MD413Z - Device for high-precision analog-to-digital conversion - Google Patents

Abstract

The invention relates to automation and measurement technology, as well as to the pattern recognition technique and can be used in systems for controlling and recording of signals received from telemetry information sensors, in robotics, communication engineering, medical engineering upon the supervision and control of physiological parameters of biological objects, etc.The device for high-precision analog-to-digital conversion contains, connected in series, an analog-digital converter (1), a switch-demultiplexer (2) with two outputs for connection/disconnection of the statistical processing mode, a statistical processing unit (3), including a sorter (3.1) and a mean value calculator (3.2); a switch-multiplexer (4) with two inputs and an output port (5) of the device. The second output of the switch-demultiplexer (2) is connected to the second input of the switch-multiplexer (4).The result of the invention is the device possibility of operating in two modes depending on the type of signal.

Description

The invention relates to automation and measurement technology, as well as to image recognition technology and can be used in control and signal recording systems obtained from telemetric information sensors, in robotics, in telecommunications technology, in medical technology for observing and controlling physiological parameters of biological objects, etc.

The analog-to-digital conversion device is known, which includes an analog-to-digital converter coupled to an output port [1].

The disadvantage of this device is the large irregular conversion error, because the device converts the input signal, composed of a useful signal and irregular noise.

Also known is the coherent filter of average values and arithmetic mean for removing noise from the touch screen signal, which includes the touch screen and its controller, connected to the terminals of the screen. The controller contains a block for sorting signals in ascending order by value and a block for calculating the average value, connected to an analog-to-digital converter [2].

The disadvantage of this filter is the low conversion speed due to statistical processing.

The problem that the invention solves consists in the possibility of connecting/disconnecting the statistical processing mode, thus increasing the device's precision/speed of operation.

The device, according to the invention, eliminates the above-mentioned disadvantages by containing, connected consecutively, an analog-to-digital converter, a switch-demultiplexer with two outputs for connecting/disconnecting the statistical processing mode, a statistical processing block, which includes a sorting device and an average value calculator; a switch-multiplexer with two inputs, an output port of the device. At the same time, the second output of the switch-demultiplexer is connected to the second input of the switch-multiplexer.

The result of the invention consists in the possibility of the device operating in two modes depending on the type of signal.

The invention is explained by the drawing in the figure, which represents the structural diagram of the device.

The analog-to-digital conversion device contains an analog-to-digital converter 1 of any type, the output of which is connected to the input of a switch-demultiplexer 2. The first output of the switch-demultiplexer 2 is connected to the input of a sorting device 3.1 of a block for statistical processing of measured values 3, the second output of the switch-demultiplexer 2 is connected to the second input of a switch-multiplexer 4. The statistical processing block 3, in turn, consists of the sorting device 3.1 and an average value calculator 3.2. The output of the sorting device 3.1 is connected to the input of the average value calculator 3.2, the output of which is connected to the first input of the switch-multiplexer 4, connected with the output to the input of an output port 5 of the device.

The analog-to-digital conversion device operates in two modes.

In the mode without statistical data processing, the data flows through the circuit: analog-to-digital converter 1, switch-demultiplexer 2, switch-multiplexer 4, output port 5.

In the statistical data processing mode, the data passes through the circuit: analog-to-digital converter 1, switch-demultiplexer 2, sorting device 3.1, average value calculator 3.2, switch-multiplexer 4, output port 5. In this mode, the time interval measured from the beginning of reading the input signal to its output in digital form increases proportionally to the memory volume of the sorting device 3.1.

In the mode with statistical data processing, the algorithm is used, according to which the slowly varying signal is read at least 10 times and the result is entered into the memory of the sorting device 3.1. The slowly varying signal is understood as the constant value of the signal throughout the entire period of reading the analog-digital converter 1. As an example of this type of signal can serve: pressure, gas composition in gas pipelines, gas heaters, voltage of batteries - sources of electricity. The signal change time in the indicated cases is more than 0.1 s, and the reading time of the average speed analog-digital converter is ~10-6 s.

In the sorting device 3.1, the received values are sorted in ascending order, starting from the null address - the minimum value A0, Al being a value greater than at the previous address and so on, up to the maximum value.

When the sorting is finished, the average value calculator 3.2 saves the measured values except for the lowest and highest values, which are ignored. The number of sorted and saved values is determined by the size of the first σ in the range 0.6…0.68 of the Gaussian normal distribution. In this way, the sorting block 3.1 performs filtering - selection for further processing.

The average value calculator 3.2 determines the average value of the saved values according to the formula:

, where:

µ - arithmetic mean value;

n - number of measurements;

i = 1…n - index of the current measurement;

xi - the value of the measured signal.

The obtained value is recorded in output port 5 of the device.

The device can be made entirely based on an integral crystal and can be connected directly to a data indicating, recording or transmitting device.

Example

For example, the +3.0 V signal is applied to the input and 10 values were recorded by the analog-to-digital converter 1 (see table, column “Measured values”). After sorting and ignoring the smallest and largest values, the filtered values were obtained (see table, column “Sorted values”, highlighted elements).

After calculating the filtered arithmetic mean value, a value closer to the value of the applied signal is obtained than the arithmetic mean value without statistical processing.

Table

Measurement step Measured values Average value Sorted values Sorted average value 1 3.0 2.1 2 3.1 2.3 3 3.0 2.83 4 2.1 2.95 5 2.95 3.0 6 2.83 3.0 7 4.5 3.05 8 2.3 3.1 9 5.6 4.5 10 3.05 5.6 3.243 2.988333333

1. GB 2452751 A 2009.03.18

2. US 20080224912 A1 2008.09.18

Claims (1)

High-precision analog-to-digital conversion device, which contains, connected in series, an analog-to-digital converter, a switch-demultiplexer with two outputs for connecting/disconnecting the statistical processing mode, a statistical processing block, which includes a sorting device and an average value calculator; a switch-multiplexer with two inputs, an output port of the device, while the second output of the demultiplexer switch is connected to the second input of the switch-multiplexer.