RU2446557C1 - Recursive code scale - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: recursive code scale comprises the first information code path made in compliance with symbols of non-linear binary sequence with length of N=2ⁿ, n reading elements placed with an angular pitch equal to the quantum value of the code path δ=360°/N, the second information code path made in compliance with symbols N of periods of non-linear binary sequence with length M=2^m, m reading elements placed with an angular pitch (δ+δ₂), where δ₂=360°/NM - quantum value, a regular code path made in compliance with symbols of binary sequence with length of 2NM, with quantization period of δ_sc=360°/2NM, being simultaneously the quantum value of the recursive code scale, a reading element of the regular code path, displaced relative to the first of n reading elements by an angular distance k=2eδ_sk+(δ_sc/2), m additional reading elements displaced relative to the first of m reading elements by an angular distance k_m=(j+m)δ+δ_sc., and arranged along the second information code parth with an angular pitch (δ+δ₂), n additional reading elements displaced relative to the first of n reading elements by an angular distance k_n=(iδ+δ_sc.) and placed along the first information code path with an angular pitch δ, a code converter, outputs of which, as well as outputs n, m, m_add of reading elements and an output of a reading element of a regular code path are designed to remove information on the angular position of the recursive code scale.

EFFECT: simplification of a recursive code scale.

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Description

The invention relates to measuring equipment, in particular to analog-to-digital conversion, and in particular to the code scales of angular displacement converters to code.

At present, and in the future, one of the urgent and technically challenging tasks is the digital measurement of the angular displacements of the moving organs of numerous automatic control systems for various objects. This function is performed by angular displacement transducers.

The development of angular displacement transducers - suppliers of primary information - is largely due to the widespread use of control micro-computers and various computing devices based on microprocessor and other large and very large integrated circuits.

In general, the angular displacement transducers, which are very diverse, are presented with a combination of the most diverse and, as a rule, high technical requirements.

An analysis of literary sources allows us to note the following advantages for transducers with direct conversion of displacement to code, based on reading using spatial coding: the ability to use various physical methods of information reading, high speed, for encoders of angular displacement, high rotation speed of the encoded shaft from 100 to 150 rpm / min, high resolution (up to 20 binary bits), resistance to external destabilizing their factors, the ability to meet various application conditions, the possibility of functional conversion of movement to code, etc. The main element of such converters that determines their most important characteristics is the code scale (KS).

The elementary section (quantum) of the code track (CD) of the scale is represented, as a rule, by one binary symbol, where the active sections of the scale correspond to single symbols, and passive sections correspond to zero.

Considering that the angular displacement transducers constructed by the reading method can be implemented on various physical methods of reading information, the active and passive elementary sections of the CD scale mean, respectively, the conductive and non-conductive parts of the scale with the contact method of reading information, transparent and opaque parts of the scale with photoelectric the method of information retrieval, the presence of a metal plate and insulation on the sections of the scale with the capacitive method of information retrieval, the presence and the absence of magnetic material on the parts of the scale with the electromagnetic method of reading information, etc.

Currently, microelectronics makes a significant contribution to the development of angular displacement transducers, the use of which makes it possible to more fully solve the problem of manufacturability, providing the maximum simplification of precision mechanical components, the main of which is KS [1].

Known recursive code scale (RCS) for angular displacement transducers, built on the basis of nonlinear binary sequences [2]. The advantage of RCS can be considered the possibility of its implementation using most well-known methods of reading information. The disadvantages of this scale are the low resolution and the ambiguity of reading from the code combination scale.

Closest to the technical solution and chosen by the authors for the prototype is a recursive code scale for angular displacement transducers, built on the basis of nonlinear binary sequences [3].

