CN106383469A - Single path synchronous acquisition device of multiple paths of unipolar square wave modulation signals with raised levels - Google Patents

Abstract

The invention discloses a single path synchronous acquisition device of multiple paths of unipolar square wave modulation signals with raised levels. The unipolar square wave with a raised preset level controls the on and off of at least two paths of switch circuits, at least two paths of tested signals go through the switch circuits, and chopping modulation is realized by the switch circuits. After modulated signals with different frequencies are added by an add operation circuit, a single path analog-to-digital converter carries out analog-to-digital conversion to obtain a digital signal. Since the preset level of a unipolar square wave signal as driving is raised, at the low level part of the unipolar square wave signal, the unipolar square wave signal is improved obviously compared with noise, thus the unipolar square wave signal low level section is improved, the single path analog-to-digital converter carries out analog-to-digital conversion to obtain the signal to noise ratio of the digital signal, and thus the precision of the digital signal inputted into a microprocessor is improved. The microprocessor processes the digital signal, and each tested signal is demodulated.

Description

Multichannel raises the single channel synchronous acquisition device of the unipolarity square-wave modulation signal of level

Technical field

The present invention relates to signal measurement field, more particularly, to a kind of multichannel raises the unipolarity square-wave modulation signal of level Single channel synchronous acquisition device.

Background technology

The variable quantity of the carrying informations such as voltage signal, represents in its relaxed state in an analogue form, but, in order to It is easy to computer disposal, transmission and storage, ADC (analog-digital converter) generally to be passed through is transformed into digital signal, therefore exists In signal processing, analog digital conversion is requisite.

In existing multiplexed signal sampling system, generally need to arrange in pairs or groups monolithic ADC's using multi-disc ADC or multiway analog switch Scheme, the former has, and circuit is complicated, the shortcoming that system power dissipation is high and circuit size is big；And the latter then can in gatherer process, by In the switching of variable connector, insertion switch noise, and because variable connector has setup time, adjacent channel signals can be led to Between interfere.

In order to improve the acquisition quality of signal, notification number of the prior art is CN 104811202 A, and the day for announcing is The patent application in July 29 in 2015 improves the quality of signals collecting by the use of unipolarity square wave as pumping signal.

Because existing harvester is bar none all using analog-digital converter, analog-digital converter is near input limits Exist significantly non-linear when (maximum or minimum amplitude), the analog signal level of particularly input analog-to-digital converter is lower, obtains The uncertainty of the digital conversion results arriving is bigger.

Therefore, using unipolarity square wave as pumping signal when, the numeral obtaining in the low level part of unipolarity square wave The signal to noise ratio of signal is just very low, thus have impact on the acquisition precision of signal.

Content of the invention

In order to improve deficiency of the prior art, the invention provides a kind of multichannel raises the unipolarity square-wave frequency modulation of level The single channel synchronous acquisition device of signal, the present invention improves the signal to noise ratio of the digital signal obtaining in low level part, Jin Erti The high acquisition precision of signal, described below：

A kind of multichannel raises the single channel synchronous acquisition device of the unipolarity square-wave modulation signal of level, and described single channel is synchronously adopted Acquisition means include：Microprocessor, described single channel synchronous acquisition device also includes：At least 2 path switching circuits, adder operation circuit and Single channel analog-digital converter；

Described microprocessor exports different frequency and becomes the unipolarity square wave raising predetermined level of 2 times of ratio；

The unipolarity square wave raising predetermined level controls the break-make of at least 2 path switching circuits, and at least 2 tunnel measured signals are passed through On-off circuit, described on-off circuit is made up of analog switch and resistance, and described on-off circuit achieves copped wave amplitude modulation；After amplitude modulation After the signal of different frequency is added through described adder operation circuit, analog digital conversion is carried out by described single channel analog-digital converter and obtains number Word signal；

As the unipolarity square-wave signal driving due to having raised predetermined level, in the low level portion of unipolarity square-wave signal Point, unipolarity square-wave signal improves substantially compared to noise, thus improve in unipolarity square-wave signal low level section, single channel mould Number converter carries out the signal to noise ratio that analog digital conversion obtains digital signal, and then improves the digital signal being input in microprocessor Precision；

Described microprocessor is processed to digital signal, demodulates each measured signal.

Wherein, described as drive unipolar signal due to having raised predetermined level, in the height of unipolarity square-wave signal Level portions, improve single channel analog-digital converter and carry out the signal to noise ratio that analog digital conversion obtains digital signal.

Wherein, described adder operation circuit is superimposed a predetermined DC voltage；Described microprocessor adopts MCU, ARM, DSP Or any one in FPGA.

