposed DC magnetic signals show no special multipa...
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A positioning system is introduced which overcomes the limitations of existing indoor positioning systems by the use of artificial quasi static magnetic fields. The proposed DC magnetic signals show no special multipath effects and have excellent characteristics for penetrating various obstacles. In this contribution the theory of coil-based magnetic fields as well as the basic function principle of the positioning system are described. Furthermore, a prototype that is currently under development is presented.
A model aimed to describe the capacitance between probe electrodes and the conductive parts of planar electronic devices is presented. The probe electrodes are the constitutive part of a sensor chip used in an inspect...
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A model aimed to describe the capacitance between probe electrodes and the conductive parts of planar electronic devices is presented. The probe electrodes are the constitutive part of a sensor chip used in an inspection system which is exclusively based on capacitive coupling and employed for the inspection of devices such as flat panel displays and printed electronic circuits. Finite element (FE) simulations of the sensor signal are used to determine the model parameters and to verify the obtained results. The capacitive coupling for arbitrary configurations of parallel arranged conductor tracks and various distances between the tracks and the sensor chip is reproduced by the model. Absolute values of the capacitance with deviations below 5% can be obtained.
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