The recursive code scale contains the first information code track, made in accordance with the symbols of a nonlinear binary sequence of length N = 2 ⁿ , n read elements, placed along the first information code track with an angular step equal to the quantum value of the first information code track δ = 360 ° / N , the second information code track formed in accordance with the symbol periods N nonlinear binary sequences of length M = 2 ^{m, m} sensing elements arranged along a second informational odovoy track with an angular pitch (δ ₂ + δ), where δ ₂ = 360 ° / NM - value quantum second information code the track regular code track formed in accordance with the symbols {0,1, ..., 0,1, ..., 0,1} of a binary sequence of length 2NM uniformly quantized with a quantization period of δ _nk. = 360 ° / 2NM, which is simultaneously the quantum value of the recursive code scale, the reading element of the regular code track, offset from the first of n reading elements by an angular distance k = 2еδ _шк. + (δ _шк. / 2), e = 0,1,2,3, ... and placed along a regular code track, m _add. additional reading elements offset relative to the first of m reading elements by an angular distance k _m = (j + m) δ + δ _pc. , j = 0,1,2, ... and placed along the second information code track with an angular step (δ + δ ₂ ), an additional information code track made in accordance with the symbols of a nonlinear binary sequence of length N = 2 ⁿ and cyclically shifted relative to the first information code track 180 ° clockwise, n _add. = n additional reading elements offset relative to the first of n reading elements by an angular distance k _n = Nδ / 2 + δ _pc. and placed along an additional information code track with an angular step equal to the quantum value of the first information code track δ, from outputs n, n _add. , m, m _add. reading elements and the output of the reading element of the regular code track is removed information about the angular position of the recursive code scale.

The disadvantages of the prototype is its complexity and, as a result, the increased dimensions of the recursive code scale due to the use of four code tracks.

The present invention solves the problem of simplifying the recursive code scale in terms of reducing its size while maintaining all the functionality of the prototype.

To achieve a technical result, the recursive code scale contains the first information code track, made in accordance with the symbols of a nonlinear binary sequence of length N = 2 ⁿ , n reading elements, placed along the first information code track with an angular step equal to the quantum value of the information code track δ = 360 ° / N, the second information code track, made in accordance with the characters N periods of a nonlinear binary sequence of length M = 2 ^m , m reading elements, is placed along the second information code track with an angular step (δ + δ ₂ ), where δ ₂ = 360 ° / NM is the quantum value of the second information code track, a regular code track made in accordance with the symbols {0,1, ..., 0,1, ..., 0,1} of a binary sequence of length 2NM uniformly quantized with a quantization period of δ _nk. = 360 ° / 2NM, which is simultaneously the quantum value of the recursive code scale, the reading element of the regular code track, offset from the first of n reading elements by an angular distance k = 2еδ _шк. + (δ _шк. / 2), е = 0,1,2,3, ... and placed along a regular code track, m _add. = m additional reading elements offset relative to the first of m reading elements by an angular distance k _m = (j + m) δ + δ _pc. , j = 0,1,2, ... and placed along the second information code track with an angular step (δ + δ ₂ ), n _add. = n additional reading elements offset relative to the last of n reading elements by an angular distance k _n = (iδ + δ pc _. ), i = 1,2,3, ... and placed along the first information code track with an angular step equal to δ, code converter for n inputs and n outputs, outputs n _add. reading elements are connected to the inputs of the code converter, n outputs of which, as well as outputs n, m, m _add. reading elements and the reading element output of the regular code track are designed to remove information about the angular position of the recursive code scale.

New in the invention is:

- placement along the first information code track with an angular step equal to δ, n _add. = n additional reading elements offset relative to the last of n reading elements by an angular distance k _n = (iδ + δ pc _. ), i = 1,2,3, ...;

- supplying a recursive code scale with a code converter for n inputs and n outputs that performs the function of matching samples, i.e. reduction of the code combination read from n _add. reading elements, to a code combination obtained from n reading elements.

The set of essential features in the present invention allowed to simplify the recursive code scale in terms of reducing its dimensions by using three code tracks instead of four tracks while maintaining all the functionality of the prototype.

As a result, we can conclude that

- the proposed technical solution has an inventive step, because it does not explicitly follow from the prior art;

- the invention is new, since the prior art on available sources of information did not reveal analogues with a similar set of features;

- the invention is industrially applicable, as it can be used in all areas where high-precision positional determination of the angular position of the object is required using angular displacement transducers based on the claimed recursive code scales.

The invention is illustrated in the drawing, which shows a linear scan of a seven-bit recursive code scale.

The inventive recursive code scale 1 contains a first information code track 2, a second information code track 3, a regular code track 4, n = 3 of reading elements 5, 6, 7, n _add. = 3 reading elements 8, 9, 10, m = 3 reading elements 11, 12, 13, m _add. = 3 readout elements 14, 15, 16, readout element 17 of the regular code track, code converter 18 for three inputs and three outputs.

To clarify the essence of the invention, we give some theoretical background.