Wherein, mixed signal is converted into digital signal by single channel analog-digital converter and sends into microprocessor；

Raise the unipolarity square wave drive on-off circuit of predetermined level with 4 kinds of frequencies, collection 4 tunnel measured signals are said Bright：

The square-wave signal frequency of described microprocessor output control switch circuit is respectively 8f, 4f, 2f, 1f, described single channel The sample frequency of analog-digital converter is f_s, and f_s=16f, and ensure in the high and low level intermediate samples of high-frequency driving signal；

Sample frequency f_SFar above the change frequency of measured signal, in the lift of a cycle of minimum driving signal frequency each road The unipolarity square-wave signal amplitude of high predetermined level is constant, enters row operation with every 16 digital signals of order for one group, try to achieve by Survey the signal amplitude of 8 times of signal.

The beneficial effect of technical scheme that the present invention provides is：The present invention adopts different frequency and becomes 2 times of ratio The unipolarity square wave raising predetermined level controls the break-make of 2 path switching circuits；The signal of the different frequency after amplitude modulation is transported through addition Calculate circuit to be added, and plus after a predetermined DC level, carry out analog digital conversion through single channel analog-digital converter and obtain higher letter Make an uproar than digital signal, and then improve the precision of the digital signal being input in microprocessor, compared in background technology Notification number is CN 104811202A, and the day for announcing is the patent application in July 29 in 2015, invention significantly increases in one pole The signal to noise ratio of the digital signal of property square-wave signal low level section, thus improve the precision of signals collecting, meets practical application In multiple needs.

Brief description

Fig. 1 raises the single channel synchronous acquisition dress of the unipolarity square-wave modulation signal of level for a kind of multichannel that the present invention provides The structural representation put；

The schematic diagram of the separation different wave length signal that Fig. 2 provides for the present invention；

Fig. 3 raises the single channel synchronous acquisition side of the unipolarity square-wave modulation signal of level for a kind of multichannel that the present invention provides The flow chart of method.

In accompanying drawing, the list of parts representated by each label is as follows：

1：On-off circuit； 2：Adder operation circuit；

3：Single channel analog-digital converter； 4：Microprocessor.

Specific embodiment

For making the object, technical solutions and advantages of the present invention clearer, below embodiment of the present invention is made further Ground describes in detail.

Embodiment 1

A kind of multichannel raises the single channel synchronous acquisition device of the unipolarity square-wave modulation signal of level, referring to Fig. 1, this single channel Synchronous acquisition device includes：At least 2 path switching circuits 1, adder operation circuit 2, single channel analog-digital converter 3 and microprocessor 4,

Microprocessor 4 exports different frequency and becomes the unipolarity square wave raising predetermined level of 2 times of ratio, unipolarity Square wave controls the break-make of at least 2 path switching circuits 1, N (N>=2) road measured signal through on-off circuit 1 (this on-off circuit 1 by Resistance and analog switch composition), on-off circuit 1 is used for realizing copped wave amplitude modulation.

The signal of the different frequency after amplitude modulation is added through adder operation circuit 2, and plus after a predetermined DC level, Analog digital conversion is carried out by single channel analog-digital converter 3 and obtains digital signal.Microprocessor 4 is processed to digital signal, demodulates Each measured signal.

Wherein, due to the addition of a predetermined DC level, unipolarity square-wave signal low level part so that through list Road analog-digital converter 3 carries out the digital signal that analog digital conversion obtains compared with high s/n ratio, and then improves and be input in microprocessor 4 Digital signal precision.

Further, since raising predetermined level, noise level is not changed in, in the high level part of unipolarity square-wave signal, Unipolarity square-wave signal also has some improvement compared to noise, improves the signal in unipolarity square-wave signal high level section Signal to noise ratio.

And then, because single channel analog-digital converter 3 carries out the digital signal that analog digital conversion obtains relatively high s/n ratio, and then improve It is input to the precision of the digital signal in microprocessor 4.

Wherein, the quantity of on-off circuit 2 is more than or equal to 2.When implementing, the quantity of on-off circuit 2 and implement shape Formula is set according to the needs in practical application, and the embodiment of the present invention is without limitation.

Microprocessor 1 can be using any one in MCU, ARM, DSP or FPGA.

In sum, because the embodiment of the present invention is with respect to the application documents in background technology, considerably improve in list The signal to noise ratio of the digital signal of polarity square wave signal low level section, thus improve the precision of signals collecting, meets actual answering With in multiple needs.

Embodiment 2

A kind of multichannel raises the software flow of the single channel synchronous acquisition device of the unipolarity square-wave modulation signal of level, referring to Fig. 2 and Fig. 3, the method comprises the following steps：

101：Mixed signal is converted into digital signal by single channel analog-digital converter 3 and sends into microprocessor 1；

102：Microprocessor is processed to digital signal, demodulates each measured signal.

