CN202274885U - Rotary transformer-digital conversion module - Google Patents

Abstract

The utility model provides a rotary transformer-digital conversion module. The conversion module comprises at least one sampling holding circuit, a path selection circuit, two A/D (Analog/Digital) conversion circuits and a memory circuit including an ROM (Read Only Memory). The rotary transformer- digital conversion module not only can process signals of a plurality of rotary transformer channels simultaneously, but also has the advantages of simple structure, small size, low power consumption and low cost, and on the other hand, has short responding time to phase steps, good real-time performance and high measuring accuracy.

Description

Rotary transformer-data-converting block

Technical field

The utility model relates to a kind of rotary transformer-data-converting block.

Background technology

Rotary transformer has been widely used in the servo control mechanism of lathe, aircraft, radar, fly bomb, robot etc. as the axis angle measurement element.Because rotary transformer output is analog voltage amount, need carries out analog voltage amount in actual use to the resolving of digital angle amount, and then offer computer system processor.Chinese invention patent CN100575884C discloses a kind of signals of rotating transformer-data-converting block, and it can realize the conversion to digital angle of hyperchannel, multi-frequency signals of rotating transformer.This signals of rotating transformer-data-converting block comprises that a plurality of signal processings and an angle of connecting with a plurality of rotary transformers resolve part: signal processing with hardware circuit realize with each rotary transformer output just, cosine modulation signal Vs, Vc just be converted into, the voltage effective value Vsin of cosine signal, Vcos; Each signal processing all is made up of a signal conditioning circuit and a digital integrator, and each signal conditioning circuit comprises two A/D converters and a zero-crossing detector; It is the DSP signal processor software that angle is resolved part, and it is just receiving, the voltage effective value Vsin of cosine signal, Vcos, calls the arctan function storehouse again, through formula: θ=arctan (Vsin/Vcos), calculates the digital angle θ of each passage.The structure principle chart of this signals of rotating transformer-data-converting block is shown in Fig. 1.

Yet when handling n passage signals of rotating transformer simultaneously, above-mentioned signals of rotating transformer-data-converting block comprises n signal conditioning circuit, and this just needs 2n A/D converter, causes problems such as volume is big, power consumption is high, cost height.In addition, above-mentioned signals of rotating transformer-data-converting block comprises digital integrator, and when the signal generation step of input changed, the response of output signal needed milliseconds up to a hundred, and the response time is long, can't satisfy the high speed requirement.In addition, above-mentioned signals of rotating transformer-data-converting block has adopted the arctan function storehouse of DSP digital signal processor that digital signal is handled, and utilizes software to calculate, and the processing time is longer.

The utility model content

The purpose of the utility model solves the aforementioned problems in the prior or other problems exactly, and a kind of a plurality of rotary transformer-data-converting blocks cheaply that revolve varying signal of high speed processing simultaneously are provided.

Rotary transformer-the data-converting block of the utility model comprises: at least one sampling hold circuit, and can the peak value of the input signal Vsin that receive from rotary transformer, Vcos be sampled and obtain and export Usin, Vcos; Path is selected circuit, comprises analog switch; Two A/D change-over circuits respectively comprise an A/D converter, and will carry out digital conversion from Usin, the Ucos that at least one sampling hold circuit receives respectively is Dsin, Dcos; And memory circuit, comprise ROM, store a database, wherein Dsin is as the high address of ROM, and Dcos is as the low order address of ROM, and D θ=arctan (Dsin/Dcos) is as the data in the ROM cell.

Through said structure, the rotary transformer-data-converting block of the utility model is simple in structure, volume is little, low in energy consumption, cost is low, and handles the signal of the individual rotary transformer of N (N >=2) simultaneously; The feasible response time to step of the utility model rotary transformer-data-converting block is reduced to the microsecond level from Millisecond.On the other hand; The utility model rotary transformer-data-converting block utilization computing machine carries out computing to the digital signal that will handle in advance; And generated operation result and can be solidificated in the binary file in the storer; The digital quantity that when handling, only needs to be converted to A/D is inquired about data in the ROM address as the address of ROM, the result that ROM output ground digital quantity is ascended the throne and will be obtained.Because not in the needs software processes, the processing time is shorter.

In a preferred embodiment of the utility model, said A/D converter is 12 A/D converters or 14 A/D converters, thereby realizes the high precision conversion.

In another preferred embodiment of the utility model, said at least one sampling hold circuit comprises 1-1000 sampling hold circuit.

In another preferred embodiment of the utility model, said ROM is selected from PROM, EPROM, OTPROM, EEPROM, flash memory.

Description of drawings

Those of ordinary skill in the art can more be expressly understood the above-mentioned of the utility model and other advantages through the following description of carrying out with reference to accompanying drawing, in the accompanying drawings:

Fig. 1 is the structural representation of the rotary transformer-data-converting block of prior art;

Fig. 2 is the structural representation of the rotary transformer-data-converting block of the utility model.

Embodiment

Fig. 2 shows the structural representation of rotary transformer-data-converting block of an exemplary of the utility model.As shown in the figure, this rotary transformer-data-converting block comprises basically: at least one peak sampling hold circuit, channel selection circuit, two A/D change-over circuits and memory circuit.Above circuit both can be designed as and had been welded on a PCB circuit board, also can for example be integrated into single module or chip through circuit integrated technology (MEMS), made its microminiaturization, integrated.