In [4], KS for angular displacement transducers, called pseudorandom code scales (PSCS), and based on the use of the theory of maximum length pseudorandom binary sequences (M-sequences), were proposed. PCSS have only one information code track, made in accordance with the symbols of the M-sequence a ₀ a ₁ ... a _L-1 , and n readout elements (SE) located along the track. Reading elements make it possible to obtain, with a full turn of the scale L = 2 ⁿ -1, various n-bit code combinations and provide the resolution of the angular displacement transducer based on the PSCH δ = 360 ° / L.

As follows from the method of constructing PCSS, its resolution is determined by the length of the M-sequence L = 2 ⁿ -1. Obviously, for any scale resolution, one (zero) code combination is lost. However, when constructing some technical systems using angular displacement transducers, it is necessary to provide a resolution of the latter equal to 2 ⁿ .

In [5], the recursive code scales (RCS) used in the invention, which are called nonlinear code scales (NCC) and are constructed on the basis of nonlinear binary sequences that provide the resolution of the scale δ = 360 ° / 2 ^{n, are considered} .

A non-linear sequence is a sequence of binary symbols {a _j } of length N = 2 ⁿ satisfying the recursive relation [6]

where the sign ⊕ means summation modulo two, and the indices for the characters of the sequence are taken modulo N. The initial values of the characters a ₀ a ₁ ... α _n-1 sequences are chosen arbitrarily.

In (1), h _i are coefficients depending on the form of a primitive polynomial of degree n with coefficients of the Galois field GF (2) [7], that is,

where h ₀ = h _n = 1, ah _i = 0,1 for 0 <i <n,

The first term in (1) defines the rule of formation linear with respect to the summation operator modulo 2 M-sequence. The second term (3) in (1) indicates the operation of multiplying the values of n-1 code symbols. This leads to the fact that the resulting sequence of characters becomes non-linear and a combination appears in it containing n consecutive zeros.

Table 1 shows the polynomials h (x) up to n = 20 inclusive, which can be used to generate the corresponding M-sequences [7].

Consider a method for constructing an n-bit single-rail RCS based on a nonlinear sequence.

1. Depending on the required bit depth of the scale n, a polynomial h (x) of degree n is selected from Table 1.

2. Using the recursive relation (1), the sequence {a _j } is generated.

3. The elementary sections (quanta) of the scale δ are performed in accordance with the symbols of the nonlinear sequence {a _j }, where symbols 1 of the sequence correspond to active and symbols to 0, passive sections of the information track. For definiteness, the sequence symbols are displayed on the information code track clockwise in the order a ₀ a ₁ ... a _N-1.

4. Placing n reading elements on a scale with a step equal to one quantum, i.e. in accordance with the placement polynomial

The uniqueness of this arrangement is explained by the nonlinear properties of the sequence in question.

Let us explain the construction of information code tracks RKSH 1, shown in the drawing.

In the example, the first information code track 2 of RCS 1 is constructed in accordance with the symbols of the nonlinear sequence {a _j } = a ₀ a _j ... a ₇ = 00010111 of length N = 2 ⁿ = 2 ³ = 8, to obtain which the primitive polynomial h (x ) = x ³ + x + 1, and the characters a _{3 + j of the} sequence {a _j } for initial values a ₀ = a ₁ = a ₂ = 0 satisfy the recursive relation a _{3 + j} = a _{1 + j} ⊕a _j ⊕ā _{+ j} ā _{2 + j} , j = 0,1, ... 4. A non-linear sequence should be plotted on the CSC in the form of active (sequence units) and passive (sequence zeros) sections (quanta) of the first information code track 2, for example, clockwise, and only one period is applied to the first information code track 2 of CSC 1 sequence. A non-linear sequence with a period of N = 2 ⁿ determines the number of quanta of the first information code track 2 of the CSC 1, which in this example is N = 8. Hence, the quantum value is δ = 360 ° / N = 360 ° / 8 = 45 °. In the example, the placement of solar cells 5, 6, and 7 (n = 3) along the first information code track 2 is determined by the polynomial r (x) = 1 + x + x ² and is carried out with a step equal to the value of one quantum of the first information code track δ along the clock arrows.

By fixing reading elements 5, 6 and 7 sequentially, the code combination when moving RCS 1 cyclically to one elementary section (quantum), for example, counterclockwise, we get eight different three-digit code combinations: 000, 001, 010, 101, 011, 111, 110 and 100.

By this principle, a one-way recursive code scale of any capacity can be constructed.