With unipolarity square wave drive on-off circuit 2, the collection 4 of raising predetermined level of 4 kinds of frequencies for the sake of concise explanation Illustrate it is assumed that measured signal V as a example the measured signal of road₁、V₂、V₃And V₄Predetermined level is raised in the driving of corresponding switch circuit 1 Unipolarity square wave frequency be respectively 8f, 4f, 2f and f.

It is assumed that the sample frequency of single channel analog-digital converter 3 is f_S, and f_S=16f, and ensure in V₁In the high and low level of signal Between sample.

Digital signal sequencesCan be expressed as：

$D_i^t=D_i^{V_1}+{D_i}^{V_2}+D_i^{V_3}+{D_i}^{V_4}+D_i^B---\left(1\right)$

Wherein,WithIt is respectively collection signal V₁、V₂、V₃And V₄Amplitude,For DC component width Value.

It is assumed that sample frequency f_SFar above the change frequency of measured signal, can in a cycle of minimum driving signal frequency Be approximately considered each road raise predetermined level unipolarity square-wave signal amplitude constant, taking the most front 16 sampled datas as a example：

$\left\{\begin{array}{c}{D}_0^{V1}=D_1^{V1}=D_4^{V1}=D_6^{V1}=D_8^{V1}=D_{10}^{V1}=D_{12}^{V1}=D_{14}^{V1}=D_A^{V1}\\ D_1^{V1}=D_3^{V1}=D_5^{V1}=D_7^{V1}=D_9^{V1}=D_{11}^{V1}=D_{13}^{V1}=D_{15}^{V1}=0\\ D_0^{V2}=D_1^{V2}=D_4^{V2}=D_5^{V2}=D_8^{V2}=D_9^{V2}=D_{12}^{V2}=D_{13}^{V2}=D_A^{V2}\\ D_3^{V2}=D_4^{V2}=D_7^{V2}=D_8^{V2}=D_{11}^{V2}=D_{12}^{V2}=D_{15}^{V2}=D_{16}^{V2}=0\\ D_0^{V3}=D_1^{V3}=D_2^{V3}=D_3^{V3}=D_8^{V3}=D_9^{V3}=D_{10}^{V3}=D_{11}^{V3}=D_A^{V3}\\ D_4^{V3}=D_5^{V3}=D_6^{V3}=D_7^{V3}=D_{12}^{V3}=D_{13}^{V3}=D_{14}^{V3}=D_{15}^{V3}=0\\ D_0^{V4}=D_1^{V4}=D_2^{V4}=D_3^{V4}=D_4^{V4}=D_5^{V4}=D_6^{V4}=D_7^{V4}=D_A^{V4}\\ D_8^{V4}=D_9^{V4}=D_{10}^{V4}=D_{11}^{V4}=D_{12}^{V4}=D_{13}^{V4}=D_{14}^{V4}=D_{15}^{V4}=0\\ D_0^B=D_1^B=D_2^B=D_3^B=D_4^B=D_5^B=D_6^B=D_7^B=D_8^B=D_9^B\\ =D_{\mathrm{10}}^B=D_{\mathrm{11}}^B=D_{\mathrm{12}}^B=D_{\mathrm{13}}^B=D_{\mathrm{14}}^B=D_{\mathrm{15}}^B=D_A^B\end{array}\right.---\left(2\right)$

Wherein,WithIt is respectively V₁、V₂、V₃And V₄Amplitude with DC component.

In other words, enter row operation with every 16 digital signals of order for one group：

$\begin{array}{c}{D}_{16n+0}-D_{16n+1}+D_{16n+2}-D_{16n+3}+D_{16n+4}-D_{16n+5}+D_{16n+6}-D_{16n+7}+D_{16n+8}-D_{16n+9}+\\ D_{16n+10}-D_{16n+11}+D_{16n+12}-D_{16n+13}+D_{16n+14}-D_{16n+15}=8D_{An}^{V1},n=0,1,\mathrm{2......}\end{array}---\left(3\right)$

Obtain 8 times of V₁Signal amplitudeAnd completely eliminate DC componentImpact.

$\begin{array}{c}{D}_{16n+0}+D_{16n+1}-D_{16n+2}-D_{16n+3}+D_{16n+4}+D_{16n+5}-D_{16n+6}-D_{16n+7}+D_{16n+8}+D_{16n+9}-\\ D_{16n+10}-D_{16n+11}+D_{16n+12}+D_{16n+13}-D_{16n+14}-D_{16n+15}=8D_{An}^{V3},n=0,1,\mathrm{2.......}\end{array}---\left(4\right)$

Obtain 8 times of V₂Signal amplitudeAnd completely eliminate DC componentImpact.