The signal of two winding outputs of rotary transformer 1-n is:

Vsin＝kU0sinwtsinθ

Vcos＝kU0s?inwtcosθ

Wherein:

KU0 is and excitation voltage one group of constant that transformer characteristic is relevant;

W is the frequency of excitation voltage;

The angle that on behalf of axle, θ rotate.

Said at least one peak value sampling circuit connects among the rotary transformer 1-n respectively, the peak value of Vsin Vcos sampled, even sinwt=1 just can obtain:

Usin＝kU0sinθ；

Ucos＝kU0cosθ。

Said channel selection circuit is made up of analog switch, is known in the prior art, does not therefore detail at this.

Said two A/D change-over circuits comprise A/D converter, respectively Usin, Ucos are carried out the A/D conversion.In an embodiment of the utility model, said A/D converter is 12 A/D converters.In other embodiments, can select the A/D converter of other types, for example 14 A/D converters according to accuracy requirement.In using the embodiment of i.e. 12 A/D converters, A/D converter is quantified as 4096 parts and use binary representation to it to Usin, Ucos.

$U\sin =U\sin /4095*(D11*2^{11}+D10*2^{10}+D9*2^9+D8*2^8+D7*2^7+D6*2^6+D5*2^5+D4*2^4+$

$D3*2^3+D2*2^2+D1*2^1+D0*2^0)=U\sin /4095\underset{n=0}{\overset{11}{\mathrm{\Σ}}}\mathrm{Dn}{2}^n$

$U\cos =U\cos /4095*(D11*2^{11}+D10*2^{10}+D9*2^9+D8*2^8+D7*2^7+D6*2^6+D5*2^5+D4*2^4+$

$D3*2^3+D2*2^2+D1*2^1+D0*2^0)=U\cos /4095\underset{n=0}{\overset{11}{\mathrm{\Σ}}}\mathrm{Dn}{2}^n$

In other embodiments, said A/D change-over circuit also comprises totalizer and register, to improve precision and stability.For example, use the AD574 chip to carry out 4 A/D conversions, to the data summation that is converted to for 4 times, ask its mean value then, the method for averaging is to cast out minimum two of register.After adding the digital filter of averaging method, 12 conversion accuracy can reach 12.

Represent 12 bit digital quantity that Usin has quantized with Dsin, represent 12 bit digital quantity that Ucos has quantized, represent digitized 12 parallactic angles tolerance with D θ with Dcos.

Because θ=arctan (Usin/Ucos), so D θ=arctan (Dsin/Dcos).

Because the calculating of D θ=arctan (Dsin/Dcos) is very complicated, the rotary transformer-data-converting block of this embodiment takes look-up table to solve.

Said memory circuit comprises ROM (ROM (read-only memory)), is selected from chips such as PROM, EPROM, OTPROM, EEPROM, flash memory.The method of combination of ROM table is that example is described with three A/D converters:

If the figure place of A/D conversion has only 4 and do not have sign bit; 111 represent 4.375v, and 000 represents 0v, so only use the high address of Dsin as ROM; Dcos has just accomplished make a list work with D θ=arctan (Dsin/Dcos) as the data in the ROM cell as the low order address of ROM.

1. Usin=1.875V after if rotary transformer output is sampled, Ucos=1.875V,

To Usin, Ucos carries out 3 AD and is converted to Dsin=011, Dcos=011, D θ=arctan (Dsin/Dcos)=arctan1=45 °

2. Usin=3.75V after if rotary transformer output is sampled, Ucos=0V,

To Usin, Ucos carries out 3 AD conversion Dsin=110, Dcos=000, D θ=arctan (Dsin/Dcos)=arctan ∞=90 °

12 algorithm is identical with three computing method, and what only will fill in is the form of one 4096 row and 4096 row, is 4096*4096 data among the ROM.

Certainly, the rotary transformer-data-converting block of the utility model also comprises sequential control circuit, is used for starting the A/D conversion, produces sheet choosing and the read signal of ROM, produces the control signal of digital filter, produces and converts signal.

Intactly understand and realize the utility model for clear, carried out above description with reference to accompanying drawing.Rotary transformer-the data-converting block that However, it should be understood that the utility model is not limited to above description.The protection domain of the utility model is limited appending claims.

Claims (4)

1. a rotary transformer-data-converting block is characterized in that, comprising:

At least one sampling hold circuit can be sampled the peak value of the input signal Vsin that receives from rotary transformer, Vcos respectively and obtained and export Usin, Vcos;

Path is selected circuit, comprises analog switch;

Two A/D change-over circuits respectively comprise an A/D converter, and will carry out digital conversion from Usin, the Ucos that at least one sampling hold circuit receives respectively is Dsin, Dcos; And

Memory circuit comprises ROM, stores a database, and wherein Dsin is as the high address of ROM, and Dcos is as the low order address of ROM, and D θ=arctan (Dsin/Dcos) is as the data in the ROM cell.

2. rotary transformer-data-converting block according to claim 1 is characterized in that, said A/D converter is 12 A/D converters or 14 A/D converters.

3. rotary transformer-data-converting block according to claim 1 is characterized in that, said at least one sampling hold circuit comprises 1-1000 sampling hold circuit.

4. rotary transformer-data-converting block according to claim 1 is characterized in that said ROM is selected from PROM, EPROM, OTPROM, EEPROM, flash memory.

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