Coded data generation or conversion – Converter compensation
Patent
1989-11-13
1992-06-09
Williams, Howard L.
Coded data generation or conversion
Converter compensation
341166, 36457101, H03M 100
Patent
active
051211181
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The disclosure concerns a process and a device for compensating for, or correcting, measurement errors, and/or signal shaping of analog measurement signals, especially for sensors such as piezo-resistive sensors, in which a transformation of analog measurement signals into digital values is undertaken.
2. Related Prior Art
Sensors, to include also piezo-resistive sensors, have been completely integrated into modern technology and form an indispensable component for a measurement, control and/or regulatory circuit. By their use, precise measurement values can be obtained and then be further processed.
In contrast to previous decades, modern sensors are available on the market at relatively favorable prices.
In practice, the problem certainly arises that, for example, the measurement signal picked off at a measurement bridge can be contaminated with many measurement errors. Further, traditional sensors can be employed in association with microprocessors only by means of expensive switching, as a result of which, in any case, the measurement signal obtained from the analog measurement circuit must first of all be subjected to an analog-digital transformation.
In order to at least permit a temperature compensation, U.S. Pat. No. 4,192,005 discloses that a measurement value compensation switch can be provided downstream from the measurement point, in order to at least compensate for the errors arising from the influence of temperature in the analog measurement signal. But even this analog temperature compensation is imperfect, based on results.
On the other hand, U.S. Pat. No. 4,192,005 discloses how to digitize an analog signal measurement signal of a piezo-resistive sensor and process it digitally, through an analog-digital converter. This leads to an extreme loss of analog-digital converter resolution, since the sensitivity and offset compensation cannot be set from the start. In other words, with this known device, the entire measurement signal, including all errors, will be digitized from the outset. In this situation, the resolution can, at the maximum, openly reflect the individual digital steps. In addition, an enormous fabrication expense and, above all, a multiplicity of storage registers is required in the downstream digital processing electronics, in order to at least begin, at the outset, to process the original analog measurement signal after its transformation in the analog-digital converter, so that at least a part of the measurement errors will be compensated from the outset. Since the fabrication cost is enormous, the use of a downstream microprocessor was recommended in this connection in the U.S. patent document mentioned above.
By comparison to the state of the art just discussed, a greatly enhanced system for measurement error compensation has been made known in EP-A 0 169 414. The measurement processing and the corresponding device set forth in this document for the accomplishment of measurement processing includes a compensation circuit working in digitized form. The measurement signals, received in analog form, are further processed in analog form in the course of which an analog measurement signal is digitized only in a regulatory circuit, in order to then call up a corresponding prestored compensation or signal-shaping value based on a calibration and feed it back into the measurement switch. By this means, for example, the power supply for the measurement bridge and/or the amplification curve in the operational amplifier connected downstream from the measurement bridge can be influenced. With the state of the art just discussed, on the other hand, far better results can be achieved than by earlier methods. Particularly, by this approach, not only can a temperature compensation be provided but, above all, a zero pint and linearity compensation of the received measurement signal can also be undertaken.
With improved switching, there are also disadvantages to the state of the art which lie in the areas of long-term instability and a
REFERENCES:
patent: 3654545 (1972-04-01), Demark
patent: 3681577 (1972-08-01), Gasiunas
patent: 3694745 (1972-09-01), Thrap
patent: 3733600 (1973-05-01), Hellwarth et al.
patent: 3737891 (1973-06-01), Metcalf
patent: 3806916 (1974-04-01), Diaz et al.
patent: 3826983 (1974-07-01), Garratt et al.
patent: 3883863 (1975-05-01), Willard
patent: 3979745 (1976-09-01), Bishop
patent: 3982241 (1976-09-01), Lipcon
patent: 4107667 (1978-08-01), Kronlage
patent: 4192005 (1980-03-01), Kurtz
patent: 4354176 (1982-10-01), Aihara
patent: 4357600 (1982-11-01), Ressmeyer et al.
patent: 4484177 (1984-11-01), Jobbagy
patent: 4535857 (1985-08-01), Haze
patent: 4605920 (1986-08-01), Naisuler
patent: 4705126 (1987-11-01), Naito
patent: 4765188 (1988-08-01), Krechmery et al.
patent: 4870863 (1989-10-01), Duncan et al.
"Enhancing the dynamic range of an A/D converter", Lacey et al Electronic Engineering, Aug. 1983, pp. 49-52 and 57.
Divertronic AG
Williams Howard L.
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