$\begin{array}{c}{D}_{16n+0}+D_{16n+1}+D_{16n+2}+D_{16n+3}-D_{16n+4}-D_{16n+5}-D_{16n+6}-D_{16n+7}+D_{16n+8}+D_{16n+9}+\\ D_{16n+10}+D_{16n+11}-D_{16n+12}-D_{16n+13}-D_{16n+14}-D_{16n+15}=8D_{An}^{V3},n=0,1,\mathrm{2.......}\end{array}---\left(5\right)$

Obtain 8 times of V₃Signal amplitudeAnd completely eliminate DC componentImpact.

$\begin{array}{c}{D}_{16n+0}+D_{16n+1}+D_{16n+2}+D_{16n+3}+D_{16n+4}+D_{16n+5}+D_{16n+6}+D_{16n+7}-D_{16n+8}-D_{16n+9}-\\ D_{16n+10}-D_{16n+11}-D_{16n+12}-D_{16n+13}-D_{16n+14}-D_{16n+15}=8D_{An}^{V4},n=0,1,\mathrm{2......}\end{array}---\left(6\right)$

Obtain 8 times of V₄Signal amplitudeAnd completely eliminate DC componentImpact.

In sum, because the embodiment of the present invention is with respect to the application documents in background technology, considerably improve in list The signal to noise ratio of the digital signal of polarity square wave signal low level section, thus improve the precision of signals collecting, meets actual answering With in multiple needs.

To the model of each device in addition to doing specified otherwise, the model of other devices is not limited the embodiment of the present invention, As long as the device of above-mentioned functions can be completed.

It will be appreciated by those skilled in the art that accompanying drawing is the schematic diagram of a preferred embodiment, the embodiments of the present invention Sequence number is for illustration only, does not represent the quality of embodiment.

The foregoing is only presently preferred embodiments of the present invention, not in order to limit the present invention, all spirit in the present invention and Within principle, any modification, equivalent substitution and improvement made etc., should be included within the scope of the present invention.

Claims (5)

1. a kind of multichannel raises the single channel synchronous acquisition device of the unipolarity square-wave modulation signal of level, described single channel synchronous acquisition Device includes：Microprocessor, described single channel synchronous acquisition device also includes：At least 2 path switching circuits, adder operation circuit and list Road analog-digital converter；It is characterized in that,

Described microprocessor exports different frequency and becomes the unipolarity square wave raising predetermined level of 2 times of ratio；

The unipolarity square wave raising predetermined level controls the break-make of at least 2 path switching circuits, and at least 2 tunnel measured signals are through switch Circuit, described on-off circuit is made up of analog switch and resistance, and described on-off circuit achieves copped wave amplitude modulation；Difference after amplitude modulation After the signal of frequency is added through described adder operation circuit, analog digital conversion is carried out by described single channel analog-digital converter and obtains numeral letter Number；

As the unipolarity square-wave signal driving due to having raised predetermined level, in the low level part of unipolarity square-wave signal, Unipolarity square-wave signal improves substantially compared to noise, thus improve in unipolarity square-wave signal low level section, single channel modulus Transducer carries out the signal to noise ratio that analog digital conversion obtains digital signal, and then improves the digital signal being input in microprocessor Precision；

Described microprocessor is processed to digital signal, demodulates each measured signal.

2. a kind of multichannel according to claim 1 raises the single channel synchronous acquisition dress of the unipolarity square-wave modulation signal of level Put it is characterised in that the described unipolar signal as driving is due to having raised predetermined level, in the height of unipolarity square-wave signal Level portions, improve single channel analog-digital converter and carry out the signal to noise ratio that analog digital conversion obtains digital signal.

3. a kind of multichannel according to claim 1 raises the single channel synchronous acquisition dress of the unipolarity square-wave modulation signal of level Put it is characterised in that described adder operation circuit is superimposed a predetermined DC voltage.

4. a kind of multichannel according to claim 1 raises the single channel synchronous acquisition dress of the unipolarity square-wave modulation signal of level Put it is characterised in that described microprocessor adopts any one in MCU, ARM, DSP or FPGA.

5. a kind of multichannel according to claim 1 raises the single channel synchronous acquisition dress of the unipolarity square-wave modulation signal of level Put it is characterised in that described device includes：

Mixed signal is converted into digital signal by single channel analog-digital converter and sends into microprocessor；

Raise the unipolarity square wave drive on-off circuit of predetermined level with 4 kinds of frequencies, collection 4 tunnel measured signals illustrate：

The square-wave signal frequency of described microprocessor output control switch circuit is respectively 8f, 4f, 2f, 1f, described single channel modulus The sample frequency of transducer is f_s, and f_s=16f, and ensure in the high and low level intermediate samples of high-frequency driving signal；

Sample frequency f_SFar above the change frequency of measured signal, raise pre- on each road of a cycle of minimum driving signal frequency If the unipolarity square-wave signal amplitude of level is constant, enters row operation with every 16 digital signals of order for one group, try to achieve tested letter Numbers 8 times of signal amplitude.