In the drawing, the second information code track 3 of RKSH 1 is constructed in accordance with the symbols of the nonlinear sequence {a _j } = a ₀ a ₁ ... a ₇ = 00010111 of length M = 2 ^m = 2 ³ = 8, to obtain which the primitive polynomial h (x ) = x ³ + x + 1, and the characters a _{3 + j of the} sequence {a _j } for initial values a ₀ = a ₁ = a ₂ = 0 satisfy the recursive relation a _{3 + j} = a _{1 + j} ⊕a _j ⊕ā _{1 + j} ā _{2 + j} , j = 0,1, ..., 4. A non-linear sequence should be plotted on RKSh 1 in the form of active (sequence units) and passive (sequence zeros) sections (quanta) of the second information code track 3, for example, clockwise, with N = 2 being applied to the second information code track 3 8 periods of sequence. Eight periods of a nonlinear sequence of length M = 2 ³ = 8 determine the number of quanta of the second information code track 3 of RCS 1, which in this example is NM = 64. Hence, the quantum value of the second information code track 3 δ ₂ = 360 ° / NM = 360 ° / 64 = 5,625 °.

Thus, in the example, the placement of solar cells 11, 12 and 13 (m = 3) along the second information code track 2 is carried out with a step equal to the value (δ + δ ₂ ) = 45 ° + 5.625 ° = 50.625 ° clockwise.

In our example, the total bit depth provided by the first information and second information code tracks during the placement of the SC considered above will be (n + m) = 3 + 3 = 6.

Fixing the reading elements 5, 6, 7 and 11, 12, 13 sequentially a code combination, when moving the RCS cyclically to one elementary section (quantum) of the second information code track 3 δ ₂ , for example, counterclockwise, we get 64 different six-digit code combinations that correspond to 64 angular positions of the scale. These code combinations are given in table 2.

In this example, to build the first information code track 2 and the second information code track 3, the same nonlinear binary sequence was used, i.e. N = M = 8. In the general case, N ≠ M is allowed. For example, a six-bit recursive code scale can be constructed in two other ways, where (n = 4, m = 2) and (n = 2, m = 4). With an increase in the bit depth of a two-track recursive code scale, the number of variants of its construction also increases. This approach provides additional opportunities for choosing the most technologically advanced option for constructing an RCS (and, as a result, an angular displacement transducer based on it), which is associated with the possibility of multivariate placement of reading elements on the scale.

In the drawing, the regular code track 4 is made in accordance with the symbols {0,1, ..., 0,1, ..., 01} of a binary sequence of length 2NM = 2 × 8 × 8 = 128, uniformly quantized with a quantization period of δ _pc. = 360 ° / 2NW = 360 ° / 128 = 2.8125 °. The reading element 17 of the regular code track is placed along the regular code track relative to the first 5 of n = 3 reading elements 5, 6, 7 at an angular distance

k = 2eδ _wk. + (δ _шк. / 2) = 2 × 4 × 2.8125 ° + (2.8125 ° / 2) = 22.50 ° + 1.40625 ° = 23.90626 °, е = 4.

In the drawing, n _ext. = 3 reading elements 8, 9 and 10 are offset relative to the last 7 of n reading elements by an angular distance k _n = (iδ + δ pc _. ) = Δ + δ _pc. = 45 ° + 2.8125 ° = 47.8125 °, i = 1 and placed along the first information code track with an angular step equal to the quantum value of the first information code track δ = 45 °; m _add. = 3 sensing elements 14, 15 and 16 are offset relative to the first 11 of m reading elements by an angular distance k _m = (j + m) δ + δ _pc. = mδ + δ pc _. = 3 × 45 ° + 2.8125 ° = 137.8125 °, j = 0 and placed along the second information code track with an angular pitch (δ + δ ₂ ) = 45 ° + 2.8125 ° = 47.8125 °.

The process of reading information from RCS 1 is as follows.

With an arbitrary position of RCS 1 with regular 4, first information 2 and second information 3 code tracks, the corresponding six-digit digital code is removed by means of reading elements. The output signal from the reading element 17 of the regular code track 4 forms the least significant seventh bit of the PCB, and also controls the reading mode of the code combination with the first information 2 and second information 3 code tracks.

Moreover, if the output signal from the reading element 17 is zero, then the recursive digital code is removed from n _add. = 3 reading elements 8, 9 and 10 and m _add. = 3 readout elements 14, 15 and 16. If the output signal from the readout element 17 is equal to one, then a recursive digital code is removed from n = 3 readout elements 5, 6 and 7 and m = 3 readout elements 11, 12 and 13.

In the present invention, at the outputs of the reading elements 5, 6 and 7 and additional reading elements 8, 9 and 10, various recursive codes are generated. In this regard, coordination of samples is required, i.e. reduction of the code combination read from n _add. reading elements, to a code combination obtained from n reading elements. Such coordination of samples is carried out by means of a code converter 18, which can be implemented, for example, using a read-only memory (ROM) with three inputs and three outputs.

If we take the zero code combination as the starting position of RCS 1, then the input 8, 9, and 10 and the output 19, 20, and 21 of the code converter 18 should look like that shown in Table 3.

Obviously, from the outputs of the reading elements 5-7, 11-16, as well as from the outputs 19-21 of the code converter, six bits of RCS will be generated, and three high order bits are removed from the reading elements 5-7 and the outputs of 19-21 of the code converter, the first one the second and third, and from the reading elements 11-16 - the fourth, fifth and sixth digits. The seventh junior bit of the RCS is formed directly by the reading element 17 of the regular code track 4. Table 4 shows the output code combinations of the seven-bit recursive code scale shown in the drawing.

Thus, the present invention allows to simplify the recursive code scale, reducing its dimensions by using only three code tracks instead of four, while maintaining all the functionality of the prototype. As noted earlier, the code scale is precisely that element of the angular displacement transducers, which basically determines its dimensions and mass. Reducing the overall dimensions of angular displacement transducers is especially important when using this class of devices in various special-purpose aircraft.

Literature

1. Domrachev V.G., Meiko B.S. Digital angle converters: principles of construction, accuracy theory, control methods. - M .: Energoatomizdat, 1984. - 328 p.

2. Application for invention RU 2010134251, priority 16.08.2010.

3. Application for invention RU 2010147699, priority 11/22/2010.

4. Ozhiganov A.A. Pseudorandom code scales // Izv. universities. Instrument Engineering, 1987.V.30. No. 2. S.40-43.

5. Azov A.K., Ozhiganov A.A., Tarasyuk M.V. Recursive code scales // Mashinostroenie Publishing House Information Technologies, 1998, No. 6. S.39-43.

6. Agulnik A.R., Musaelyan S.S. Construction of nonlinear binary sequences // Radioelectronics. 1983. No. 4. S.19-28.

7. MacWilliams F.D., Sloan N.D. Pseudorandom sequences and tables // TIIER. 1976.V.64. No. 12. S.80-95.

Claims (1)

A recursive code scale containing the first information code track, made in accordance with the symbols of a nonlinear binary sequence of length N = 2 ⁿ , n read elements, placed along the first information code track with an angular step equal to the quantum value of the information code track δ = 360 ° / N , the second information code track, made in accordance with the characters N periods of the nonlinear binary sequence of length M = 2 ^m , m reading elements located along the second information codes second track with an angular step (δ + δ ₂ ), where δ ₂ = 360 ° / NM is the quantum value of the second information code track, a regular code track made in accordance with the symbols {0,1, ..., 0,1, ..., 0,1} binary sequence length 2NM, uniformly quantized with quantization period _shk δ = 360 ° / 2NM, being simultaneously the value of a quantum scale recursive code, the code read element a regular track displaced relative to the first of the n sensing elements on the angular distance k = _wk 2eδ + (δ _шк / 2), е = 0, 1, 2, 3, ... and placed along a regular code th track, m _add = m additional readout elements offset from the first of m readout elements by an angular distance k _m = (j + m) δ + δ _шк , j = 0, 1, 2, ... and placed along the second information code track with an angular step (δ + δ ₂ ), n _extra = n additional reading elements, the outputs n, m, m _additional reading elements and the output of the reading element of the regular code track are designed to remove information about the angular position of the recursive code scale, characterized in that it is recursive the code scale is equipped with a converter to yes to n inputs and n outputs, n _ext additional sensing elements are offset relative to the first of the n sensing elements on the angular distance k _n = (iδ + δ _wk), i = 1, 2, 3, ... and arranged along a first information code tracks with an angular step equal to δ, the outputs of n _additional reading elements are connected to the inputs of the code converter, the outputs of which are designed to remove information about the angular position of the recursive code scale.